diff --git a/main.py b/main.py
index 288fe39..0b9a702 100755
--- a/main.py
+++ b/main.py
@@ -2,218 +2,7 @@
 # SPDX-License-Identifier: MIT
 # Copyright 2021 Jookia <contact@jookia.org>
 
-def tokenizer(code):
-    tokens = []
-    token = ""
-    text = ""
-    mode = "normal" # normal/note/text
-    for symbol in code:
-        if symbol == " " or symbol == "\t" or symbol == "\n":
-            lowered = token.lower()
-            if lowered == "":
-                pass
-            elif lowered == "beginnote":
-                mode = "note"
-            elif lowered == "endnote":
-                mode = "normal"
-            elif lowered == "begintext":
-                mode = "text"
-            elif lowered == "endtext":
-                tokens.append(("text", text[1:-8]))
-                mode = "normal"
-                text = ""
-            elif token != "":
-                if mode == "normal":
-                    keywords = ["newlang", "done", "set", "to", "endset",
-                                "if", "then", "else", "endif"]
-                    if lowered in keywords:
-                        type = "keyword"
-                    else:
-                        type = "symbol"
-                    tokens.append((type, lowered))
-            token = ""
-        else:
-            token += symbol
-        if mode == "text":
-            text += symbol
-    return tokens
-
-parser_tokens = None
-parser_pos = 0
-
-def parser_reset(tokens):
-    global parser_pos
-    global parser_tokens
-    parser_tokens = tokens
-    parser_pos = 0
-
-def parser_eof():
-    global parser_pos
-    global parser_tokens
-    return parser_pos >= len(parser_tokens)
-
-def parser_next():
-    global parser_pos
-    global parser_tokens
-    if parser_eof():
-        print("Reached end of file early")
-        sys.exit(1)
-    (type, value) = parser_tokens[parser_pos]
-    parser_pos += 1
-    print("Read %s %s" % (type, value))
-    return (type, value)
-
-def parser_peek():
-    global parser_pos
-    global parser_tokens
-    (type, value) = parser_tokens[parser_pos]
-    print("Peeked %s %s" % (type, value))
-    return (type, value)
-
-def parser_skip():
-    global parser_pos
-    global parser_tokens
-    parser_pos += 1
-
-def parse_version():
-    (type, value) = parser_next()
-    if type != "keyword" or value != "newlang":
-        print("Expected NewLang keyword")
-        return None
-    (type, value) = parser_next()
-    print("Parsed language version %s" % (value))
-    return value
-
-def parse_subject():
-    (type, value) = parser_next()
-    if type != "symbol":
-        print("Expected symbol, got %s" % (type))
-        return None
-    return value
-
-def parse_verb():
-    (type, value) = parser_next()
-    if type != "symbol":
-        print("Expected symbol, got %s" % (type))
-        return None
-    return value
-
-def parse_arguments(terminator):
-    args = []
-    while True:
-        (type, value) = parser_next()
-        if type == "keyword":
-            if value == terminator:
-                return args
-            else:
-                print("Unexpected keyword %s" % (value))
-                return None
-        elif type == "text" or type == "symbol":
-            args.append((type, value))
-        else:
-            print("Unexpected type %s" % (type))
-            return None
-
-def parse_statement(terminator):
-    subject = parse_subject()
-    if not subject:
-        print("While parsing subject")
-        return None
-    verb = parse_verb()
-    if not verb:
-        print("While parsing verb")
-        return None
-    arguments = parse_arguments(terminator)
-    if arguments is None:
-        print("While parsing arguments")
-        return None
-    print("Parsed statement: subject %s verb %s args %s" % (subject, verb, arguments))
-    return ('statement', subject, verb, arguments)
-
-def parse_set():
-    subject = parse_subject()
-    if not subject:
-        print("While parsing subject")
-        return None
-    (type, value) = parser_next()
-    if type != "keyword" or value != "to":
-        print("Expect to, got %s %s" % (type, value))
-        return None
-    print("Parsing set value...")
