--- /dev/null
+// Copyright 2015 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// TODO(gri): This file and the file src/go/format/internal.go are
+// the same (but for this comment and the package name). Do not modify
+// one without the other. Determine if we can factor out functionality
+// in a public API. See also #11844 for context.
+
+package main
+
+import (
+ "bytes"
+ "go/ast"
+ "go/parser"
+ "go/printer"
+ "go/token"
+ "strings"
+)
+
+// parse parses src, which was read from the named file,
+// as a Go source file, declaration, or statement list.
+func parse(fset *token.FileSet, filename string, src []byte, fragmentOk bool) (
+ file *ast.File,
+ sourceAdj func(src []byte, indent int) []byte,
+ indentAdj int,
+ err error,
+) {
+ // Try as whole source file.
+ file, err = parser.ParseFile(fset, filename, src, parserMode)
+ // If there's no error, return. If the error is that the source file didn't begin with a
+ // package line and source fragments are ok, fall through to
+ // try as a source fragment. Stop and return on any other error.
+ if err == nil || !fragmentOk || !strings.Contains(err.Error(), "expected 'package'") {
+ return
+ }
+
+ // If this is a declaration list, make it a source file
+ // by inserting a package clause.
+ // Insert using a ';', not a newline, so that the line numbers
+ // in psrc match the ones in src.
+ psrc := append([]byte("package p;"), src...)
+ file, err = parser.ParseFile(fset, filename, psrc, parserMode)
+ if err == nil {
+ sourceAdj = func(src []byte, indent int) []byte {
+ // Remove the package clause.
+ // Gofmt has turned the ';' into a '\n'.
+ src = src[indent+len("package p\n"):]
+ return bytes.TrimSpace(src)
+ }
+ return
+ }
+ // If the error is that the source file didn't begin with a
+ // declaration, fall through to try as a statement list.
+ // Stop and return on any other error.
+ if !strings.Contains(err.Error(), "expected declaration") {
+ return
+ }
+
+ // If this is a statement list, make it a source file
+ // by inserting a package clause and turning the list
+ // into a function body. This handles expressions too.
+ // Insert using a ';', not a newline, so that the line numbers
+ // in fsrc match the ones in src. Add an extra '\n' before the '}'
+ // to make sure comments are flushed before the '}'.
+ fsrc := append(append([]byte("package p; func _() {"), src...), '\n', '\n', '}')
+ file, err = parser.ParseFile(fset, filename, fsrc, parserMode)
+ if err == nil {
+ sourceAdj = func(src []byte, indent int) []byte {
+ // Cap adjusted indent to zero.
+ if indent < 0 {
+ indent = 0
+ }
+ // Remove the wrapping.
+ // Gofmt has turned the "; " into a "\n\n".
+ // There will be two non-blank lines with indent, hence 2*indent.
+ src = src[2*indent+len("package p\n\nfunc _() {"):]
+ // Remove only the "}\n" suffix: remaining whitespaces will be trimmed anyway
+ src = src[:len(src)-len("}\n")]
+ return bytes.TrimSpace(src)
+ }
+ // Gofmt has also indented the function body one level.
+ // Adjust that with indentAdj.
+ indentAdj = -1
+ }
+
+ // Succeeded, or out of options.
+ return
+}
+
+// format formats the given package file originally obtained from src
+// and adjusts the result based on the original source via sourceAdj
+// and indentAdj.
+func format(
+ fset *token.FileSet,
+ file *ast.File,
+ sourceAdj func(src []byte, indent int) []byte,
+ indentAdj int,
+ src []byte,
+ cfg printer.Config,
+) ([]byte, error) {
+ if sourceAdj == nil {
+ // Complete source file.
+ var buf bytes.Buffer
+ err := cfg.Fprint(&buf, fset, file)
+ if err != nil {
+ return nil, err
+ }
+ return buf.Bytes(), nil
+ }
+
+ // Partial source file.
+ // Determine and prepend leading space.
+ i, j := 0, 0
+ for j < len(src) && isSpace(src[j]) {
+ if src[j] == '\n' {
+ i = j + 1 // byte offset of last line in leading space
+ }
+ j++
+ }
+ var res []byte
+ res = append(res, src[:i]...)
+
+ // Determine and prepend indentation of first code line.
+ // Spaces are ignored unless there are no tabs,
+ // in which case spaces count as one tab.
+ indent := 0
+ hasSpace := false
+ for _, b := range src[i:j] {
+ switch b {
+ case ' ':
+ hasSpace = true
+ case '\t':
+ indent++
+ }
+ }
+ if indent == 0 && hasSpace {
+ indent = 1
+ }
+ for i := 0; i < indent; i++ {
+ res = append(res, '\t')
+ }
+
+ // Format the source.
+ // Write it without any leading and trailing space.
+ cfg.Indent = indent + indentAdj
+ var buf bytes.Buffer
+ err := cfg.Fprint(&buf, fset, file)
+ if err != nil {
+ return nil, err
+ }
+ out := sourceAdj(buf.Bytes(), cfg.Indent)
+
+ // If the adjusted output is empty, the source
+ // was empty but (possibly) for white space.
+ // The result is the incoming source.
+ if len(out) == 0 {
+ return src, nil
+ }
+
+ // Otherwise, append output to leading space.
+ res = append(res, out...)
+
+ // Determine and append trailing space.
+ i = len(src)
+ for i > 0 && isSpace(src[i-1]) {
+ i--
+ }
+ return append(res, src[i:]...), nil
+}
+
+// isSpace reports whether the byte is a space character.
+// isSpace defines a space as being among the following bytes: ' ', '\t', '\n' and '\r'.
+func isSpace(b byte) bool {
+ return b == ' ' || b == '\t' || b == '\n' || b == '\r'
+}
projects / dotfiles / .git / blobdiff