class Prism::IfNode

Represents the use of the ‘if` keyword, either in the block form or the modifier form.

bar if foo
^^^^^^^^^^

if foo then bar end
^^^^^^^^^^^^^^^^^^^

Attributes

consequent[R]

attr_reader consequent: Node?

end_keyword_loc[R]

attr_reader end_keyword_loc: Location?

if_keyword_loc[R]

attr_reader if_keyword_loc: Location?

predicate[R]

attr_reader predicate: Node

statements[R]

attr_reader statements: StatementsNode?

then_keyword_loc[R]

attr_reader then_keyword_loc: Location?

Public Class Methods

new(if_keyword_loc, predicate, then_keyword_loc, statements, consequent, end_keyword_loc, location) click to toggle source

def initialize: (if_keyword_loc: Location?, predicate: Node, then_keyword_loc: Location?, statements: StatementsNode?, consequent: Node?, end_keyword_loc: Location?, location: Location) -> void

# File lib/prism/node.rb, line 7733
def initialize(if_keyword_loc, predicate, then_keyword_loc, statements, consequent, end_keyword_loc, location)
  @if_keyword_loc = if_keyword_loc
  @predicate = predicate
  @then_keyword_loc = then_keyword_loc
  @statements = statements
  @consequent = consequent
  @end_keyword_loc = end_keyword_loc
  @location = location
end

type() click to toggle source

Similar to type, this method returns a symbol that you can use for splitting on the type of the node without having to do a long === chain. Note that like type, it will still be slower than using == for a single class, but should be faster in a case statement or an array comparison.

def self.type: () -> Symbol

# File lib/prism/node.rb, line 7854
def self.type
  :if_node
end

Public Instance Methods

accept(visitor) click to toggle source

def accept: (visitor: Visitor) -> void

# File lib/prism/node.rb, line 7744
def accept(visitor)
  visitor.visit_if_node(self)
end

child_nodes() click to toggle source

def child_nodes: () -> Array[nil | Node]

# File lib/prism/node.rb, line 7753
def child_nodes
  [predicate, statements, consequent]
end

Also aliased as: deconstruct

comment_targets() click to toggle source

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

# File lib/prism/node.rb, line 7767
def comment_targets
  [*if_keyword_loc, predicate, *then_keyword_loc, *statements, *consequent, *end_keyword_loc]
end

compact_child_nodes() click to toggle source

def compact_child_nodes: () -> Array

# File lib/prism/node.rb, line 7758
def compact_child_nodes
  compact = []
  compact << predicate
  compact << statements if statements
  compact << consequent if consequent
  compact
end

copy(**params) click to toggle source

def copy: (**params) -> IfNode

# File lib/prism/node.rb, line 7772
def copy(**params)
  IfNode.new(
    params.fetch(:if_keyword_loc) { if_keyword_loc },
    params.fetch(:predicate) { predicate },
    params.fetch(:then_keyword_loc) { then_keyword_loc },
    params.fetch(:statements) { statements },
    params.fetch(:consequent) { consequent },
    params.fetch(:end_keyword_loc) { end_keyword_loc },
    params.fetch(:location) { location },
  )
end

deconstruct()

def deconstruct: () -> Array[nil | Node]

Alias for: child_nodes

deconstruct_keys(keys) click to toggle source

# File lib/prism/node.rb, line 7788
def deconstruct_keys(keys)
  { if_keyword_loc: if_keyword_loc, predicate: predicate, then_keyword_loc: then_keyword_loc, statements: statements, consequent: consequent, end_keyword_loc: end_keyword_loc, location: location }
end

end_keyword() click to toggle source

def end_keyword: () -> String?

# File lib/prism/node.rb, line 7803
def end_keyword
  end_keyword_loc&.slice
end

if_keyword() click to toggle source

def if_keyword: () -> String?

# File lib/prism/node.rb, line 7793
def if_keyword
  if_keyword_loc&.slice
end

inspect(inspector = NodeInspector.new) click to toggle source

def inspect(inspector: NodeInspector) -> String

# File lib/prism/node.rb, line 7808
def inspect(inspector = NodeInspector.new)
  inspector << inspector.header(self)
  inspector << "├── if_keyword_loc: #{inspector.location(if_keyword_loc)}\n"
  inspector << "├── predicate:\n"
  inspector << inspector.child_node(predicate, "│   ")
  inspector << "├── then_keyword_loc: #{inspector.location(then_keyword_loc)}\n"
  if (statements = self.statements).nil?
    inspector << "├── statements: ∅\n"
  else
    inspector << "├── statements:\n"
    inspector << statements.inspect(inspector.child_inspector("│   ")).delete_prefix(inspector.prefix)
  end
  if (consequent = self.consequent).nil?
    inspector << "├── consequent: ∅\n"
  else
    inspector << "├── consequent:\n"
    inspector << consequent.inspect(inspector.child_inspector("│   ")).delete_prefix(inspector.prefix)
  end
  inspector << "└── end_keyword_loc: #{inspector.location(end_keyword_loc)}\n"
  inspector.to_str
end

then_keyword() click to toggle source

def then_keyword: () -> String?

# File lib/prism/node.rb, line 7798
def then_keyword
  then_keyword_loc&.slice
end

type() click to toggle source

Sometimes you want to check an instance of a node against a list of classes to see what kind of behavior to perform. Usually this is done by calling ‘[cls1, cls2].include?(node.class)` or putting the node into a case statement and doing `case node; when cls1; when cls2; end`. Both of these approaches are relatively slow because of the constant lookups, method calls, and/or array allocations.

Instead, you can call type, which will return to you a symbol that you can use for comparison. This is faster than the other approaches because it uses a single integer comparison, but also because if you’re on CRuby you can take advantage of the fact that case statements with all symbol keys will use a jump table.

def type: () -> Symbol

# File lib/prism/node.rb, line 7844
def type
  :if_node
end