From 2dfef5d9abca0be0067910571d0d53e9aa424fda Mon Sep 17 00:00:00 2001
From: Jake Bailey <5341706+jakebailey@users.noreply.github.com>
Date: Thu, 6 Dec 2018 14:58:38 -0800
Subject: [PATCH] add hack to prevent True/False/None/... from being
 use-before-def

---
 .../Engine/Impl/Analyzer/ExpressionEvaluator.cs   | 15 +++++++++++++--
 1 file changed, 13 insertions(+), 2 deletions(-)

diff --git a/src/Analysis/Engine/Impl/Analyzer/ExpressionEvaluator.cs b/src/Analysis/Engine/Impl/Analyzer/ExpressionEvaluator.cs
index c45691a34..78508cc01 100644
--- a/src/Analysis/Engine/Impl/Analyzer/ExpressionEvaluator.cs
+++ b/src/Analysis/Engine/Impl/Analyzer/ExpressionEvaluator.cs
@@ -149,8 +149,19 @@ public IAnalysisSet LookupAnalysisSetByName(Node node, string name, bool addRef
                         refs = createIn.CreateVariable(node, _unit, name, addRef);
                         res = refs.Types;
                     } else {
-                        // ... warn the user
-                        warn = true;
+                        switch (name) {
+                            // "atom" in Python grammar.
+                            case "True":
+                            case "False":
+                            case "None":
+                            case "...":
+                                Debug.Fail($"Known good name '{name}' not found in scope");
+                                break;
+                            default:
+                                // ... warn the user
+                                warn = true;
+                                break;
+                        }
                     }
                 }
             }