Golang Uint64Val示例

示例#1

文件： const.go 项目： nagyistge/hm-workspace

// Uint64 returns the numeric value of this constant truncated to fit
// an unsigned 64-bit integer.
//
func (c *Const) Uint64() uint64 {
	switch x := c.Value; x.Kind() {
	case exact.Int:
		if u, ok := exact.Uint64Val(x); ok {
			return u
		}
		return 0
	case exact.Float:
		f, _ := exact.Float64Val(x)
		return uint64(f)
	}
	panic(fmt.Sprintf("unexpected constant value: %T", c.Value))
}

示例#2

文件： literal.go 项目： pombredanne/go.tools

// Uint64 returns the numeric value of this literal truncated to fit
// an unsigned 64-bit integer.
//
func (l *Literal) Uint64() uint64 {
	switch x := l.Value; x.Kind() {
	case exact.Int:
		if u, ok := exact.Uint64Val(x); ok {
			return u
		}
		return 0
	case exact.Float:
		f, _ := exact.Float64Val(x)
		return uint64(f)
	}
	panic(fmt.Sprintf("unexpected literal value: %T", l.Value))
}

示例#3

文件： expr.go 项目： rjammala/emgo

func writeInt(w *bytes.Buffer, ev exact.Value, k types.BasicKind) {
	if k == types.Uintptr {
		u, _ := exact.Uint64Val(ev)
		w.WriteString("0x")
		w.WriteString(strconv.FormatUint(u, 16))
		return
	}

	w.WriteString(ev.String())
	switch k {
	case types.Int32:
		w.WriteByte('L')

	case types.Uint32:
		w.WriteString("UL")

	case types.Int64:
		w.WriteString("LL")

	case types.Uint64:
		w.WriteString("ULL")
	}
}

示例#4

文件： expr.go 项目： hackrole/daily-program

func (check *Checker) shift(x, y *operand, op token.Token) {
	untypedx := isUntyped(x.typ)

	// The lhs must be of integer type or be representable
	// as an integer; otherwise the shift has no chance.
	if !isInteger(x.typ) && (!untypedx || !representableConst(x.val, nil, UntypedInt, nil)) {
		check.invalidOp(x.pos(), "shifted operand %s must be integer", x)
		x.mode = invalid
		return
	}

	// spec: "The right operand in a shift expression must have unsigned
	// integer type or be an untyped constant that can be converted to
	// unsigned integer type."
	switch {
	case isInteger(y.typ) && isUnsigned(y.typ):
		// nothing to do
	case isUntyped(y.typ):
		check.convertUntyped(y, Typ[UntypedInt])
		if y.mode == invalid {
			x.mode = invalid
			return
		}
	default:
		check.invalidOp(y.pos(), "shift count %s must be unsigned integer", y)
		x.mode = invalid
		return
	}

	if x.mode == constant {
		if y.mode == constant {
			// rhs must be within reasonable bounds
			const stupidShift = 1023 - 1 + 52 // so we can express smallestFloat64
			s, ok := exact.Uint64Val(y.val)
			if !ok || s > stupidShift {
				check.invalidOp(y.pos(), "stupid shift count %s", y)
				x.mode = invalid
				return
			}
			// The lhs is representable as an integer but may not be an integer
			// (e.g., 2.0, an untyped float) - this can only happen for untyped
			// non-integer numeric constants. Correct the type so that the shift
			// result is of integer type.
			if !isInteger(x.typ) {
				x.typ = Typ[UntypedInt]
			}
			x.val = exact.Shift(x.val, op, uint(s))
			return
		}

		// non-constant shift with constant lhs
		if untypedx {
			// spec: "If the left operand of a non-constant shift
			// expression is an untyped constant, the type of the
			// constant is what it would be if the shift expression
			// were replaced by its left operand alone.".
			//
			// Delay operand checking until we know the final type:
			// The lhs expression must be in the untyped map, mark
			// the entry as lhs shift operand.
			info, found := check.untyped[x.expr]
			assert(found)
			info.isLhs = true
			check.untyped[x.expr] = info
			// keep x's type
			x.mode = value
			return
		}
	}

	// constant rhs must be >= 0
	if y.mode == constant && exact.Sign(y.val) < 0 {
		check.invalidOp(y.pos(), "shift count %s must not be negative", y)
	}

	// non-constant shift - lhs must be an integer
	if !isInteger(x.typ) {
		check.invalidOp(x.pos(), "shifted operand %s must be integer", x)
		x.mode = invalid
		return
	}

	x.mode = value
}

示例#5

文件： value.go 项目： qioixiy/llgo

func (c *compiler) NewConstValue(v exact.Value, typ types.Type) *LLVMValue {
	switch {
	case v.Kind() == exact.Unknown:
		// TODO nil literals should be represented more appropriately once the exact-package supports it.
		llvmtyp := c.types.ToLLVM(typ)
		return c.NewValue(llvm.ConstNull(llvmtyp), typ)

	case isString(typ):
		if isUntyped(typ) {
			typ = types.Typ[types.String]
		}
		llvmtyp := c.types.ToLLVM(typ)
		strval := exact.StringVal(v)
		strlen := len(strval)
		i8ptr := llvm.PointerType(llvm.Int8Type(), 0)
		var ptr llvm.Value
		if strlen > 0 {
			init := llvm.ConstString(strval, false)
			ptr = llvm.AddGlobal(c.module.Module, init.Type(), "")
			ptr.SetInitializer(init)
			ptr = llvm.ConstBitCast(ptr, i8ptr)
		} else {
			ptr = llvm.ConstNull(i8ptr)
		}
		len_ := llvm.ConstInt(c.types.inttype, uint64(strlen), false)
		llvmvalue := llvm.Undef(llvmtyp)
		llvmvalue = llvm.ConstInsertValue(llvmvalue, ptr, []uint32{0})
		llvmvalue = llvm.ConstInsertValue(llvmvalue, len_, []uint32{1})
		return c.NewValue(llvmvalue, typ)

	case isInteger(typ):
		if isUntyped(typ) {
			typ = types.Typ[types.Int]
		}
		llvmtyp := c.types.ToLLVM(typ)
		var llvmvalue llvm.Value
		if isUnsigned(typ) {
			v, _ := exact.Uint64Val(v)
			llvmvalue = llvm.ConstInt(llvmtyp, v, false)
		} else {
			v, _ := exact.Int64Val(v)
			llvmvalue = llvm.ConstInt(llvmtyp, uint64(v), true)
		}
		return c.NewValue(llvmvalue, typ)

	case isBoolean(typ):
		if isUntyped(typ) {
			typ = types.Typ[types.Bool]
		}
		var llvmvalue llvm.Value
		if exact.BoolVal(v) {
			llvmvalue = llvm.ConstAllOnes(llvm.Int1Type())
		} else {
			llvmvalue = llvm.ConstNull(llvm.Int1Type())
		}
		return c.NewValue(llvmvalue, typ)

	case isFloat(typ):
		if isUntyped(typ) {
			typ = types.Typ[types.Float64]
		}
		llvmtyp := c.types.ToLLVM(typ)
		floatval, _ := exact.Float64Val(v)
		llvmvalue := llvm.ConstFloat(llvmtyp, floatval)
		return c.NewValue(llvmvalue, typ)

	case typ == types.Typ[types.UnsafePointer]:
		llvmtyp := c.types.ToLLVM(typ)
		v, _ := exact.Uint64Val(v)
		llvmvalue := llvm.ConstInt(llvmtyp, v, false)
		return c.NewValue(llvmvalue, typ)

	case isComplex(typ):
		if isUntyped(typ) {
			typ = types.Typ[types.Complex128]
		}
		llvmtyp := c.types.ToLLVM(typ)
		floattyp := llvmtyp.StructElementTypes()[0]
		llvmvalue := llvm.ConstNull(llvmtyp)
		realv := exact.Real(v)
		imagv := exact.Imag(v)
		realfloatval, _ := exact.Float64Val(realv)
		imagfloatval, _ := exact.Float64Val(imagv)
		llvmre := llvm.ConstFloat(floattyp, realfloatval)
		llvmim := llvm.ConstFloat(floattyp, imagfloatval)
		llvmvalue = llvm.ConstInsertValue(llvmvalue, llvmre, []uint32{0})
		llvmvalue = llvm.ConstInsertValue(llvmvalue, llvmim, []uint32{1})
		return c.NewValue(llvmvalue, typ)
	}

	// Special case for string -> [](byte|rune)
	if u, ok := typ.Underlying().(*types.Slice); ok && isInteger(u.Elem()) {
		if v.Kind() == exact.String {
			strval := c.NewConstValue(v, types.Typ[types.String])
			return strval.Convert(typ).(*LLVMValue)
		}
	}

	panic(fmt.Sprintf("unhandled: t=%s(%T), v=%v(%T)", c.types.TypeString(typ), typ, v, v))
}

示例#6

文件： expressions.go 项目： nvdnkpr/gopherjs

func (c *funcContext) translateExpr(expr ast.Expr) *expression {
	exprType := c.p.info.Types[expr].Type
	if value := c.p.info.Types[expr].Value; value != nil {
		basic := types.Typ[types.String]
		if value.Kind() != exact.String { // workaround for bug in go/types
			basic = exprType.Underlying().(*types.Basic)
		}
		switch {
		case basic.Info()&types.IsBoolean != 0:
			return c.formatExpr("%s", strconv.FormatBool(exact.BoolVal(value)))
		case basic.Info()&types.IsInteger != 0:
			if is64Bit(basic) {
				d, _ := exact.Uint64Val(value)
				if basic.Kind() == types.Int64 {
					return c.formatExpr("new %s(%s, %s)", c.typeName(exprType), strconv.FormatInt(int64(d)>>32, 10), strconv.FormatUint(d&(1<<32-1), 10))
				}
				return c.formatExpr("new %s(%s, %s)", c.typeName(exprType), strconv.FormatUint(d>>32, 10), strconv.FormatUint(d&(1<<32-1), 10))
			}
			d, _ := exact.Int64Val(value)
			return c.formatExpr("%s", strconv.FormatInt(d, 10))
		case basic.Info()&types.IsFloat != 0:
			f, _ := exact.Float64Val(value)
			return c.formatExpr("%s", strconv.FormatFloat(f, 'g', -1, 64))
		case basic.Info()&types.IsComplex != 0:
			r, _ := exact.Float64Val(exact.Real(value))
			i, _ := exact.Float64Val(exact.Imag(value))
			if basic.Kind() == types.UntypedComplex {
				exprType = types.Typ[types.Complex128]
			}
			return c.formatExpr("new %s(%s, %s)", c.typeName(exprType), strconv.FormatFloat(r, 'g', -1, 64), strconv.FormatFloat(i, 'g', -1, 64))
		case basic.Info()&types.IsString != 0:
			return c.formatExpr("%s", encodeString(exact.StringVal(value)))
		default:
			panic("Unhandled constant type: " + basic.String())
		}
	}

	switch e := expr.(type) {
	case *ast.CompositeLit:
		if ptrType, isPointer := exprType.(*types.Pointer); isPointer {
			exprType = ptrType.Elem()
		}

		collectIndexedElements := func(elementType types.Type) []string {
			elements := make([]string, 0)
			i := 0
			zero := c.zeroValue(elementType)
			for _, element := range e.Elts {
				if kve, isKve := element.(*ast.KeyValueExpr); isKve {
					key, _ := exact.Int64Val(c.p.info.Types[kve.Key].Value)
					i = int(key)
					element = kve.Value
				}
				for len(elements) <= i {
					elements = append(elements, zero)
				}
				elements[i] = c.translateImplicitConversionWithCloning(element, elementType).String()
				i++
			}
			return elements
		}

		switch t := exprType.Underlying().(type) {
		case *types.Array:
			elements := collectIndexedElements(t.Elem())
			if len(elements) == 0 {
				return c.formatExpr("%s", c.zeroValue(t))
			}
			zero := c.zeroValue(t.Elem())
			for len(elements) < int(t.Len()) {
				elements = append(elements, zero)
			}
			return c.formatExpr(`$toNativeArray("%s", [%s])`, typeKind(t.Elem()), strings.Join(elements, ", "))
		case *types.Slice:
			return c.formatExpr("new %s([%s])", c.typeName(exprType), strings.Join(collectIndexedElements(t.Elem()), ", "))
		case *types.Map:
			mapVar := c.newVariable("_map")
			keyVar := c.newVariable("_key")
			assignments := ""
			for _, element := range e.Elts {
				kve := element.(*ast.KeyValueExpr)
				assignments += c.formatExpr(`%s = %s, %s[%s] = { k: %s, v: %s }, `, keyVar, c.translateImplicitConversion(kve.Key, t.Key()), mapVar, c.makeKey(c.newIdent(keyVar, t.Key()), t.Key()), keyVar, c.translateImplicitConversion(kve.Value, t.Elem())).String()
			}
			return c.formatExpr("(%s = new $Map(), %s%s)", mapVar, assignments, mapVar)
		case *types.Struct:
			elements := make([]string, t.NumFields())
			isKeyValue := true
			if len(e.Elts) != 0 {
				_, isKeyValue = e.Elts[0].(*ast.KeyValueExpr)
			}
			if !isKeyValue {
				for i, element := range e.Elts {
					elements[i] = c.translateImplicitConversion(element, t.Field(i).Type()).String()
				}
			}
			if isKeyValue {
				for i := range elements {
					elements[i] = c.zeroValue(t.Field(i).Type())
				}
				for _, element := range e.Elts {
					kve := element.(*ast.KeyValueExpr)
					for j := range elements {
						if kve.Key.(*ast.Ident).Name == t.Field(j).Name() {
							elements[j] = c.translateImplicitConversion(kve.Value, t.Field(j).Type()).String()
							break
						}
					}
				}
			}
			return c.formatExpr("new %s.Ptr(%s)", c.typeName(exprType), strings.Join(elements, ", "))
		default:
			panic(fmt.Sprintf("Unhandled CompositeLit type: %T\n", t))
		}

	case *ast.FuncLit:
		innerContext := c.p.analyzeFunction(exprType.(*types.Signature), e.Body)
		params, body := innerContext.translateFunction(e.Type, e.Body.List, c.allVars)
		if len(c.p.escapingVars) != 0 {
			names := make([]string, 0, len(c.p.escapingVars))
			for obj := range c.p.escapingVars {
				names = append(names, c.p.objectVars[obj])
			}
			list := strings.Join(names, ", ")
			return c.formatExpr("(function(%s) { return function(%s) {\n%s%s}; })(%s)", list, strings.Join(params, ", "), string(body), strings.Repeat("\t", c.p.indentation), list)
		}
		return c.formatExpr("(function(%s) {\n%s%s})", strings.Join(params, ", "), string(body), strings.Repeat("\t", c.p.indentation))

	case *ast.UnaryExpr:
		t := c.p.info.Types[e.X].Type
		switch e.Op {
		case token.AND:
			switch t.Underlying().(type) {
			case *types.Struct, *types.Array:
				return c.translateExpr(e.X)
			}

			switch x := removeParens(e.X).(type) {
			case *ast.CompositeLit:
				return c.formatExpr("$newDataPointer(%e, %s)", x, c.typeName(c.p.info.Types[e].Type))
			case *ast.Ident:
				if obj := c.p.info.Uses[x]; c.p.escapingVars[obj] {
					return c.formatExpr("new %s(function() { return this.$target[0]; }, function($v) { this.$target[0] = $v; }, %s)", c.typeName(exprType), c.p.objectVars[obj])
				}
				return c.formatExpr("new %s(function() { return %e; }, function($v) { %s })", c.typeName(exprType), x, c.translateAssign(x, "$v", exprType, false))
			case *ast.SelectorExpr:
				newSel := &ast.SelectorExpr{X: c.newIdent("this.$target", c.p.info.Types[x.X].Type), Sel: x.Sel}
				c.p.info.Selections[newSel] = c.p.info.Selections[x]
				return c.formatExpr("new %s(function() { return %e; }, function($v) { %s }, %e)", c.typeName(exprType), newSel, c.translateAssign(newSel, "$v", exprType, false), x.X)
			case *ast.IndexExpr:
				newIndex := &ast.IndexExpr{X: c.newIdent("this.$target", c.p.info.Types[x.X].Type), Index: x.Index}
				return c.formatExpr("new %s(function() { return %e; }, function($v) { %s }, %e)", c.typeName(exprType), newIndex, c.translateAssign(newIndex, "$v", exprType, false), x.X)
			default:
				panic(fmt.Sprintf("Unhandled: %T\n", x))
			}

