This matrix defines the current compatibility baseline for multilingual. The source of truth is:
examples/complete_features_en.ml and equivalents in all 17 languagestests/ (858 tests across 78 test suites)
Target runtime: CPython 3.12.x
Scope Statement
multilingual supports a broad Python 3.12-aligned syntax and runtime subset. It is not full drop-in compatibility for every existing Python project or third-party ecosystem. It is a forward-compilation framework: surface language → Core AST → Python.
Supported Languages
17 natural languages with localized keywords and error messages:
| Language |
Code |
if keyword |
| English |
en |
if |
| French |
fr |
si |
| Spanish |
es |
si |
| German |
de |
wenn |
| Italian |
it |
se |
| Portuguese |
pt |
se |
| Polish |
pl |
jezeli |
| Dutch |
nl |
als |
| Swedish |
sv |
om |
| Danish |
da |
hvis |
| Finnish |
fi |
jos |
| Hindi |
hi |
अगर |
| Arabic |
ar |
إذا |
| Bengali |
bn |
যদি |
| Tamil |
ta |
என்றால் |
| Chinese |
zh |
如果 |
| Japanese |
ja |
もし |
Core Constructs
| Area |
Status |
Notes |
| Imports |
✅ |
import math, from math import sqrt as root_fn |
| Wildcard imports |
✅ |
from os import * |
| Variable declarations |
✅ |
let x = 0, const PI = 3.14 |
| Type annotations |
✅ |
let x: int = 0, def f(x: int) -> str: |
| Arithmetic and expressions |
✅ |
+, -, *, /, //, %, **, bitwise ops |
| Augmented assignment |
✅ |
+=, -=, *=, /=, **=, //=, %=, &=, \|=, ^=, <<=, >>= |
| Chained assignment |
✅ |
a = b = c = 0 |
| Starred unpacking |
✅ |
a, *rest = [1, 2, 3], first, *mid, last = items |
Data Structures
| Area |
Status |
Notes |
| Lists |
✅ |
literals, iteration, indexing, slicing |
| Dictionaries |
✅ |
literals, comprehensions, unpacking (**d) |
| Sets |
✅ |
literals, comprehensions |
| Tuples |
✅ |
literals, unpacking |
| Strings |
✅ |
single/double/triple quotes, f-strings |
| F-string format specs |
✅ |
f"{x:.2f}", f"{x!r}", f"{x!s}", f"{x!a}" |
| Hex/octal/binary literals |
✅ |
0xFF, 0o77, 0b1010 |
| Scientific notation |
✅ |
1.5e10 |
Control Flow
| Area |
Status |
Notes |
if / elif / else |
✅ |
full conditional chains |
while loops |
✅ |
while condition: |
while / else |
✅ |
else block when loop completes without break |
for loops |
✅ |
for item in items:, tuple unpacking targets |
for / else |
✅ |
else block when loop completes without break |
break / continue |
✅ |
loop control |
pass |
✅ |
no-op placeholder |
match / case |
✅ |
structural pattern matching |
case guard clauses |
✅ |
case n if n > 0: |
case OR patterns |
✅ |
case 1 \| 2 \| 3: |
case AS bindings |
✅ |
case pattern as name: |
case _ (default) |
✅ |
wildcard/default case |
| Ternary expressions |
✅ |
x if cond else y |
Functions and Classes
| Area |
Status |
Notes |
| Function definitions |
✅ |
def f(x):, with defaults, *args, **kwargs |
| Positional-only params |
✅ |
def f(a, b, /, c): |
| Keyword-only params |
✅ |
def f(a, *, b): |
| Return annotations |
✅ |
def f() -> int: |
| Decorators |
✅ |
@decorator on functions and classes |
| Lambda expressions |
✅ |
lambda x: x + 1 |
yield / yield from |
✅ |
generator functions and delegation |
async def / await |
✅ |
async functions, async for, async with |
| Class definitions |
✅ |
inheritance, methods, attributes |
| Walrus operator |
✅ |
(x := expr) |
Error Handling
| Area |
Status |
Notes |
try / except / else / finally |
✅ |
full exception handling |
raise |
✅ |
bare raise, raise ValueError("msg") |
raise … from |
✅ |
exception chaining: raise X from Y |
assert |
✅ |
assert expr, assert expr, msg |
Scope and Variables
| Area |
Status |
Notes |
global |
✅ |
declares global scope |
nonlocal |
✅ |
