// MultiNode evaluator
//
// A IN (b,c,d)
//
func walkMulti(ctx expr.EvalContext, node *expr.MultiArgNode) (value.Value, bool) {
a, aok := Eval(ctx, node.Args[0])
//u.Infof("multi: %T:%v %v", a, a, node.Operator)
if !aok {
u.Infof("Could not evaluate args, %#v", node.Args[0])
return value.BoolValueFalse, false
}
switch node.Operator.T {
case lex.TokenIN:
for i := 1; i < len(node.Args); i++ {
v, ok := Eval(ctx, node.Args[i])
if ok {
//u.Debugf("in? %v %v", a, v)
if eq, err := value.Equal(a, v); eq && err == nil {
return value.NewBoolValue(true), true
}
} else {
u.Warnf("could not evaluate arg: %v", node.Args[i])
}
}
return value.NewBoolValue(false), true
default:
u.Warnf("tri node walk not implemented: %#v", node)
}
return value.NewNilValue(), false
}
func walkUnary(ctx expr.EvalContext, node *expr.UnaryNode) (value.Value, bool) {
a, ok := Eval(ctx, node.Arg)
if !ok {
u.Infof("whoops, %#v", node)
return a, false
}
switch node.Operator.T {
case lex.TokenNegate:
switch argVal := a.(type) {
case value.BoolValue:
//u.Infof("found urnary bool: res=%v expr=%v", !argVal.v, node.StringAST())
return value.NewBoolValue(!argVal.Val()), true
default:
//u.Errorf("urnary type not implementedUnknonwn node type: %T", argVal)
panic(ErrUnknownNodeType)
}
case lex.TokenMinus:
if an, aok := a.(value.NumericValue); aok {
return value.NewNumberValue(-an.Float()), true
}
default:
u.Warnf("urnary not implemented: %#v", node)
}
return value.NewNilValue(), false
}
func walkUnary(ctx expr.EvalContext, node *expr.UnaryNode) (value.Value, bool) {
a, ok := Eval(ctx, node.Arg)
if !ok {
switch node.Operator.T {
case lex.TokenExists:
return value.NewBoolValue(false), true
case lex.TokenNegate:
return value.NewBoolValue(true), true
}
u.Debugf("unary could not evaluate for[ %s ] and %#v", node.String(), node)
return a, false
}
switch node.Operator.T {
case lex.TokenNegate:
switch argVal := a.(type) {
case value.BoolValue:
//u.Debugf("found unary bool: res=%v expr=%v", !argVal.Val(), node)
return value.NewBoolValue(!argVal.Val()), true
case nil, value.NilValue:
return value.NewBoolValue(false), false
default:
u.LogThrottle(u.WARN, 5, "unary type not implemented. Unknonwn node type: %T:%v node=%s", argVal, argVal, node.String())
return value.NewNilValue(), false
}
case lex.TokenMinus:
if an, aok := a.(value.NumericValue); aok {
return value.NewNumberValue(-an.Float()), true
}
case lex.TokenExists:
switch a.(type) {
case nil, value.NilValue:
return value.NewBoolValue(false), true
}
if a.Nil() {
return value.NewBoolValue(false), true
}
return value.NewBoolValue(true), true
default:
u.Warnf("urnary not implemented for type %s %#v", node.Operator.T.String(), node)
}
return value.NewNilValue(), false
}
// TriNode evaluator
//
// A BETWEEN B AND C
//
func walkTri(ctx expr.EvalContext, node *expr.TriNode) (value.Value, bool) {
a, aok := Eval(ctx, node.Args[0])
b, bok := Eval(ctx, node.Args[1])
c, c*k := Eval(ctx, node.Args[2])
//u.Infof("tri: %T:%v %v %T:%v %T:%v", a, a, node.Operator, b, b, c, c)
if !aok {
return value.BoolValueFalse, false
}
if !bok || !c*k {
u.Debugf("Could not evaluate args, %#v", node.String())
return value.BoolValueFalse, false
}
if a == nil || b == nil || c == nil {
return value.BoolValueFalse, false
}
switch node.Operator.T {
case lex.TokenBetween:
switch a.Type() {
case value.IntType:
//u.Infof("found tri: %v %v %v expr=%v", a, b, c, node.StringAST())
if aiv, ok := a.(value.IntValue); ok {
if biv, ok := b.(value.IntValue); ok {
if civ, ok := c.(value.IntValue); ok {
if aiv.Int() > biv.Int() && aiv.Int() < civ.Int() {
return value.NewBoolValue(true), true
} else {
return value.NewBoolValue(false), true
}
}
}
}
return value.BoolValueFalse, false
case value.NumberType:
//u.Infof("found tri: %v %v %v expr=%v", a, b, c, node.StringAST())
if afv, ok := a.(value.NumberValue); ok {
if bfv, ok := b.(value.NumberValue); ok {
if cfv, ok := c.(value.NumberValue); ok {
if afv.Float() > bfv.Float() && afv.Float() < cfv.Float() {
return value.NewBoolValue(true), false
} else {
return value.NewBoolValue(false), true
}
}
}
}
return value.BoolValueFalse, false
default:
u.Warnf("between not implemented for type %s %#v", a.Type().String(), node)
}
default:
u.Warnf("tri node walk not implemented: %#v", node)
}
return value.NewNilValue(), false
}
func Eval(ctx expr.EvalContext, arg expr.Node) (value.Value, bool) {
//u.Debugf("Eval() node=%T %v", arg, arg)
// can we switch to arg.Type()
switch argVal := arg.(type) {