		case token.ARROW:
			call := &ast.CallExpr{
				Fun:  c.newIdent("$recv", types.NewSignature(nil, nil, types.NewTuple(types.NewVar(0, nil, "", t)), types.NewTuple(types.NewVar(0, nil, "", exprType), types.NewVar(0, nil, "", types.Typ[types.Bool])), false)),
				Args: []ast.Expr{e.X},
			}
			c.blocking[call] = true
			if _, isTuple := exprType.(*types.Tuple); isTuple {
				return c.formatExpr("%e", call)
			}
			return c.formatExpr("%e[0]", call)
		}

		basic := t.Underlying().(*types.Basic)
		switch e.Op {
		case token.ADD:
			return c.translateExpr(e.X)
		case token.SUB:
			switch {
			case is64Bit(basic):
				return c.formatExpr("new %1s(-%2h, -%2l)", c.typeName(t), e.X)
			case basic.Info()&types.IsComplex != 0:
				return c.formatExpr("new %1s(-%2r, -%2i)", c.typeName(t), e.X)
			case basic.Info()&types.IsUnsigned != 0:
				return c.fixNumber(c.formatExpr("-%e", e.X), basic)
			default:
				return c.formatExpr("-%e", e.X)
			}
		case token.XOR:
			if is64Bit(basic) {
				return c.formatExpr("new %1s(~%2h, ~%2l >>> 0)", c.typeName(t), e.X)
			}
			return c.fixNumber(c.formatExpr("~%e", e.X), basic)
		case token.NOT:
			x := c.translateExpr(e.X)
			if x.String() == "true" {
				return c.formatExpr("false")
			}
			if x.String() == "false" {
				return c.formatExpr("true")
			}
			return c.formatExpr("!%s", x)
		default:
			panic(e.Op)
		}

	case *ast.BinaryExpr:
		if e.Op == token.NEQ {
			return c.formatExpr("!(%s)", c.translateExpr(&ast.BinaryExpr{
				X:  e.X,
				Op: token.EQL,
				Y:  e.Y,
			}))
		}

		t := c.p.info.Types[e.X].Type
		t2 := c.p.info.Types[e.Y].Type
		_, isInterface := t2.Underlying().(*types.Interface)
		if isInterface {
			t = t2
		}

		if basic, isBasic := t.Underlying().(*types.Basic); isBasic && basic.Info()&types.IsNumeric != 0 {
			if is64Bit(basic) {
				switch e.Op {
				case token.MUL:
					return c.formatExpr("$mul64(%e, %e)", e.X, e.Y)
				case token.QUO:
					return c.formatExpr("$div64(%e, %e, false)", e.X, e.Y)
				case token.REM:
					return c.formatExpr("$div64(%e, %e, true)", e.X, e.Y)
				case token.SHL:
					return c.formatExpr("$shiftLeft64(%e, %f)", e.X, e.Y)
				case token.SHR:
					return c.formatExpr("$shiftRight%s(%e, %f)", toJavaScriptType(basic), e.X, e.Y)
				case token.EQL:
					return c.formatExpr("(%1h === %2h && %1l === %2l)", e.X, e.Y)
				case token.LSS:
					return c.formatExpr("(%1h < %2h || (%1h === %2h && %1l < %2l))", e.X, e.Y)
				case token.LEQ:
					return c.formatExpr("(%1h < %2h || (%1h === %2h && %1l <= %2l))", e.X, e.Y)
				case token.GTR:
					return c.formatExpr("(%1h > %2h || (%1h === %2h && %1l > %2l))", e.X, e.Y)
				case token.GEQ:
					return c.formatExpr("(%1h > %2h || (%1h === %2h && %1l >= %2l))", e.X, e.Y)
				case token.ADD, token.SUB:
					return c.formatExpr("new %3s(%1h %4t %2h, %1l %4t %2l)", e.X, e.Y, c.typeName(t), e.Op)
				case token.AND, token.OR, token.XOR:
					return c.formatExpr("new %3s(%1h %4t %2h, (%1l %4t %2l) >>> 0)", e.X, e.Y, c.typeName(t), e.Op)
				case token.AND_NOT:
					return c.formatExpr("new %3s(%1h &~ %2h, (%1l &~ %2l) >>> 0)", e.X, e.Y, c.typeName(t))
				default:
					panic(e.Op)
				}
			}

			if basic.Info()&types.IsComplex != 0 {
				switch e.Op {
				case token.EQL:
					if basic.Kind() == types.Complex64 {
						return c.formatExpr("($float32IsEqual(%1r, %2r) && $float32IsEqual(%1i, %2i))", e.X, e.Y)
					}
					return c.formatExpr("(%1r === %2r && %1i === %2i)", e.X, e.Y)
				case token.ADD, token.SUB:
					return c.formatExpr("new %3s(%1r %4t %2r, %1i %4t %2i)", e.X, e.Y, c.typeName(t), e.Op)
				case token.MUL:
					return c.formatExpr("new %3s(%1r * %2r - %1i * %2i, %1r * %2i + %1i * %2r)", e.X, e.Y, c.typeName(t))
				case token.QUO:
					return c.formatExpr("$divComplex(%e, %e)", e.X, e.Y)
				default:
					panic(e.Op)
				}
			}

			switch e.Op {
			case token.EQL:
				if basic.Kind() == types.Float32 {
					return c.formatParenExpr("$float32IsEqual(%e, %e)", e.X, e.Y)
				}
				return c.formatParenExpr("%e === %e", e.X, e.Y)
			case token.LSS, token.LEQ, token.GTR, token.GEQ:
				return c.formatExpr("%e %t %e", e.X, e.Op, e.Y)
			case token.ADD, token.SUB:
				if basic.Info()&types.IsInteger != 0 {
					return c.fixNumber(c.formatExpr("%e %t %e", e.X, e.Op, e.Y), basic)
				}
				return c.formatExpr("%e %t %e", e.X, e.Op, e.Y)
			case token.MUL:
				switch basic.Kind() {
				case types.Int32, types.Int:
					return c.formatParenExpr("(((%1e >>> 16 << 16) * %2e >> 0) + (%1e << 16 >>> 16) * %2e) >> 0", e.X, e.Y)
				case types.Uint32, types.Uint, types.Uintptr:
					return c.formatParenExpr("(((%1e >>> 16 << 16) * %2e >>> 0) + (%1e << 16 >>> 16) * %2e) >>> 0", e.X, e.Y)
				case types.Float32, types.Float64:
					return c.formatExpr("%e * %e", e.X, e.Y)
				default:
					return c.fixNumber(c.formatExpr("%e * %e", e.X, e.Y), basic)
				}
			case token.QUO:
				if basic.Info()&types.IsInteger != 0 {
					// cut off decimals
					shift := ">>"
					if basic.Info()&types.IsUnsigned != 0 {
						shift = ">>>"
					}
					return c.formatExpr(`(%1s = %2e / %3e, (%1s === %1s && %1s !== 1/0 && %1s !== -1/0) ? %1s %4s 0 : $throwRuntimeError("integer divide by zero"))`, c.newVariable("_q"), e.X, e.Y, shift)
				}
				return c.formatExpr("%e / %e", e.X, e.Y)
			case token.REM:
				return c.formatExpr(`(%1s = %2e %% %3e, %1s === %1s ? %1s : $throwRuntimeError("integer divide by zero"))`, c.newVariable("_r"), e.X, e.Y)
			case token.SHL, token.SHR:
				op := e.Op.String()
				if e.Op == token.SHR && basic.Info()&types.IsUnsigned != 0 {
					op = ">>>"
				}
				if c.p.info.Types[e.Y].Value != nil {
					return c.fixNumber(c.formatExpr("%e %s %e", e.X, op, e.Y), basic)
				}
				if e.Op == token.SHR && basic.Info()&types.IsUnsigned == 0 {
					return c.fixNumber(c.formatParenExpr("%e >> $min(%e, 31)", e.X, e.Y), basic)
				}
				y := c.newVariable("y")
				return c.fixNumber(c.formatExpr("(%s = %s, %s < 32 ? (%e %s %s) : 0)", y, c.translateImplicitConversion(e.Y, types.Typ[types.Uint]), y, e.X, op, y), basic)
			case token.AND, token.OR:
				if basic.Info()&types.IsUnsigned != 0 {
					return c.formatParenExpr("(%e %t %e) >>> 0", e.X, e.Op, e.Y)
				}
				return c.formatParenExpr("%e %t %e", e.X, e.Op, e.Y)
			case token.AND_NOT:
				return c.formatParenExpr("%e & ~%e", e.X, e.Y)
			case token.XOR:
				return c.fixNumber(c.formatParenExpr("%e ^ %e", e.X, e.Y), basic)
			default:
				panic(e.Op)
			}
		}

		switch e.Op {
		case token.ADD, token.LSS, token.LEQ, token.GTR, token.GEQ:
			return c.formatExpr("%e %t %e", e.X, e.Op, e.Y)
		case token.LAND:
			x := c.translateExpr(e.X)
			y := c.translateExpr(e.Y)
			if x.String() == "false" {
				return c.formatExpr("false")
			}
			return c.formatExpr("%s && %s", x, y)
		case token.LOR:
			x := c.translateExpr(e.X)
			y := c.translateExpr(e.Y)
			if x.String() == "true" {
				return c.formatExpr("true")
			}
			return c.formatExpr("%s || %s", x, y)
		case token.EQL:
			switch u := t.Underlying().(type) {
			case *types.Array, *types.Struct:
				return c.formatExpr("$equal(%e, %e, %s)", e.X, e.Y, c.typeName(t))
			case *types.Interface:
				if isJsObject(t) {
					return c.formatExpr("%s === %s", c.translateImplicitConversion(e.X, t), c.translateImplicitConversion(e.Y, t))
				}
				return c.formatExpr("$interfaceIsEqual(%s, %s)", c.translateImplicitConversion(e.X, t), c.translateImplicitConversion(e.Y, t))
			case *types.Pointer:
				xUnary, xIsUnary := e.X.(*ast.UnaryExpr)
				yUnary, yIsUnary := e.Y.(*ast.UnaryExpr)
				if xIsUnary && xUnary.Op == token.AND && yIsUnary && yUnary.Op == token.AND {
					xIndex, xIsIndex := xUnary.X.(*ast.IndexExpr)
					yIndex, yIsIndex := yUnary.X.(*ast.IndexExpr)
					if xIsIndex && yIsIndex {
						return c.formatExpr("$sliceIsEqual(%e, %f, %e, %f)", xIndex.X, xIndex.Index, yIndex.X, yIndex.Index)
					}
				}
				switch u.Elem().Underlying().(type) {
				case *types.Struct, *types.Interface:
					return c.formatExpr("%s === %s", c.translateImplicitConversion(e.X, t), c.translateImplicitConversion(e.Y, t))
				case *types.Array:
					return c.formatExpr("$equal(%s, %s, %s)", c.translateImplicitConversion(e.X, t), c.translateImplicitConversion(e.Y, t), c.typeName(u.Elem()))
				default:
					return c.formatExpr("$pointerIsEqual(%s, %s)", c.translateImplicitConversion(e.X, t), c.translateImplicitConversion(e.Y, t))
				}
			default:
				return c.formatExpr("%s === %s", c.translateImplicitConversion(e.X, t), c.translateImplicitConversion(e.Y, t))
			}
		default:
			panic(e.Op)
		}

	case *ast.ParenExpr:
		x := c.translateExpr(e.X)
		if x.String() == "true" || x.String() == "false" {
			return x
		}
		return c.formatParenExpr("%s", x)

	case *ast.IndexExpr:
		switch t := c.p.info.Types[e.X].Type.Underlying().(type) {
		case *types.Array, *types.Pointer:
			if c.p.info.Types[e.Index].Value != nil {
				return c.formatExpr("%e[%f]", e.X, e.Index)
			}
			return c.formatExpr(`((%2f < 0 || %2f >= %1e.length) ? $throwRuntimeError("index out of range") : %1e[%2f])`, e.X, e.Index)
		case *types.Slice:
			return c.formatExpr(`((%2f < 0 || %2f >= %1e.$length) ? $throwRuntimeError("index out of range") : %1e.$array[%1e.$offset + %2f])`, e.X, e.Index)
		case *types.Map:
			key := c.makeKey(e.Index, t.Key())
			if _, isTuple := exprType.(*types.Tuple); isTuple {
				return c.formatExpr(`(%1s = %2e[%3s], %1s !== undefined ? [%1s.v, true] : [%4s, false])`, c.newVariable("_entry"), e.X, key, c.zeroValue(t.Elem()))
			}
			return c.formatExpr(`(%1s = %2e[%3s], %1s !== undefined ? %1s.v : %4s)`, c.newVariable("_entry"), e.X, key, c.zeroValue(t.Elem()))
		case *types.Basic:
			return c.formatExpr("%e.charCodeAt(%f)", e.X, e.Index)
		default:
			panic(fmt.Sprintf("Unhandled IndexExpr: %T\n", t))
		}

	case *ast.SliceExpr:
		if b, isBasic := c.p.info.Types[e.X].Type.Underlying().(*types.Basic); isBasic && b.Info()&types.IsString != 0 {
			switch {
			case e.Low == nil && e.High == nil:
				return c.translateExpr(e.X)
			case e.Low == nil:
				return c.formatExpr("%e.substring(0, %f)", e.X, e.High)
			case e.High == nil:
				return c.formatExpr("%e.substring(%f)", e.X, e.Low)
			default:
				return c.formatExpr("%e.substring(%f, %f)", e.X, e.Low, e.High)
			}
		}
		slice := c.translateConversionToSlice(e.X, exprType)
		switch {
		case e.Low == nil && e.High == nil:
			return c.formatExpr("%s", slice)
		case e.Low == nil:
			if e.Max != nil {
				return c.formatExpr("$subslice(%s, 0, %f, %f)", slice, e.High, e.Max)
			}
			return c.formatExpr("$subslice(%s, 0, %f)", slice, e.High)
		case e.High == nil:
			return c.formatExpr("$subslice(%s, %f)", slice, e.Low)
		default:
			if e.Max != nil {
				return c.formatExpr("$subslice(%s, %f, %f, %f)", slice, e.Low, e.High, e.Max)
			}
			return c.formatExpr("$subslice(%s, %f, %f)", slice, e.Low, e.High)
		}

	case *ast.SelectorExpr:
		sel, ok := c.p.info.Selections[e]
		if !ok {
			// qualified identifier
			obj := c.p.info.Uses[e.Sel]
			if isJsPackage(obj.Pkg()) {
				switch obj.Name() {
				case "Global":
					return c.formatExpr("$global")
				case "This":
					if len(c.flattened) != 0 {
						return c.formatExpr("$this")
					}
					return c.formatExpr("this")
				case "Arguments":
					args := "arguments"
					if len(c.flattened) != 0 {
						args = "$args"
					}
					return c.formatExpr(`new ($sliceType(%s.Object))($global.Array.prototype.slice.call(%s, []))`, c.p.pkgVars["github.com/gopherjs/gopherjs/js"], args)
				case "Module":
					return c.formatExpr("$module")
				default:
					panic("Invalid js package object: " + obj.Name())
				}
			}
			return c.formatExpr("%s", c.objectName(obj))
		}

		parameterName := func(v *types.Var) string {
			if v.Anonymous() || v.Name() == "" {
				return c.newVariable("param")
			}
			return c.newVariable(v.Name())
		}
		makeParametersList := func() []string {
			params := sel.Obj().Type().(*types.Signature).Params()
			names := make([]string, params.Len())
			for i := 0; i < params.Len(); i++ {
				names[i] = parameterName(params.At(i))
			}
			return names
		}

		switch sel.Kind() {
		case types.FieldVal:
			fields, jsTag := c.translateSelection(sel)
			if jsTag != "" {
				if _, ok := sel.Type().(*types.Signature); ok {
					return c.formatExpr("$internalize(%1e.%2s.%3s, %4s, %1e.%2s)", e.X, strings.Join(fields, "."), jsTag, c.typeName(sel.Type()))
				}
				return c.internalize(c.formatExpr("%e.%s.%s", e.X, strings.Join(fields, "."), jsTag), sel.Type())
			}
			return c.formatExpr("%e.%s", e.X, strings.Join(fields, "."))
		case types.MethodVal:
			if !sel.Obj().Exported() {
				c.p.dependencies[sel.Obj()] = true
			}
			parameters := makeParametersList()
			target := c.translateExpr(e.X)
			if isWrapped(sel.Recv()) {
				target = c.formatParenExpr("new %s(%s)", c.typeName(sel.Recv()), target)
			}
			recv := c.newVariable("_recv")
			return c.formatExpr("(%s = %s, function(%s) { $stackDepthOffset--; try { return %s.%s(%s); } finally { $stackDepthOffset++; } })", recv, target, strings.Join(parameters, ", "), recv, e.Sel.Name, strings.Join(parameters, ", "))
		case types.MethodExpr:
			if !sel.Obj().Exported() {
				c.p.dependencies[sel.Obj()] = true
			}
			recv := "recv"
			if isWrapped(sel.Recv()) {
				recv = fmt.Sprintf("(new %s(recv))", c.typeName(sel.Recv()))
			}
			parameters := makeParametersList()
			return c.formatExpr("(function(%s) { $stackDepthOffset--; try { return %s.%s(%s); } finally { $stackDepthOffset++; } })", strings.Join(append([]string{"recv"}, parameters...), ", "), recv, sel.Obj().(*types.Func).Name(), strings.Join(parameters, ", "))
		}
		panic("")

