Changeset 205 for branches/interpreter2/UParser.pas

Timestamp:

Apr 20, 2020, 1:10:44 AM (5 years ago)

Author:

chronos

Message:

• Added: Support for repeat-until.

Location:

branches/interpreter2

Files:

• . (modified) (1 prop)
• UParser.pas (modified) (5 diffs)

branches/interpreter2

@@ -4 +4 @@
 interpreter.res
 heaptrclog.trc
+Generated

@@ -4 +4 @@
 interpreter.res
 heaptrclog.trc
+Generated

branches/interpreter2/UParser.pas

@@ -32 +32 @@
     function ParseIfThenElse(Block: TBlock; out IfThenElse: TIfThenElse): Boolean;
     function ParseWhileDo(Block: TBlock; out WhileDo: TWhileDo): Boolean;
+    function ParseRepeatUntil(Block: TBlock; out RepeatUntil: TRepeatUntil): Boolean;
     function ParseForToDo(Block: TBlock; out ForToDo: TForToDo): Boolean;
     procedure TokenizerError(Pos: TPoint; Text: string);
@@ -55 +56 @@
 begin
   if Tokenizer.CheckNext('begin', tkKeyword) then begin
+    Tokenizer.Expect('begin', tkKeyword);
     BeginEnd := TBeginEnd.Create;
     Result := True;
-    Tokenizer.Expect('begin', tkKeyword);
     while not Tokenizer.CheckNext('end', tkKeyword) do begin
       if ParseCommand(Block, Command) then begin
@@ -119 +120 @@
   WhileDo: TWhileDo;
   ForToDo: TForToDo;
+  RepeatUntil: TRepeatUntil;
 begin
   if ParseIfThenElse(Block, IfThenElse) then begin
@@ -139 +141 @@
     Result := True;
     Command := FunctionCall;
+  end else
+  if ParseRepeatUntil(Block, RepeatUntil) then begin
+    Result := True;
+    Command := RepeatUntil;
   end else
   if ParseAssignment(Block, Assignment) then begin
@@ -496 +502 @@
 end;
 
+function TParser.ParseRepeatUntil(Block: TBlock; out RepeatUntil: TRepeatUntil
+  ): Boolean;
+var
+  Expression: TExpression;
+  Command: TCommand;
+begin
+  Result := False;
+  if Tokenizer.CheckNext('repeat', tkKeyword) then begin
+    Tokenizer.Expect('repeat', tkKeyword);
+    RepeatUntil := TRepeatUntil.Create;
+    Result := True;
+    while not Tokenizer.CheckNext('until', tkKeyword) do begin
+      if ParseCommand(Block, Command) then begin
+        RepeatUntil.Commands.Add(Command);
+        Tokenizer.Expect(';', tkSpecialSymbol);
+      end else begin
+        Error('Unexpected token ' + Tokenizer.GetNext.Text);
+        Result := False;
+        Break;
+      end;
+    end;
+    Tokenizer.Expect('until', tkKeyword);
+    if ParseExpression(Block, Expression) then begin
+      RepeatUntil.Expression.Free;
+      RepeatUntil.Expression := Expression;
+    end else Error('Expected expression');
+  end else Result := False;
+end;
+
 function TParser.ParseForToDo(Block: TBlock; out ForToDo: TForToDo): Boolean;
 var

@@ -4 +4 @@
 interpreter.res
 heaptrclog.trc
+Generated