Reset() and Clean() have new, simpler signature

common-type-names.go

@@ -6,6 +6,7 @@ package expr
 
 const (
 	TypeAny           = "any"
+	TypeNil           = "nil"
 	TypeBoolean       = "boolean"
 	TypeFloat         = "float"
 	TypeFraction      = "fraction"
@@ -15,6 +16,7 @@ const (
 	TypeNumber        = "number"
 	TypePair          = "pair"
 	TypeString        = "string"
+	TypeDict          = "dict"
 	TypeListOf        = "list-of-"
 	TypeListOfStrings = "list-of-strings"
 )

data-cursor.go

@@ -6,12 +6,14 @@ package expr
 
 import (
 	"io"
+	"slices"
 )
 
 type dataCursor struct {
 	ds        map[string]Functor
 	ctx       ExprContext
-	initState bool // true if no item has prodiced yet (this replace di initial Next() call in the contructor)
+	initState bool // true if no item has produced yet (this replace di initial Next() call in the contructor)
+	// cursorValid bool // true if resource is nil or if clean has not yet been called
 	index     int
 	count     int
 	current   any
@@ -26,6 +28,7 @@ func NewDataCursor(ctx ExprContext, ds map[string]Functor, resource any) (dc *da
 	dc = &dataCursor{
 		ds:        ds,
 		initState: true,
+		// cursorValid: true,
 		index:     -1,
 		count:     0,
 		current:   nil,
@@ -36,7 +39,6 @@ func NewDataCursor(ctx ExprContext, ds map[string]Functor, resource any) (dc *da
 		cleanFunc: ds[CleanName],
 		resetFunc: ds[ResetName],
 	}
-	//dc.Next()
 	return
 }
 
@@ -77,7 +79,7 @@ func (dc *dataCursor) String() string {
 }
 
 func (dc *dataCursor) HasOperation(name string) (exists bool) {
-	exists = name == IndexName
+	exists = slices.Contains([]string{CleanName, ResetName, CurrentName, IndexName}, name)
 	if !exists {
 		f, ok := dc.ds[name]
 		exists = ok && isFunctor(f)
@@ -88,63 +90,83 @@ func (dc *dataCursor) HasOperation(name string) (exists bool) {
 func (dc *dataCursor) CallOperation(name string, args map[string]any) (value any, err error) {
 	if name == IndexName {
 		value = int64(dc.Index())
+	} else if name == CleanName {
+		err = dc.Clean()
+	} else if name == ResetName {
+		err = dc.Reset()
 	} else if functor, ok := dc.ds[name]; ok && isFunctor(functor) {
-		if functor == dc.cleanFunc {
-			value, err = dc.Clean()
-		} else if functor == dc.resetFunc {
-			value, err = dc.Reset()
-		} else {
-			ctx := cloneContext(dc.ctx)
-			value, err = functor.InvokeNamed(ctx, name, args)
-			exportObjects(dc.ctx, ctx)
-		}
+		ctx := cloneContext(dc.ctx)
+		value, err = functor.InvokeNamed(ctx, name, args)
+		exportObjects(dc.ctx, ctx)
 	} else {
 		err = errNoOperation(name)
 	}
 	return
 }
 