	case *ast.CallExpr:
		plainFun := e.Fun
		for {
			if p, isParen := plainFun.(*ast.ParenExpr); isParen {
				plainFun = p.X
				continue
			}
			break
		}

		var isType func(ast.Expr) bool
		isType = func(expr ast.Expr) bool {
			switch e := expr.(type) {
			case *ast.ArrayType, *ast.ChanType, *ast.FuncType, *ast.InterfaceType, *ast.MapType, *ast.StructType:
				return true
			case *ast.StarExpr:
				return isType(e.X)
			case *ast.Ident:
				_, ok := c.p.info.Uses[e].(*types.TypeName)
				return ok
			case *ast.SelectorExpr:
				_, ok := c.p.info.Uses[e.Sel].(*types.TypeName)
				return ok
			case *ast.ParenExpr:
				return isType(e.X)
			default:
				return false
			}
		}

		if isType(plainFun) {
			return c.formatExpr("%s", c.translateConversion(e.Args[0], c.p.info.Types[plainFun].Type))
		}

		var fun *expression
		switch f := plainFun.(type) {
		case *ast.Ident:
			if o, ok := c.p.info.Uses[f].(*types.Builtin); ok {
				return c.translateBuiltin(o.Name(), e.Args, e.Ellipsis.IsValid(), exprType)
			}
			fun = c.translateExpr(plainFun)

		case *ast.SelectorExpr:
			sel, ok := c.p.info.Selections[f]
			if !ok {
				// qualified identifier
				obj := c.p.info.Uses[f.Sel]
				if isJsPackage(obj.Pkg()) {
					switch obj.Name() {
					case "InternalObject":
						return c.translateExpr(e.Args[0])
					}
				}
				fun = c.translateExpr(f)
				break
			}

			externalizeExpr := func(e ast.Expr) string {
				t := c.p.info.Types[e].Type
				if types.Identical(t, types.Typ[types.UntypedNil]) {
					return "null"
				}
				return c.externalize(c.translateExpr(e).String(), t)
			}
			externalizeArgs := func(args []ast.Expr) string {
				s := make([]string, len(args))
				for i, arg := range args {
					s[i] = externalizeExpr(arg)
				}
				return strings.Join(s, ", ")
			}

			switch sel.Kind() {
			case types.MethodVal:
				if !sel.Obj().Exported() {
					c.p.dependencies[sel.Obj()] = true
				}

				methodName := sel.Obj().Name()
				if reservedKeywords[methodName] {
					methodName += "$"
				}

				recvType := sel.Recv()
				_, isPointer := recvType.Underlying().(*types.Pointer)
				methodsRecvType := sel.Obj().Type().(*types.Signature).Recv().Type()
				_, pointerExpected := methodsRecvType.(*types.Pointer)
				var recv *expression
				switch {
				case !isPointer && pointerExpected:
					recv = c.translateExpr(c.setType(&ast.UnaryExpr{Op: token.AND, X: f.X}, methodsRecvType))
				default:
					recv = c.translateExpr(f.X)
				}

				for _, index := range sel.Index()[:len(sel.Index())-1] {
					if ptr, isPtr := recvType.(*types.Pointer); isPtr {
						recvType = ptr.Elem()
					}
					s := recvType.Underlying().(*types.Struct)
					recv = c.formatExpr("%s.%s", recv, fieldName(s, index))
					recvType = s.Field(index).Type()
				}

				if isJsPackage(sel.Obj().Pkg()) {
					globalRef := func(id string) string {
						if recv.String() == "$global" && id[0] == '$' {
							return id
						}
						return recv.String() + "." + id
					}
					switch sel.Obj().Name() {
					case "Get":
						if id, ok := c.identifierConstant(e.Args[0]); ok {
							return c.formatExpr("%s", globalRef(id))
						}
						return c.formatExpr("%s[$externalize(%e, $String)]", recv, e.Args[0])
					case "Set":
						if id, ok := c.identifierConstant(e.Args[0]); ok {
							return c.formatExpr("%s = %s", globalRef(id), externalizeExpr(e.Args[1]))
						}
						return c.formatExpr("%s[$externalize(%e, $String)] = %s", recv, e.Args[0], externalizeExpr(e.Args[1]))
					case "Delete":
						return c.formatExpr("delete %s[$externalize(%e, $String)]", recv, e.Args[0])
					case "Length":
						return c.formatExpr("$parseInt(%s.length)", recv)
					case "Index":
						return c.formatExpr("%s[%e]", recv, e.Args[0])
					case "SetIndex":
						return c.formatExpr("%s[%e] = %s", recv, e.Args[0], externalizeExpr(e.Args[1]))
					case "Call":
						if id, ok := c.identifierConstant(e.Args[0]); ok {
							if e.Ellipsis.IsValid() {
								objVar := c.newVariable("obj")
								return c.formatExpr("(%s = %s, %s.%s.apply(%s, %s))", objVar, recv, objVar, id, objVar, externalizeExpr(e.Args[1]))
							}
							return c.formatExpr("%s(%s)", globalRef(id), externalizeArgs(e.Args[1:]))
						}
						if e.Ellipsis.IsValid() {
							objVar := c.newVariable("obj")
							return c.formatExpr("(%s = %s, %s[$externalize(%e, $String)].apply(%s, %s))", objVar, recv, objVar, e.Args[0], objVar, externalizeExpr(e.Args[1]))
						}
						return c.formatExpr("%s[$externalize(%e, $String)](%s)", recv, e.Args[0], externalizeArgs(e.Args[1:]))
					case "Invoke":
						if e.Ellipsis.IsValid() {
							return c.formatExpr("%s.apply(undefined, %s)", recv, externalizeExpr(e.Args[0]))
						}
						return c.formatExpr("%s(%s)", recv, externalizeArgs(e.Args))
					case "New":
						if e.Ellipsis.IsValid() {
							return c.formatExpr("new ($global.Function.prototype.bind.apply(%s, [undefined].concat(%s)))", recv, externalizeExpr(e.Args[0]))
						}
						return c.formatExpr("new (%s)(%s)", recv, externalizeArgs(e.Args))
					case "Bool":
						return c.internalize(recv, types.Typ[types.Bool])
					case "Str":
						return c.internalize(recv, types.Typ[types.String])
					case "Int":
						return c.internalize(recv, types.Typ[types.Int])
					case "Int64":
						return c.internalize(recv, types.Typ[types.Int64])
					case "Uint64":
						return c.internalize(recv, types.Typ[types.Uint64])
					case "Float":
						return c.internalize(recv, types.Typ[types.Float64])
					case "Interface":
						return c.internalize(recv, types.NewInterface(nil, nil))
					case "Unsafe":
						return recv
					case "IsUndefined":
						return c.formatParenExpr("%s === undefined", recv)
					case "IsNull":
						return c.formatParenExpr("%s === null", recv)
					default:
						panic("Invalid js package object: " + sel.Obj().Name())
					}
				}

				if isWrapped(methodsRecvType) {
					fun = c.formatExpr("(new %s(%s)).%s", c.typeName(methodsRecvType), recv, methodName)
					break
				}
				fun = c.formatExpr("%s.%s", recv, methodName)

			case types.FieldVal:
				fields, jsTag := c.translateSelection(sel)
				if jsTag != "" {
					sig := sel.Type().(*types.Signature)
					return c.internalize(c.formatExpr("%e.%s.%s(%s)", f.X, strings.Join(fields, "."), jsTag, externalizeArgs(e.Args)), sig.Results().At(0).Type())
				}
				fun = c.formatExpr("%e.%s", f.X, strings.Join(fields, "."))

			case types.MethodExpr:
				fun = c.translateExpr(f)

			default:
				panic("")
			}
		default:
			fun = c.translateExpr(plainFun)
		}

		sig := c.p.info.Types[plainFun].Type.Underlying().(*types.Signature)
		if len(e.Args) == 1 {
			if tuple, isTuple := c.p.info.Types[e.Args[0]].Type.(*types.Tuple); isTuple {
				tupleVar := c.newVariable("_tuple")
				args := make([]ast.Expr, tuple.Len())
				for i := range args {
					args[i] = c.newIdent(c.formatExpr("%s[%d]", tupleVar, i).String(), tuple.At(i).Type())
				}
				return c.formatExpr("(%s = %e, %s(%s))", tupleVar, e.Args[0], fun, strings.Join(c.translateArgs(sig, args, false), ", "))
			}
		}
		args := c.translateArgs(sig, e.Args, e.Ellipsis.IsValid())
		if c.blocking[e] {
			resumeCase := c.caseCounter
			c.caseCounter++
			returnVar := "$r"
			if sig.Results().Len() != 0 {
				returnVar = c.newVariable("_r")
			}
			c.Printf("%[1]s = %[2]s(%[3]s); /* */ $s = %[4]d; case %[4]d: if (%[1]s && %[1]s.constructor === Function) { %[1]s = %[1]s(); }", returnVar, fun, strings.Join(append(args, "true"), ", "), resumeCase)
			if sig.Results().Len() != 0 {
				return c.formatExpr("%s", returnVar)
			}
			return nil
		}
		return c.formatExpr("%s(%s)", fun, strings.Join(args, ", "))

	case *ast.StarExpr:
		if c1, isCall := e.X.(*ast.CallExpr); isCall && len(c1.Args) == 1 {
			if c2, isCall := c1.Args[0].(*ast.CallExpr); isCall && len(c2.Args) == 1 && types.Identical(c.p.info.Types[c2.Fun].Type, types.Typ[types.UnsafePointer]) {
				if unary, isUnary := c2.Args[0].(*ast.UnaryExpr); isUnary && unary.Op == token.AND {
					return c.translateExpr(unary.X) // unsafe conversion
				}
			}
		}
		switch exprType.Underlying().(type) {
		case *types.Struct, *types.Array:
			return c.translateExpr(e.X)
		}
		return c.formatExpr("%e.$get()", e.X)

	case *ast.TypeAssertExpr:
		if e.Type == nil {
			return c.translateExpr(e.X)
		}
		t := c.p.info.Types[e.Type].Type
		check := "%1e !== null && " + c.typeCheck("%1e.constructor", t)
		valueSuffix := ""
		if _, isInterface := t.Underlying().(*types.Interface); !isInterface {
			valueSuffix = ".$val"
		}
		if _, isTuple := exprType.(*types.Tuple); isTuple {
			return c.formatExpr("("+check+" ? [%1e%2s, true] : [%3s, false])", e.X, valueSuffix, c.zeroValue(c.p.info.Types[e.Type].Type))
		}
		return c.formatExpr("("+check+" ? %1e%2s : $typeAssertionFailed(%1e, %3s))", e.X, valueSuffix, c.typeName(t))

	case *ast.Ident:
		if e.Name == "_" {
			panic("Tried to translate underscore identifier.")
		}
		obj := c.p.info.Defs[e]
		if obj == nil {
			obj = c.p.info.Uses[e]
		}
		switch o := obj.(type) {
		case *types.PkgName:
			return c.formatExpr("%s", c.p.pkgVars[o.Pkg().Path()])
		case *types.Var, *types.Const:
			return c.formatExpr("%s", c.objectName(o))
		case *types.Func:
			return c.formatExpr("%s", c.objectName(o))
		case *types.TypeName:
			return c.formatExpr("%s", c.typeName(o.Type()))
		case *types.Nil:
			return c.formatExpr("%s", c.zeroValue(c.p.info.Types[e].Type))
		default:
			panic(fmt.Sprintf("Unhandled object: %T\n", o))
		}

	case *This:
		this := "this"
		if len(c.flattened) != 0 {
			this = "$this"
		}
		if isWrapped(c.p.info.Types[e].Type) {
			this += ".$val"
		}
		return c.formatExpr(this)

	case nil:
		return c.formatExpr("")

	default:
		panic(fmt.Sprintf("Unhandled expression: %T\n", e))

	}
}

示例#7

文件： expressions.go 项目： nvdnkpr/gopherjs

func (c *funcContext) formatExprInternal(format string, a []interface{}, parens bool) *expression {
	processFormat := func(f func(uint8, uint8, int)) {
		n := 0
		for i := 0; i < len(format); i++ {
			b := format[i]
			if b == '%' {
				i++
				k := format[i]
				if k >= '0' && k <= '9' {
					n = int(k - '0' - 1)
					i++
					k = format[i]
				}
				f(0, k, n)
				n++
				continue
			}
			f(b, 0, 0)
		}
	}

	counts := make([]int, len(a))
	processFormat(func(b, k uint8, n int) {
		switch k {
		case 'e', 'f', 'h', 'l', 'r', 'i':
			counts[n]++
		}
	})

	out := bytes.NewBuffer(nil)
	vars := make([]string, len(a))
	hasAssignments := false
	for i, e := range a {
		if counts[i] <= 1 {
			continue
		}
		if _, isIdent := e.(*ast.Ident); isIdent {
			continue
		}
		if val := c.p.info.Types[e.(ast.Expr)].Value; val != nil {
			continue
		}
		if !hasAssignments {
			hasAssignments = true
			out.WriteByte('(')
			parens = false
		}
		v := c.newVariable("x")
		out.WriteString(v + " = " + c.translateExpr(e.(ast.Expr)).String() + ", ")
		vars[i] = v
	}

	processFormat(func(b, k uint8, n int) {
		writeExpr := func(suffix string) {
			if vars[n] != "" {
				out.WriteString(vars[n] + suffix)
				return
			}
			out.WriteString(c.translateExpr(a[n].(ast.Expr)).StringWithParens() + suffix)
		}
		switch k {
		case 0:
			out.WriteByte(b)
		case 's':
			if e, ok := a[n].(*expression); ok {
				out.WriteString(e.StringWithParens())
				return
			}
			out.WriteString(a[n].(string))
		case 'd':
			out.WriteString(strconv.Itoa(a[n].(int)))
		case 't':
			out.WriteString(a[n].(token.Token).String())
		case 'e':
			e := a[n].(ast.Expr)
			if val := c.p.info.Types[e].Value; val != nil {
				out.WriteString(c.translateExpr(e).String())
				return
			}
			writeExpr("")
		case 'f':
			e := a[n].(ast.Expr)
			if val := c.p.info.Types[e].Value; val != nil {
				d, _ := exact.Int64Val(val)
				out.WriteString(strconv.FormatInt(d, 10))
				return
			}
			if is64Bit(c.p.info.Types[e].Type.Underlying().(*types.Basic)) {
				out.WriteString("$flatten64(")
				writeExpr("")
				out.WriteString(")")
				return
			}
			writeExpr("")
		case 'h':
			e := a[n].(ast.Expr)
			if val := c.p.info.Types[e].Value; val != nil {
				d, _ := exact.Uint64Val(val)
				if c.p.info.Types[e].Type.Underlying().(*types.Basic).Kind() == types.Int64 {
					out.WriteString(strconv.FormatInt(int64(d)>>32, 10))
					return
				}
				out.WriteString(strconv.FormatUint(d>>32, 10))
				return
			}
			writeExpr(".$high")
		case 'l':
			if val := c.p.info.Types[a[n].(ast.Expr)].Value; val != nil {
				d, _ := exact.Uint64Val(val)
				out.WriteString(strconv.FormatUint(d&(1<<32-1), 10))
				return
			}
			writeExpr(".$low")
		case 'r':
			if val := c.p.info.Types[a[n].(ast.Expr)].Value; val != nil {
				r, _ := exact.Float64Val(exact.Real(val))
				out.WriteString(strconv.FormatFloat(r, 'g', -1, 64))
				return
			}
			writeExpr(".$real")
		case 'i':
			if val := c.p.info.Types[a[n].(ast.Expr)].Value; val != nil {
				i, _ := exact.Float64Val(exact.Imag(val))
				out.WriteString(strconv.FormatFloat(i, 'g', -1, 64))
				return
			}
			writeExpr(".$imag")
		case '%':
			out.WriteRune('%')
		default:
			panic(fmt.Sprintf("formatExpr: %%%c%d", k, n))
		}
	})

	if hasAssignments {
		out.WriteByte(')')
	}
	return &expression{str: out.String(), parens: parens}
}

