libgo/go/go/format/example_test.go

   1 // Copyright 2018 The Go Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style
   3 // license that can be found in the LICENSE file.
   4
   5 // +build gccgo_examples
   6
   7 package format_test
   8
   9 import (
  10         "bytes"
  11         "fmt"
  12         "go/format"
  13         "go/parser"
  14         "go/token"
  15         "log"
  16 )
  17
  18 func ExampleNode() {
  19         const expr = "(6+2*3)/4"
  20
  21         // parser.ParseExpr parses the argument and returns the
  22         // corresponding ast.Node.
  23         node, err := parser.ParseExpr(expr)
  24         if err != nil {
  25                 log.Fatal(err)
  26         }
  27
  28         // Create a FileSet for node. Since the node does not come
  29         // from a real source file, fset will be empty.
  30         fset := token.NewFileSet()
  31
  32         var buf bytes.Buffer
  33         err = format.Node(&buf, fset, node)
  34         if err != nil {
  35                 log.Fatal(err)
  36         }
  37
  38         fmt.Println(buf.String())
  39
  40         // Output: (6 + 2*3) / 4
  41 }