anko / eslisp-fancy-function

eslisp macro: function expression with argument-splats and implicit return

eslisp-fancy-function

An eslisp macro that works like an the usual lambda expression macro but also

• parses splats (atoms starting with ...) in the arguments and turns them into appropriate variable assignments prepended to the function body, and
• implicitly returns the last thing in the body if it's an expression.

Note that despite the name, this module is strictly a function expressions (lambda-ish) macro, not a function declaration. I'll rearrange that eventually.

Example

(macro fun (require "eslisp-fancy-function"))
(fun (a b ...c d) (* a b d))

↓

(function (a, b) {
    var c = Array.prototype.slice.call(arguments, 2, -1);
    var d = arguments[arguments.length - 1];
    return a * (b * d);
});

See the tests for fuller usage.

License

ISC.

eslisp-fancy-function's Issues

TypeError: splatAndAfter.filter is not a function

I was just trying out fancy-function for the first time. I ran this code and got the following error.

(macro fun (require "eslisp-fancy-function"))
(fun (a b ...c d) (* a b d))

λ eslc main.lisp
C:\Users\ktodyruik\AppData\Roaming\npm\node_modules\eslisp\lib\cli.js:102
      throw err;
      ^

TypeError: splatAndAfter.filter is not a function
    at env.module.exports (C:\Projects\TheButtonMobile\ESLisp\node_modules\eslisp-fancy-function\index.js:14:33)
    at listToEstree (C:\Users\ktodyruik\AppData\Roaming\npm\node_modules\eslisp\lib\compile.js:177:27)
    at astToEstree (C:\Users\ktodyruik\AppData\Roaming\npm\node_modules\eslisp\lib\compile.js:236:25)
    at C:\Users\ktodyruik\AppData\Roaming\npm\node_modules\eslisp\lib\translate.js:35:14
    at C:\Users\ktodyruik\AppData\Roaming\npm\node_modules\eslisp\node_modules\prelude-ls\lib\List.js:158:21
    at C:\Users\ktodyruik\AppData\Roaming\npm\node_modules\eslisp\node_modules\prelude-ls\lib\List.js:161:4
    at C:\Users\ktodyruik\AppData\Roaming\npm\node_modules\eslisp\node_modules\prelude-ls\lib\List.js:665:42
    at module.exports (C:\Users\ktodyruik\AppData\Roaming\npm\node_modules\eslisp\lib\translate.js:36:7)
    at toEstree (C:\Users\ktodyruik\AppData\Roaming\npm\node_modules\eslisp\lib\index.js:9:10)
    at compile (C:\Users\ktodyruik\AppData\Roaming\npm\node_modules\eslisp\lib\index.js:17:12)

Fails when nested

Reported by @kiasaki in chat.

(var fun (require "eslisp-fancy-function"))
(fun () (fun () x))

—errors when it should give function() { return function() { return x; } }.