示例#8

文件： expressions.go 项目： umisama/gopherjs

func (c *PkgContext) translateExpr(expr ast.Expr) string {
	exprType := c.info.Types[expr]
	if value, valueFound := c.info.Values[expr]; valueFound {
		basic := types.Typ[types.String]
		if value.Kind() != exact.String { // workaround for bug in go/types
			basic = exprType.Underlying().(*types.Basic)
		}
		switch {
		case basic.Info()&types.IsBoolean != 0:
			return strconv.FormatBool(exact.BoolVal(value))
		case basic.Info()&types.IsInteger != 0:
			if is64Bit(basic) {
				d, _ := exact.Uint64Val(value)
				return fmt.Sprintf("new %s(%d, %d)", c.typeName(exprType), d>>32, d&(1<<32-1))
			}
			d, _ := exact.Int64Val(value)
			return strconv.FormatInt(d, 10)
		case basic.Info()&types.IsFloat != 0:
			f, _ := exact.Float64Val(value)
			return strconv.FormatFloat(f, 'g', -1, 64)
		case basic.Info()&types.IsComplex != 0:
			r, _ := exact.Float64Val(exact.Real(value))
			i, _ := exact.Float64Val(exact.Imag(value))
			if basic.Kind() == types.UntypedComplex {
				exprType = types.Typ[types.Complex128]
			}
			return fmt.Sprintf("new %s(%s, %s)", c.typeName(exprType), strconv.FormatFloat(r, 'g', -1, 64), strconv.FormatFloat(i, 'g', -1, 64))
		case basic.Info()&types.IsString != 0:
			buffer := bytes.NewBuffer(nil)
			for _, r := range []byte(exact.StringVal(value)) {
				switch r {
				case '\b':
					buffer.WriteString(`\b`)
				case '\f':
					buffer.WriteString(`\f`)
				case '\n':
					buffer.WriteString(`\n`)
				case '\r':
					buffer.WriteString(`\r`)
				case '\t':
					buffer.WriteString(`\t`)
				case '\v':
					buffer.WriteString(`\v`)
				case '"':
					buffer.WriteString(`\"`)
				case '\\':
					buffer.WriteString(`\\`)
				default:
					if r < 0x20 || r > 0x7E {
						fmt.Fprintf(buffer, `\x%02X`, r)
						continue
					}
					buffer.WriteByte(r)
				}
			}
			return `"` + buffer.String() + `"`
		default:
			panic("Unhandled constant type: " + basic.String())
		}
	}

	switch e := expr.(type) {
	case *ast.CompositeLit:
		if ptrType, isPointer := exprType.(*types.Pointer); isPointer {
			exprType = ptrType.Elem()
		}

		collectIndexedElements := func(elementType types.Type) []string {
			elements := make([]string, 0)
			i := 0
			zero := c.zeroValue(elementType)
			for _, element := range e.Elts {
				if kve, isKve := element.(*ast.KeyValueExpr); isKve {
					key, _ := exact.Int64Val(c.info.Values[kve.Key])
					i = int(key)
					element = kve.Value
				}
				for len(elements) <= i {
					elements = append(elements, zero)
				}
				elements[i] = c.translateExprToType(element, elementType)
				i++
			}
			return elements
		}

		switch t := exprType.Underlying().(type) {
		case *types.Array:
			elements := collectIndexedElements(t.Elem())
			if len(elements) != 0 {
				zero := c.zeroValue(t.Elem())
				for len(elements) < int(t.Len()) {
					elements = append(elements, zero)
				}
				return createListComposite(t.Elem(), elements)
			}
			return fmt.Sprintf("Go$makeArray(%s, %d, function() { return %s; })", toArrayType(t.Elem()), t.Len(), c.zeroValue(t.Elem()))
		case *types.Slice:
			return fmt.Sprintf("new %s(%s)", c.typeName(exprType), createListComposite(t.Elem(), collectIndexedElements(t.Elem())))
		case *types.Map:
			elements := make([]string, len(e.Elts)*2)
			for i, element := range e.Elts {
				kve := element.(*ast.KeyValueExpr)
				elements[i*2] = c.translateExprToType(kve.Key, t.Key())
				elements[i*2+1] = c.translateExprToType(kve.Value, t.Elem())
			}
			return fmt.Sprintf("new %s([%s])", c.typeName(exprType), strings.Join(elements, ", "))
		case *types.Struct:
			elements := make([]string, t.NumFields())
			isKeyValue := true
			if len(e.Elts) != 0 {
				_, isKeyValue = e.Elts[0].(*ast.KeyValueExpr)
			}
			if !isKeyValue {
				for i, element := range e.Elts {
					elements[i] = c.translateExprToType(element, t.Field(i).Type())
				}
			}
			if isKeyValue {
				for i := range elements {
					elements[i] = c.zeroValue(t.Field(i).Type())
				}
				for _, element := range e.Elts {
					kve := element.(*ast.KeyValueExpr)
					for j := range elements {
						if kve.Key.(*ast.Ident).Name == t.Field(j).Name() {
							elements[j] = c.translateExprToType(kve.Value, t.Field(j).Type())
							break
						}
					}
				}
			}
			if named, isNamed := exprType.(*types.Named); isNamed {
				return fmt.Sprintf("new %s(%s)", c.objectName(named.Obj()), strings.Join(elements, ", "))
			}
			structVar := c.newVariable("_struct")
			c.translateTypeSpec(&ast.TypeSpec{
				Name: c.newIdent(structVar, t),
				Type: e.Type,
			})
			return fmt.Sprintf("new %s(%s)", structVar, strings.Join(elements, ", "))
		default:
			panic(fmt.Sprintf("Unhandled CompositeLit type: %T\n", t))
		}

	case *ast.FuncLit:
		return strings.TrimSpace(string(c.CatchOutput(func() {
			c.newScope(func() {
				params := c.translateParams(e.Type)
				closurePrefix := "("
				closureSuffix := ")"
				if len(c.escapingVars) != 0 {
					list := strings.Join(c.escapingVars, ", ")
					closurePrefix = "(function(" + list + ") { return "
					closureSuffix = "; })(" + list + ")"
				}
				c.Printf("%sfunction(%s) {", closurePrefix, strings.Join(params, ", "))
				c.Indent(func() {
					c.translateFunctionBody(e.Body.List, exprType.(*types.Signature))
				})
				c.Printf("}%s", closureSuffix)
			})
		})))

	case *ast.UnaryExpr:
		switch e.Op {
		case token.AND:
			switch c.info.Types[e.X].Underlying().(type) {
			case *types.Struct, *types.Array:
				return c.translateExpr(e.X)
			default:
				if _, isComposite := e.X.(*ast.CompositeLit); isComposite {
					return fmt.Sprintf("Go$newDataPointer(%s, %s)", c.translateExpr(e.X), c.typeName(c.info.Types[e]))
				}
				closurePrefix := ""
				closureSuffix := ""
				if len(c.escapingVars) != 0 {
					list := strings.Join(c.escapingVars, ", ")
					closurePrefix = "(function(" + list + ") { return "
					closureSuffix = "; })(" + list + ")"
				}
				vVar := c.newVariable("v")
				return fmt.Sprintf("%snew %s(function() { return %s; }, function(%s) { %s; })%s", closurePrefix, c.typeName(exprType), c.translateExpr(e.X), vVar, c.translateAssign(e.X, vVar), closureSuffix)
			}
		case token.ARROW:
			return "undefined"
		}

		t := c.info.Types[e.X]
		basic := t.Underlying().(*types.Basic)
		op := e.Op.String()
		switch e.Op {
		case token.ADD:
			return c.translateExpr(e.X)
		case token.SUB:
			if is64Bit(basic) {
				x := c.newVariable("x")
				return fmt.Sprintf("(%s = %s, new %s(-%s.high, -%s.low))", x, c.translateExpr(e.X), c.typeName(t), x, x)
			}
			if basic.Info()&types.IsComplex != 0 {
				x := c.newVariable("x")
				return fmt.Sprintf("(%s = %s, new %s(-%s.real, -%s.imag))", x, c.translateExpr(e.X), c.typeName(t), x, x)
			}
		case token.XOR:
			if is64Bit(basic) {
				x := c.newVariable("x")
				return fmt.Sprintf("(%s = %s, new %s(~%s.high, ~%s.low >>> 0))", x, c.translateExpr(e.X), c.typeName(t), x, x)
			}
			op = "~"
		}
		return fixNumber(fmt.Sprintf("%s%s", op, c.translateExpr(e.X)), basic)

	case *ast.BinaryExpr:
		if e.Op == token.NEQ {
			return fmt.Sprintf("!(%s)", c.translateExpr(&ast.BinaryExpr{
				X:  e.X,
				Op: token.EQL,
				Y:  e.Y,
			}))
		}

		t := c.info.Types[e.X]
		t2 := c.info.Types[e.Y]
		_, isInterface := t2.Underlying().(*types.Interface)
		if isInterface {
			t = t2
		}

		if basic, isBasic := t.Underlying().(*types.Basic); isBasic && basic.Info()&types.IsNumeric != 0 {
			if is64Bit(basic) {
				var expr string
				switch e.Op {
				case token.MUL:
					return fmt.Sprintf("Go$mul64(%s, %s)", c.translateExpr(e.X), c.translateExpr(e.Y))
				case token.QUO:
					return fmt.Sprintf("Go$div64(%s, %s, false)", c.translateExpr(e.X), c.translateExpr(e.Y))
				case token.REM:
					return fmt.Sprintf("Go$div64(%s, %s, true)", c.translateExpr(e.X), c.translateExpr(e.Y))
				case token.SHL:
					return fmt.Sprintf("Go$shiftLeft64(%s, %s)", c.translateExpr(e.X), c.flatten64(e.Y))
				case token.SHR:
					return fmt.Sprintf("Go$shiftRight%s(%s, %s)", toJavaScriptType(basic), c.translateExpr(e.X), c.flatten64(e.Y))
				case token.EQL:
					expr = "x.high === y.high && x.low === y.low"
				case token.LSS:
					expr = "x.high < y.high || (x.high === y.high && x.low < y.low)"
				case token.LEQ:
					expr = "x.high < y.high || (x.high === y.high && x.low <= y.low)"
				case token.GTR:
					expr = "x.high > y.high || (x.high === y.high && x.low > y.low)"
				case token.GEQ:
					expr = "x.high > y.high || (x.high === y.high && x.low >= y.low)"
				case token.ADD, token.SUB:
					expr = fmt.Sprintf("new %s(x.high %s y.high, x.low %s y.low)", c.typeName(t), e.Op, e.Op)
				case token.AND, token.OR, token.XOR:
					expr = fmt.Sprintf("new %s(x.high %s y.high, (x.low %s y.low) >>> 0)", c.typeName(t), e.Op, e.Op)
				case token.AND_NOT:
					expr = fmt.Sprintf("new %s(x.high &~ y.high, (x.low &~ y.low) >>> 0)", c.typeName(t))
				default:
					panic(e.Op)
				}
				x := c.newVariable("x")
				y := c.newVariable("y")
				expr = strings.Replace(expr, "x.", x+".", -1)
				expr = strings.Replace(expr, "y.", y+".", -1)
				return fmt.Sprintf("(%s = %s, %s = %s, %s)", x, c.translateExpr(e.X), y, c.translateExpr(e.Y), expr)
			}

			if basic.Info()&types.IsComplex != 0 {
				var expr string
				switch e.Op {
				case token.EQL:
					expr = "x.real === y.real && x.imag === y.imag"
				case token.ADD, token.SUB:
					expr = fmt.Sprintf("new %s(x.real %s y.real, x.imag %s y.imag)", c.typeName(t), e.Op, e.Op)
				case token.MUL:
					expr = fmt.Sprintf("new %s(x.real * y.real - x.imag * y.imag, x.real * y.imag + x.imag * y.real)", c.typeName(t))
				case token.QUO:
					return fmt.Sprintf("Go$divComplex(%s, %s)", c.translateExpr(e.X), c.translateExpr(e.Y))
				default:
					panic(e.Op)
				}
				x := c.newVariable("x")
				y := c.newVariable("y")
				expr = strings.Replace(expr, "x.", x+".", -1)
				expr = strings.Replace(expr, "y.", y+".", -1)
				return fmt.Sprintf("(%s = %s, %s = %s, %s)", x, c.translateExpr(e.X), y, c.translateExpr(e.Y), expr)
			}

			switch e.Op {
			case token.EQL:
				return fmt.Sprintf("%s === %s", c.translateExpr(e.X), c.translateExpr(e.Y))
			case token.LSS, token.LEQ, token.GTR, token.GEQ:
				return fmt.Sprintf("%s %s %s", c.translateExpr(e.X), e.Op, c.translateExpr(e.Y))
			case token.ADD, token.SUB:
				return fixNumber(fmt.Sprintf("%s %s %s", c.translateExpr(e.X), e.Op, c.translateExpr(e.Y)), basic)
			case token.MUL:
				if basic.Kind() == types.Int32 {
					x := c.newVariable("x")
					y := c.newVariable("y")
					return fmt.Sprintf("(%s = %s, %s = %s, (((%s >>> 16 << 16) * %s >> 0) + (%s << 16 >>> 16) * %s) >> 0)", x, c.translateExpr(e.X), y, c.translateExpr(e.Y), x, y, x, y)
				}
				if basic.Kind() == types.Uint32 || basic.Kind() == types.Uintptr {
					x := c.newVariable("x")
					y := c.newVariable("y")
					return fmt.Sprintf("(%s = %s, %s = %s, (((%s >>> 16 << 16) * %s >>> 0) + (%s << 16 >>> 16) * %s) >>> 0)", x, c.translateExpr(e.X), y, c.translateExpr(e.Y), x, y, x, y)
				}
				return fixNumber(fmt.Sprintf("%s * %s", c.translateExpr(e.X), c.translateExpr(e.Y)), basic)
			case token.QUO:
				value := fmt.Sprintf("%s / %s", c.translateExpr(e.X), c.translateExpr(e.Y))
				if basic.Info()&types.IsInteger != 0 {
					value = "(Go$obj = " + value + `, (Go$obj === Go$obj && Go$obj !== 1/0 && Go$obj !== -1/0) ? Go$obj : Go$throwRuntimeError("integer divide by zero"))`
				}
				switch basic.Kind() {
				case types.Int, types.Uint:
					return "(" + value + " >> 0)" // cut off decimals
				default:
					return fixNumber(value, basic)
				}
			case token.REM:
				return fmt.Sprintf(`(Go$obj = %s %% %s, Go$obj === Go$obj ? Go$obj : Go$throwRuntimeError("integer divide by zero"))`, c.translateExpr(e.X), c.translateExpr(e.Y))
			case token.SHL, token.SHR:
				op := e.Op.String()
				if e.Op == token.SHR && basic.Info()&types.IsUnsigned != 0 {
					op = ">>>"
				}
				if c.info.Values[e.Y] != nil {
					return fixNumber(fmt.Sprintf("%s %s %s", c.translateExpr(e.X), op, c.translateExpr(e.Y)), basic)
				}
				if e.Op == token.SHR && basic.Info()&types.IsUnsigned == 0 {
					return fixNumber(fmt.Sprintf("(%s >> Go$min(%s, 31))", c.translateExpr(e.X), c.translateExpr(e.Y)), basic)
				}
				y := c.newVariable("y")
				return fixNumber(fmt.Sprintf("(%s = %s, %s < 32 ? (%s %s %s) : 0)", y, c.translateExprToType(e.Y, types.Typ[types.Uint]), y, c.translateExpr(e.X), op, y), basic)
			case token.AND, token.OR, token.XOR:
				return fixNumber(fmt.Sprintf("(%s %s %s)", c.translateExpr(e.X), e.Op, c.translateExpr(e.Y)), basic)
			case token.AND_NOT:
				return fixNumber(fmt.Sprintf("(%s &~ %s)", c.translateExpr(e.X), c.translateExpr(e.Y)), basic)
			default:
				panic(e.Op)
			}
		}

