Revert "Restructure {reasoning_gym, tests}/{core, exercises, curricula}"

This reverts commit 10dbb374b0.

reasoning_gym/code/contrib/bfit/Compiler/Functions.py

@@ -0,0 +1,37 @@
+from copy import deepcopy
+
+from .Exceptions import BFSemanticError
+
+functions = dict()  # Global dictionary of function_name --> FunctionCompiler objects
+
+
+def insert_function_object(function):
+    functions[function.name] = function
+
+
+def get_function_object(name):
+    """
+    must return a copy of the function
+    because we might need to compile function recursively
+    and if we don't work on different copies then we will interfere with the current token pointer etc
+
+    for example:
+        int increase(int n) { return n+1;}
+        int main() {int x = increase(increase(1));}
+
+    while compiling the first call, we start a compilation of the same function object in the second call
+    """
+    return deepcopy(functions[name])
+
+
+def check_function_exists(function_token, parameters_amount):
+    function_name = function_token.data
+    if function_name not in functions:
+        raise BFSemanticError("Function '%s' is undefined" % str(function_token))
+
+    function = functions[function_name]
+    if len(function.parameters) != parameters_amount:
+        raise BFSemanticError(
+            "Function '%s' has %s parameters (called it with %s parameters)"
+            % (str(function_token), len(function.parameters), parameters_amount)
+        )