Golang go/scanner.Scanner.Scan() function examples

package go/scanner

Scan scans the next token and returns the token position, the token, and its literal string if applicable. The source end is indicated by token.EOF.

Golang go/scanner.Scanner.Scan() function usage examples

Example 1:

 var s scanner.Scanner
 pos, tok, lit = s.Scan()
 if tok != token.IDENT || (lit != "true" && lit != "false") {
 fmt.Println("expected boolean value")
 }

Example 2: (from http://golang.org/pkg/go/scanner/#Scanner.Scan )

 package main

 import (
  "fmt"
  "go/scanner"
  "go/token"
 )

 func main() {
  // 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)
  }

 }

Reference :

http://golang.org/pkg/go/scanner/#Scanner.Scan