class Prism::MatchRequiredNode - Documentation for Ruby 4.0
Description: class Prism::MatchRequiredNode: Represents the use of the `=>` operator.
Keywords: ruby,class,Prism::MatchRequiredNode

🔍

No recent searches

# class Prism::MatchRequiredNode

Represents the use of the `=>` operator.

    foo => bar
    ^^^^^^^^^^

### Attributes

pattern [R]

Represents the right-hand side of the operator. The type of the node depends on the expression.

Anything that looks like a local variable name (including `_`) will result in a `LocalVariableTargetNode`.

    foo => a # This is equivalent to writing `a = foo`
           ^

Using an explicit `Array` or combining expressions with `,` will result in a `ArrayPatternNode`. This can be preceded by a constant.

    foo => [a]
           ^^^

    foo => a, b
           ^^^^

    foo => Bar[a, b]
           ^^^^^^^^^

If the array pattern contains at least two wildcard matches, a `FindPatternNode` is created instead.

    foo => *, 1, *a
           ^^^^^

Using an explicit `Hash` or a constant with square brackets and hash keys in the square brackets will result in a `HashPatternNode`.

    foo => { a: 1, b: }

    foo => Bar[a: 1, b:]

    foo => Bar[**]

To use any variable that needs run time evaluation, pinning is required. This results in a `PinnedVariableNode`

    foo => ^a
           ^^

Similar, any expression can be used with pinning. This results in a `PinnedExpressionNode`.

    foo => ^(a + 1)

Anything else will result in the regular node for that expression, for example a `ConstantReadNode`.

    foo => CONST

value [R]

Represents the left-hand side of the operator.

    foo => bar
    ^^^

### Public Class Methods

new (source, node_id, location, flags, value, pattern, operator_loc)
Source

    # File lib/prism/node.rb, line 13519
    def initialize(source, node_id, location, flags, value, pattern, operator_loc)
      @source = source
      @node_id = node_id
      @location = location
      @flags = flags
      @value = value
      @pattern = pattern
      @operator_loc = operator_loc
    end

Initialize a new `MatchRequiredNode` node.

type ()
Source

    # File lib/prism/node.rb, line 13653
    def self.type
      :match_required_node
    end

Return a symbol representation of this node type. See `Node::type`.

### Public Instance Methods

=== (other)
Source

    # File lib/prism/node.rb, line 13659
    def ===(other)
      other.is_a?(MatchRequiredNode) &&
        (value === other.value) &&
        (pattern === other.pattern) &&
        (operator_loc.nil? == other.operator_loc.nil?)
    end

Implements case-equality for the node. This is effectively == but without comparing the value of locations. Locations are checked only for presence.

accept (visitor)
Source

    # File lib/prism/node.rb, line 13530
    def accept(visitor)
      visitor.visit_match_required_node(self)
    end

def accept: (`Visitor` visitor) -> void

child_nodes ()
Source

    # File lib/prism/node.rb, line 13535
    def child_nodes
      [value, pattern]
    end

def `child_nodes`: () -> Array

Also aliased as: deconstruct
comment_targets ()
Source

    # File lib/prism/node.rb, line 13553
    def comment_targets
      [value, pattern, operator_loc] #: Array[Prism::node | Location]
    end

def `comment_targets`: () -> Array[Node | Location]

compact_child_nodes ()
Source

    # File lib/prism/node.rb, line 13548
    def compact_child_nodes
      [value, pattern]
    end

def `compact_child_nodes`: () -> Array

copy (node_id: self.node_id, location: self.location, flags: self.flags, value: self.value, pattern: self.pattern, operator_loc: self.operator_loc)
Source

    # File lib/prism/node.rb, line 13558
    def copy(node_id: self.node_id, location: self.location, flags: self.flags, value: self.value, pattern: self.pattern, operator_loc: self.operator_loc)
      MatchRequiredNode.new(source, node_id, location, flags, value, pattern, operator_loc)
    end

def copy: (?node_id: `Integer`, ?location: `Location`, ?flags: `Integer`, ?value: Prism::node, ?pattern: Prism::node, ?operator_loc: `Location`) -> `MatchRequiredNode`

deconstruct ()

def deconstruct: () -> Array

Alias for: child_nodes
deconstruct_keys (keys)
Source

    # File lib/prism/node.rb, line 13566
    def deconstruct_keys(keys)
      { node_id: node_id, location: location, value: value, pattern: pattern, operator_loc: operator_loc }
    end

def `deconstruct_keys`: (Array keys) -> { node_id: `Integer`, location: `Location`, value: Prism::node, pattern: Prism::node, `operator_loc`: `Location` }

each_child_node () { |value| ... }
Source

    # File lib/prism/node.rb, line 13540
    def each_child_node
      return to_enum(:each_child_node) unless block_given?

      yield value
      yield pattern
    end

def `each_child_node`: () { (Prism::node) -> void } -> void | () -> Enumerator

inspect ()
Source

    # File lib/prism/node.rb, line 13643
    def inspect
      InspectVisitor.compose(self)
    end

def inspect -> `String`

operator ()
Source

    # File lib/prism/node.rb, line 13638
    def operator
      operator_loc.slice
    end

def operator: () -> `String`

operator_loc ()
Source

    # File lib/prism/node.rb, line 13625
    def operator_loc
      location = @operator_loc
      return location if location.is_a?(Location)
      @operator_loc = Location.new(source, location >> 32, location & 0xFFFFFFFF)
    end

The location of the operator.

    foo => bar
        ^^

save_operator_loc (repository)
Source

    # File lib/prism/node.rb, line 13633
    def save_operator_loc(repository)
      repository.enter(node_id, :operator_loc)
    end

Save the `operator_loc` location using the given saved source so that it can be retrieved later.

type ()
Source

    # File lib/prism/node.rb, line 13648
    def type
      :match_required_node
    end

Return a symbol representation of this node type. See `Node#type`.