mrtazz/checkmake

// Package parser implements all the parser functionality for Makefiles
// this specific file holds the functionality for the scanner. The
// implementation is a thin wrapper around bufio.Scanner with some extra
// niceties to make parsing Makefiles easier.
package parser

import (
    "bufio"
    "fmt"
    "os"
)

// MakefileScanner is a wrapping struct around bufio.Scanner which provides
// extra functionality like the current line number
type MakefileScanner struct {
    Scanner    *bufio.Scanner
    LineNumber int
    FileHandle *os.File
    Finished   bool
}

// Scan is a thin wrapper around the bufio.Scanner Scan() function
func (s *MakefileScanner) Scan() bool {
    s.LineNumber++
    scanResult := s.Scanner.Scan()
    if scanResult == false && s.Scanner.Err() == nil {
        s.Finished = true
    }
    return scanResult
}

// Close closes all open handles the scanner has
func (s *MakefileScanner) Close() {
    s.FileHandle.Close()
}

// Text is a thin wrapper around bufio.Scanner Text()
func (s *MakefileScanner) Text() string {
    return s.Scanner.Text()
}

// NewMakefileScanner returns a MakefileScanner struct for parsing a Makefile
func NewMakefileScanner(filepath string) (*MakefileScanner, error) {
    ret := &MakefileScanner{}
    var fileOpenErr error
    ret.FileHandle, fileOpenErr = os.Open(filepath)
    if fileOpenErr != nil {
        return ret, fmt.Errorf("Error opening the provided filepath '%s'", filepath)
    }
    ret.Scanner = bufio.NewScanner(ret.FileHandle)
    ret.Scanner.Split(bufio.ScanLines)
    ret.LineNumber = 1

    return ret, nil
}