and

a → b → a | b

Added in v0.1.0

Returns the first argument if it is falsy, otherwise the second argument. Acts as the boolean and statement if both inputs are Booleans.

See also both, or.

R.and(true, true); //=> true
R.and(true, false); //=> false
R.and(false, true); //=> false
R.and(false, false); //=> false

isEmpty

a → Boolean

Added in v0.1.0

Returns true if the given value is its type’s empty value; false otherwise.

See also empty, isNotEmpty.

R.isEmpty([1, 2, 3]);           //=> false
R.isEmpty([]);                  //=> true
R.isEmpty('');                  //=> true
R.isEmpty(null);                //=> false
R.isEmpty({});                  //=> true
R.isEmpty({length: 0});         //=> false
R.isEmpty(Uint8Array.from('')); //=> true

not

* → Boolean

Parameters

• aany value

Returns Boolean the logical inverse of passed argument.

Added in v0.1.0

A function that returns the ! of its argument. It will return true when passed false-y value, and false when passed a truth-y one.

See also complement.

R.not(true); //=> false
R.not(false); //=> true
R.not(0); //=> true
R.not(1); //=> false

or

a → b → a | b

Added in v0.1.0

Returns the first argument if it is truthy, otherwise the second argument. Acts as the boolean or statement if both inputs are Booleans.

See also either, and.

R.or(true, true); //=> true
R.or(true, false); //=> true
R.or(false, true); //=> true
R.or(false, false); //=> false