		switch e.Op {
		case token.ADD, token.LSS, token.LEQ, token.GTR, token.GEQ, token.LAND, token.LOR:
			return fmt.Sprintf("%s %s %s", c.translateExpr(e.X), e.Op, c.translateExpr(e.Y))
		case token.EQL:
			switch u := t.Underlying().(type) {
			case *types.Struct:
				x := c.newVariable("x")
				y := c.newVariable("y")
				var conds []string
				for i := 0; i < u.NumFields(); i++ {
					field := u.Field(i)
					if field.Name() == "_" {
						continue
					}
					conds = append(conds, c.translateExpr(&ast.BinaryExpr{
						X:  c.newIdent(x+"."+field.Name(), field.Type()),
						Op: token.EQL,
						Y:  c.newIdent(y+"."+field.Name(), field.Type()),
					}))
				}
				if len(conds) == 0 {
					conds = []string{"true"}
				}
				return fmt.Sprintf("(%s = %s, %s = %s, %s)", x, c.translateExpr(e.X), y, c.translateExpr(e.Y), strings.Join(conds, " && "))
			case *types.Interface:
				return fmt.Sprintf("Go$interfaceIsEqual(%s, %s)", c.translateExprToType(e.X, t), c.translateExprToType(e.Y, t))
			case *types.Array:
				return fmt.Sprintf("Go$arrayIsEqual(%s, %s)", c.translateExpr(e.X), c.translateExpr(e.Y))
			case *types.Pointer:
				xUnary, xIsUnary := e.X.(*ast.UnaryExpr)
				yUnary, yIsUnary := e.Y.(*ast.UnaryExpr)
				if xIsUnary && xUnary.Op == token.AND && yIsUnary && yUnary.Op == token.AND {
					xIndex, xIsIndex := xUnary.X.(*ast.IndexExpr)
					yIndex, yIsIndex := yUnary.X.(*ast.IndexExpr)
					if xIsIndex && yIsIndex {
						return fmt.Sprintf("Go$sliceIsEqual(%s, %s, %s, %s)", c.translateExpr(xIndex.X), c.flatten64(xIndex.Index), c.translateExpr(yIndex.X), c.flatten64(yIndex.Index))
					}
				}
				switch u.Elem().Underlying().(type) {
				case *types.Struct, *types.Interface:
					return c.translateExprToType(e.X, t) + " === " + c.translateExprToType(e.Y, t)
				case *types.Array:
					return fmt.Sprintf("Go$arrayIsEqual(%s, %s)", c.translateExprToType(e.X, t), c.translateExprToType(e.Y, t))
				default:
					return fmt.Sprintf("Go$pointerIsEqual(%s, %s)", c.translateExprToType(e.X, t), c.translateExprToType(e.Y, t))
				}
			default:
				return c.translateExprToType(e.X, t) + " === " + c.translateExprToType(e.Y, t)
			}
		default:
			panic(e.Op)
		}

	case *ast.ParenExpr:
		return fmt.Sprintf("(%s)", c.translateExpr(e.X))

	case *ast.IndexExpr:
		xType := c.info.Types[e.X]
		if ptr, isPointer := xType.(*types.Pointer); isPointer {
			xType = ptr.Elem()
		}
		switch t := xType.Underlying().(type) {
		case *types.Array:
			return fmt.Sprintf("%s[%s]", c.translateExpr(e.X), c.flatten64(e.Index))
		case *types.Slice:
			sliceVar := c.newVariable("_slice")
			indexVar := c.newVariable("_index")
			return fmt.Sprintf(`(%s = %s, %s = %s, (%s >= 0 && %s < %s.length) ? %s.array[%s.offset + %s] : Go$throwRuntimeError("index out of range"))`, sliceVar, c.translateExpr(e.X), indexVar, c.flatten64(e.Index), indexVar, indexVar, sliceVar, sliceVar, sliceVar, indexVar)
		case *types.Map:
			key := c.makeKey(e.Index, t.Key())
			if _, isTuple := exprType.(*types.Tuple); isTuple {
				return fmt.Sprintf(`(Go$obj = (%s || false)[%s], Go$obj !== undefined ? [Go$obj.v, true] : [%s, false])`, c.translateExpr(e.X), key, c.zeroValue(t.Elem()))
			}
			return fmt.Sprintf(`(Go$obj = (%s || false)[%s], Go$obj !== undefined ? Go$obj.v : %s)`, c.translateExpr(e.X), key, c.zeroValue(t.Elem()))
		case *types.Basic:
			return fmt.Sprintf("%s.charCodeAt(%s)", c.translateExpr(e.X), c.flatten64(e.Index))
		default:
			panic(fmt.Sprintf("Unhandled IndexExpr: %T\n", t))
		}

	case *ast.SliceExpr:
		b, isBasic := c.info.Types[e.X].(*types.Basic)
		isString := isBasic && b.Info()&types.IsString != 0
		slice := c.translateExprToType(e.X, exprType)
		if e.High == nil {
			if e.Low == nil {
				return slice
			}
			if isString {
				return fmt.Sprintf("%s.substring(%s)", slice, c.flatten64(e.Low))
			}
			return fmt.Sprintf("Go$subslice(%s, %s)", slice, c.flatten64(e.Low))
		}
		low := "0"
		if e.Low != nil {
			low = c.flatten64(e.Low)
		}
		if isString {
			return fmt.Sprintf("%s.substring(%s, %s)", slice, low, c.flatten64(e.High))
		}
		if e.Max != nil {
			return fmt.Sprintf("Go$subslice(%s, %s, %s, %s)", slice, low, c.flatten64(e.High), c.flatten64(e.Max))
		}
		return fmt.Sprintf("Go$subslice(%s, %s, %s)", slice, low, c.flatten64(e.High))

	case *ast.SelectorExpr:
		sel := c.info.Selections[e]
		parameterName := func(v *types.Var) string {
			if v.Anonymous() || v.Name() == "" {
				return c.newVariable("param")
			}
			return c.newVariable(v.Name())
		}
		makeParametersList := func() []string {
			params := sel.Obj().Type().(*types.Signature).Params()
			names := make([]string, params.Len())
			for i := 0; i < params.Len(); i++ {
				names[i] = parameterName(params.At(i))
			}
			return names
		}

		switch sel.Kind() {
		case types.FieldVal:
			return c.translateExpr(e.X) + "." + translateSelection(sel)
		case types.MethodVal:
			parameters := makeParametersList()
			recv := c.newVariable("_recv")
			return fmt.Sprintf("(%s = %s, function(%s) { return %s.%s(%s); })", recv, c.translateExpr(e.X), strings.Join(parameters, ", "), recv, e.Sel.Name, strings.Join(parameters, ", "))
		case types.MethodExpr:
			recv := "recv"
			if isWrapped(sel.Recv()) {
				recv = fmt.Sprintf("(new %s(recv))", c.typeName(sel.Recv()))
			}
			parameters := makeParametersList()
			return fmt.Sprintf("(function(%s) { return %s.%s(%s); })", strings.Join(append([]string{"recv"}, parameters...), ", "), recv, sel.Obj().(*types.Func).Name(), strings.Join(parameters, ", "))
		case types.PackageObj:
			return fmt.Sprintf("%s.%s", c.translateExpr(e.X), e.Sel.Name)
		}
		panic("")

	case *ast.CallExpr:
		plainFun := e.Fun
		for {
			if p, isParen := plainFun.(*ast.ParenExpr); isParen {
				plainFun = p.X
				continue
			}
			break
		}

		switch f := plainFun.(type) {
		case *ast.Ident:
			switch o := c.info.Objects[f].(type) {
			case *types.Builtin:
				switch o.Name() {
				case "new":
					t := c.info.Types[e].(*types.Pointer)
					if types.IsIdentical(t.Elem().Underlying(), types.Typ[types.Uintptr]) {
						return "new Uint8Array(8)"
					}
					switch t.Elem().Underlying().(type) {
					case *types.Struct, *types.Array:
						return c.zeroValue(t.Elem())
					default:
						return fmt.Sprintf("Go$newDataPointer(%s, %s)", c.zeroValue(t.Elem()), c.typeName(t))
					}
				case "make":
					switch t2 := c.info.Types[e.Args[0]].Underlying().(type) {
					case *types.Slice:
						if len(e.Args) == 3 {
							return fmt.Sprintf("Go$subslice(new %s(Go$makeArray(%s, %s, function() { return %s; })), 0, %s)", c.typeName(c.info.Types[e.Args[0]]), toArrayType(t2.Elem()), c.translateExprToType(e.Args[2], types.Typ[types.Int]), c.zeroValue(t2.Elem()), c.translateExprToType(e.Args[1], types.Typ[types.Int]))
						}
						return fmt.Sprintf("new %s(Go$makeArray(%s, %s, function() { return %s; }))", c.typeName(c.info.Types[e.Args[0]]), toArrayType(t2.Elem()), c.translateExprToType(e.Args[1], types.Typ[types.Int]), c.zeroValue(t2.Elem()))
					default:
						args := []string{"undefined"}
						for _, arg := range e.Args[1:] {
							args = append(args, c.translateExpr(arg))
						}
						return fmt.Sprintf("new %s(%s)", c.typeName(c.info.Types[e.Args[0]]), strings.Join(args, ", "))
					}
				case "len":
					arg := c.translateExpr(e.Args[0])
					switch argType := c.info.Types[e.Args[0]].Underlying().(type) {
					case *types.Basic, *types.Slice:
						return arg + ".length"
					case *types.Pointer:
						return fmt.Sprintf("(%s, %d)", arg, argType.Elem().(*types.Array).Len())
					case *types.Map:
						return fmt.Sprintf("(Go$obj = %s, Go$obj !== null ? Go$keys(Go$obj).length : 0)", arg)
					case *types.Chan:
						return "0"
					// length of array is constant
					default:
						panic(fmt.Sprintf("Unhandled len type: %T\n", argType))
					}
				case "cap":
					arg := c.translateExpr(e.Args[0])
					switch argType := c.info.Types[e.Args[0]].Underlying().(type) {
					case *types.Slice:
						return arg + ".capacity"
					case *types.Pointer:
						return fmt.Sprintf("(%s, %d)", arg, argType.Elem().(*types.Array).Len())
					case *types.Chan:
						return "0"
					// capacity of array is constant
					default:
						panic(fmt.Sprintf("Unhandled cap type: %T\n", argType))
					}
				case "panic":
					return fmt.Sprintf("throw new Go$Panic(%s)", c.translateExprToType(e.Args[0], types.NewInterface(nil, nil)))
				case "append":
					if e.Ellipsis.IsValid() {
						return fmt.Sprintf("Go$append(%s, %s)", c.translateExpr(e.Args[0]), c.translateExprToType(e.Args[1], exprType))
					}
					sliceType := exprType.Underlying().(*types.Slice)
					toAppend := createListComposite(sliceType.Elem(), c.translateExprSlice(e.Args[1:], sliceType.Elem()))
					return fmt.Sprintf("Go$append(%s, new %s(%s))", c.translateExpr(e.Args[0]), c.typeName(exprType), toAppend)
				case "delete":
					return fmt.Sprintf(`delete (%s || Go$Map.Go$nil)[%s]`, c.translateExpr(e.Args[0]), c.makeKey(e.Args[1], c.info.Types[e.Args[0]].Underlying().(*types.Map).Key()))
				case "copy":
					return fmt.Sprintf("Go$copy(%s, %s)", c.translateExprToType(e.Args[0], types.NewSlice(types.Typ[types.Byte])), c.translateExprToType(e.Args[1], types.NewSlice(types.Typ[types.Byte])))
				case "print", "println":
					return fmt.Sprintf("console.log(%s)", strings.Join(c.translateExprSlice(e.Args, nil), ", "))
				case "complex":
					return fmt.Sprintf("new %s(%s, %s)", c.typeName(c.info.Types[e]), c.translateExpr(e.Args[0]), c.translateExpr(e.Args[1]))
				case "real":
					return c.translateExpr(e.Args[0]) + ".real"
				case "imag":
					return c.translateExpr(e.Args[0]) + ".imag"
				case "recover":
					return "Go$recover()"
				case "close":
					return `Go$throwRuntimeError("not supported by GopherJS: close")`
				default:
					panic(fmt.Sprintf("Unhandled builtin: %s\n", o.Name()))
				}
			case *types.TypeName: // conversion
				if basic, isBasic := o.Type().Underlying().(*types.Basic); isBasic && !types.IsIdentical(c.info.Types[e.Args[0]], types.Typ[types.UnsafePointer]) {
					return fixNumber(c.translateExprToType(e.Args[0], o.Type()), basic)
				}
				return c.translateExprToType(e.Args[0], o.Type())
			}
		case *ast.FuncType: // conversion
			return c.translateExprToType(e.Args[0], c.info.Types[plainFun])
		}

		funType := c.info.Types[plainFun]
		sig, isSig := funType.Underlying().(*types.Signature)
		if !isSig { // conversion
			if c.pkg.Path() == "reflect" {
				if call, isCall := e.Args[0].(*ast.CallExpr); isCall && types.IsIdentical(c.info.Types[call.Fun], types.Typ[types.UnsafePointer]) {
					if named, isNamed := funType.(*types.Pointer).Elem().(*types.Named); isNamed {
						return c.translateExpr(call.Args[0]) + "." + named.Obj().Name() // unsafe conversion
					}
				}
			}
			return c.translateExprToType(e.Args[0], funType)
		}

		var fun string
		switch f := plainFun.(type) {
		case *ast.SelectorExpr:
			sel := c.info.Selections[f]

			switch sel.Kind() {
			case types.MethodVal:
				methodsRecvType := sel.Obj().(*types.Func).Type().(*types.Signature).Recv().Type()
				_, pointerExpected := methodsRecvType.(*types.Pointer)
				_, isPointer := sel.Recv().Underlying().(*types.Pointer)
				_, isStruct := sel.Recv().Underlying().(*types.Struct)
				_, isArray := sel.Recv().Underlying().(*types.Array)
				if pointerExpected && !isPointer && !isStruct && !isArray {
					target := c.translateExpr(f.X)
					vVar := c.newVariable("v")
					fun = fmt.Sprintf("(new %s(function() { return %s; }, function(%s) { %s = %s; })).%s", c.typeName(methodsRecvType), target, vVar, target, vVar, f.Sel.Name)
					break
				}
				if isWrapped(sel.Recv()) {
					fun = fmt.Sprintf("(new %s(%s)).%s", c.typeName(sel.Recv()), c.translateExpr(f.X), f.Sel.Name)
					break
				}
				fun = fmt.Sprintf("%s.%s", c.translateExpr(f.X), f.Sel.Name)
			case types.FieldVal, types.MethodExpr, types.PackageObj:
				fun = c.translateExpr(f)
			default:
				panic("")
			}
		default:
			fun = c.translateExpr(plainFun)
		}
		if len(e.Args) == 1 {
			if tuple, isTuple := c.info.Types[e.Args[0]].(*types.Tuple); isTuple {
				args := make([]ast.Expr, tuple.Len())
				for i := range args {
					args[i] = c.newIdent(fmt.Sprintf("Go$tuple[%d]", i), tuple.At(i).Type())
				}
				return fmt.Sprintf("(Go$tuple = %s, %s(%s))", c.translateExpr(e.Args[0]), fun, c.translateArgs(sig, args, false))
			}
		}
		return fmt.Sprintf("%s(%s)", fun, c.translateArgs(sig, e.Args, e.Ellipsis.IsValid()))

	case *ast.StarExpr:
		if c1, isCall := e.X.(*ast.CallExpr); isCall && len(c1.Args) == 1 {
			if c2, isCall := c1.Args[0].(*ast.CallExpr); isCall && len(c2.Args) == 1 && types.IsIdentical(c.info.Types[c2.Fun], types.Typ[types.UnsafePointer]) {
				if unary, isUnary := c2.Args[0].(*ast.UnaryExpr); isUnary && unary.Op == token.AND {
					return c.translateExpr(unary.X) // unsafe conversion
				}
			}
		}
		switch exprType.Underlying().(type) {
		case *types.Struct, *types.Array:
			return c.translateExpr(e.X)
		}
		return c.translateExpr(e.X) + ".Go$get()"

	case *ast.TypeAssertExpr:
		if e.Type == nil {
			return c.translateExpr(e.X)
		}
		t := c.info.Types[e.Type]
		check := "Go$obj !== null && " + c.typeCheck("Go$obj.constructor", t)
		value := "Go$obj"
		if _, isInterface := t.Underlying().(*types.Interface); !isInterface {
			value += ".Go$val"
		}
		if _, isTuple := exprType.(*types.Tuple); isTuple {
			return fmt.Sprintf("(Go$obj = %s, %s ? [%s, true] : [%s, false])", c.translateExpr(e.X), check, value, c.zeroValue(c.info.Types[e.Type]))
		}
		return fmt.Sprintf("(Go$obj = %s, %s ? %s : Go$typeAssertionFailed(Go$obj))", c.translateExpr(e.X), check, value)

	case *ast.Ident:
		if e.Name == "_" {
			panic("Tried to translate underscore identifier.")
		}
		switch o := c.info.Objects[e].(type) {
		case *types.PkgName:
			return c.pkgVars[o.Pkg().Path()]
		case *types.Var, *types.Const:
			return c.objectName(o)
		case *types.Func:
			return c.objectName(o)
		case *types.TypeName:
			return c.typeName(o.Type())
		case *types.Nil:
			return c.zeroValue(c.info.Types[e])
		case nil:
			return e.Name
		default:
			panic(fmt.Sprintf("Unhandled object: %T\n", o))
		}

	case nil:
		return ""

	default:
		panic(fmt.Sprintf("Unhandled expression: %T\n", e))

