akira
Functional language that transpiles to JavaScript.
Installing
with nodejs and npm
npm install akira
git
git clone git://github.com/goatslacker/akira.git
sudo npm link
Usage
ast [file] - output the Mozilla Parse API for that file
compile [file] [target] - compile to JavaScript
help - dis
output [file] - compile to JS and output
repl - start the repl
run [file] - compile and interpret said file
tokens [file] - output the lexer tokens for that file
version - akira version
Overview
Literals
String
'i am a string'
Numbers
42
2.0
9,000
-3
Boolean
true
false
Maps
cat = {
:name 'Luna'
:age 2
}
Vectors
[1 2 3 4]
[true false]
Regular Expressions
/[A-Z]+/g
Operators
Math
1 + 2
4 - 1
3 * 1
9 / 3
Exponents
| akira | javascript |
|---|---|
| 3 ** 3 | Math.pow(3, 3) |
Equality
true == true
false != true
3 > 2
2 < 3
3 >= 3
3 <= 3
Logical
false || true
true && true
Concat and Cons
| akira | javascript |
|---|---|
| [1] ++ [2] | [1].concat(2) |
| 'hello' ++ 'world' | 'hello'.concat('world') |
| 1 +: [2 3] | [1].concat(2, 3) |
Property Access
| akira | javascript |
|---|---|
| { :key 'value' } !! 'key' | { key: 'value' }['key'] |
| { :key 'value' }.key | { key: 'value' }.key |
| [1 2 3 4] !! 2 | [1, 2, 3, 4][2] |
| [1 2 3].1 | [1, 2, 3][0] |
Functions
Defining functions
sum = fn [a b]
a + b
sub = fn [a b]
a - b
Invoking
sum 1 2
Invoking with no arguments
| 'hello-world'.to-string
IIFE/Beta-redex
| ->
number-of-balloons = 99
Anonymous functions
fn [x] x * x
Pipes
Functions can also be invoked or chained with pipes
sum 1 2 | print -- print(sum(1, 2))
Multiple expressions can be piped together
1 | id | print -- print(id(1))
Previous arguments are carried over into the next function call...
1 | sum 2 | (== 3) -- sum(2, 1) === 3
...and you can use _ (underscore) to place your argument
2 | sub _ 1 | (== 1) -- sub(2, 1) === 1
Scope
In akira you may not redeclare a variable, so in reality variables are not really variables, they are symbols; you can also think of them as constants.
a = 1
b = true
c = [1 2 3]
b = false -- throws a ReferenceError at compile time
So this prevents you from shadowing symbols and misusing scope. You also don't need to include the 'var' as there are no globals.
a = 1 -- outter `a`
b = 2
c = fn []
a = 2 -- creates a local `a`
b -- `b` can be accessed in here
Conditionals
If statements
n = 4
is-n-four = if n == 4
then true
else false
Multiple conditions
cond
n == 4 ? n
n == 2 ? n + 2
else ? 0
Pattern Matching
Factorial implemented using pattern matching
fact = match
[1] 1
[n] n * (fact n - 1)
This splits up the list into x = head(list) and xs = tail(list)
sort-even-odd = fn [[x, & xs]]
cond
not x ? []
odd x ? (sort-even-odd xs) ++ [x]
else ? x +: (sort-even-odd xs)
[1 2 3 4 5 6] | sort-even-odd | assert-deep [2 4 6 5 3 1]
Exceptions
try
| some-function-that-may-crash
catch err
raise err
Async/Await
For handling async functions there are a few tools you can use
get-file = async [filepath] file = path.join process.env.PWD filepath data = await fs.read-file-async file new File filepath (show data)
do get-file 'README.md' then fn [x] print x catch fn [err] print err
Text Editor Support
ViM: https://github.com/goatslacker/akira.vim