use return keyword for function return calls

pkg/ast/evaluate.go

@@ -153,6 +153,10 @@ func (e *Evaluator) Visit(node types.Node) interface{} {
 	case types.Function:
 		e.SymbolTable[n.Name] = n
 	case types.FunctionCall:
+		_, ok := e.SymbolTable[n.Name]
+		if !ok {
+			log.Fatalf("variable '%s' not defined", n.Name)
+		}
 		for _, v := range e.SymbolTable[n.Name].(types.Function).Children {
 			e.Visit(v)
 		}

pkg/token/token.go

@@ -248,7 +248,7 @@ func Tokenize(source string) *Source {
 					s.Tokens = append(s.Tokens, types.Token{TokenType: types.IF, Value: types.Literal{Value: "if", Type: types.STATEMENT}, LineNumber: s.CurrentLineNumber})
 				case "fn":
 					s.Tokens = append(s.Tokens, types.Token{TokenType: types.FUNCTION, Value: types.Literal{Value: "fn", Type: types.STATEMENT}, LineNumber: s.CurrentLineNumber})
-				case "ret":
+				case "return":
 					s.Tokens = append(s.Tokens, types.Token{TokenType: types.FUNCTION_RETURN, Value: types.Literal{Value: "return", Type: types.STATEMENT}, LineNumber: s.CurrentLineNumber})
 				default:
 					switch s.getCurrentToken() {

source.lark

@@ -11,10 +11,8 @@ tt <- !false;
 c <-> e;
 a <-> c;
 
-fn hi[] <<
-		a <- 1000;
-		bbb <- 123;
-		ret a+bbb;
+fn add[] <<
+		return 1000+500;
 >>
 
-fnval <- hi();
+fnval <- add();

test_source_files/function.lark

@@ -1,7 +1,7 @@
 fn addstatic[] <<
 		fna <- 1000;
 		fnb <- 500;
-		ret fna+fnb;
+		return fna+fnb;
 >>
 
 fnval <- addstatic();