Literal

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Built in types ​

Literal::Types defines a number of built-in types that you can use. This module is included in Literal::Properties, Literal::Object, Literal::Struct and Literal::Data already.

Once you’ve created a type — which usually happens at boot time when a class is defined — you can use it as many times as you like with no runtime allocations.

_Any ​

Matches any object apart from nil.

_Any? ​

_Nilable(_Any).

_Array(T) ​

Matches an array where all elements match the type T.

_Array?(T) ​

_Nilable(_Array(T)).

_Boolean ​

Matches true or false.

_Boolean? ​

_Nilable(_Boolean).

_Callable ​

Matches any object that responds to call.

_Callable? ​

_Nilable(_Callable).

_Class(T) ​

Matches if the object is a class and is either the class T or a subclass of T.

_Class?(T) ​

_Nilable(_Class(T)).

_Constraint(*T, **K) ​

Matches if all of the given T types match and the object responds to each K key matching the corresponding type.

This, for example, will check that the object is a Person, then it will call name on the object and check that the result is a String.

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_Constraint(Person, name: String)

_Constraint?(*T, **K) ​

_Nilable(_Constraint?(*T, **K)).

_Date(*T, **K) ​

_Constraint(Date, *T, **K)

_Date?(*T, **K) ​

_Nilable(_Date(*T, **K))

_Descendant(T) ​

Matches if the object is a module and is descendant of the module T. Remember classes are modules too.

_Descendant?(T) ​

_Nilable(_Descendant(T)).

_Enumerable(T) ​

Matches if the object is an enumerable and all elements match the type T.

_Enumerable?(T) ​

_Nilable(_Enumerable(T)).

_Falsy ​

Matches nil or false.

_Float(T) ​

Matches if the object is a Float and also matches the type T.

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_Float(10..20)

_Float?(T) ​

_Nilable(_Float(T)).

_Frozen(T) ​

Matches if the object is frozen and matches the type T.

_Frozen?(T) ​

_Nilable(_Frozen(T)).

_Hash(K, V) ​

Matches if the object is a Hash where all keys match the type K and all values match the type V.

_Hash?(K, V) ​

_Nilable(_Hash(K, V)).

_Integer(T) ​

Matches if the object is an Integer and also matches the type T.

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_Integer(18..)

_Integer?(T) ​

_Nilable(_Integer(T)).

_Interface(*M) ​

Uses respond_to? to check if the object implements all the M methods.

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_Interface(:name, :age)

_Interface?(*M) ​

_Nilable(_Interface(*M)).

_Intersection(*T) ​

Matches if all of the given T types match.

_Intersection?(*T) ​

_Nilable(_Intersection(*T)).

_JSONData ​

Matches any object that could have been parsed out from JSON, i.e. it came from JSON.parse.

_JSONData? ​

_Nilable(_JSONData).

_Lambda ​

Matches a Proc where the lambda? predicate is truthy.

_Lambda? ​

_Nilable(_Lambda).

_Map(**K) ​

Matches if the object maps each key to the corresponding type.

For example, this type:

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_Map(name: String, age: Integer)

Will check that [:name] matches String and [:age] matches Integer.

_Map?(**K) ​

_Nilable(_Map(**K)).

_Never ​

Matches nothing. It will always fail.

_Nilable(T) ​

Matches nil or an object that matches the type T.

_Not(T) ​

Matches if the object does not match the type T.

_Procable ​

Matches any object that responds to #to_proc. This is essentially _Interface(:to_proc).

_Procable? ​

_Nilable(_Procable).

_Range(T) ​

Matches if the object is a Range of the given type T.

_Range?(T) ​

_Nilable(_Range(T)).

_Set(T) ​

Matches if the object is a Set where all elements match the type T.

_Set?(T) ​

_Nilable(_Set(T)).

_String(*T, **K) ​

Matches if the object is a String and all of the given T types match and the object responds to each K key matching the corresponding type. This is like _Constraint(*T, **K), but it’s already constrained to strings.

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_String(length: 5..15)

If you don’t need to apply any constraints, you should just use String.

_String?(*T, **K) ​

_Nilable(_String(*T, **K)).

_Symbol(*T, **K) ​

Matches if the object is a Symbol and all of the given T types match and the object responds to each K key matching the corresponding type. Similar to _Constraint but specifically for symbols.

_Symbol?(*T, **K) ​

_Nilable(_Symbol(*T, **K)).

_Time(*T, **K) ​

_Constraint(Time, *T, **K)

_Time?(*T, **K) ​

_Nilable(_Time(*T, **K))

_Truthy ​

Matches any object apart from nil and false.

_Tuple(*T) ​

Matches if the object is an array with the same number of elements as the given T types and each element matches the corresponding type.

_Tuple?(*T) ​

_Nilable(_Tuple(*T)).

_Union(*T) ​

Matches if any of the given T types match. For example, this will match if the object is either a String or a Symbol.

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_Union(String, Symbol)

_Union?(*T) ​

_Nilable(_Union(*T)).

_Void ​

Always matches. This will never fail, it’s the opposite of _Never.