func lexInside(l *lex.Lexer) lex.StateFn {
for {
switch r := l.Next(); {
case r == rightCurl:
l.Depth -= 1
l.Emit(itemRightCurl)
if l.Depth == 0 {
return lexText
}
case r == leftCurl:
l.Depth += 1
l.Emit(itemLeftCurl)
case r == lex.EOF:
return l.Errorf("unclosed action")
case isSpace(r) || isEndOfLine(r) || r == ',':
l.Ignore()
case isNameBegin(r):
return lexName
case r == '#':
l.Backup()
return lexComment
case r == '(':
l.Emit(itemLeftRound)
return lexArgInside
default:
return l.Errorf("Unrecognized character in lexInside: %#U", r)
}
}
}
func lexInsideMutation(l *lex.Lexer) lex.StateFn {
for {
switch r := l.Next(); {
case r == rightCurl:
l.Depth -= 1
l.Emit(itemRightCurl)
if l.Depth == 0 {
return lexText
}
case r == leftCurl:
l.Depth += 1
l.Emit(itemLeftCurl)
if l.Depth >= 2 {
return lexTextMutation
}
case r == lex.EOF:
return l.Errorf("Unclosed mutation action")
case isSpace(r) || isEndOfLine(r):
l.Ignore()
case isNameBegin(r):
return lexNameMutation
default:
return l.Errorf("Unrecognized character in lexInsideMutation: %#U", r)
}
}
}
func lexLabel(l *lex.Lexer) lex.StateFn {
r := l.Next()
if r == '<' {
l.Depth += 1
return lexUntilClosing(l, itemLabel, lexText)
}
if r == '_' {
l.Depth += 1
return lexBlankNode(l, itemLabel, lexText)
}
return l.Errorf("Invalid char: %v at lexLabel", r)
}
func lexSubject(l *lex.Lexer) lex.StateFn {
r := l.Next()
if r == '<' {
l.Depth += 1
return lexUntilClosing(l, itemSubject, lexText)
}
if r == '_' {
l.Depth += 1
return lexBlankNode(l, itemSubject, lexText)
}
return l.Errorf("Invalid character during lexSubject: %v", r)
}
func lexText(l *lex.Lexer) lex.StateFn {
Loop:
for {
switch r := l.Next(); {
case r == leftCurl:
l.Backup()
l.Emit(itemText) // emit whatever we have so far.
l.Next() // advance one to get back to where we saw leftCurl.
l.Depth += 1 // one level down.
l.Emit(itemLeftCurl)
return lexInside // we're in.
case r == rightCurl:
return l.Errorf("Too many right characters")
case r == lex.EOF:
break Loop
case isNameBegin(r):
l.Backup()
l.Emit(itemText)
return lexOperationType
}
}
if l.Pos > l.Start {
l.Emit(itemText)
}
l.Emit(lex.ItemEOF)
return nil
}
// Assumes '"' has already been encountered.
func lexLiteral(l *lex.Lexer) lex.StateFn {
for {
r := l.Next()
if r == '\u005c' { // backslash
r = l.Next()
continue // This would skip over the escaped rune.
}
if r == lex.EOF || isEndLiteral(r) {
break
}
}
l.Backup()
l.Emit(itemLiteral)
l.Next() // Move to end literal.
l.Ignore() // Ignore end literal.
l.Depth += 1
r := l.Peek()
if r == '@' {
return lexLanguage(l)
} else if r == '^' {
return lexObjectType(l)
} else {
return lexText
}
}
func lexObject(l *lex.Lexer) lex.StateFn {
r := l.Next()
if r == '<' {
l.Depth += 1
return lexUntilClosing(l, itemObject, lexText)
}
if r == '_' {
l.Depth += 1
return lexBlankNode(l, itemObject, lexText)
}
if r == '"' {
l.Ignore()
return lexLiteral(l)
}
return l.Errorf("Invalid char: %v at lexObject", r)
}
func lexPredicate(l *lex.Lexer) lex.StateFn {
r := l.Next()
if r != '<' {
return l.Errorf("Invalid character in lexPredicate: %v", r)
}
l.Depth += 1
return lexUntilClosing(l, itemPredicate, lexText)
}