3 examples of 'iteration variable' in Go

267
func iteration(rv *resolver, in *ast.Iteration) semantic.Statement {
268
	v := &semantic.Local{Named: semantic.Named(in.Variable.Value)}
269
	rv.mappings.Add(in.Variable, v)
270
	iterable := expression(rv, in.Iterable)
271
	b, ok := iterable.(*semantic.BinaryOp)
272
	if !ok {
273
		rv.errorf(in, "iterable can only be range operator, got %T", b)
274
		return semantic.Invalid{}
275
	} else if b.Operator != ast.OpRange {
276
		rv.errorf(in, "iterable can only be range operator, got %s\n", b.Operator)
277
	}
278
	rv.mappings.Remove(b) // The binary op is no longer referenced directly.
279
	out := &semantic.Iteration{AST: in, Iterator: v, From: b.LHS, To: b.RHS}
280
	v.Type = iterable.ExpressionType()
281
	rv.with(semantic.VoidType, func() {
282
		rv.addNamed(v)
283
		out.Block = block(rv, in.Block, out)
284
	})
285
	rv.mappings.Add(in, out)
286
	return out
287
}

888
func (lq *LinqObj) ForEach(line string, scope *Scope, args ...Object) Object {
889
	if len(args) != 1 {
890
		return NewError(line, ARGUMENTERROR, "1", len(args))
891
	}
892
893
	block, ok := args[0].(*Function)
894
	if !ok {
895
		return NewError(line, PARAMTYPEERROR, "first", "forEach", "*Function", args[0].Type())
896
	}
897
898
	s := NewScope(scope, nil)
899
900
	next := lq.Query.Iterate()
901
902
	for item, ok := next(); ok.Bool; item, ok = next() {
903
		s.Set(block.Literal.Parameters[0].(*ast.Identifier).Value, item)
904
		Eval(block.Literal.Body, s)
905
	}
906
907
	return NIL
908
}

107
func (it *Loop) advanceLoop() {
108
	// Set the loop iterator to feed from the previous iteration results
109
	it.loopEntryIt.SetIterator(it.prevValuesIt)
110
111
	// Reset the loop iterator - will also clean the values in the underlying fixed iterator.
112
	it.loopIt.Reset()
113
114
	it.filterIt.Reset()
115
116
	// Increment the completed loops count
117
	it.loopsCompleted += 1
118
119
	// Mark the loop as finished - no more results can be expected.
120
	// Either the number of loops has been executed, or there are
121
	// no more expandable nodes.
122
	if size, _ := it.prevValuesIt.Size(); (it.bounded && it.loopsCompleted >= it.loops) || size == 0 {
123
		it.finished = true
124
	}
125
126
	// Clean the set of values seen in the previous loop
127
	it.prevValuesIt = it.ts.FixedIterator()
128
}