docs:
configuration.md
environment.md
functions.md
getting-started.md
language-definition.md
patch.md
visitor.md

optimizer:
const_expr.go
count_any.go
count_any_test.go
count_threshold.go
count_threshold_test.go
filter_first.go
filter_last.go
filter_len.go
filter_map.go
filter_map_test.go
fold.go
fold_test.go
in_array.go
in_range.go
optimizer.go
optimizer_test.go
predicate_combination.go
sum_array.go
sum_array_test.go
sum_map.go
sum_map_test.go
sum_range.go
sum_range_test.go
10:type fold struct {
15:func (fold *fold) Visit(node *Node) {
17:		fold.applied = true
21:		fold.applied = true
177:						fold.err = &file.Error{
287:	case *BuiltinNode:
294:			if base, ok := n.Arguments[0].(*BuiltinNode); ok && base.Name == "filter" {
295:				patchCopy(&BuiltinNode{
