Mochi is a dynamically typed programming language for functional programming and actor-style programming.
Its interpreter is written in Python3. The interpreter translates a program written in Mochi to Python3's AST / bytecode.
- Python-like syntax
- Tail recursion optimization (self tail recursion only), and no loop syntax
- Re-assignments are not allowed in function definition.
- Basic collection type is a persistent data structure. (using Pyrsistent)
- Pattern matching / Data types, like algebraic data types
- Pipeline operator
- Syntax sugar of anonymous function definition
- Actor, like the actor of Erlang (using Eventlet)
- Macro, like the traditional macro of Lisp
- Builtin functions includes functions exported by itertools module, recipes, functools module and operator module
def factorial(n, m):
if n == 1:
m
else:
factorial(n - 1, n * m)
factorial(10000, 1)
# => 28462596809170545189064132121198688...
# Or
def factorial:
n: factorial(n, 1)
0, acc: acc
n, acc: factorial(n - 1, acc * n)
factorial(10000)
# => 28462596809170545189064132121198688...
def fizzbuzz(n):
match [n % 3, n % 5]:
[0, 0]: "fizzbuzz"
[0, _]: "fizz"
[_, 0]: "buzz"
_: n
range(1, 31) |> map(fizzbuzz) |> pvector() |> print()
# Or
pipeline(range(1, 31),
map(fizzbuzz),
pvector(),
print())
def show():
receive:
message:
print(message)
show()
actor = spawn(show)
send('foo', actor)
actor ! 'bar' # send('bar', actor)
sleep(1)
# -> foo
# -> bar
'foo' !> spawn(show)
sleep(1)
# -> foo
['foo', 'bar'] !&> spawn(show)
# The meaning of the above is the same as the meaning of the following.
# spawn(show) ! 'foo'
# spawn(show) ! 'bar'
sleep(1)
# -> foo
# -> bar
from flask import Flask
app = Flask('demo')
@app.route('/')
def hello():
'Hello World!'
app.run()
macro aif(test, true_expr, false_expr):
quasi_quote:
it = unquote(test)
if it:
unquote(true_expr)
else:
unquote(false_expr)
aif([], first(it), "empty")
# => "empty"
aif([10, 20], first(it), "empty")
# => 10
- CPython >= 3.2 or PyPy >= 3.2.1
- rply >= 0.7.2
- pyrsistent >= 0.6.3
- pathlib >= 1.0.1
- eventlet >= 0.15.2
$ pip3 install mochi
$ mochi
>>>
$ cat kinako.mochi
print('kinako')
$ mochi kinako.mochi
kinako
$
$ mochi -c kinako.mochi > kinako.mochic
$ mochi -e kinako.mochic
kinako
$
[1, 2, 3]
# => pvector([1, 2, 3])
v(1, 2, 3)
# => pvector([1, 2, 3])
vec = [1, 2, 3]
vec2 = vec.set(0, 8)
# => pvector([8, 2, 3]
vec
# => pvector([1, 2, 3])
[x, y, z] = vec
x # => 1
y # => 2
z # => 3
get(vec, 0) # => 1
get(vec, 0, 2) # => [1, 2]
{'x': 100, 'y': 200}
# => pmap({'y': 200, 'x': 100})
ma = {'x': 100, 'y': 200}
ma.get('x') # => 100
ma.x # => 100
ma2 = ma.set('x', 10000)
# => pmap({'y': 200, 'x': 10000})
ma # => pmap({'y': 200, 'x': 100})
get(ma, 'y') # => 200
m(x=100, y=200)
# => pmap({'y': 200, 'x': 100})
s(1, 2, 3)
# => pset([1, 2, 3])
b(1, 2, 3)
# => pbag([1, 2, 3])
def hoge(x):
'hoge' + str(x)
hoge(3)
# => hoge3
lis = [1, 2, 3]
match lis:
[1, 2, x]: x
_: None
# => 3
match lis:
[1, &rest]: rest
_: None
# => pvector (2, 3)
foo_map = {'foo' : 'bar'}
match foo_map:
{'foo' : value}: value
_: None
# => 'bar'
match 10:
int(x): 'int'
float(x): 'float'
str(x): 'str'
bool(x): 'bool'
_: 'other'
# => 'int'
match [1, 2, 3]:
[1, str(x), 3]: 'str'
[1, int(x), 3]: 'int'
_: 'other'
# => 'int'
record Mochi
record AnkoMochi(anko) < Mochi
record KinakoMochi(kinako) < Mochi
anko_mochi = AnkoMochi(anko=3)
isinstance(anko_mochi, Mochi)
# => True
isinstance(anko_mochi, AnkoMochi)
# => True
isinstance(anko_mochi, KinakoMochi)
# => False
match anko_mochi:
KinakoMochi(kinako): 'kinako ' * kinako + ' mochi'
AnkoMochi(anko): 'anko ' * anko + 'mochi'
Mochi(_): 'mochi'
# => 'anko anko anko mochi'
record Person(name, age):
def show(self):
print(self.name + ': ' + self.age)
foo = Person('foo', '32')
foo.show()
# -> foo: 32
x = 3000
# => 3000
[a, b] = [1, 2]
a
# => 1
b
# => 2
[c, &d] = [1, 2, 3]
c
# => 1
d
# => pvector([2, 3])
data Point:
Point2D(x, y)
Point3D(x, y, z)
