KobraScript is a language that harvests the power of JavaScript with an incredibly intuitive syntax.
Install
You can install KobraScript into your global environment so that you can execute KobraScript programs from anywhere. To do so, run this command:
npm install -g kobrascript
You can execute KobraScript programs like so:
kobra <name_of_program.ks>
You can also see the transpiled version of your code by running kobrac:
kobrac <name_of_program.ks>
To see a list of commands available, type kobra or kobrac with no arguments.
Kobra Demands Respect (Hello, world!)
Say my name...
say "Kobra!" console.log("Kobra!");
Variable Declarations
In KobraScript, variable declarations are simplified to one character: $. Declare multiple variables at the same time with , or the slick .. "dot-dot". KobraScript knows no semi-colons.
$ name = "Samson" var name = "Samson";
$ likesMusic = true, var likesMusic = true,
likesJazz likesJazz = undefined;
$ isRed = true var isRed = true,
.. isFood = false isFood = false,
.. isMine = true isMine = true;
Variables with uninitialized values are set to undefined.
$ total var total = undefined;
Functions
Declare a function easily with fn. Open the block with :, and close using end, or ... Also note that the return statement always expects an expression–use the leave statement to return early from a function without an expression.
fn average_intake(x): function averageIntake(x) {
$ total = 0 var total = 0;
for ($ i = 0; i < x.length; i++): for (var i = 0; i < x.length; i++) {
total = total + x[i] total = total + x[i];
end }
say total console.log(total);
return total / x.length return total / x.length;
end }
$ getSoup = fn (): return Res.soupOfTheDay() .. var getSoup = function () {return Res.soupOfTheDay()},
.. getDrink = fn (): return Res.specdrinks .. getDrink = function () {return Res.spacdrinks},
.. placeOrder = fn (item, quantity): placeOrder = function (item, quantity) {
Kitchen.addOrder(item, quantity) Kitchen.addOrder(item, quantity);
end };
fn bomb(code): function bomb(code) {
if (code == "Password1"): if (code === "Password1") {
leave return;
.. else: } else {
say "Boom!" console.log("Boom!")
end }
end }
Similar to Javascript, anonymous self-calling functions are in KobraScript. These are typically used to create a private scope. In KobraScript, a closure literal may be constructed with close, followed by the inteded arguments as parameters enclosed in curly braces. One never has to worry about whether ones functions are being invoked on the fly. Closed to the world, KobraScript may evaluate.
close{}: (function() {
$ x = 10 var x = 10;
say x console.log(x);
end }());
$ x = [1, 2, 3] var x = [1, 2, 3];
close{x}: (function(x) {
print "I am " + x[1] + " good" console.log("I am " + x[1] + " good");
end }(x));
Blocks
Blocks in KobraScript are beautiful. Start a multiline block with : and terminate it with the clear end, or the elegantly-flowing ..
Fearlessly create a single-statement block by pointing -> to it. Nice.
while (i--): while (i--) {
say "Countdown ... " + i console.log("Countdown ... " + i);
end }
fn numResponse (x): function numResponse (x) {
if (x == 1): if (x === 1) {
say "that's one!" console.log("that's one!");
.. else if (x == 2): } else if (x === 2) {
say "that's two!" console.log("that's two!");
.. else: } else {
say "that's somthin' else!" console.log("that's somthin' else!");
end }
end }
for ($ i = 0; i < nums["length"]; i++): for (var i = 0; i < nums.length; i++) {
$ p = nums[i] var p = nums[i];
if (p) -> primes.push(p) if (p) { primes.push(p) }
end }
if (socket) if (socket) {
-> this.active[socket] = i++ this.active[socket] = i++;
}
Conditional Statement
In KobraScript the if statement is written with a preference to .. between conditional blocks. An end after the final block signals the conclusion of the statement. Kobra is cold as ice.
if (is_red && is_food): if (is_red && is_food) {
eat() eat ();
.. else if (is_food && is_mine): } else if (is_food && is_mine) {
add_butter() add_butter ();
.. else: } else {
keep() keep();
end }
Only If Statement
Bite first, ask for booleans later. Kobrascript allows a lightning-quick, conditional alternative to the garden-variety if statement.
only: if (feelingLucky) {
rollDice() .. if (feelingLucky) rollDice();
}
only:
abandonShip() .. if (sinking) else: if (sinking) {
justKeepSwiming() .. abandonShip();
} else {
justKeepSwimming();
}
Exchange Statement
KobraScript utilizes a Go/Python-inspired statement in order to exchange :=: the values of two variables.
$ a = 2, var a = 2,
b = 3 b = 3;
a :=: b var swap = a; a = b; b = swap; // Awful.
say a // 3 console.log(a); // 3
say b // 2 console.log(b); // 2
for and while loops
For and while loops look beautiful as expected; keyword, condition, block, nice.
