parser: introduce ErrPlusPosition to apply a position offset to a lexer.Error

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

basic/error.go

@@ -4,6 +4,7 @@ import (
 	"errors"
 
 	"asciigoat.org/core/lexer"
+	"asciigoat.org/ini/parser"
 )
 
 var (
@@ -11,23 +12,11 @@ var (
 )
 
 func newErrInvalidToken(t *token) *lexer.Error {
-	err := &lexer.Error{
+	return parser.NewError(t.pos, t.value, "", errInvalidToken)
-		Line:    t.pos.Line,
-		Column:  t.pos.Column,
-		Content: t.value,
-		Err:     errInvalidToken,
-	}
-	return err
 }
 
 func (dec *decoder) OnError(pos lexer.Position, content string, err error) error {
-	err = &lexer.Error{
+	err := parser.NewError(pos, content, "", err)
-		Line:    pos.Line,
-		Column:  pos.Column,
-		Content: content,
-		Err:     err,
-	}
-
 	dec.executeFinal()
 	return err
 }

parser/error.go

@@ -14,3 +14,14 @@ func NewError(pos lexer.Position, content, hint string, err error) *lexer.Error
 		Err:     err,
 	}
 }
+
+// ErrPlusPosition returns a copy of the given [lexer.Error]
+// offsetting the Line/Column information.
+func ErrPlusPosition(pos lexer.Position, e *lexer.Error) *lexer.Error {
+	pos.Add(lexer.Position{
+		Line:   e.Line,
+		Column: e.Column,
+	})
+
+	return NewError(pos, e.Content, e.Hint, e.Err)
+}