-    ast = parse_statement("endset")
-    if not ast:
-        print("While parsing statement")
-        return None
-    print("Parsed set for %s" % (subject))
-    return ('set', subject, ast)
-
-def parse_if():
-    print("Parsing if test condition...")
-    test = parse_statement("then")
-    if not test:
-        print("While parsing test condition")
-        return None
-    print("Parsing if success statement...")
-    success = parse_statement("else")
-    if not success:
-        print("While parsing success statement")
-        return None
-    print("Parsing if failure statement...")
-    failure = parse_statement("endif")
-    if not failure:
-        print("While parsing failure statement")
-        return None
-    print("Parsed conditional")
-    return ('if', test, success, failure)
-
-def parse_directive():
-    (type, value) = parser_peek()
-    if type != "keyword" and type != "symbol":
-        print("Expected keyword or symbol here, got %s" % (type))
-        return None
-    if type == "keyword":
-        parser_skip()
-        if value == "set":
-            ast = parse_set()
-            if not ast:
-                print("While parsing set directive")
-                return None
-            return ast
-        elif value == "if":
-            ast = parse_if()
-            if not ast:
-                print("While parsing set directive")
-                return None
-            return ast
-        else:
-            print("Unexpected keyword %s" % (value))
-            return None
-    else:
-        ast = parse_statement("done")
-        if not ast:
-            print("While parsing statement")
-            return None
-        return ast
-
-def parse_file():
-    print("Parsing file...")
-    ast = []
-    version = parse_version()
-    if not version:
-        print("While parsing version identifier at start of file")
-        return None
-    if version != "0":
-        print("Invalid version identifier %s" % (version))
-        return None
-    while not parser_eof():
-        directive = parse_directive()
-        if directive == None:
-            print("While parsing directive in file")
-            return None
-        else:
-            ast.append(directive)
-    print("Parsed file")
-    return ast
+import parse
 
 def do_system_print(env, args):
     (text_type, text_value) = args[0]
@@ -270,9 +59,9 @@
     if code[0:2] == '#!':
         next_line = code.find('\n') + 1
         code = code[next_line:]
-    tokens = tokenizer(code)
-    parser_reset(tokens)
-    ast = parse_file()
+    tokens = parse.tokenizer(code)
+    parse.parser_reset(tokens)
+    ast = parse.parse_file()
     if not ast:
         return 1
     for command in ast:
diff --git a/parse.py b/parse.py
new file mode 100644
index 0000000..c6e9517
--- /dev/null
+++ b/parse.py
@@ -0,0 +1,217 @@
+#!/usr/bin/env python3
+# SPDX-License-Identifier: MIT
+# Copyright 2021 Jookia <contact@jookia.org>
+
+parser_tokens = None
+parser_pos = 0
+
+def tokenizer(code):
+    tokens = []
+    token = ""
+    text = ""
+    mode = "normal" # normal/note/text
+    for symbol in code:
+        if symbol == " " or symbol == "\t" or symbol == "\n":
+            lowered = token.lower()
+            if lowered == "":
+                pass
+            elif lowered == "beginnote":
+                mode = "note"
+            elif lowered == "endnote":
+                mode = "normal"
+            elif lowered == "begintext":
+                mode = "text"
+            elif lowered == "endtext":
+                tokens.append(("text", text[1:-8]))
+                mode = "normal"
+                text = ""
+            elif token != "":
+                if mode == "normal":
+                    keywords = ["newlang", "done", "set", "to", "endset",
+                                "if", "then", "else", "endif"]
+                    if lowered in keywords:
+                        type = "keyword"
+                    else:
+                        type = "symbol"
+                    tokens.append((type, lowered))
+            token = ""
+        else:
+            token += symbol
+        if mode == "text":
+            text += symbol
+    return tokens
+
+def parser_reset(tokens):
+    global parser_pos
+    global parser_tokens
+    parser_tokens = tokens
+    parser_pos = 0
+
+def parser_eof():
+    global parser_pos
+    global parser_tokens
+    return parser_pos >= len(parser_tokens)
+
+def parser_next():
+    global parser_pos
+    global parser_tokens
+    if parser_eof():
+        print("Reached end of file early")
+        sys.exit(1)
