Updated expression_utilities to ensure that input symbol alternatives take priority

Author: KarlLundengaard

app/expression_utilities.py

@@ -233,19 +233,26 @@ def substitute_input_symbols(exprs, params):
 
     substitutions = [(expr, expr) for expr in params.get("reserved_keywords",[])]
 
+    input_symbols = params.get("symbols",dict())
+
+    input_symbols_alternatives = []
+    for (code, definition) in input_symbols.items():
+        input_symbols_alternatives += definition["aliases"]
+
     if params.get("elementary_functions", False) is True:
         alias_substitutions = []
         for expr in exprs:
             for (name, alias_list) in elementary_functions_names+special_symbols_names:
-                if name in expr:
-                    alias_substitutions += [(name, " "+name)]
-                for alias in alias_list:
-                    if alias in expr:
-                        alias_substitutions += [(alias, " "+name)]
+                if name in input_symbols_alternatives:
+                    continue
+                else:
+                    if (name in expr) and not (name in input_symbols_alternatives):
+                        alias_substitutions += [(name, " "+name)]
+                    for alias in alias_list:
+                        if (alias in expr) and not (alias in input_symbols_alternatives):
+                            alias_substitutions += [(alias, " "+name)]
         substitutions += alias_substitutions
 
-    input_symbols = params.get("symbols",dict())
-
     if "symbols" in params.keys():
         # Removing invalid input symbols
         input_symbols_to_remove = []

app/symbolic_comparison_evaluation_tests.py

@@ -1558,6 +1558,21 @@ def test_as_substring_in_expression(self):
         result = evaluation_function(response, answer, params)
         assert result["is_correct"] is True
 
+    def test_alternatives_to_input_symbols_takes_priority_over_elementary_function_alternatives(self):
+        answer = "Ef*a/b"
+        params = {
+            "strict_syntax": False,
+            "elementary_functions": True,
+            "symbols": {
+                "Ef": {"aliases": ["E"], "latex": r"$E$"},
+            },
+        }
+        response = "E*a/b"
+        result = evaluation_function(response, answer, params)
+        assert result["is_correct"] is True
+        response = "e*a/b"
+        result = evaluation_function(response, answer, params)
+        assert result["is_correct"] is False
 
 if __name__ == "__main__":
     pytest.main(['-xk not slow', "--tb=line", '--durations=10', os.path.abspath(__file__)])