Add tokens to startTokensExpression

parser/expression.go

@@ -5,7 +5,12 @@ import "git.tebibyte.media/sashakoshka/fspl/entity"
 
 var descriptionExpression = "Expression"
 var startTokensExpression = []lexer.TokenKind {
-	// TODO
+	lexer.Ident,
+	lexer.LBracket,
+	lexer.LParen,
+	lexer.Int,
+	lexer.Float,
+	lexer.String,
 }
 
 func (this *Parser) parseExpression () (entity.Expression, error) {
@@ -20,6 +25,10 @@ func (this *Parser) parseExpression () (entity.Expression, error) {
 	// 4. Repeat from step 2 if needed.
 	// 5. Return the expression, whether it was directly parsed or is a tree
 	//    of infix operator(s).
+	err := this.expectDescription (
+		descriptionExpression,
+		startTokensDescription...)
+	if err != nil { return nil, err }
 	return nil, nil
 }