this repo has no description
Add basic fragment parsing function
This should work, but does no validation on the fragment after parsing.
+85
-7
+23
gitdiff/gitdiff.go
+23
gitdiff/gitdiff.go
···
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NewPosition int64
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NewLines int64
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+
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LinesAdded int64
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LinesDeleted int64
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Lines []FragmentLine
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}
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// FragmentLine is a line in a fragment.
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type FragmentLine struct {
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Op LineOp
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Line string
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}
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// LineOp describes the type of a fragment line: context, added, or removed.
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type LineOp int
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const (
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// OpContext indicates a context line
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OpContext LineOp = iota
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// OpDelete indicates a deleted line
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OpDelete
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// OpAdd indicates an added line
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OpAdd
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)
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// Header returns the cannonical header of this fragment.
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func (f *Fragment) Header() string {
+62
-7
gitdiff/parser.go
+62
-7
gitdiff/parser.go
···
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// by allowing users to set or override defaults
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// parser invariants:
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-
// - methods that parse objects start on the first line of the first object
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// - methods that parse objects return on the first line after the last object
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// - if a parse method returns a nil object, the parser was not advanced
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// - methods that parse objects:
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// - start with the parser on the first line of the first object
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// - if returning nil, do not advance
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// - if returning an error, do not advance past the object
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// - if returning an object, advance to the first line after the object
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// - any exported parsing methods must initialize the parser by calling Next()
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type parser struct {
···
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parts := strings.SplitAfterN(p.Line(0), endMark, 2)
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if len(parts) < 2 {
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return nil, fmt.Errorf("invalid fragment header")
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return nil, p.Errorf(0, "invalid fragment header")
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}
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f := &Fragment{}
···
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header := parts[0][len(startMark) : len(parts[0])-len(endMark)]
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ranges := strings.Split(header, " +")
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if len(ranges) != 2 {
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return nil, fmt.Errorf("invalid fragment header")
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return nil, p.Errorf(0, "invalid fragment header")
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}
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var err error
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if f.OldPosition, f.OldLines, err = parseRange(ranges[0]); err != nil {
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return nil, fmt.Errorf("invalid fragment header: %v", err)
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return nil, p.Errorf(0, "invalid fragment header: %v", err)
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}
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if f.NewPosition, f.NewLines, err = parseRange(ranges[1]); err != nil {
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return nil, fmt.Errorf("invalid fragment header: %v", err)
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return nil, p.Errorf(0, "invalid fragment header: %v", err)
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}
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if err := p.Next(); err != nil && err != io.EOF {
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return nil, err
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}
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return f, nil
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}
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func (p *parser) ParseFragment() (*Fragment, error) {
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frag, err := p.ParseFragmentHeader()
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if err != nil {
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return nil, err
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}
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if frag == nil {
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return nil, nil
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}
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if p.Line(0) == "" {
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return nil, p.Errorf(0, "no content following fragment header")
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}
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oldLines, newLines := frag.OldLines, frag.NewLines
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for oldLines > 0 && newLines > 0 {
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line := p.Line(0)
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switch line[0] {
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case '\n':
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fallthrough // newer GNU diff versions create empty context lines
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case ' ':
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oldLines--
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newLines--
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frag.Lines = append(frag.Lines, FragmentLine{OpContext, line[1:]})
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case '-':
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frag.LinesDeleted++
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oldLines--
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frag.Lines = append(frag.Lines, FragmentLine{OpDelete, line[1:]})
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case '+':
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frag.LinesAdded++
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newLines--
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frag.Lines = append(frag.Lines, FragmentLine{OpAdd, line[1:]})
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default:
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// this could be "\ No newline at end of file", which we allow
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// only check the prefix because the text changes by locale
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// git also asserts that any translation is at least 12 characters
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if len(line) >= 12 && strings.HasPrefix("\\ ", line) {
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break
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}
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return nil, p.Errorf(0, "invalid fragment line")
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}
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if err := p.Next(); err != nil {
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if err == io.EOF {
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break
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}
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return nil, err
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}
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}
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// TODO(bkeyes): verify stuff about the fragment
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return frag, nil
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}
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func parseRange(s string) (start int64, end int64, err error) {