// ParseTextForChords parses a line of text for chords and their positions. It returns true if
// this was just a line of chords and false if it contains text other than chords.
func parseTextForChords(text string) ([]*songtools.Chord, []int, bool) {
chords := []*songtools.Chord{}
positions := []int{}
i := 0
for i < len(text) {
for i < len(text) && text[i] == ' ' {
i++
}
if i == len(text) {
break
}
name := ""
pos := i
for i < len(text) && text[i] != ' ' {
name += string(text[i])
i++
}
chord, ok := songtools.ParseChord(name)
if !ok {
// we aren't a chord line
return nil, nil, false
}
chords = append(chords, chord)
positions = append(positions, pos)
}
return chords, positions, len(chords) > 0
}
func (p *parser) parseSong() (*songtools.Song, error) {
song := &songtools.Song{}
token, text, err := p.scanner.next()
if err != nil {
return nil, err
}
var section *songtools.Section
var line *songtools.Line
numNewLines := 0
for token != eofToken {
switch token {
case commentToken:
comment := &songtools.Comment{
Text: text,
Hidden: true,
}
if section != nil {
section.Nodes = append(section.Nodes, comment)
} else {
song.Nodes = append(song.Nodes, comment)
}
case directiveToken:
d, err := parseDirective(text)
if err != nil {
return nil, err
}
switch d.Name {
case startOfChorusDirectiveName:
section = &songtools.Section{
Kind: songtools.SectionKind("Chorus"),
}
song.Nodes = append(song.Nodes, section)
case endOfChorusDirectiveName:
section = nil
case startOfBridgeDirectiveName:
section = &songtools.Section{
Kind: songtools.SectionKind("Bridge"),
}
song.Nodes = append(song.Nodes, section)
case endOfBridgeDirectiveName:
section = nil
case commentDirectiveName:
if section == nil {
la := 1
for {
// we are going to look forward past all the comments until we find a non-comment
nextToken, _, nextErr := p.scanner.la(la)
if nextErr != nil {
break
}
if nextToken == directiveToken {
innerD, err := parseDirective(text)
if err != nil {
break
}
if innerD.Name != commentDirectiveName {
break
}
la += 2
} else if nextToken == chordToken || nextToken == textToken {
section = &songtools.Section{
Kind: songtools.SectionKind(d.Value),
}
song.Nodes = append(song.Nodes, section)
break
} else {
break
}
}
} else {
comment := &songtools.Comment{
Text: d.Value,
Hidden: false,
}
if section == nil {
song.Nodes = append(song.Nodes, comment)
} else {
section.Nodes = append(section.Nodes, comment)
}
}
case titleDirectiveName:
song.Title = d.Value
case subtitleDirectiveName:
song.Subtitles = append(song.Subtitles, d.Value)
case authorDirectiveName:
song.Authors = append(song.Authors, d.Value)
case keyDirectiveName:
song.Key = songtools.Key(d.Value)
default:
// choruses and bridges have end tags, which means we can just wait until those show up
// and not have to guess at the end of a section.
if section != nil && numNewLines == 2 && section.Kind != "Chorus" && section.Kind != "Bridge" {
section = nil
}
if section != nil {
section.Nodes = append(section.Nodes, d)
} else {
song.Nodes = append(song.Nodes, d)
}
line = nil
numNewLines = 0
}
case chordToken:
if section == nil {
section = &songtools.Section{}
song.Nodes = append(song.Nodes, section)
}
if line == nil {
line = &songtools.Line{}
section.Nodes = append(section.Nodes, line)
}
chord, ok := songtools.ParseChord(text)
if !ok {
return nil, fmt.Errorf("The text '%v' is not a chord.", text)
}
line.Chords = append(line.Chords, chord)
line.ChordPositions = append(line.ChordPositions, len(line.Text))
case textToken:
if section == nil {
section = &songtools.Section{}
song.Nodes = append(song.Nodes, section)
}
if line == nil {
line = &songtools.Line{}
section.Nodes = append(section.Nodes, line)
}
line.Text += text
numNewLines = 0
case newLineToken:
line = nil
numNewLines++
if section != nil && numNewLines == 2 && section.Kind != "Chorus" && section.Kind != "Bridge" {
section = nil
numNewLines = 0
}
break
}
token, text, err = p.scanner.next()
if err != nil {
return nil, err
}
}
return song, nil
}
