iter-iter: changed item operation from function and args to a list of expressions

iter-iter.go

@@ -9,33 +9,20 @@ import (
 	"io"
 
 	"git.portale-stac.it/go-pkg/expr/kern"
+	"git.portale-stac.it/go-pkg/expr/scan"
 )
 
 type IterIter struct {
-	it      kern.Iterator
-	count   int64
-	index   int64
-	ctx     kern.ExprContext
-	op      kern.Functor
-	opName  string
-	args    map[string]any
-	current any
+	it       kern.Iterator
+	count    int64
+	index    int64
+	ctx      kern.ExprContext
+	exprList []*scan.Term
+	current  any
 }
 
-func NewIterIter(it kern.Iterator, ctx kern.ExprContext, op kern.Functor, args map[string]any) (iter kern.Iterator, err error) {
-	var opName string
-	if op != nil {
-		if f := op.GetFunc(); f != nil {
-			opName = f.Name()
-			// } else {
-			// 	return nil, fmt.Errorf("invalid functor argument for iter-iter: expected kern.Functor, got %T", args["op"])
-		}
-	}
-	if len(opName) == 0 {
-		opName = "anonymous"
-	}
-	iter = &IterIter{it: it, count: 0, index: -1, ctx: ctx, op: op, opName: opName, args: args}
-
+func NewIterIter(it kern.Iterator, ctx kern.ExprContext, exprs []*scan.Term) (iter kern.Iterator, err error) {
+	iter = &IterIter{it: it, count: 0, index: -1, ctx: ctx, exprList: exprs, current: nil}
 	return
 }
 
@@ -48,7 +35,7 @@ func (it *IterIter) TypeName() string {
 }
 
 func (it *IterIter) HasOperation(name string) bool {
-	return HasStandardOperation(name)
+	return HasIterStandardOperations(name)
 }
 
 func (it *IterIter) CallOperation(name string, args map[string]any) (v any, err error) {
@@ -74,9 +61,17 @@ func (it *IterIter) CallOperation(name string, args map[string]any) (v any, err
 func (it *IterIter) Current() (item any, err error) {
 	if it.current != nil {
 		item = it.current
-	} else if it.op != nil {
-		if item, err = it.op.InvokeNamed(it.ctx, it.opName, it.args); err == nil {
-			it.current = item
+	} else if len(it.exprList) > 0 {
+		// Evaluate the expression list and use the result as the current item
+		var exprValue any
+		for _, expr := range it.exprList {
+			if exprValue, err = expr.Compute(it.ctx); err != nil {
+				break
+			}
+			it.ctx.UnsafeSetVar(kern.ControlLastResult, exprValue)
+		}
+		if err == nil {
+			item = exprValue
 		}
 	} else {
 		var exists bool