	}
}

示例#9

文件： expressions.go 项目： hajimehoshi/gopherjs

func (c *funcContext) translateExpr(expr ast.Expr) *expression {
	exprType := c.p.info.Types[expr].Type
	if value := c.p.info.Types[expr].Value; value != nil {
		basic := types.Typ[types.String]
		if value.Kind() != exact.String { // workaround for bug in go/types
			basic = exprType.Underlying().(*types.Basic)
		}
		switch {
		case basic.Info()&types.IsBoolean != 0:
			return c.formatExpr("%s", strconv.FormatBool(exact.BoolVal(value)))
		case basic.Info()&types.IsInteger != 0:
			if is64Bit(basic) {
				d, _ := exact.Uint64Val(value)
				if basic.Kind() == types.Int64 {
					return c.formatExpr("new %s(%s, %s)", c.typeName(exprType), strconv.FormatInt(int64(d)>>32, 10), strconv.FormatUint(d&(1<<32-1), 10))
				}
				return c.formatExpr("new %s(%s, %s)", c.typeName(exprType), strconv.FormatUint(d>>32, 10), strconv.FormatUint(d&(1<<32-1), 10))
			}
			d, _ := exact.Int64Val(value)
			return c.formatExpr("%s", strconv.FormatInt(d, 10))
		case basic.Info()&types.IsFloat != 0:
			f, _ := exact.Float64Val(value)
			return c.formatExpr("%s", strconv.FormatFloat(f, 'g', -1, 64))
		case basic.Info()&types.IsComplex != 0:
			r, _ := exact.Float64Val(exact.Real(value))
			i, _ := exact.Float64Val(exact.Imag(value))
			if basic.Kind() == types.UntypedComplex {
				exprType = types.Typ[types.Complex128]
			}
			return c.formatExpr("new %s(%s, %s)", c.typeName(exprType), strconv.FormatFloat(r, 'g', -1, 64), strconv.FormatFloat(i, 'g', -1, 64))
		case basic.Info()&types.IsString != 0:
			return c.formatExpr("%s", encodeString(exact.StringVal(value)))
		default:
			panic("Unhandled constant type: " + basic.String())
		}
	}

	switch e := expr.(type) {
	case *ast.CompositeLit:
		if ptrType, isPointer := exprType.(*types.Pointer); isPointer {
			exprType = ptrType.Elem()
		}

		collectIndexedElements := func(elementType types.Type) []string {
			elements := make([]string, 0)
			i := 0
			zero := c.zeroValue(elementType)
			for _, element := range e.Elts {
				if kve, isKve := element.(*ast.KeyValueExpr); isKve {
					key, _ := exact.Int64Val(c.p.info.Types[kve.Key].Value)
					i = int(key)
					element = kve.Value
				}
				for len(elements) <= i {
					elements = append(elements, zero)
				}
				elements[i] = c.translateImplicitConversion(element, elementType).String()
				i++
			}
			return elements
		}

		switch t := exprType.Underlying().(type) {
		case *types.Array:
			elements := collectIndexedElements(t.Elem())
			if len(elements) != 0 {
				zero := c.zeroValue(t.Elem())
				for len(elements) < int(t.Len()) {
					elements = append(elements, zero)
				}
				return c.formatExpr(`go$toNativeArray("%s", [%s])`, typeKind(t.Elem()), strings.Join(elements, ", "))
			}
			return c.formatExpr(`go$makeNativeArray("%s", %d, function() { return %s; })`, typeKind(t.Elem()), int(t.Len()), c.zeroValue(t.Elem()))
		case *types.Slice:
			return c.formatExpr("new %s([%s])", c.typeName(exprType), strings.Join(collectIndexedElements(t.Elem()), ", "))
		case *types.Map:
			mapVar := c.newVariable("_map")
			keyVar := c.newVariable("_key")
			assignments := ""
			for _, element := range e.Elts {
				kve := element.(*ast.KeyValueExpr)
				assignments += c.formatExpr(`%s = %s, %s[%s] = { k: %s, v: %s }, `, keyVar, c.translateImplicitConversion(kve.Key, t.Key()), mapVar, c.makeKey(c.newIdent(keyVar, t.Key()), t.Key()), keyVar, c.translateImplicitConversion(kve.Value, t.Elem())).String()
			}
			return c.formatExpr("(%s = new Go$Map(), %s%s)", mapVar, assignments, mapVar)
		case *types.Struct:
			elements := make([]string, t.NumFields())
			isKeyValue := true
			if len(e.Elts) != 0 {
				_, isKeyValue = e.Elts[0].(*ast.KeyValueExpr)
			}
			if !isKeyValue {
				for i, element := range e.Elts {
					elements[i] = c.translateImplicitConversion(element, t.Field(i).Type()).String()
				}
			}
			if isKeyValue {
				for i := range elements {
					elements[i] = c.zeroValue(t.Field(i).Type())
				}
				for _, element := range e.Elts {
					kve := element.(*ast.KeyValueExpr)
					for j := range elements {
						if kve.Key.(*ast.Ident).Name == t.Field(j).Name() {
							elements[j] = c.translateImplicitConversion(kve.Value, t.Field(j).Type()).String()
							break
						}
					}
				}
			}
			return c.formatExpr("new %s.Ptr(%s)", c.typeName(exprType), strings.Join(elements, ", "))
		default:
			panic(fmt.Sprintf("Unhandled CompositeLit type: %T\n", t))
		}

	case *ast.FuncLit:
		params, body := c.translateFunction(e.Type, exprType.(*types.Signature), e.Body.List)
		if len(c.escapingVars) != 0 {
			list := strings.Join(c.escapingVars, ", ")
			return c.formatExpr("(function(%s) { return function(%s) {\n%s%s}; })(%s)", list, strings.Join(params, ", "), string(body), strings.Repeat("\t", c.p.indentation), list)
		}
		return c.formatExpr("(function(%s) {\n%s%s})", strings.Join(params, ", "), string(body), strings.Repeat("\t", c.p.indentation))

	case *ast.UnaryExpr:
		switch e.Op {
		case token.AND:
			switch c.p.info.Types[e.X].Type.Underlying().(type) {
			case *types.Struct, *types.Array:
				return c.translateExpr(e.X)
			default:
				if _, isComposite := e.X.(*ast.CompositeLit); isComposite {
					return c.formatExpr("go$newDataPointer(%e, %s)", e.X, c.typeName(c.p.info.Types[e].Type))
				}
				closurePrefix := ""
				closureSuffix := ""
				if len(c.escapingVars) != 0 {
					list := strings.Join(c.escapingVars, ", ")
					closurePrefix = "(function(" + list + ") { return "
					closureSuffix = "; })(" + list + ")"
				}
				vVar := c.newVariable("v")
				return c.formatExpr("%snew %s(function() { return %e; }, function(%s) { %s; })%s", closurePrefix, c.typeName(exprType), e.X, vVar, c.translateAssign(e.X, vVar), closureSuffix)
			}
		case token.ARROW:
			return c.formatExpr("undefined")
		}

		t := c.p.info.Types[e.X].Type
		basic := t.Underlying().(*types.Basic)
		switch e.Op {
		case token.ADD:
			return c.translateExpr(e.X)
		case token.SUB:
			switch {
			case is64Bit(basic):
				return c.formatExpr("new %1s(-%2h, -%2l)", c.typeName(t), e.X)
			case basic.Info()&types.IsComplex != 0:
				return c.formatExpr("new %1s(-%2r, -%2i)", c.typeName(t), e.X)
			case basic.Info()&types.IsUnsigned != 0:
				return c.fixNumber(c.formatExpr("-%e", e.X), basic)
			default:
				return c.formatExpr("-%e", e.X)
			}
		case token.XOR:
			if is64Bit(basic) {
				return c.formatExpr("new %1s(~%2h, ~%2l >>> 0)", c.typeName(t), e.X)
			}
			return c.fixNumber(c.formatExpr("~%e", e.X), basic)
		case token.NOT:
			x := c.translateExpr(e.X)
			if x.String() == "true" {
				return c.formatExpr("false")
			}
			if x.String() == "false" {
				return c.formatExpr("true")
			}
			return c.formatExpr("!%s", x)
		default:
			panic(e.Op)
		}

	case *ast.BinaryExpr:
		if e.Op == token.NEQ {
			return c.formatExpr("!(%s)", c.translateExpr(&ast.BinaryExpr{
				X:  e.X,
				Op: token.EQL,
				Y:  e.Y,
			}))
		}

		t := c.p.info.Types[e.X].Type
		t2 := c.p.info.Types[e.Y].Type
		_, isInterface := t2.Underlying().(*types.Interface)
		if isInterface {
			t = t2
		}

		if basic, isBasic := t.Underlying().(*types.Basic); isBasic && basic.Info()&types.IsNumeric != 0 {
			if is64Bit(basic) {
				switch e.Op {
				case token.MUL:
					return c.formatExpr("go$mul64(%e, %e)", e.X, e.Y)
				case token.QUO:
					return c.formatExpr("go$div64(%e, %e, false)", e.X, e.Y)
				case token.REM:
					return c.formatExpr("go$div64(%e, %e, true)", e.X, e.Y)
				case token.SHL:
					return c.formatExpr("go$shiftLeft64(%e, %f)", e.X, e.Y)
				case token.SHR:
					return c.formatExpr("go$shiftRight%s(%e, %f)", toJavaScriptType(basic), e.X, e.Y)
				case token.EQL:
					return c.formatExpr("(%1h === %2h && %1l === %2l)", e.X, e.Y)
				case token.LSS:
					return c.formatExpr("(%1h < %2h || (%1h === %2h && %1l < %2l))", e.X, e.Y)
				case token.LEQ:
					return c.formatExpr("(%1h < %2h || (%1h === %2h && %1l <= %2l))", e.X, e.Y)
				case token.GTR:
					return c.formatExpr("(%1h > %2h || (%1h === %2h && %1l > %2l))", e.X, e.Y)
				case token.GEQ:
					return c.formatExpr("(%1h > %2h || (%1h === %2h && %1l >= %2l))", e.X, e.Y)
				case token.ADD, token.SUB:
					return c.formatExpr("new %3s(%1h %4t %2h, %1l %4t %2l)", e.X, e.Y, c.typeName(t), e.Op)
				case token.AND, token.OR, token.XOR:
					return c.formatExpr("new %3s(%1h %4t %2h, (%1l %4t %2l) >>> 0)", e.X, e.Y, c.typeName(t), e.Op)
				case token.AND_NOT:
					return c.formatExpr("new %3s(%1h &~ %2h, (%1l &~ %2l) >>> 0)", e.X, e.Y, c.typeName(t))
				default:
					panic(e.Op)
				}
			}

			if basic.Info()&types.IsComplex != 0 {
				switch e.Op {
				case token.EQL:
					if basic.Kind() == types.Complex64 {
						return c.formatExpr("(go$float32IsEqual(%1r, %2r) && go$float32IsEqual(%1i, %2i))", e.X, e.Y)
					}
					return c.formatExpr("(%1r === %2r && %1i === %2i)", e.X, e.Y)
				case token.ADD, token.SUB:
					return c.formatExpr("new %3s(%1r %4t %2r, %1i %4t %2i)", e.X, e.Y, c.typeName(t), e.Op)
				case token.MUL:
					return c.formatExpr("new %3s(%1r * %2r - %1i * %2i, %1r * %2i + %1i * %2r)", e.X, e.Y, c.typeName(t))
				case token.QUO:
					return c.formatExpr("go$divComplex(%e, %e)", e.X, e.Y)
				default:
					panic(e.Op)
				}
			}

			switch e.Op {
			case token.EQL:
				if basic.Kind() == types.Float32 {
					return c.formatParenExpr("go$float32IsEqual(%e, %e)", e.X, e.Y)
				}
				return c.formatParenExpr("%e === %e", e.X, e.Y)
			case token.LSS, token.LEQ, token.GTR, token.GEQ:
				return c.formatExpr("%e %t %e", e.X, e.Op, e.Y)
			case token.ADD, token.SUB:
				if basic.Info()&types.IsInteger != 0 {
					return c.fixNumber(c.formatExpr("%e %t %e", e.X, e.Op, e.Y), basic)
				}
				return c.formatExpr("%e %t %e", e.X, e.Op, e.Y)
			case token.MUL:
				switch basic.Kind() {
				case types.Int32, types.Int:
					return c.formatParenExpr("(((%1e >>> 16 << 16) * %2e >> 0) + (%1e << 16 >>> 16) * %2e) >> 0", e.X, e.Y)
				case types.Uint32, types.Uint, types.Uintptr:
					return c.formatParenExpr("(((%1e >>> 16 << 16) * %2e >>> 0) + (%1e << 16 >>> 16) * %2e) >>> 0", e.X, e.Y)
				case types.Float32, types.Float64:
					return c.formatExpr("%e * %e", e.X, e.Y)
				default:
					return c.fixNumber(c.formatExpr("%e * %e", e.X, e.Y), basic)
				}
			case token.QUO:
				if basic.Info()&types.IsInteger != 0 {
					// cut off decimals
					shift := ">>"
					if basic.Info()&types.IsUnsigned != 0 {
						shift = ">>>"
					}
					return c.formatExpr(`(%1s = %2e / %3e, (%1s === %1s && %1s !== 1/0 && %1s !== -1/0) ? %1s %4s 0 : go$throwRuntimeError("integer divide by zero"))`, c.newVariable("_q"), e.X, e.Y, shift)
				}
				return c.formatExpr("%e / %e", e.X, e.Y)
			case token.REM:
				return c.formatExpr(`(%1s = %2e %% %3e, %1s === %1s ? %1s : go$throwRuntimeError("integer divide by zero"))`, c.newVariable("_r"), e.X, e.Y)
			case token.SHL, token.SHR:
				op := e.Op.String()
				if e.Op == token.SHR && basic.Info()&types.IsUnsigned != 0 {
					op = ">>>"
				}
				if c.p.info.Types[e.Y].Value != nil {
					return c.fixNumber(c.formatExpr("%e %s %e", e.X, op, e.Y), basic)
				}
				if e.Op == token.SHR && basic.Info()&types.IsUnsigned == 0 {
					return c.fixNumber(c.formatParenExpr("%e >> go$min(%e, 31)", e.X, e.Y), basic)
				}
				y := c.newVariable("y")
				return c.fixNumber(c.formatExpr("(%s = %s, %s < 32 ? (%e %s %s) : 0)", y, c.translateImplicitConversion(e.Y, types.Typ[types.Uint]), y, e.X, op, y), basic)
			case token.AND, token.OR:
				if basic.Info()&types.IsUnsigned != 0 {
					return c.formatParenExpr("(%e %t %e) >>> 0", e.X, e.Op, e.Y)
				}
				return c.formatParenExpr("%e %t %e", e.X, e.Op, e.Y)
			case token.AND_NOT:
				return c.formatParenExpr("%e & ~%e", e.X, e.Y)
			case token.XOR:
				return c.fixNumber(c.formatParenExpr("%e ^ %e", e.X, e.Y), basic)
			default:
				panic(e.Op)
			}
		}

