Support else if / else in if blocks

ethanmoffat · Feb 5, 2022 · 14cf50d · 14cf50d
1 parent aec22de
commit 14cf50d
Show file tree

Hide file tree

Showing 2 changed files with 39 additions and 0 deletions.
diff --git a/EOBot/Interpreter/States/BlockEvaluator.cs b/EOBot/Interpreter/States/BlockEvaluator.cs
@@ -60,6 +60,16 @@ protected async Task<(EvalResult, string, BotToken)> EvaluateBlockAsync(ProgramS
 
         protected void SkipBlock(ProgramState input)
         {
+            // ensure that for 'else if' the if condition is skipped as well
+            var current = input.Current();
+            if (current.TokenType == BotTokenType.Keyword && current.TokenValue == "if")
+            {
+                input.Expect(BotTokenType.Keyword);
+                input.Expect(BotTokenType.LParen);
+                while (!input.Expect(BotTokenType.RParen))
+                    input.SkipToken();
+            }
+
             // potential newline character - skip so we can advance execution beyond the block
             input.Expect(BotTokenType.NewLine);
 

diff --git a/EOBot/Interpreter/States/IfEvaluator.cs b/EOBot/Interpreter/States/IfEvaluator.cs
@@ -25,9 +25,38 @@ public override async Task<(EvalResult, string, BotToken)> EvaluateAsync(Program
                     return await EvaluateBlockAsync(input);
 
                 SkipBlock(input);
+
+                if (IsElse(input))
+                {
+                    input.Expect(BotTokenType.Keyword);
+
+                    var elseIfRes = await Evaluator<IfEvaluator>().EvaluateAsync(input);
+                    if (elseIfRes.Result == EvalResult.Failed)
+                        return elseIfRes;
+                    else if (elseIfRes.Result == EvalResult.Ok)
+                    {
+                        // skip the rest of the following blocks if evaluated
+                        while (IsElse(input))
+                        {
+                            input.Expect(BotTokenType.Keyword);
+                            SkipBlock(input);
+                        }
+
+                        return elseIfRes;
+                    }
+
+                    // if not a match for else if, it is an else block
+                    return await EvaluateBlockAsync(input);
+                }
             }
 
             return (result, reason, token);
         }
+
+        private bool IsElse(ProgramState input)
+        {
+            var current = input.Current();
+            return current.TokenType == BotTokenType.Keyword && current.TokenValue == "else";
+        }
     }
 }