go/src/cmd/gofmt/rewrite.go

func initRewrite() { … }

// parseExpr parses s as an expression.
// It might make sense to expand this to allow statement patterns,
// but there are problems with preserving formatting and also
// with what a wildcard for a statement looks like.
func parseExpr(s, what string) ast.Expr { … }

// rewriteFile applies the rewrite rule 'pattern -> replace' to an entire file.
func rewriteFile(fileSet *token.FileSet, pattern, replace ast.Expr, p *ast.File) *ast.File { … }

// set is a wrapper for x.Set(y); it protects the caller from panics if x cannot be changed to y.
func set(x, y reflect.Value) { … }

var objectPtrNil …

var scopePtrNil …

var identType …

var objectPtrType …

var positionType …

var callExprType …

var scopePtrType …

// apply replaces each AST field x in val with f(x), returning val.
// To avoid extra conversions, f operates on the reflect.Value form.
func apply(f func(reflect.Value) reflect.Value, val reflect.Value) reflect.Value { … }

func isWildcard(s string) bool { … }

// match reports whether pattern matches val,
// recording wildcard submatches in m.
// If m == nil, match checks whether pattern == val.
func match(m map[string]reflect.Value, pattern, val reflect.Value) bool { … }

// subst returns a copy of pattern with values from m substituted in place
// of wildcards and pos used as the position of tokens from the pattern.
// if m == nil, subst returns a copy of pattern and doesn't change the line
// number information.
func subst(m map[string]reflect.Value, pattern reflect.Value, pos reflect.Value) reflect.Value { … }