# The meaning of the above is the same as the meaning of the following.
# record Point
# record Point2D(x, y) < Point
# record Point3D(x, y, z) < Point
p1 = Point2D(x=1, y=2)
# => Point2D(x=1, y=2)
p2 = Point2D(3, 4)
# => Point2D(x=3, y=4)
p1.x
# => 1
data Point:
Point2D(x, y)
Point3D(x, y, z)
def offset:
Point2D(x1, y1), Point2D(x2, y2):
Point2D(x1 + x2, y1 + y2)
Point3D(x1, y1, z1), Point3D(x2, y2, z2):
Point3D(x1 + x2, y1 + y2, z1 + z2)
_: None
offset(Point2D(1, 2), Point2D(3, 4))
# => Point2D(x=4, y=6)
offset(Point3D(1, 2, 3), Point3D(4, 5, 6))
# => Point3D(x=5, y=7, z=9)
def show:
int(x), message: print('int', x, message)
float(x), message: print('float', x, message)
_: None
show(1.0, 'msg')
# -> float 1.0 msg
# => None
# Arrow expression.
add = (x, y) -> x + y
add(1, 2)
# => 3
add = -> $1 + $2
add(1, 2)
# => 3
foo = (x, y) ->
if x == 0:
y
else:
x
foo(1, 2)
# => 1
foo(0, 2)
# => 2
pvector(map(-> $1 * 2, [1, 2, 3]))
# => pvector([2, 4, 6])
add = -> $1 + $2
2 |> add(10) |> add(12)
# => 24
None |>? add(10) |>? add(12)
# => None
def fizzbuzz(n):
match [n % 3, n % 5]:
[0, 0]: "fizzbuzz"
[0, _]: "fizz"
[_, 0]: "buzz"
_: n
result = range(1, 31) |> map(fizzbuzz)
pvector(result)
# => pvector([1, 2, fizz, 4, 'buzz', 'fizz', 7, 8, 'fizz', 'buzz', 11, 'fizz', 13, 14, 'fizzbuzz', 16, 17, 'fizz', 19, 'buzz', 'fizz', 22, 23, 'fizz', 'buzz', 26, 'fizz', 28, 29, 'fizzbuzz'])
pvector(result)
# => pvector([])
pvector(result)
# => pvector([])
# Iterator -> lazyseq
lazy_result = range(1, 31) |> map(fizzbuzz) |> lazyseq()
pvector(lazy_result)
# => pvector([1, 2, fizz, 4, 'buzz', 'fizz', 7, 8, 'fizz', 'buzz', 11, 'fizz', 13, 14, 'fizzbuzz', 16, 17, 'fizz', 19, 'buzz', 'fizz', 22, 23, 'fizz', 'buzz', 26, 'fizz', 28, 29, 'fizzbuzz'])
pvector(lazy_result)
# => pvector([1, 2, fizz, 4, 'buzz', 'fizz', 7, 8, 'fizz', 'buzz', 11, 'fizz', 13, 14, 'fizzbuzz', 16, 17, 'fizz', 19, 'buzz', 'fizz', 22, 23, 'fizz', 'buzz', 26, 'fizz', 28, 29, 'fizzbuzz'])
pvector(lazy_result)
# => pvector([1, 2, fizz, 4, 'buzz', 'fizz', 7, 8, 'fizz', 'buzz', 11, 'fizz', 13, 14, 'fizzbuzz', 16, 17, 'fizz', 19, 'buzz', 'fizz', 22, 23, 'fizz', 'buzz', 26, 'fizz', 28, 29, 'fizzbuzz'])
macro rest_if_first_is_true(first, &args):
match first:
quote(True): quasi_quote(v(unquote_splicing(args)))
_: quote(False)
rest_if_first_is_true(True, 1, 2, 3)
# => pvector([1, 2, 3])
rest_if_first_is_true("foo", 1, 2, 3)
# => False
macro pipeline(&args):
[Symbol('|>')] + args
pipeline([1, 2, 3],
map(-> $1 * 2),
filter(-> $1 != 2),
pvector())
# => pvector([4, 6])
$ cat anko.mochi
x = 10000
y = 20000
require 'anko.mochi'
x
# => 10000
x = 30000
require 'anko.mochi' # include once at compile time
x
# => 30000
module Math:
export add, sub
def add(x, y):
x + y
def sub(x, y):
x - y
Math.add(1, 2)
# => 3
$ cat foobar.mochi
foo = 'foo'
bar = 'bar'
require 'foobar.mochi'
[foo, bar]
# => pvector(['foo', 'bar'])
foo = 'foofoofoo'
module X:
export foobar
require 'foobar.mochi'
def foobar:
[foo, bar]
X.foobar()
# => pvector(['foo', 'bar'])
[foo, bar]
# => pvector(['foofoofoo', 'bar'])
- Documentation
- Improvement of parsing
- Support class definition
MIT License