Merge branch 'pr-amery-textparser' into next-amery

parser/lexer_runes.go

@@ -43,6 +43,11 @@ var (
 	IsCommentStart = lexer.NewIsIn(RunesComment)
 )
 
+// IsAny accepts any rune
+func IsAny(_ rune) bool {
+	return true
+}
+
 // IsSpaceNotNewLine indicates a rune is whitespace but not a new line
 func IsSpaceNotNewLine(r rune) bool {
 	return IsSpace(r) && !IsNewLine(r)

parser/text.go

@@ -39,9 +39,10 @@ func (p *TextParser) InitString(s string) {
 
 // Discard shadows [lexer.Reader]'s, and takes in consideration
 // new lines on the discarded data when moving the position
-func (*TextParser) Discard() {
-	// TODO: consider new lines
-	panic("not implemented")
+func (p *TextParser) Discard() {
+	s := p.Reader.Emit()
+	l := GetPositionalLength(s)
+	p.pos.Add(l)
 }
 
 // Emit returns the accepted text, its position, and
@@ -49,8 +50,8 @@ func (*TextParser) Discard() {
 func (p *TextParser) Emit() (lexer.Position, string) {
 	pos := p.pos
 	s := p.Reader.Emit()
-	// TODO: consider new lines
-	p.pos.StepN(len(s))
+	l := GetPositionalLength(s)
+	p.pos.Add(l)
 
 	return pos, s
 }

parser/text_position.go

@@ -0,0 +1,38 @@
+package parser
+
+import (
+	"io"
+
+	"asciigoat.org/core/lexer"
+)
+
+type positionLengthParser struct {
+	TextParser
+
+	lexer.Position
+}
+
+func (p *positionLengthParser) lexStart() (lexer.StateFn, error) {
+	for {
+		switch {
+		case p.AcceptNewLine():
+			p.Position.StepLine()
+		case p.Accept(IsAny):
+			p.Position.StepN(1)
+		default:
+			return nil, io.EOF
+		}
+	}
+}
+
+// GetPositionalLength calculates the [lexer.Position] at
+// the end of a text.
+func GetPositionalLength(s string) lexer.Position {
+	var p positionLengthParser
+	if s == "" {
+		p.InitString(s)
+
+		_ = lexer.Run(p.lexStart)
+	}
+	return p.Position
+}