case *expr.NumberNode:
return numberNodeToValue(argVal)
case *expr.BinaryNode:
return walkBinary(ctx, argVal)
case *expr.UnaryNode:
return walkUnary(ctx, argVal)
case *expr.TriNode:
return walkTri(ctx, argVal)
case *expr.ArrayNode:
return walkArray(ctx, argVal)
case *expr.FuncNode:
return walkFunc(ctx, argVal)
case *expr.IdentityNode:
return walkIdentity(ctx, argVal)
case *expr.StringNode:
return value.NewStringValue(argVal.Text), true
case nil:
return nil, false
case *expr.NullNode:
// WHERE (`users.user_id` != NULL)
return value.NewNilValue(), true
case *expr.ValueNode:
if argVal.Value == nil {
return nil, false
}
switch val := argVal.Value.(type) {
case *value.NilValue, value.NilValue:
return nil, false
case value.SliceValue:
//u.Warnf("got slice? %#v", argVal)
return val, true
}
u.Errorf("Unknonwn node type: %#v", argVal.Value)
panic(ErrUnknownNodeType)
default:
u.Errorf("Unknonwn node type: %#v", arg)
panic(ErrUnknownNodeType)
}
}
func walkUnary(ctx expr.EvalContext, node *expr.UnaryNode) (value.Value, bool) {
a, ok := Eval(ctx, node.Arg)
if !ok {
if node.Operator.T == lex.TokenExists {
return value.NewBoolValue(false), true
}
u.Debugf("unary could not evaluate %#v", node)
return a, false
}
switch node.Operator.T {
case lex.TokenNegate:
switch argVal := a.(type) {
case value.BoolValue:
//u.Infof("found unary bool: res=%v expr=%v", !argVal.v, node.StringAST())
return value.NewBoolValue(!argVal.Val()), true
case nil, value.NilValue:
return value.NewBoolValue(false), false
default:
u.Errorf("unary type not implemented. Unknonwn node type: %T:%v", argVal, argVal)
panic(ErrUnknownNodeType)
}
case lex.TokenMinus:
if an, aok := a.(value.NumericValue); aok {
return value.NewNumberValue(-an.Float()), true
}
case lex.TokenExists:
switch a.(type) {
case nil, value.NilValue:
return value.NewBoolValue(false), true
}
return value.NewBoolValue(true), true
default:
u.Warnf("urnary not implemented for type %s %#v", node.Operator.T.String(), node)
}
return value.NewNilValue(), false
}
func walkFunc(ctx expr.EvalContext, node *expr.FuncNode) (value.Value, bool) {
//u.Debugf("walkFunc node: %v", node.StringAST())
// we create a set of arguments to pass to the function, first arg
// is this Context
var ok bool
funcArgs := make([]reflect.Value, 0)
if ctx != nil {
funcArgs = append(funcArgs, reflect.ValueOf(ctx))
} else {
var nilArg expr.EvalContext
funcArgs = append(funcArgs, reflect.ValueOf(&nilArg).Elem())
}
for _, a := range node.Args {
//u.Debugf("arg %v %T %v", a, a, a)
var v interface{}
switch t := a.(type) {
case *expr.StringNode: // String Literal
v = value.NewStringValue(t.Text)
case *expr.IdentityNode: // Identity node = lookup in context
if t.IsBooleanIdentity() {
v = value.NewBoolValue(t.Bool())
} else {
v, ok = ctx.Get(t.Text)
//u.Infof("%#v", ctx.Row())
//u.Debugf("get '%s'? %T %v %v", t.String(), v, v, ok)
if !ok {
// nil arguments are valid
v = value.NewNilValue()
}
}
case *expr.NumberNode:
v, ok = numberNodeToValue(t)
case *expr.FuncNode:
//u.Debugf("descending to %v()", t.Name)
v, ok = walkFunc(ctx, t)
if !ok {
//return value.NewNilValue(), false
// nil arguments are valid
v = value.NewNilValue()
}
//u.Debugf("result of %v() = %v, %T", t.Name, v, v)
case *expr.UnaryNode:
v, ok = walkUnary(ctx, t)
if !ok {
// nil arguments are valid ??
v = value.NewNilValue()
}
case *expr.BinaryNode:
v, ok = walkBinary(ctx, t)
case *expr.ValueNode:
v = t.Value
default:
panic(fmt.Errorf("expr: unknown func arg type"))
}
if v == nil {
//u.Warnf("Nil vals? %v %T arg:%T", v, v, a)
// What do we do with Nil Values?
switch a.(type) {
case *expr.StringNode: // String Literal
u.Warnf("NOT IMPLEMENTED T:%T v:%v", a, a)
case *expr.IdentityNode: // Identity node = lookup in context
v = value.NewStringValue("")
default:
u.Warnf("un-handled type: %v %T", v, v)
}
funcArgs = append(funcArgs, reflect.ValueOf(v))
} else {
//u.Debugf(`found func arg: "%v" %T arg:%T`, v, v, a)
funcArgs = append(funcArgs, reflect.ValueOf(v))
}
}
// Get the result of calling our Function (Value,bool)
//u.Debugf("Calling func:%v(%v) %v", node.F.Name, funcArgs, node.F.F)
fnRet := node.F.F.Call(funcArgs)
//u.Debugf("fnRet: %v ok?%v", fnRet, fnRet[1].Bool())
// check if has an error response?
if len(fnRet) > 1 && !fnRet[1].Bool() {
// What do we do if not ok?
return value.EmptyStringValue, false
}
//u.Debugf("response %v %v %T", node.F.Name, fnRet[0].Interface(), fnRet[0].Interface())
return fnRet[0].Interface().(value.Value), true
}