		switch e.Op {
		case token.ADD, token.LSS, token.LEQ, token.GTR, token.GEQ:
			return c.formatExpr("%e %t %e", e.X, e.Op, e.Y)
		case token.LAND:
			x := c.translateExpr(e.X)
			y := c.translateExpr(e.Y)
			if x.String() == "false" {
				return c.formatExpr("false")
			}
			return c.formatExpr("%s && %s", x, y)
		case token.LOR:
			x := c.translateExpr(e.X)
			y := c.translateExpr(e.Y)
			if x.String() == "true" {
				return c.formatExpr("true")
			}
			return c.formatExpr("%s || %s", x, y)
		case token.EQL:
			switch u := t.Underlying().(type) {
			case *types.Struct:
				x := c.newVariable("x")
				y := c.newVariable("y")
				var conds []string
				for i := 0; i < u.NumFields(); i++ {
					field := u.Field(i)
					if field.Name() == "_" {
						continue
					}
					conds = append(conds, c.translateExpr(&ast.BinaryExpr{
						X:  c.newIdent(x+"."+fieldName(u, i), field.Type()),
						Op: token.EQL,
						Y:  c.newIdent(y+"."+fieldName(u, i), field.Type()),
					}).String())
				}
				if len(conds) == 0 {
					conds = []string{"true"}
				}
				return c.formatExpr("(%s = %e, %s = %e, %s)", x, e.X, y, e.Y, strings.Join(conds, " && "))
			case *types.Interface:
				if isJsObject(t) {
					return c.formatExpr("%s === %s", c.translateImplicitConversion(e.X, t), c.translateImplicitConversion(e.Y, t))
				}
				return c.formatExpr("go$interfaceIsEqual(%s, %s)", c.translateImplicitConversion(e.X, t), c.translateImplicitConversion(e.Y, t))
			case *types.Array:
				return c.formatExpr("go$arrayIsEqual(%e, %e)", e.X, e.Y)
			case *types.Pointer:
				xUnary, xIsUnary := e.X.(*ast.UnaryExpr)
				yUnary, yIsUnary := e.Y.(*ast.UnaryExpr)
				if xIsUnary && xUnary.Op == token.AND && yIsUnary && yUnary.Op == token.AND {
					xIndex, xIsIndex := xUnary.X.(*ast.IndexExpr)
					yIndex, yIsIndex := yUnary.X.(*ast.IndexExpr)
					if xIsIndex && yIsIndex {
						return c.formatExpr("go$sliceIsEqual(%e, %f, %e, %f)", xIndex.X, xIndex.Index, yIndex.X, yIndex.Index)
					}
				}
				switch u.Elem().Underlying().(type) {
				case *types.Struct, *types.Interface:
					return c.formatExpr("%s === %s", c.translateImplicitConversion(e.X, t), c.translateImplicitConversion(e.Y, t))
				case *types.Array:
					return c.formatExpr("go$arrayIsEqual(%s, %s)", c.translateImplicitConversion(e.X, t), c.translateImplicitConversion(e.Y, t))
				default:
					return c.formatExpr("go$pointerIsEqual(%s, %s)", c.translateImplicitConversion(e.X, t), c.translateImplicitConversion(e.Y, t))
				}
			default:
				return c.formatExpr("%s === %s", c.translateImplicitConversion(e.X, t), c.translateImplicitConversion(e.Y, t))
			}
		default:
			panic(e.Op)
		}

	case *ast.ParenExpr:
		x := c.translateExpr(e.X)
		if x.String() == "true" || x.String() == "false" {
			return x
		}
		return c.formatParenExpr("%s", x)

	case *ast.IndexExpr:
		switch t := c.p.info.Types[e.X].Type.Underlying().(type) {
		case *types.Array, *types.Pointer:
			return c.formatExpr("%e[%f]", e.X, e.Index)
		case *types.Slice:
			return c.formatExpr(`((%2f < 0 || %2f >= %1e.length) ? go$throwRuntimeError("index out of range") : %1e.array[%1e.offset + %2f])`, e.X, e.Index)
		case *types.Map:
			key := c.makeKey(e.Index, t.Key())
			if _, isTuple := exprType.(*types.Tuple); isTuple {
				return c.formatExpr(`(%1s = %2e[%3s], %1s !== undefined ? [%1s.v, true] : [%4s, false])`, c.newVariable("_entry"), e.X, key, c.zeroValue(t.Elem()))
			}
			return c.formatExpr(`(%1s = %2e[%3s], %1s !== undefined ? %1s.v : %4s)`, c.newVariable("_entry"), e.X, key, c.zeroValue(t.Elem()))
		case *types.Basic:
			return c.formatExpr("%e.charCodeAt(%f)", e.X, e.Index)
		default:
			panic(fmt.Sprintf("Unhandled IndexExpr: %T\n", t))
		}

	case *ast.SliceExpr:
		if b, isBasic := c.p.info.Types[e.X].Type.Underlying().(*types.Basic); isBasic && b.Info()&types.IsString != 0 {
			switch {
			case e.Low == nil && e.High == nil:
				return c.translateExpr(e.X)
			case e.Low == nil:
				return c.formatExpr("%e.substring(0, %f)", e.X, e.High)
			case e.High == nil:
				return c.formatExpr("%e.substring(%f)", e.X, e.Low)
			default:
				return c.formatExpr("%e.substring(%f, %f)", e.X, e.Low, e.High)
			}
		}
		slice := c.translateConversionToSlice(e.X, exprType)
		switch {
		case e.Low == nil && e.High == nil:
			return c.formatExpr("%s", slice)
		case e.Low == nil:
			if e.Max != nil {
				return c.formatExpr("go$subslice(%s, 0, %f, %f)", slice, e.High, e.Max)
			}
			return c.formatExpr("go$subslice(%s, 0, %f)", slice, e.High)
		case e.High == nil:
			return c.formatExpr("go$subslice(%s, %f)", slice, e.Low)
		default:
			if e.Max != nil {
				return c.formatExpr("go$subslice(%s, %f, %f, %f)", slice, e.Low, e.High, e.Max)
			}
			return c.formatExpr("go$subslice(%s, %f, %f)", slice, e.Low, e.High)
		}

	case *ast.SelectorExpr:
		sel := c.p.info.Selections[e]
		parameterName := func(v *types.Var) string {
			if v.Anonymous() || v.Name() == "" {
				return c.newVariable("param")
			}
			return c.newVariable(v.Name())
		}
		makeParametersList := func() []string {
			params := sel.Obj().Type().(*types.Signature).Params()
			names := make([]string, params.Len())
			for i := 0; i < params.Len(); i++ {
				names[i] = parameterName(params.At(i))
			}
			return names
		}

		switch sel.Kind() {
		case types.FieldVal:
			fields, jsTag := c.translateSelection(sel)
			if jsTag != "" {
				if _, ok := sel.Type().(*types.Signature); ok {
					return c.formatExpr("go$internalize(%1e.%2s.%3s, %4s, %1e.%2s)", e.X, strings.Join(fields, "."), jsTag, c.typeName(sel.Type()))
				}
				return c.internalize(c.formatExpr("%e.%s.%s", e.X, strings.Join(fields, "."), jsTag), sel.Type())
			}
			return c.formatExpr("%e.%s", e.X, strings.Join(fields, "."))
		case types.MethodVal:
			if !sel.Obj().Exported() {
				c.p.dependencies[sel.Obj()] = true
			}
			parameters := makeParametersList()
			target := c.translateExpr(e.X)
			if isWrapped(sel.Recv()) {
				target = c.formatParenExpr("new %s(%s)", c.typeName(sel.Recv()), target)
			}
			recv := c.newVariable("_recv")
			return c.formatExpr("(%s = %s, function(%s) { return %s.%s(%s); })", recv, target, strings.Join(parameters, ", "), recv, e.Sel.Name, strings.Join(parameters, ", "))
		case types.MethodExpr:
			if !sel.Obj().Exported() {
				c.p.dependencies[sel.Obj()] = true
			}
			recv := "recv"
			if isWrapped(sel.Recv()) {
				recv = fmt.Sprintf("(new %s(recv))", c.typeName(sel.Recv()))
			}
			parameters := makeParametersList()
			return c.formatExpr("(function(%s) { return %s.%s(%s); })", strings.Join(append([]string{"recv"}, parameters...), ", "), recv, sel.Obj().(*types.Func).Name(), strings.Join(parameters, ", "))
		case types.PackageObj:
			if isJsPackage(sel.Obj().Pkg()) {
				switch sel.Obj().Name() {
				case "Global":
					return c.formatExpr("go$global")
				case "This":
					if c.flattened {
						return c.formatExpr("go$this")
					}
					return c.formatExpr("this")
				case "Arguments":
					args := "arguments"
					if c.flattened {
						args = "go$args"
					}

					return c.formatExpr(`new (go$sliceType(%s.Object))(go$global.Array.prototype.slice.call(%s))`, c.p.pkgVars["github.com/gopherjs/gopherjs/js"], args)
				default:
					panic("Invalid js package object: " + sel.Obj().Name())
				}
			}
			return c.formatExpr("%s", c.objectName(sel.Obj()))
		}
		panic("")

	case *ast.CallExpr:
		plainFun := e.Fun
		for {
			if p, isParen := plainFun.(*ast.ParenExpr); isParen {
				plainFun = p.X
				continue
			}
			break
		}

		var isType func(ast.Expr) bool
		isType = func(expr ast.Expr) bool {
			switch e := expr.(type) {
			case *ast.ArrayType, *ast.ChanType, *ast.FuncType, *ast.InterfaceType, *ast.MapType, *ast.StructType:
				return true
			case *ast.StarExpr:
				return isType(e.X)
			case *ast.Ident:
				_, ok := c.p.info.Uses[e].(*types.TypeName)
				return ok
			case *ast.SelectorExpr:
				_, ok := c.p.info.Uses[e.Sel].(*types.TypeName)
				return ok
			case *ast.ParenExpr:
				return isType(e.X)
			default:
				return false
			}
		}

		if isType(plainFun) {
			return c.formatExpr("%s", c.translateConversion(e.Args[0], c.p.info.Types[plainFun].Type))
		}

		var fun *expression
		switch f := plainFun.(type) {
		case *ast.Ident:
			if o, ok := c.p.info.Uses[f].(*types.Builtin); ok {
				switch o.Name() {
				case "new":
					t := c.p.info.Types[e].Type.(*types.Pointer)
					if c.p.pkg.Path() == "syscall" && types.Identical(t.Elem().Underlying(), types.Typ[types.Uintptr]) {
						return c.formatExpr("new Uint8Array(8)")
					}
					switch t.Elem().Underlying().(type) {
					case *types.Struct, *types.Array:
						return c.formatExpr("%s", c.zeroValue(t.Elem()))
					default:
						return c.formatExpr("go$newDataPointer(%s, %s)", c.zeroValue(t.Elem()), c.typeName(t))
					}
				case "make":
					switch argType := c.p.info.Types[e.Args[0]].Type.Underlying().(type) {
					case *types.Slice:
						t := c.typeName(c.p.info.Types[e.Args[0]].Type)
						if len(e.Args) == 3 {
							return c.formatExpr("%s.make(%f, %f, function() { return %s; })", t, e.Args[1], e.Args[2], c.zeroValue(argType.Elem()))
						}
						return c.formatExpr("%s.make(%f, 0, function() { return %s; })", t, e.Args[1], c.zeroValue(argType.Elem()))
					case *types.Map:
						return c.formatExpr("new Go$Map()")
					case *types.Chan:
						return c.formatExpr("new %s()", c.typeName(c.p.info.Types[e.Args[0]].Type))
					default:
						panic(fmt.Sprintf("Unhandled make type: %T\n", argType))
					}
				case "len":
					arg := c.translateExpr(e.Args[0])
					switch argType := c.p.info.Types[e.Args[0]].Type.Underlying().(type) {
					case *types.Basic, *types.Slice:
						return c.formatExpr("%s.length", arg)
					case *types.Pointer:
						return c.formatExpr("(%s, %d)", arg, argType.Elem().(*types.Array).Len())
					case *types.Map:
						return c.formatExpr("go$keys(%s).length", arg)
					case *types.Chan:
						return c.formatExpr("0")
					// length of array is constant
					default:
						panic(fmt.Sprintf("Unhandled len type: %T\n", argType))
					}
				case "cap":
					arg := c.translateExpr(e.Args[0])
					switch argType := c.p.info.Types[e.Args[0]].Type.Underlying().(type) {
					case *types.Slice:
						return c.formatExpr("%s.capacity", arg)
					case *types.Pointer:
						return c.formatExpr("(%s, %d)", arg, argType.Elem().(*types.Array).Len())
					case *types.Chan:
						return c.formatExpr("0")
					// capacity of array is constant
					default:
						panic(fmt.Sprintf("Unhandled cap type: %T\n", argType))
					}
				case "panic":
					return c.formatExpr("throw go$panic(%s)", c.translateImplicitConversion(e.Args[0], types.NewInterface(nil, nil)))
				case "append":
					if len(e.Args) == 1 {
						return c.translateExpr(e.Args[0])
					}
					if e.Ellipsis.IsValid() {
						return c.formatExpr("go$appendSlice(%e, %s)", e.Args[0], c.translateConversionToSlice(e.Args[1], exprType))
					}
					sliceType := exprType.Underlying().(*types.Slice)
					return c.formatExpr("go$append(%e, %s)", e.Args[0], strings.Join(c.translateExprSlice(e.Args[1:], sliceType.Elem()), ", "))
				case "delete":
					return c.formatExpr(`delete %e[%s]`, e.Args[0], c.makeKey(e.Args[1], c.p.info.Types[e.Args[0]].Type.Underlying().(*types.Map).Key()))
				case "copy":
					if basic, isBasic := c.p.info.Types[e.Args[1]].Type.Underlying().(*types.Basic); isBasic && basic.Info()&types.IsString != 0 {
						return c.formatExpr("go$copyString(%e, %e)", e.Args[0], e.Args[1])
					}
					return c.formatExpr("go$copySlice(%e, %e)", e.Args[0], e.Args[1])
				case "print", "println":
					return c.formatExpr("console.log(%s)", strings.Join(c.translateExprSlice(e.Args, nil), ", "))
				case "complex":
					return c.formatExpr("new %s(%e, %e)", c.typeName(c.p.info.Types[e].Type), e.Args[0], e.Args[1])
				case "real":
					return c.formatExpr("%e.real", e.Args[0])
				case "imag":
					return c.formatExpr("%e.imag", e.Args[0])
				case "recover":
					return c.formatExpr("go$recover()")
				case "close":
					return c.formatExpr(`go$notSupported("close")`)
				default:
					panic(fmt.Sprintf("Unhandled builtin: %s\n", o.Name()))
				}
			}
			fun = c.translateExpr(plainFun)

		case *ast.SelectorExpr:
			sel := c.p.info.Selections[f]
			o := sel.Obj()

			externalizeExpr := func(e ast.Expr) string {
				t := c.p.info.Types[e].Type
				if types.Identical(t, types.Typ[types.UntypedNil]) {
					return "null"
				}
				return c.externalize(c.translateExpr(e).String(), t)
			}
			externalizeArgs := func(args []ast.Expr) string {
				s := make([]string, len(args))
				for i, arg := range args {
					s[i] = externalizeExpr(arg)
				}
				return strings.Join(s, ", ")
			}

			switch sel.Kind() {
			case types.MethodVal:
				if !sel.Obj().Exported() {
					c.p.dependencies[sel.Obj()] = true
				}

				methodName := o.Name()
				if reservedKeywords[methodName] {
					methodName += "$"
				}

				fun = c.translateExpr(f.X)
				t := sel.Recv()
				for _, index := range sel.Index()[:len(sel.Index())-1] {
					if ptr, isPtr := t.(*types.Pointer); isPtr {
						t = ptr.Elem()
					}
					s := t.Underlying().(*types.Struct)
					fun = c.formatExpr("%s.%s", fun, fieldName(s, index))
					t = s.Field(index).Type()
				}

				if isJsPackage(o.Pkg()) {
					globalRef := func(id string) string {
						if fun.String() == "go$global" && len(id) > 3 && strings.EqualFold(id[:3], "go$") {
							return id
						}
						return fun.String() + "." + id
					}
					switch o.Name() {
					case "Get":
						if id, ok := c.identifierConstant(e.Args[0]); ok {
							return c.formatExpr("%s", globalRef(id))
						}
						return c.formatExpr("%s[go$externalize(%e, Go$String)]", fun, e.Args[0])
					case "Set":
						if id, ok := c.identifierConstant(e.Args[0]); ok {
							return c.formatExpr("%s = %s", globalRef(id), externalizeExpr(e.Args[1]))
						}
						return c.formatExpr("%s[go$externalize(%e, Go$String)] = %s", fun, e.Args[0], externalizeExpr(e.Args[1]))
					case "Delete":
						return c.formatExpr("delete %s[go$externalize(%e, Go$String)]", fun, e.Args[0])
					case "Length":
						return c.formatExpr("go$parseInt(%s.length)", fun)
					case "Index":
						return c.formatExpr("%s[%e]", fun, e.Args[0])
					case "SetIndex":
						return c.formatExpr("%s[%e] = %s", fun, e.Args[0], externalizeExpr(e.Args[1]))
					case "Call":
						if id, ok := c.identifierConstant(e.Args[0]); ok {
							if e.Ellipsis.IsValid() {
								objVar := c.newVariable("obj")
								return c.formatExpr("(%s = %s, %s.%s.apply(%s, %s))", objVar, fun, objVar, id, objVar, externalizeExpr(e.Args[1]))
							}
							return c.formatExpr("%s(%s)", globalRef(id), externalizeArgs(e.Args[1:]))
						}
						if e.Ellipsis.IsValid() {
							objVar := c.newVariable("obj")
							return c.formatExpr("(%s = %s, %s[go$externalize(%e, Go$String)].apply(%s, %s))", objVar, fun, objVar, e.Args[0], objVar, externalizeExpr(e.Args[1]))
						}
						return c.formatExpr("%s[go$externalize(%e, Go$String)](%s)", fun, e.Args[0], externalizeArgs(e.Args[1:]))
					case "Invoke":
						if e.Ellipsis.IsValid() {
							return c.formatExpr("%s.apply(undefined, %s)", fun, externalizeExpr(e.Args[0]))
						}
						return c.formatExpr("%s(%s)", fun, externalizeArgs(e.Args))
					case "New":
						if e.Ellipsis.IsValid() {
							return c.formatExpr("new (go$global.Function.prototype.bind.apply(%s, [undefined].concat(%s)))", fun, externalizeExpr(e.Args[0]))
						}
						return c.formatExpr("new (%s)(%s)", fun, externalizeArgs(e.Args))
					case "Bool":
						return c.internalize(fun, types.Typ[types.Bool])
					case "Str":
						return c.internalize(fun, types.Typ[types.String])
					case "Int":
						return c.internalize(fun, types.Typ[types.Int])
					case "Int64":
						return c.internalize(fun, types.Typ[types.Int64])
					case "Uint64":
						return c.internalize(fun, types.Typ[types.Uint64])
					case "Float":
						return c.internalize(fun, types.Typ[types.Float64])
					case "Interface":
						return c.internalize(fun, types.NewInterface(nil, nil))
					case "Unsafe":
						return fun
					case "IsUndefined":
						return c.formatParenExpr("%s === undefined", fun)
					case "IsNull":
						return c.formatParenExpr("%s === null", fun)
					default:
						panic("Invalid js package object: " + o.Name())
					}
				}