-func (dc *dataCursor) Reset() (success bool, err error) {
+// func (dc *dataCursor) Reset() (err error) {
+// 	if dc.resetFunc != nil {
+// 		if dc.resource != nil {
+// 			ctx := cloneContext(dc.ctx)
+// 			actualParams := bindActualParams(dc.resetFunc, []any{dc.resource})
+// 			_, err = dc.resetFunc.InvokeNamed(ctx, ResetName, actualParams)
+// 			exportObjects(dc.ctx, ctx)
+// 			dc.index = -1
+// 			dc.count = 0
+// 			dc.initState = true
+// 			dc.current = nil
+// 			dc.lastErr = nil
+// 		} else {
+// 			err = errInvalidDataSource()
+// 		}
+// 	} else {
+// 		err = errNoOperation(ResetName)
+// 	}
+// 	return
+// }
+
+func (dc *dataCursor) Reset() (err error) {
 	if dc.resetFunc != nil {
-		if dc.resource != nil {
-			ctx := cloneContext(dc.ctx)
-			actualParams := bindActualParams(dc.resetFunc, []any{dc.resource})
-			_, err = dc.resetFunc.InvokeNamed(ctx, ResetName, actualParams)
-			exportObjects(dc.ctx, ctx)
-			dc.index = -1
-			dc.count = 0
-			dc.initState = true
-			dc.current = nil
-			dc.lastErr = nil
-			//dc.Next()
-		} else {
-			err = errInvalidDataSource()
-		}
-	} else {
-		err = errNoOperation(ResetName)
+		ctx := cloneContext(dc.ctx)
+		actualParams := bindActualParams(dc.resetFunc, []any{dc.resource})
+		_, err = dc.resetFunc.InvokeNamed(ctx, ResetName, actualParams)
+		exportObjects(dc.ctx, ctx)
 	}
-	success = err == nil
+	dc.index = -1
+	dc.count = 0
+	dc.initState = true
+	dc.current = nil
+	dc.lastErr = nil
 	return
 }
 
-func (dc *dataCursor) Clean() (success bool, err error) {
+func (dc *dataCursor) Clean() (err error) {
 	if dc.cleanFunc != nil {
-		if dc.resource != nil {
-			ctx := cloneContext(dc.ctx)
-			actualParams := bindActualParams(dc.cleanFunc, []any{dc.resource})
-			_, err = dc.cleanFunc.InvokeNamed(ctx, CleanName, actualParams)
-			//			dc.resource = nil
-			exportObjects(dc.ctx, ctx)
-		} else {
-			err = errInvalidDataSource()
-		}
-	} else {
-		err = errNoOperation(CleanName)
+		ctx := cloneContext(dc.ctx)
+		actualParams := bindActualParams(dc.cleanFunc, []any{dc.resource})
+		_, err = dc.cleanFunc.InvokeNamed(ctx, CleanName, actualParams)
+		exportObjects(dc.ctx, ctx)
 	}
-	success = err == nil
+	dc.lastErr = io.EOF
 	return
 }
 
+// func (dc *dataCursor) Clean() (err error) {
+// 	if dc.cleanFunc != nil {
+// 		if dc.resource != nil {
+// 			ctx := cloneContext(dc.ctx)
+// 			actualParams := bindActualParams(dc.cleanFunc, []any{dc.resource})
+// 			_, err = dc.cleanFunc.InvokeNamed(ctx, CleanName, actualParams)
+// 			exportObjects(dc.ctx, ctx)
+// 		} else {
+// 			err = errInvalidDataSource()
+// 		}
+// 	} else {
+// 		err = errNoOperation(CleanName)
+// 	}
+// 	return
+// }
+
 func (dc *dataCursor) Current() (item any, err error) { // must return io.EOF at the last item
 	dc.init()
 
@@ -191,46 +213,89 @@ func (dc *dataCursor) Next() (current any, err error) { // must return io.EOF af
 		return
 	}
 	current = dc.current
-	if dc.resource != nil {
-		filter := dc.ds[FilterName]
-		mapper := dc.ds[MapName]
-		var item any
-		for item == nil && dc.lastErr == nil {
-			ctx := cloneContext(dc.ctx)
-			dc.index++
+	filter := dc.ds[FilterName]
+	mapper := dc.ds[MapName]
+	var item any
+	for item == nil && dc.lastErr == nil {
+		ctx := cloneContext(dc.ctx)
+		dc.index++
 
