dfn

Dynamic Function Definition, using map pattern guard something.

install

npm i dfn --save

example

var dfn = require('dfn');
var defFun = dfn.defFun;
var special = dfn.special;
var guard = dfn.guard;

var fun = defFun();
special(fun, [1, 2], 5);
guard(fun, (x) => x < 0, (x) => -1 * x);

console.log(fun(1, 2)); // 5
console.log(fun(-3)); // 3

create a function

var dfn = require('dfn');
var defFun = dfn.defFun;
var fun = defFun();

special case

You can set a special case for a function.

• special(fun, args, ret)

var dfn = require('dfn');
var defFun = dfn.defFun;
var special = dfn.special;
var fun = defFun();

special(fun, [1, 2], 5);

console.log(fun(1, 2)); // 5

guard

You can set a guard for function

• guard(fun, condition, expression)

When arguments satisfy condition (a function), function fun will get result from expression (a function).

var dfn = require('dfn');
var defFun = dfn.defFun;
var guard = dfn.guard;

var fun = defFun();
guard(fun, (x) => x < 0, (x) => -1 * x);

console.log(fun(-3)); // 3

default

You can set default expression for function.

When there is no special case or condition, default function will execute.

def(fun, defFun)

var dfn = require('dfn');

var fun = defFun();
guard(fun, (x) => x < 0, (x) => -1 * x);
def(fun, (x) => x * x);

console.log(fun(3)); // 9