				methodsRecvType := o.Type().(*types.Signature).Recv().Type()
				_, pointerExpected := methodsRecvType.(*types.Pointer)
				_, isPointer := t.Underlying().(*types.Pointer)
				_, isStruct := t.Underlying().(*types.Struct)
				_, isArray := t.Underlying().(*types.Array)
				if pointerExpected && !isPointer && !isStruct && !isArray {
					vVar := c.newVariable("v")
					fun = c.formatExpr("(new %s(function() { return %s; }, function(%s) { %s = %s; })).%s", c.typeName(methodsRecvType), fun, vVar, fun, vVar, methodName)
					break
				}

				if isWrapped(t) {
					fun = c.formatExpr("(new %s(%s)).%s", c.typeName(t), fun, methodName)
					break
				}
				fun = c.formatExpr("%s.%s", fun, methodName)

			case types.PackageObj:
				if isJsPackage(o.Pkg()) && o.Name() == "InternalObject" {
					return c.translateExpr(e.Args[0])
				}
				fun = c.translateExpr(f)

			case types.FieldVal:
				fields, jsTag := c.translateSelection(sel)
				if jsTag != "" {
					sig := sel.Type().(*types.Signature)
					return c.internalize(c.formatExpr("%e.%s.%s(%s)", f.X, strings.Join(fields, "."), jsTag, externalizeArgs(e.Args)), sig.Results().At(0).Type())
				}
				fun = c.formatExpr("%e.%s", f.X, strings.Join(fields, "."))

			case types.MethodExpr:
				fun = c.translateExpr(f)

			default:
				panic("")
			}
		default:
			fun = c.translateExpr(plainFun)
		}

		sig := c.p.info.Types[plainFun].Type.Underlying().(*types.Signature)
		if len(e.Args) == 1 {
			if tuple, isTuple := c.p.info.Types[e.Args[0]].Type.(*types.Tuple); isTuple {
				tupleVar := c.newVariable("_tuple")
				args := make([]ast.Expr, tuple.Len())
				for i := range args {
					args[i] = c.newIdent(c.formatExpr("%s[%d]", tupleVar, i).String(), tuple.At(i).Type())
				}
				return c.formatExpr("(%s = %e, %s(%s))", tupleVar, e.Args[0], fun, strings.Join(c.translateArgs(sig, args, false), ", "))
			}
		}
		return c.formatExpr("%s(%s)", fun, strings.Join(c.translateArgs(sig, e.Args, e.Ellipsis.IsValid()), ", "))

	case *ast.StarExpr:
		if c1, isCall := e.X.(*ast.CallExpr); isCall && len(c1.Args) == 1 {
			if c2, isCall := c1.Args[0].(*ast.CallExpr); isCall && len(c2.Args) == 1 && types.Identical(c.p.info.Types[c2.Fun].Type, types.Typ[types.UnsafePointer]) {
				if unary, isUnary := c2.Args[0].(*ast.UnaryExpr); isUnary && unary.Op == token.AND {
					return c.translateExpr(unary.X) // unsafe conversion
				}
			}
		}
		switch exprType.Underlying().(type) {
		case *types.Struct, *types.Array:
			return c.translateExpr(e.X)
		}
		return c.formatExpr("%e.go$get()", e.X)

	case *ast.TypeAssertExpr:
		if e.Type == nil {
			return c.translateExpr(e.X)
		}
		t := c.p.info.Types[e.Type].Type
		check := "%1e !== null && " + c.typeCheck("%1e.constructor", t)
		valueSuffix := ""
		if _, isInterface := t.Underlying().(*types.Interface); !isInterface {
			valueSuffix = ".go$val"
		}
		if _, isTuple := exprType.(*types.Tuple); isTuple {
			return c.formatExpr("("+check+" ? [%1e%2s, true] : [%3s, false])", e.X, valueSuffix, c.zeroValue(c.p.info.Types[e.Type].Type))
		}
		return c.formatExpr("("+check+" ? %1e%2s : go$typeAssertionFailed(%1e, %3s))", e.X, valueSuffix, c.typeName(t))

	case *ast.Ident:
		if e.Name == "_" {
			panic("Tried to translate underscore identifier.")
		}
		switch o := c.p.info.Uses[e].(type) {
		case *types.PkgName:
			return c.formatExpr("%s", c.p.pkgVars[o.Pkg().Path()])
		case *types.Var, *types.Const:
			return c.formatExpr("%s", c.objectName(o))
		case *types.Func:
			return c.formatExpr("%s", c.objectName(o))
		case *types.TypeName:
			return c.formatExpr("%s", c.typeName(o.Type()))
		case *types.Nil:
			return c.formatExpr("%s", c.zeroValue(c.p.info.Types[e].Type))
		default:
			panic(fmt.Sprintf("Unhandled object: %T\n", o))
		}

	case *This:
		this := "this"
		if c.flattened {
			this = "go$this"
		}
		if isWrapped(c.p.info.Types[e].Type) {
			this += ".go$val"
		}
		return c.formatExpr(this)

	case nil:
		return c.formatExpr("")

	default:
		panic(fmt.Sprintf("Unhandled expression: %T\n", e))

	}
}

示例#10

文件： literals.go 项目： hzmangel/llgo

func (c *compiler) VisitCompositeLit(lit *ast.CompositeLit) (v *LLVMValue) {
	typ := c.types.expr[lit].Type
	var valuemap map[interface{}]Value
	var valuelist []Value

	if ptr, ok := typ.(*types.Pointer); ok {
		typ = ptr.Elem()
		defer func() {
			v = v.pointer
		}()
	}

	var isstruct, isarray, isslice, ismap bool
	switch typ.Underlying().(type) {
	case *types.Struct:
		isstruct = true
	case *types.Array:
		isarray = true
	case *types.Slice:
		isslice = true
	case *types.Map:
		ismap = true
	default:
		panic(fmt.Errorf("Unhandled type: %s", typ))
	}

	if lit.Elts != nil {
		for i, elt := range lit.Elts {
			if kv, iskv := elt.(*ast.KeyValueExpr); iskv {
				if valuemap == nil {
					valuemap = make(map[interface{}]Value)
				}
				var key interface{}
				var elttyp types.Type
				switch {
				case isstruct:
					name := kv.Key.(*ast.Ident).Name
					key = name
					typ := typ.Underlying().(*types.Struct)
					elttyp = typ.Field(fieldIndex(typ, name)).Type
				case isarray:
					key = c.types.expr[kv.Key].Value
					typ := typ.Underlying().(*types.Array)
					elttyp = typ.Elem()
				case isslice:
					key = c.types.expr[kv.Key].Value
					typ := typ.Underlying().(*types.Slice)
					elttyp = typ.Elem()
				case ismap:
					key = c.VisitExpr(kv.Key)
					typ := typ.Underlying().(*types.Map)
					elttyp = typ.Elem()
				default:
					panic("unreachable")
				}
				c.convertUntyped(kv.Value, elttyp)
				valuemap[key] = c.VisitExpr(kv.Value)
			} else {
				switch {
				case isstruct:
					typ := typ.Underlying().(*types.Struct)
					c.convertUntyped(elt, typ.Field(i).Type)
				case isarray:
					typ := typ.Underlying().(*types.Array)
					c.convertUntyped(elt, typ.Elem())
				case isslice:
					typ := typ.Underlying().(*types.Slice)
					c.convertUntyped(elt, typ.Elem())
				}
				value := c.VisitExpr(elt)
				valuelist = append(valuelist, value)
			}
		}
	}

	// For array/slice types, convert key:value to contiguous
	// values initialiser.
	switch typ.Underlying().(type) {
	case *types.Array, *types.Slice:
		if len(valuemap) > 0 {
			var maxkey uint64
			for key, _ := range valuemap {
				key, _ := exact.Uint64Val(key.(exact.Value))
				if key > maxkey {
					maxkey = key
				}
			}
			valuelist = make([]Value, maxkey+1)
			for key, value := range valuemap {
				key, _ := exact.Uint64Val(key.(exact.Value))
				valuelist[key] = value
			}
		}
	}

	origtyp := typ
	switch typ := typ.Underlying().(type) {
	case *types.Array:
		elttype := typ.Elem()
		llvmelttype := c.types.ToLLVM(elttype)
		llvmvalues := make([]llvm.Value, typ.Len())
		for i := range llvmvalues {
			var value Value
			if i < len(valuelist) {
				value = valuelist[i]
			}
			if value == nil {
				llvmvalues[i] = llvm.ConstNull(llvmelttype)
			} else if value.LLVMValue().IsConstant() {
				llvmvalues[i] = value.Convert(elttype).LLVMValue()
			} else {
				llvmvalues[i] = llvm.Undef(llvmelttype)
			}
		}
		array := llvm.ConstArray(llvmelttype, llvmvalues)
		for i, value := range valuelist {
			if llvmvalues[i].IsUndef() {
				value := value.Convert(elttype).LLVMValue()
				array = c.builder.CreateInsertValue(array, value, i, "")
			}
		}
		return c.NewValue(array, origtyp)

	case *types.Slice:
		ptr := c.createTypeMalloc(c.types.ToLLVM(typ))

		eltType := c.types.ToLLVM(typ.Elem())
		arrayType := llvm.ArrayType(eltType, len(valuelist))
		valuesPtr := c.createMalloc(llvm.SizeOf(arrayType))
		valuesPtr = c.builder.CreateIntToPtr(valuesPtr, llvm.PointerType(eltType, 0), "")

		//valuesPtr = c.builder.CreateBitCast(valuesPtr, llvm.PointerType(valuesPtr.Type(), 0), "")
		length := llvm.ConstInt(c.types.inttype, uint64(len(valuelist)), false)
		c.builder.CreateStore(valuesPtr, c.builder.CreateStructGEP(ptr, 0, "")) // data
		c.builder.CreateStore(length, c.builder.CreateStructGEP(ptr, 1, ""))    // len
		c.builder.CreateStore(length, c.builder.CreateStructGEP(ptr, 2, ""))    // cap
		null := llvm.ConstNull(c.types.ToLLVM(typ.Elem()))
		for i, value := range valuelist {
			index := llvm.ConstInt(llvm.Int32Type(), uint64(i), false)
			valuePtr := c.builder.CreateGEP(valuesPtr, []llvm.Value{index}, "")
			if value == nil {
				c.builder.CreateStore(null, valuePtr)
			} else {
				c.builder.CreateStore(value.Convert(typ.Elem()).LLVMValue(), valuePtr)
			}
		}
		m := c.NewValue(ptr, types.NewPointer(origtyp))
		return m.makePointee()

	case *types.Struct:
		values := valuelist
		llvmtyp := c.types.ToLLVM(typ)
		ptr := c.createTypeMalloc(llvmtyp)

		if valuemap != nil {
			for key, value := range valuemap {
				index := fieldIndex(typ, key.(string))
				for len(values) <= index {
					values = append(values, nil)
				}
				values[index] = value
			}
		}
		for i, value := range values {
			if value != nil {
				elttype := typ.Field(i).Type
				llvm_value := value.Convert(elttype).LLVMValue()
				ptr := c.builder.CreateStructGEP(ptr, i, "")
				c.builder.CreateStore(llvm_value, ptr)
			}
		}
		m := c.NewValue(ptr, types.NewPointer(origtyp))
		return m.makePointee()

	case *types.Map:
		value := llvm.ConstNull(c.types.ToLLVM(typ))
		// TODO initialise map
		return c.NewValue(value, origtyp)
	}
	panic(fmt.Sprint("Unhandled type kind: ", typ))
}

示例#11

文件： gcexporter.go 项目： kpsmith/gopherjs

func Write(pkg *types.Package, out io.Writer, sizes types.Sizes) {
	fmt.Fprintf(out, "package %s\n", pkg.Name())

	e := &exporter{pkg: pkg, imports: make(map[*types.Package]bool), out: out}

	for _, imp := range pkg.Imports() {
		e.addImport(imp)
	}

	for _, name := range pkg.Scope().Names() {
		obj := pkg.Scope().Lookup(name)

		_, isTypeName := obj.(*types.TypeName)
		if obj.Exported() || isTypeName {
			e.toExport = append(e.toExport, obj)
		}
	}

	for i := 0; i < len(e.toExport); i++ {
		switch o := e.toExport[i].(type) {
		case *types.TypeName:
			fmt.Fprintf(out, "type %s %s\n", e.makeName(o), e.makeType(o.Type().Underlying()))
			if _, isInterface := o.Type().Underlying().(*types.Interface); !isInterface {
				writeMethods := func(t types.Type) {
					methods := types.NewMethodSet(t)
					for i := 0; i < methods.Len(); i++ {
						m := methods.At(i)
						if len(m.Index()) > 1 {
							continue // method of embedded field
						}
						out.Write([]byte("func (? " + e.makeType(m.Recv()) + ") " + e.makeName(m.Obj()) + e.makeSignature(m.Type()) + "\n"))
					}
				}
				writeMethods(o.Type())
				writeMethods(types.NewPointer(o.Type()))
			}
		case *types.Func:
			out.Write([]byte("func " + e.makeName(o) + e.makeSignature(o.Type()) + "\n"))
		case *types.Const:
			optType := ""
			basic, isBasic := o.Type().(*types.Basic)
			if !isBasic || basic.Info()&types.IsUntyped == 0 {
				optType = " " + e.makeType(o.Type())
			}

			basic = o.Type().Underlying().(*types.Basic)
			var val string
			switch {
			case basic.Info()&types.IsBoolean != 0:
				val = strconv.FormatBool(exact.BoolVal(o.Val()))
			case basic.Info()&types.IsInteger != 0:
				if basic.Kind() == types.Uint64 {
					d, _ := exact.Uint64Val(o.Val())
					val = fmt.Sprintf("%#x", d)
					break
				}
				d, _ := exact.Int64Val(o.Val())
				if basic.Kind() == types.UntypedRune {
					switch {
					case d < 0 || d > unicode.MaxRune:
						val = fmt.Sprintf("('\\x00' + %d)", d)
					case d > 0xffff:
						val = fmt.Sprintf("'\\U%08x'", d)
					default:
						val = fmt.Sprintf("'\\u%04x'", d)
					}
					break
				}
				val = fmt.Sprintf("%#x", d)
			case basic.Info()&types.IsFloat != 0:
				f, _ := exact.Float64Val(o.Val())
				val = strconv.FormatFloat(f, 'b', -1, 64)
			case basic.Info()&types.IsComplex != 0:
				r, _ := exact.Float64Val(exact.Real(o.Val()))
				i, _ := exact.Float64Val(exact.Imag(o.Val()))
				val = fmt.Sprintf("(%s+%si)", strconv.FormatFloat(r, 'b', -1, 64), strconv.FormatFloat(i, 'b', -1, 64))
			case basic.Info()&types.IsString != 0:
				val = fmt.Sprintf("%#v", exact.StringVal(o.Val()))
			default:
				panic("Unhandled constant type: " + basic.String())
			}
			out.Write([]byte("const " + e.makeName(o) + optType + " = " + val + "\n"))
		case *types.Var:
			out.Write([]byte("var " + e.makeName(o) + " " + e.makeType(o.Type()) + "\n"))
		default:
			panic(fmt.Sprintf("Unhandled object: %T\n", o))
		}
	}

	fmt.Fprintf(out, "$$\n")
}