parser.TextParser: AcceptNewLine() and AcceptRune()

Signed-off-by: Alejandro Mery <amery@jpi.io>

parser/text.go

@@ -74,3 +74,29 @@ func (p *TextParser) StepLine() {
 func (p *TextParser) Position() lexer.Position {
 	return p.pos
 }
+
+// AcceptNewLine checks if next is a new line.
+// It accepts "\n", "\n\r", "\r" and "\r\n".
+func (p *TextParser) AcceptNewLine() bool {
+	r1, _, err := p.ReadRune()
+	switch {
+	case err != nil:
+		return false
+	case r1 == '\n':
+		p.AcceptRune('\r')
+		return true
+	case r1 == '\r':
+		p.AcceptRune('\n')
+		return true
+	default:
+		p.UnreadRune()
+		return false
+	}
+}
+
+// AcceptRune checks if next is the specified rune
+func (p *TextParser) AcceptRune(r rune) bool {
+	return p.Accept(func(r2 rune) bool {
+		return r == r2
+	})
+}