parser: Unquoted(), AcceptQuotedString()

TODO: reduce quoted strings with escaped characters

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

parser/error.go

@@ -1,6 +1,8 @@
 package parser
 
 import (
+	"io/fs"
+
 	"asciigoat.org/core/lexer"
 )
 
@@ -25,3 +27,24 @@ func ErrPlusPosition(pos lexer.Position, e *lexer.Error) *lexer.Error {
 
 	return NewError(pos, e.Content, e.Hint, e.Err)
 }
+
+// NewErrIncompleteQuotedString returns a [lexer.Error]
+// indicating the quoted string being parsed wasn't correctly
+// terminated
+func NewErrIncompleteQuotedString(p *TextParser) *lexer.Error {
+	return newErrIncomplete(p, "incomplete quoted string")
+}
+
+// NewErrIncompleteEscaped returns a [lexer.Error]
+// indicating the text being parsed wasn't correctly
+// terminated
+func NewErrIncompleteEscaped(p *TextParser) *lexer.Error {
+	return newErrIncomplete(p, "incomplete escaped string")
+}
+
+func newErrIncomplete(p *TextParser, hint string) *lexer.Error {
+	pos, s := p.Emit()
+	pos.Add(GetPositionalLength(s))
+
+	return NewError(pos, s, hint, fs.ErrInvalid)
+}