$ a = 0 // A test variable for loops. var a = 0; // A test variable for loops.
for ($ i = 0; i < 4; i++): for (var i = 0; i < 4; i++) {
a++ a++;
end }
while (a < 10): while (a < 10) {
a++ a++;
end }
Objects
Objects are easily specified and finely readable in KobraScript. Braces are used specifically for objects in this language, {} is an object (the one with no properties).
$ bicycle = { var bicycle = {
frame: "aluminum", frame: "aluminum",
year: 2009, year: 2009,
gears: 10, gears: 10,
speed: 12.7, speed: 12.7,
move: fn (): move: function () {
Transform.translate(FORWARD * this.speed) Transform.translate(FORWARD * this.speed);
.., },
upgrade_speed: fn (): upgradeSpeed: function () {
return this.speed = this.speed * 1.1 return this.speed = this.speed * 1.1;
.., },
get_frame: fn (): return this.frame end getFrame: function () {return this.frame;}
} }
Arrays
Arrays in KobraScript follow normal scripting language convention.
$ protein_intake = [12, 21.3, 7.2, 20] var protein_intake = [12.0, 21.3, 7.2, 20.0];
$ enigma = [{code: '8878'}, [], false] var enigma = [{code: '8878'}, [], false];
Macrosyntax
This is regarded as the the most up-to-date specification of KS. Except for the compiler itself of course.
KobraScript Syntax v.2.2.0
UNIT ::= PROGRAM
PROGRAM ::= STMT+ (as BLOCK)
BLOCK ::= FREEBLK
| SINGLE
FREEBLK ::= ':' STMT+ ('end' | '..')
SINGLE ::= '->' STMT
STMT ::= VARDEC
| FNDEC
| 'if' '(' EXP ')' BLOCK
('else' 'if' '(' EXP ')' BLOCK)*
('else' '(' EXP ')' BLOCK)?
| 'only' BLOCK 'if' '(' EXP ')'
('else' BLOCK)?
| 'for' '(' (VARDEC | ASSIGN (','))? ';' EXP ';' INCREMENT ')' BLOCK
| 'while' '(' EXP ')' BLOCK
| 'break'
| 'continue'
| 'return' EXP
| 'leave'
| EXP
VARDEC ::= '$' ID '=' EXP ((',' | '..') ID '=' EXP)*
FNDEC ::= 'fn' ID PARAMS BLOCK
PARAMS ::= '(' ID (',' ID)* ')'
EXP ::= EXP0 (('=' | '+=' | '-=' | '*=' | '/=' | '%=' | ':=:') EXP0)?
EXP0 ::= EXP1 (('||' | '#') EXP1)*
EXP1 ::= EXP2 ('&&' EXP2)*
EXP2 ::= EXP3 (('==' | '~=' | '!=' | 'is') EXP3)?
EXP3 ::= EXP4 (('<' | '<=' | '>=' | '>') EXP4)?
EXP4 ::= EXP5 ([+-] EXP5)*
EXP5 ::= EXP6 ([%*/] EXP6)*
EXP6 ::= EXP7 (('**' | '-**') EXP7)
EXP7 ::= ('~!' | '~?')? EXP8
EXP8 ::= ('!' | '++' | '--' | 'new')? EXP9
EXP9 ::= EXPRT ('++' | '--' | '.' ID | '[' EXP ']' | '(' EXP (',' EXP)* ')')*
EXPRT ::= UNDEFLIT | NULLLIT | BOOLIT | STRLIT | NUMLIT
| | ID | CLOSLIT | FNLIT | ARRAY | OBJECT
| '(' EXP ')'
FNLIT ::= 'fn' (ID)? PARAMS BLOCK
CLOSLIT ::= 'close' '{' (ID (',' ID)*)? '}' BLOCK
ARRAYLIT::= '[' (EXP (',' EXP)*)? ']'
OBJLIT ::= '{' (PROP (',' PROP)*)? '}'
PROP ::= ID ':' EXP
| STRLIT ':' EXP
| NUMLIT ':' EXP
| BOOLIT ':' EXP
Microsyntax
NUMLIT ::= -?(?:[1-9]\d*|0)(?:.\d+)?(?:[eE][+-]?\d+)?
STRLIT ::= (\"|\')(\\[bfnrtv0\"\']|\\c[a-zA-z]|\\u[a-fA-F0-9]{4}|\\x[a-fA-F0-9]{2}|.)*\1
BOOLIT ::= 'true' | 'false'
UNDEFLIT::= 'undefined'
NULLLIT ::= 'null'
ID ::= [_a-zA-Z]\w*
COMMENT ::= '//' TEXT '\n'