declares enclosing scope |
del |
✅ |
del variable |
Comprehensions and Generators
| Area |
Status |
Notes |
| List comprehensions |
✅ |
[x for x in items if cond], nested |
| Dict comprehensions |
✅ |
{k: v for k, v in items} |
| Set comprehensions |
✅ |
{x for x in items if cond}, nested |
| Generator expressions |
✅ |
(x for x in items) |
Context Managers
| Area |
Status |
Notes |
with statement |
✅ |
with open(f) as h: |
| Multiple contexts |
✅ |
with A() as a, B() as b: |
async with |
✅ |
async context managers |
Built-in Coverage
| Coverage area |
Status |
Notes |
| Python keywords (3.12) |
✅ Complete |
51 concept IDs, 7 categories |
| Universal built-in functions |
✅ 70+ available |
len, range, abs, pow, divmod, complex, format, ascii, compile, eval, exec, globals, locals, issubclass, delattr, slice, aiter, anext, and more |
| Exception types |
✅ 45+ |
BaseException, ValueError, TypeError, KeyError, ModuleNotFoundError, ExceptionGroup, BaseExceptionGroup, all warnings, and more |
| Special values |
✅ |
True, False, None, Ellipsis, NotImplemented |
| Localized built-in aliases |
✅ 41 concepts |
41 builtins with aliases in all 16 non-English languages |
| Canonical Python built-in names |
✅ |
Always usable in all languages |
Surface Syntax Normalization
SOV and RTL languages can use natural word order. The surface normalizer rewrites tokens to canonical order before parsing.
| Statement |
Languages with normalization |
Example |
for loop |
ja, ar, es, pt, hi, bn, ta |
Iterable-first: 範囲(6) 内の 各 i に対して: |
while loop |
ja, ar, hi, bn, ta |
Condition-first |
if statement |
ja, ar, hi, bn, ta |
Condition-first |
with statement |
ja, ar, hi, bn, ta |
Expression-first |
Test Coverage
858 tests across 78 test suites:
| Test area |
Suites |
Description |
| Numerals and dates |
8 |
Multilingual numerals, Unicode, Roman, complex, fractions, datetime |
| Lexer |
2 |
Tokenization and lexer behavior |
| Parser |
5 |
Expressions, statements, compounds, multilingual, errors |
| Semantic analysis |
6 |
Scopes, constants, control flow, definitions, multilingual errors, symbol table |
| Code generation |
4 |
Expressions, statements, compounds, multilingual |
| Execution |
4 |
Basic, multilingual, transpile, errors |
| Critical features |
8 |
Triple-quoted strings, slices, parameters, tuples, comprehensions, decorators, f-strings |
| Language completeness and CLI |
8 |
Augmented assignment, membership, ternary, assert, chained assignment, CLI, REPL |
| Advanced language features |
23 |
Loop else, yield/raise from, set comprehensions, parameter separators, f-string formatting, match guards/OR/AS, global/nonlocal, builtins, exceptions, surface normalization, extended builtins, alias resolution, starred unpacking, integration, multilingual |
| Infrastructure |
10 |
Keyword registry, AST nodes, AST printer, error messages, runtime builtins, REPL |
Not Guaranteed
The following are not claimed as universally compatible:
- Arbitrary Python projects running unchanged
- Full behavioral parity with all CPython edge cases
- Full third-party package/runtime ecosystem compatibility
- Every advanced metaprogramming/introspection scenario
- Complete localization aliases for all CPython built-in functions (41 of 70+ have aliases)
- Starred unpacking in deeply nested expression contexts
- Complex decorator chains with arguments
Recommendation
When evaluating compatibility for a real codebase:
- Start from this matrix
- Run smoke tests:
python -m multilingualprogramming smoke --all
- Run focused tests:
python -m multilingualprogramming run yourprogram.ml --lang en
- Track gaps as concrete syntax/runtime items