Predicate Functions

All functions in this group have a signature of * -> Boolean and are used with the many predicate based functions that ship with crocks, like safe, ifElse and filter to name a few. They also fit naturally with the Pred ADT. All predicate functions can be referenced from crocks/predicates.

Below is a list of all the current predicates that are included with a description of their truth:

• hasProp :: (String | Integer) -> a -> Boolean: an Array or Object that contains the provided index or key
• hasProps :: Foldable f => f (String | Integer) -> a -> Boolean: an Array or Object that contains the provided indexs or keys
• hasPropPath :: [ String | Integer ] -> a -> Boolean: an Array or Object that contains the provided index path
• isAlt :: a -> Boolean: an ADT that provides map and alt methods
• isAlternative :: a -> Boolean: an ADT that provides alt, zero, map, ap, chain and ofmethods
• isApplicative :: a -> Boolean: an ADT that provides map, ap and of methods
• isApply :: a -> Boolean: an ADT that provides map and ap methods
• isArray :: a -> Boolean: Array
• isBifunctor :: a -> Boolean: an ADT that provides map and bimap methods
• isBoolean :: a -> Boolean: Boolean
• isCategory :: a -> Boolean: an ADT that provides id and compose methods
• isChain :: a -> Boolean: an ADT that provides map, ap and chain methods
• isContravariant :: a -> Boolean: an ADT that provides contramap method
• isDate :: a -> Boolean: Date
• isDefined :: a -> Boolean: Every value that is not undefined, null included
• isEmpty :: a -> Boolean: Empty Monoid, Object, Array, String, undefined, null, all Numbers and Boolean values
• isExtend :: a -> Boolean: an ADT that provides map and extend methods
• isFalse :: a -> Boolean: a value that is strictly equal to false
• isFalsy :: a -> Boolean: a value that is considered to be falsy
• isFoldable :: a -> Boolean: Array, List or any structure with a reduce method
• isFunction :: a -> Boolean: Function
• isFunctor :: a -> Boolean: an ADT that provides a map method
• isInteger :: a -> Boolean: Integer
• isIterable :: a -> Boolean: an Object with an iterator method
• isMap :: a -> Boolean: Map
• isMonad :: a -> Boolean: an ADT that provides map, ap, chain and of methods
• isMonoid :: a -> Boolean: an ADT that provides concat and empty methods
• isNil :: a -> Boolean: undefined or null or NaN
• isNumber :: a -> Boolean: Number that is not a NaN value, Infinity included
• isObject :: a -> Boolean: Plain Old JavaScript Object (POJO)
• isPlus :: a -> Boolean: an ADT that provides map, alt and zero methods
• isProfunctor :: a -> Boolean: an ADT that provides map, contramap and promap methods
• isPromise :: a -> Boolean: an object implementing then and catch
• isSame :: a -> b -> Boolean: same value or reference, use equals for value equality
• isSameType :: a -> b -> Boolean: Constructor matches a values type, or two values types match
• isSemigroup :: a -> Boolean: an ADT that provides a concat method
• isSemigroupoid :: a -> Boolean: an ADT that provides a compose method
• isSetoid :: a -> Boolean: an ADT that provides an equals method
• isString :: a -> Boolean: String
• isSymbol :: a -> Boolean: Symbol
• isTraversable :: a -> Boolean: an ADT that provides map and traverse methods
• isTrue :: a -> Boolean: a value that is strictly equal to true
• isTruthy :: a -> Boolean: a value that is considered to be truthy
• pathEq :: [ String | Integer ] -> a -> Object -> Boolean: an Object that contains the provided key in the traversal path, with a value equal to the provided value. (equality by value)
• pathSatisfies :: [ String | Integer ] -> ((a -> Boolean) | Pred) -> Object -> Boolean: an Object that contains the provided key in the traversal path with a value that passes the provided predicate.
• propEq :: (String | Integer) -> a -> Object -> Boolean: an Object that contains the provided key with a value equal to the provided value. (equality by value)
• propSatisfies :: (String | Integer) -> ((a -> Boolean) | Pred) -> Object -> Boolean: an Object that contains the provided key with a value that passes the provided predicate.