func buildString(b *builder, op *lex8.Token) tast.Expr {
v, e := strconv.Unquote(op.Lit)
if e != nil {
b.Errorf(op.Pos, "invalid string: %s", e)
return nil
}
ref := tast.NewConstRef(types.String, v)
return &tast.Const{ref}
}
func buildChar(b *builder, op *lex8.Token) tast.Expr {
v, e := strconv.Unquote(op.Lit)
if e != nil {
b.Errorf(op.Pos, "invalid char: %s", e)
return nil
} else if len(v) != 1 {
b.Errorf(op.Pos, "invalid char in quote: %q", v)
return nil
}
ref := tast.NewConstRef(types.Int8, int64(v[0]))
return &tast.Const{ref}
}
func buildInt(b *builder, op *lex8.Token) tast.Expr {
ret, e := strconv.ParseInt(op.Lit, 0, 64)
if e != nil {
b.Errorf(op.Pos, "invalid integer: %s", e)
return nil
}
if ret < math.MinInt32 {
b.Errorf(op.Pos, "integer too small to fit in 32-bit")
return nil
} else if ret > math.MaxUint32 {
b.Errorf(op.Pos, "integer too large to fit in 32-bit")
return nil
}
ref := tast.NewConstRef(types.NewNumber(ret), ret)
return &tast.Const{ref}
}
func buildArrayLit(b *builder, lit *ast.ArrayLiteral) tast.Expr {
hold := b.lhsSwap(false)
defer b.lhsRestore(hold)
if lit.Type.Len != nil {
b.Errorf(
ast.ExprPos(lit),
"array literal with length not supported yet",
)
return nil
}
buf := new(bytes.Buffer)
t := buildType(b, lit.Type.Type)
if t == nil {
return nil
}
if !types.IsInteger(t) {
pos := ast.ExprPos(lit.Type.Type)
b.Errorf(pos, "array literal must be integer type")
return nil
}
bt := t.(types.Basic)
if lit.Exprs != nil {
for _, expr := range lit.Exprs.Exprs {
n := b.buildConstExpr(expr)
if n == nil {
return nil
}
ntype := n.R().T
if _, ok := ntype.(*types.Const); !ok {
b.Errorf(ast.ExprPos(expr), "array literal not a constant")
return nil
}
if v, ok := types.NumConst(ntype); ok {
if !types.InRange(v, t) {
b.Errorf(
ast.ExprPos(expr),
"constant out of range of %s",
t,
)
return nil
}
switch bt {
case types.Int, types.Uint:
var bs [4]byte
binary.LittleEndian.PutUint32(bs[:], uint32(v))
buf.Write(bs[:])
case types.Int8, types.Uint8:
buf.Write([]byte{byte(v)})
default:
panic("not integer")
}
}
}
}
ref := tast.NewConstRef(&types.Slice{bt}, buf.Bytes())
return &tast.Const{ref}
}