Module: Enumerable

Defined in:

runtime/ext/enumerable.rb,
runtime/ext/enumerable.rbs

Overview

Enumerable — the collection predicates and projections.

Instance Method Summary

• #index_by ⇒ Hash

  the collection as a Hash keyed by the block's value; last write wins on duplicates.

• #many? ⇒ Boolean

  more than one element.

• #sole ⇒ untyped

  the one element, asserting the count instead of only reading the first: first would keep the read and drop the assertion.

Instance Method Details

#index_by ⇒ Hash

the collection as a Hash keyed by the block's value; last write wins on duplicates.

Returns:

• (Hash) —

  this collection keyed by the block's value

# File 'runtime/ext/enumerable.rb', line 7

def index_by: () { (untyped) -> untyped } -> Hash[untyped, untyped]

#many? ⇒ Boolean

more than one element.

length answers it because everything that reaches here is already materialized.

Returns:

• (Boolean) —

  true when the collection holds two or more elements

# File 'runtime/ext/enumerable.rb', line 19

def many?: () -> bool

#sole ⇒ untyped

the one element, asserting the count instead of only reading the first: first would keep the read and drop the assertion.

Returns:

• (untyped) —

  the collection's single element

Raises:

• (RuntimeError) —

  the collection is empty or holds more than one element

# File 'runtime/ext/enumerable.rb', line 28

def sole: () -> untyped