curry

Transform a function into a sequence of functions each accepting a single argument.

Installation

npm install @stdlib/utils-curry

Usage

var curry = require( '@stdlib/utils-curry' );

curry( fcn[, arity][, thisArg] )

Transforms a function into a sequence of functions each accepting a single argument.

function add( x, y ) {
    return x + y;
}

var fcn = curry( add );

var sum = fcn( 2 )( 3 );
// returns 5

By default, arity is equal to fcn.length. For functions without explicit parameters, provide an arity argument.

function add() {
    return arguments[ 0 ] + arguments[ 1 ];
}

var fcn = curry( add, 2 );

var sum = fcn( 2 )( 3 );
// returns 5

To specify the curried function execution context, provide a thisArg argument.

var obj = {
    'name': 'Ada',
    'greet': function greet( word1, word2 ) {
        return word1 + ' ' + word2 + ', ' + this.name + '!';
    }
};

var fcn = curry( obj.greet, obj );

var str = fcn( 'Hello' )( 'there' );
// returns 'Hello there, Ada!'

The function supports providing both an arity and execution context.

var obj = {
    'name': 'Ada',
    'greet': function greet() {
        return arguments[ 0 ] + ' ' + arguments[ 1 ] + ', ' + this.name + '!';
    }
};

var fcn = curry( obj.greet, 2, obj );

var str = fcn( 'Hello' )( 'there' );
// returns 'Hello there, Ada!'

Notes

• Until return value resolution, each invocation returns a new partially applied curry function.

  function add( x, y, z ) {
      return x + y + z;
  }
  
  var fcn = curry( add );
  
  var s0 = fcn( 1 )( 2 )( 3 );
  // returns 6
  
  s0 = fcn( -1 )( -2 )( -3 );
  // returns -6
  
  s0 = fcn( 10 )( 20 )( 30 );
  // returns 60
  
  // Return a partially applied curry function:
  var f1 = fcn( 3 );
  
  var s1 = f1( 4 )( 5 );
  // returns 12
  
  s1 = f1( 6 )( 7 );
  // returns 16
  
  s1 = f1( 8 )( 9 );
  // returns 20
  
  // Return a partially applied curry function:
  var f2 = fcn( 4 )( 5 );
  
  var s2 = f2( 6 );
  // returns 15
  
  s2 = f2( 70 );
  // returns 79
  
  s2 = f2( 700 );
  // returns 709

Examples

var curry = require( '@stdlib/utils-curry' );

var fcn;
var out;
var i;

function add( x, y, z, w, t, s ) {
    return x + y + z + w + t + s;
}

fcn = curry( add );
out = fcn;
for ( i = 0; i < add.length; i++ ) {
    out = out( i*10 );
}
console.log( out );

See Also

• @stdlib/utils-curry-right: transform a function into a sequence of functions each accepting a single argument.
• @stdlib/utils-uncurry: transform a curried function into a function invoked with multiple arguments.
• @stdlib/utils-uncurry-right: transform a curried function into a function invoked with multiple arguments.

Notice

This package is part of stdlib, a standard library for JavaScript and Node.js, with an emphasis on numerical and scientific computing. The library provides a collection of robust, high performance libraries for mathematics, statistics, streams, utilities, and more.

For more information on the project, filing bug reports and feature requests, and guidance on how to develop stdlib, see the main project repository.

Community

License

See LICENSE.

Copyright

Copyright © 2016-2024. The Stdlib Authors.