Functions can now return

interpreter.py

@@ -24,9 +24,11 @@ def parse_expression(variable_list, expression, all_tokens):
     if len(split_on_space) == 1:
         for param in variable_list:
             if param['signifier'] == expression:
+                if type(param['expression']) == type(dict()):
+                    return param['expression']['expression']
                 match param['type']:
                     case 'string':
-                        return param['expression']
+                        return str(param['expression'])
                     case 'number':
                         resolved = list()
                         for part in param['expression'].split(' '):

lexer.py

@@ -5,6 +5,31 @@ import sys
 def find(needle: str, haystack: str) -> bool:
     return haystack.find(needle) != -1
 
+def parse_lparen(line: str) -> list:
+    tokens = list()
+    split_on_lparen = line.split('(')
+    name = split_on_lparen[0].strip()
+    if find('=', line):
+        name = name.split('=')[1].strip()
+    without_name = '('.join(split_on_lparen[1:])
+    split_on_rparen = without_name.split(')')
+    params_str = ')'.join(split_on_rparen[:-1])
+    params = list(map(str.strip,params_str.split(',')))
+    if name not in ['if', 'while']:
+        function_call = {"variant": "function_call", "value": name, "params": params, "line_number": lineno}
+        tokens.append(function_call)
+    elif name == "if":
+        conditional = {"variant": "conditional", "value": name, "condition": ','.join(params), "line_number": lineno}
+        tokens.append(conditional)
+        expression = {"variant": "start_block", "value": "{", "line_number": lineno}
+        tokens.append(expression)
+    else:
+        loop = {"variant": "loop", "value": name, "condition": ','.join(params),  "line_number": lineno}
+        tokens.append(loop)
+        expression = {"variant": "start_block", "value": "{", "line_number": lineno}
+        tokens.append(expression)
+    return tokens
+
 source: list  = list()
 program = './prog.mn'
 if len(sys.argv) > 1:
@@ -44,14 +69,19 @@ for lineno in range(1, num_lines + 1):
                 signifier = {"variant": "function_declaration", "value": name, "params": params, "line_number": lineno}
         tokens.append(signifier)
         if find('=', line):
+            expressions = list()
             colon_equals_rhs = '='.join(colon_rhs_split_on_equals[1:])
             operator = {"variant": "operator", "value": '=', "line_number": lineno}
             tokens.append(operator)
             expr = colon_equals_rhs.strip()
-            expression = {"variant": "expression", "value": expr, "line_number": lineno}
+            expressions.append({"variant": "expression", "value": expr, "line_number": lineno})
             if expr == '{':
-                expression = {"variant": "start_block", "value": expr, "line_number": lineno}
+                expressions[0] = {"variant": "start_block", "value": expr, "line_number": lineno}
+            elif find('(', line) and find(')', line):
+                expressions = parse_lparen(line)
+            for expression in expressions:
                 tokens.append(expression)
+
     elif find('=', line):
         equals_rhs = '='.join(split_on_equals[1:])
         signifier = {"variant": "signifier", "value": equals_lhs.strip(), "line_number": lineno}
@@ -67,24 +97,11 @@ for lineno in range(1, num_lines + 1):
         expression = {"variant": "end_block", "value": '}', "line_number": lineno}
         tokens.append(expression)
     elif find('(', line):
-        split_on_lparen = line.split('(')
-        name = split_on_lparen[0].strip()
-        without_name = '('.join(split_on_lparen[1:])
-        split_on_rparen = without_name.split(')')
-        params_str = ')'.join(split_on_rparen[:-1])
-        params = list(map(str.strip,params_str.split(',')))
-        if name not in ['if', 'while']:
-            function_call = {"variant": "function_call", "value": name, "params": params, "line_number": lineno}
-            tokens.append(function_call)
-        elif name == "if":
-            conditional = {"variant": "conditional", "value": name, "condition": ','.join(params), "line_number": lineno}
-            tokens.append(conditional)
-            expression = {"variant": "start_block", "value": "{", "line_number": lineno}
+        for expression in parse_lparen(line):
             tokens.append(expression)
-        else:
-            loop = {"variant": "loop", "value": name, "condition": ','.join(params),  "line_number": lineno}
-            tokens.append(loop)
-            expression = {"variant": "start_block", "value": "{", "line_number": lineno}
+    elif find('return', line):
+        rhs = line.strip().split()[1]
+        expression = {"variant": "return", "value": rhs, "line_number": lineno}
         tokens.append(expression)
     else:
         if line.strip() == '{':

parser.py

@@ -25,6 +25,15 @@ def find_token_indicies(key: str, tokens: list) -> list:
         index = index + 1
     return result
 
+def find_return_statement(maybe_expression, usefull_tokens) -> dict:
+    expression = dict()
+    for token in usefull_tokens:
+        if maybe_expression['value'] == token['signifier'] and token['variant'] == 'function_declaration':
+            for part in token['body']:
+                if part['variant'] == 'return_statement':
+                    return part
+    return expression
+
 def collect_body(index: int, tokens: list) -> list:
     uncollapsed_tokens = list()
     token = peek(index + 1, tokens)
@@ -86,7 +95,6 @@ def collapse_tokens(uncollapsed_tokens: list) -> list:
             block_index = -1
             block_lineno = -1
 
-        # This is a declaration
         if token['variant'] == 'syntax_error':
             if in_block:
                 compare_lineno = block_lineno + 1 
@@ -118,6 +126,8 @@ def collapse_tokens(uncollapsed_tokens: list) -> list:
                     if maybe_expression and maybe_expression['variant'] == 'expression':
                         line_number = maybe_expression['line_number']
                         expression = maybe_expression['value']
+                    elif maybe_expression and maybe_expression['variant'] == 'function_call':
+                        expression = find_return_statement(maybe_expression, usefull_tokens.copy()) 
                 usefull_token = { "variant": "variable_declaration", "signifier": name, "type": token['value'], "line_number": line_number, "expression": expression } 
                 usefull_tokens.append(usefull_token)
         if token['variant'] == 'function_declaration':
@@ -131,6 +141,11 @@ def collapse_tokens(uncollapsed_tokens: list) -> list:
             usefull_token = {"variant": "function_call", "signifier": token['value'], "line_number": token['line_number'], "params": token['params']}
 
             usefull_tokens.append(usefull_token)
+        if token['variant'] == 'return':
+            for tkn in usefull_tokens.copy():
+                if token['value'] == tkn['signifier']:
+                    usefull_token = {"variant": "return_statement", "signifier": tkn['signifier'], "type": tkn['type'], "line_number": tkn['line_number'], "expression": tkn['expression']}
+                    usefull_tokens.append(usefull_token)
 
     usefull_tokens.sort(key=operator.itemgetter('line_number'))
     return usefull_tokens

return.mn

@@ -0,0 +1,14 @@
+func: test(void: i) = {
+    number: x = 10
+    return x
+}
+func: print(number: n, string: endl) = {
+	stdout: out = n
+	stdout: outln = endl
+}
+string: end = {
+
+}
+void: j = void
+number: y = test(j)
+print(y, end)