decouple iterator iteration from Interpreter

Author: turbolent

interpreter/inclusive_range_iterator.go

@@ -64,18 +64,18 @@ func NewInclusiveRangeIterator(
 	}
 }
 
-func (i *InclusiveRangeIterator) Next(interpreter *Interpreter, locationRange LocationRange) Value {
+func (i *InclusiveRangeIterator) Next(context ValueIteratorContext, locationRange LocationRange) Value {
 	valueToReturn := i.next
 
 	// Ensure that valueToReturn is within the bounds.
-	if i.stepNegative && bool(valueToReturn.Less(interpreter, i.end, locationRange)) {
+	if i.stepNegative && bool(valueToReturn.Less(context, i.end, locationRange)) {
 		return nil
-	} else if !i.stepNegative && bool(valueToReturn.Greater(interpreter, i.end, locationRange)) {
+	} else if !i.stepNegative && bool(valueToReturn.Greater(context, i.end, locationRange)) {
 		return nil
 	}
 
 	// Update the next value.
-	nextValueToReturn, ok := valueToReturn.Plus(interpreter, i.step, locationRange).(IntegerValue)
+	nextValueToReturn, ok := valueToReturn.Plus(context, i.step, locationRange).(IntegerValue)
 	if !ok {
 		panic(errors.NewUnreachableError())
 	}

interpreter/value.go

@@ -247,10 +247,15 @@ type OwnedValue interface {
 	GetOwner() common.Address
 }
 
+type ValueIteratorContext interface {
+	common.MemoryGauge
+	NumberValueArithmeticContext
+}
+
 // ValueIterator is an iterator which returns values.
 // When Next returns nil, it signals the end of the iterator.
 type ValueIterator interface {
-	Next(interpreter *Interpreter, locationRange LocationRange) Value
+	Next(context ValueIteratorContext, locationRange LocationRange) Value
 }
 
 func safeAdd(a, b int, locationRange LocationRange) int {

interpreter/value_array.go

@@ -57,7 +57,7 @@ func (v *ArrayValue) Iterator(_ *Interpreter, _ LocationRange) ValueIterator {
 
 var _ ValueIterator = ArrayValueIterator{}
 
-func (i ArrayValueIterator) Next(interpreter *Interpreter, _ LocationRange) Value {
+func (i ArrayValueIterator) Next(context ValueIteratorContext, _ LocationRange) Value {
 	atreeValue, err := i.atreeIterator.Next()
 	if err != nil {
 		panic(errors.NewExternalError(err))
@@ -69,7 +69,7 @@ func (i ArrayValueIterator) Next(interpreter *Interpreter, _ LocationRange) Valu
 
 	// atree.Array iterator returns low-level atree.Value,
 	// convert to high-level interpreter.Value
-	return MustConvertStoredValue(interpreter, atreeValue)
+	return MustConvertStoredValue(context, atreeValue)
 }
 
 func NewArrayValue(

interpreter/value_string.go

@@ -1068,7 +1068,7 @@ type StringValueIterator struct {
 
 var _ ValueIterator = StringValueIterator{}
 
-func (i StringValueIterator) Next(_ *Interpreter, _ LocationRange) Value {
+func (i StringValueIterator) Next(_ ValueIteratorContext, _ LocationRange) Value {
 	if !i.graphemes.Next() {
 		return nil
 	}