+    (type, value) = parser_tokens[parser_pos]
+    parser_pos += 1
+    print("Read %s %s" % (type, value))
+    return (type, value)
+
+def parser_peek():
+    global parser_pos
+    global parser_tokens
+    (type, value) = parser_tokens[parser_pos]
+    print("Peeked %s %s" % (type, value))
+    return (type, value)
+
+def parser_skip():
+    global parser_pos
+    global parser_tokens
+    parser_pos += 1
+
+def parse_version():
+    (type, value) = parser_next()
+    if type != "keyword" or value != "newlang":
+        print("Expected NewLang keyword")
+        return None
+    (type, value) = parser_next()
+    print("Parsed language version %s" % (value))
+    return value
+
+def parse_subject():
+    (type, value) = parser_next()
+    if type != "symbol":
+        print("Expected symbol, got %s" % (type))
+        return None
+    return value
+
+def parse_verb():
+    (type, value) = parser_next()
+    if type != "symbol":
+        print("Expected symbol, got %s" % (type))
+        return None
+    return value
+
+def parse_arguments(terminator):
+    args = []
+    while True:
+        (type, value) = parser_next()
+        if type == "keyword":
+            if value == terminator:
+                return args
+            else:
+                print("Unexpected keyword %s" % (value))
+                return None
+        elif type == "text" or type == "symbol":
+            args.append((type, value))
+        else:
+            print("Unexpected type %s" % (type))
+            return None
+
+def parse_statement(terminator):
+    subject = parse_subject()
+    if not subject:
+        print("While parsing subject")
+        return None
+    verb = parse_verb()
+    if not verb:
+        print("While parsing verb")
+        return None
+    arguments = parse_arguments(terminator)
+    if arguments is None:
+        print("While parsing arguments")
+        return None
+    print("Parsed statement: subject %s verb %s args %s" % (subject, verb, arguments))
+    return ('statement', subject, verb, arguments)
+
+def parse_set():
+    subject = parse_subject()
+    if not subject:
+        print("While parsing subject")
+        return None
+    (type, value) = parser_next()
+    if type != "keyword" or value != "to":
+        print("Expect to, got %s %s" % (type, value))
+        return None
+    print("Parsing set value...")
+    ast = parse_statement("endset")
+    if not ast:
+        print("While parsing statement")
+        return None
+    print("Parsed set for %s" % (subject))
+    return ('set', subject, ast)
+
+def parse_if():
+    print("Parsing if test condition...")
+    test = parse_statement("then")
+    if not test:
+        print("While parsing test condition")
+        return None
+    print("Parsing if success statement...")
+    success = parse_statement("else")
+    if not success:
+        print("While parsing success statement")
+        return None
+    print("Parsing if failure statement...")
+    failure = parse_statement("endif")
+    if not failure:
+        print("While parsing failure statement")
+        return None
+    print("Parsed conditional")
+    return ('if', test, success, failure)
+
+def parse_directive():
+    (type, value) = parser_peek()
+    if type != "keyword" and type != "symbol":
+        print("Expected keyword or symbol here, got %s" % (type))
+        return None
+    if type == "keyword":
+        parser_skip()
+        if value == "set":
+            ast = parse_set()
+            if not ast:
+                print("While parsing set directive")
+                return None
+            return ast
+        elif value == "if":
+            ast = parse_if()
+            if not ast:
+                print("While parsing set directive")
+                return None
+            return ast
+        else:
+            print("Unexpected keyword %s" % (value))
+            return None
+    else:
+        ast = parse_statement("done")
+        if not ast:
+            print("While parsing statement")
+            return None
+        return ast
+
+def parse_file():
+    print("Parsing file...")
+    ast = []
+    version = parse_version()
+    if not version:
+        print("While parsing version identifier at start of file")
+        return None
+    if version != "0":
+        print("Invalid version identifier %s" % (version))
+        return None
+    while not parser_eof():
+        directive = parse_directive()
+        if directive == None:
+            print("While parsing directive in file")
+            return None
+        else:
+            ast.append(directive)
+    print("Parsed file")
+    return ast
+