1 // Copyright 2012 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 package scanner_test 6 7 import ( 8 "fmt" 9 "go/scanner" 10 "go/token" 11 ) 12 13 func ExampleScanner_Scan() { 14 // src is the input that we want to tokenize. 15 src := []byte("cos(x) + 1i*sin(x) // Euler") 16 17 // Initialize the scanner. 18 var s scanner.Scanner 19 fset := token.NewFileSet() // positions are relative to fset 20 file := fset.AddFile("", fset.Base(), len(src)) // register input "file" 21 s.Init(file, src, nil /* no error handler */, scanner.ScanComments) 22 23 // Repeated calls to Scan yield the token sequence found in the input. 24 for { 25 pos, tok, lit := s.Scan() 26 if tok == token.EOF { 27 break 28 } 29 fmt.Printf("%s\t%s\t%q\n", fset.Position(pos), tok, lit) 30 } 31 32 // output: 33 // 1:1 IDENT "cos" 34 // 1:4 ( "" 35 // 1:5 IDENT "x" 36 // 1:6 ) "" 37 // 1:8 + "" 38 // 1:10 IMAG "1i" 39 // 1:12 * "" 40 // 1:13 IDENT "sin" 41 // 1:16 ( "" 42 // 1:17 IDENT "x" 43 // 1:18 ) "" 44 // 1:20 ; "\n" 45 // 1:20 COMMENT "// Euler" 46 } 47
