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// Copyright 2012 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.
package scanner_test
import (
"fmt"
"go/scanner"
"go/token"
)
func ExampleScanner_Scan() {
// src is the input that we want to tokenize.
src := []byte("cos(x) + 1i*sin(x) // Euler")
// Initialize the scanner.
var s scanner.Scanner
fset := token.NewFileSet() // positions are relative to fset
file := fset.AddFile("", fset.Base(), len(src)) // register input "file"
s.Init(file, src, nil /* no error handler */, scanner.ScanComments)
// Repeated calls to Scan yield the token sequence found in the input.
for {
pos, tok, lit := s.Scan()
if tok == token.EOF {
break
}
fmt.Printf("%s\t%s\t%q\n", fset.Position(pos), tok, lit)
}
// output:
// 1:1 IDENT "cos"
// 1:4 ( ""
// 1:5 IDENT "x"
// 1:6 ) ""
// 1:8 + ""
// 1:10 IMAG "1i"
// 1:12 * ""
// 1:13 IDENT "sin"
// 1:16 ( ""
// 1:17 IDENT "x"
// 1:18 ) ""
// 1:20 COMMENT "// Euler"
// 1:28 ; "\n"
}