-			actualParams := bindActualParams(dc.nextFunc, []any{dc.resource, dc.index})
-			if item, dc.lastErr = dc.nextFunc.InvokeNamed(ctx, NextName, actualParams); dc.lastErr == nil {
-				if item == nil {
-					dc.lastErr = io.EOF
-				} else {
-					accepted := true
-					if filter != nil {
-						if accepted, dc.lastErr = dc.checkFilter(filter, item); dc.lastErr != nil || !accepted {
-							item = nil
-						}
-					}
-					if accepted {
-						dc.count++
-					}
-					if item != nil && mapper != nil {
-						item, dc.lastErr = dc.mapItem(mapper, item)
+		actualParams := bindActualParams(dc.nextFunc, []any{dc.resource, dc.index})
+		if item, dc.lastErr = dc.nextFunc.InvokeNamed(ctx, NextName, actualParams); dc.lastErr == nil {
+			if item == nil {
+				dc.lastErr = io.EOF
+			} else {
+				accepted := true
+				if filter != nil {
+					if accepted, dc.lastErr = dc.checkFilter(filter, item); dc.lastErr != nil || !accepted {
+						item = nil
 					}
 				}
+				if accepted {
+					dc.count++
+				}
+				if item != nil && mapper != nil {
+					item, dc.lastErr = dc.mapItem(mapper, item)
+				}
 			}
-			exportObjects(dc.ctx, ctx)
 		}
-		dc.current = item
-		if dc.lastErr != nil {
-			dc.index--
-			dc.Clean()
-		}
-	} else {
-		dc.lastErr = errInvalidDataSource()
+		exportObjects(dc.ctx, ctx)
+	}
+	dc.current = item
+	if dc.lastErr != nil {
+		dc.index--
+		dc.Clean()
 	}
 	return
 }
 
+// func (dc *dataCursor) Next() (current any, err error) { // must return io.EOF after the last item
+// 	if dc.initState {
+// 		dc.init()
+// 	} else if err = dc.lastErr; err != nil {
+// 		return
+// 	}
+// 	current = dc.current
+// 	if dc.resource != nil {
+// 		filter := dc.ds[FilterName]
+// 		mapper := dc.ds[MapName]
+// 		var item any
+// 		for item == nil && dc.lastErr == nil {
+// 			ctx := cloneContext(dc.ctx)
+// 			dc.index++
+
+// 			actualParams := bindActualParams(dc.nextFunc, []any{dc.resource, dc.index})
+// 			if item, dc.lastErr = dc.nextFunc.InvokeNamed(ctx, NextName, actualParams); dc.lastErr == nil {
+// 				if item == nil {
+// 					dc.lastErr = io.EOF
+// 				} else {
+// 					accepted := true
+// 					if filter != nil {
+// 						if accepted, dc.lastErr = dc.checkFilter(filter, item); dc.lastErr != nil || !accepted {
+// 							item = nil
+// 						}
+// 					}
+// 					if accepted {
+// 						dc.count++
+// 					}
+// 					if item != nil && mapper != nil {
+// 						item, dc.lastErr = dc.mapItem(mapper, item)
+// 					}
+// 				}
+// 			}
+// 			exportObjects(dc.ctx, ctx)
+// 		}
+// 		dc.current = item
+// 		if dc.lastErr != nil {
+// 			dc.index--
+// 			dc.Clean()
+// 		}
+// 	} else {
+// 		dc.lastErr = errInvalidDataSource()
+// 	}
+// 	return
+// }
+
 func (dc *dataCursor) Index() int {
 	return dc.index - 1
 }

function.go

@@ -348,8 +348,8 @@ func CallFunctionByArgs(parentCtx ExprContext, name string, args []any) (result
 	return
 }
 
