fix error optimizing clause containing only always true/false express…

…ions (#488)
Jamiras · May 22, 2024 · 99c6ea3 · 99c6ea3
1 parent 5a5f3ed
commit 99c6ea3
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Showing 2 changed files with 16 additions and 1 deletion.
diff --git a/Source/Parser/Expressions/Trigger/RequirementClauseExpression.cs b/Source/Parser/Expressions/Trigger/RequirementClauseExpression.cs
@@ -960,6 +960,9 @@ public override RequirementExpressionBase Optimize(TriggerBuilderContext context
             if (_conditions == null || _conditions.Count == 0)
                 return this;
 
+            if (_conditions.Count == 1)
+                return _conditions[0].Optimize(context);
+
             var achievementContext = context as AchievementBuilderContext;
             if (achievementContext != null && achievementContext.HasPauseIf == null)
             {
@@ -1115,6 +1118,17 @@ public override RequirementExpressionBase Optimize(TriggerBuilderContext context
                         newRequirements.RemoveAt(i);
                 }
             }
+            else if (newRequirements.Count == 0)
+            {
+                // the only way for there to be 0 conditions left at this point is if all the
+                // conditions evaluated to true when Operation was And, or all the conditions
+                // evaluated to false when Operation was Or. return a singular expression
+                // reflecting that result.
+                RequirementExpressionBase result = (Operation == ConditionalOperation.And) ?
+                    new AlwaysTrueExpression() : new AlwaysFalseExpression();
+                CopyLocation(result);
+                return result;
+            }
             else
             {
                 if (newRequirements.Count < 100)
@@ -1638,7 +1652,7 @@ public override ExpressionBase Combine(ExpressionBase right, ConditionalOperatio
         /// </returns>
         public RequirementClauseExpression EnsureLastConditionHasNoHitTarget()
         {
-            if (_conditions != null)
+            if (_conditions != null && _conditions.Count > 0)
             {
                 var lastCondition = _conditions.Last();
 

diff --git a/Tests/Parser/Functions/RepeatedFunctionTests.cs b/Tests/Parser/Functions/RepeatedFunctionTests.cs
@@ -70,6 +70,7 @@ public void TestAppendString(string input)
             "N:0xH004567=4_Z:0xH005678=5_N:0xH001234=1_O:0xH002345=2_0xH003456=3.23.")]
         [TestCase("repeated(24, once(bit3(0x1234) < prev(bit3(0x1234)) && never(repeated(3, bit3(0x1234) == 0))) && bit5(0x1234) == 0)",
             "Z:0xP001234=0.3._N:0xP001234<d0xP001234.1._0xR001234=0.24.")]
+        [TestCase("repeated(25, always_true() && never(byte(0x1234) == 1)", "Z:0xH001234=1_1=1.25.")]
         public void TestBuildTrigger(string input, string expected)
         {
             var clause = TriggerExpressionTests.Parse<TalliedRequirementExpression>(input);