-func CallFunctionByParams(parentCtx ExprContext, name string, params map[string]any) (result any, err error) {
-	var actualParams map[string]any
+func CallFunctionByParams(parentCtx ExprContext, name string, actualParams map[string]any) (result any, err error) {
+	//var actualParams map[string]any
 	if info, exists := GetFuncInfo(parentCtx, name); exists {
 		functor := info.Functor()
 		ctx := info.AllocContext(parentCtx)

iterator.go

@@ -33,6 +33,8 @@ type Iterator interface {
 
 type ExtIterator interface {
 	Iterator
+	Reset() error
+	Clean() error
 	HasOperation(name string) bool
 	CallOperation(name string, args map[string]any) (value any, err error)
 }

list-iterator.go

@@ -99,7 +99,9 @@ func (it *ListIterator) CallOperation(name string, args map[string]any) (v any,
 	case NextName:
 		v, err = it.Next()
 	case ResetName:
-		v, err = it.Reset()
+		err = it.Reset()
+	case CleanName:
+		err = it.Clean()
 	case IndexName:
 		v = int64(it.Index())
 	case CurrentName:
@@ -147,8 +149,12 @@ func (it *ListIterator) Count() int {
 	return it.count
 }
 
-func (it *ListIterator) Reset() (bool, error) {
+func (it *ListIterator) Reset() (error) {
 	it.index = it.start - it.step
 	it.count = 0
-	return true, nil
+	return nil
+}
+
+func (it *ListIterator) Clean() (error) {
+	return nil
 }

operand-iterator.go

@@ -92,6 +92,7 @@ func evalIterator(ctx ExprContext, opTerm *term) (v any, err error) {
 
 	if ds != nil {
 		var dc *dataCursor
+		dcCtx := ctx.Clone()
 		if initFunc, exists := ds[InitName]; exists && initFunc != nil {
 			var args []any
 			var resource any
@@ -109,9 +110,10 @@ func evalIterator(ctx ExprContext, opTerm *term) (v any, err error) {
 			if resource, err = initFunc.InvokeNamed(initCtx, InitName, actualParams); err != nil {
 				return
 			}
-			dcCtx := ctx.Clone()
 			exportObjects(dcCtx, initCtx)
 			dc = NewDataCursor(dcCtx, ds, resource)
+		} else {
+			dc = NewDataCursor(dcCtx, ds, nil)
 		}
 
 		v = dc

t_iterator_test.go

@@ -17,7 +17,7 @@ func TestIteratorParser(t *testing.T) {
 		/*   6 */ {`builtin "math.arith"; include "test-resources/iterator.expr"; it=$(ds,3); mul(it)`, int64(0), nil},
 		/*   7 */ {`builtin "math.arith"; include "test-resources/file-reader.expr"; it=$(ds,"test-resources/int.list"); mul(it)`, int64(12000), nil},
 		/*   8 */ {`include "test-resources/file-reader.expr"; it=$(ds,"test-resources/int.list"); it++; it.index`, int64(0), nil},
-		/*   9 */ {`include "test-resources/file-reader.expr"; it=$(ds,"test-resources/int.list"); it.clean`, true, nil},
+		/*   9 */ {`include "test-resources/file-reader.expr"; it=$(ds,"test-resources/int.list"); it.clean`, nil, nil},
 		/*  10 */ {`it=$(1,2,3); it++`, int64(1), nil},
 		/*  11 */ {`it=$(1,2,3); it++; it.reset; it++`, int64(1), nil},
 		/*  12 */ {`it=$([1,2,3,4],1); it++`, int64(2), nil},
@@ -25,8 +25,10 @@ func TestIteratorParser(t *testing.T) {
 		/*  14 */ {`it=$([1,2,3,4],1,3,2); it++; it++;`, int64(4), nil},
 		/*  15 */ {`it=$([1,2,3,4],1,2,2); it++; it++;`, nil, `EOF`},
 		/*  16 */ {`include "test-resources/filter.expr"; it=$(ds,10); it++`, int64(2), nil},
+		/*  17 */ {`it=$({"next":func(){5}}); it++`, int64(5), nil},
+		/*  18 */ {`it=$({"next":func(){5}}); it.clean`, nil, nil},
 	}
 
-	// runTestSuiteSpec(t, section, inputs, 11)
+	//runTestSuiteSpec(t, section, inputs, 18)
 	runTestSuite(t, section, inputs)
 }