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
attr_reader consequent: Prism::node?
attr_reader predicate: Prism::node
attr_reader statements: StatementsNode
?
Public Class Methods
def initialize: (Location
? if_keyword_loc
, Prism::node predicate, Location
? then_keyword_loc
, StatementsNode
? statements, Prism::node? consequent, Location
? end_keyword_loc
, Location
location) -> void
# File lib/prism/node.rb, line 8349 def initialize(source, if_keyword_loc, predicate, then_keyword_loc, statements, consequent, end_keyword_loc, location) @source = source @newline = false @location = 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 end
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 8513 def self.type :if_node end
Public Instance Methods
def accept: (Visitor
visitor) -> void
# File lib/prism/node.rb, line 8362 def accept(visitor) visitor.visit_if_node(self) end
def child_nodes
: () -> Array[nil | Node]
# File lib/prism/node.rb, line 8371 def child_nodes [predicate, statements, consequent] end
def comment_targets
: () -> Array[Node | Location]
# File lib/prism/node.rb, line 8385 def comment_targets [*if_keyword_loc, predicate, *then_keyword_loc, *statements, *consequent, *end_keyword_loc] #: Array[Prism::node | Location] end
def compact_child_nodes
: () -> Array
# File lib/prism/node.rb, line 8376 def compact_child_nodes compact = [] #: Array[Prism::node] compact << predicate compact << statements if statements compact << consequent if consequent compact end
def copy: (?if_keyword_loc: Location
?, ?predicate: Prism::node, ?then_keyword_loc: Location
?, ?statements: StatementsNode
?, ?consequent: Prism::node?, ?end_keyword_loc: Location
?, ?location: Location
) -> IfNode
# File lib/prism/node.rb, line 8390 def copy(if_keyword_loc: self.if_keyword_loc, predicate: self.predicate, then_keyword_loc: self.then_keyword_loc, statements: self.statements, consequent: self.consequent, end_keyword_loc: self.end_keyword_loc, location: self.location) IfNode.new(source, if_keyword_loc, predicate, then_keyword_loc, statements, consequent, end_keyword_loc, location) end
def deconstruct_keys
: (Array keys) -> { if_keyword_loc
: Location
?, predicate: Prism::node, then_keyword_loc
: Location
?, statements: StatementsNode
?, consequent: Prism::node?, end_keyword_loc
: Location
?, location: Location
}
# File lib/prism/node.rb, line 8398 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
def end_keyword
: () -> String
?
# File lib/prism/node.rb, line 8462 def end_keyword end_keyword_loc&.slice end
attr_reader end_keyword_loc
: Location
?
# File lib/prism/node.rb, line 8438 def end_keyword_loc location = @end_keyword_loc case location when nil nil when Location location else @end_keyword_loc = Location.new(source, location >> 32, location & 0xFFFFFFFF) end end
def if_keyword
: () -> String
?
# File lib/prism/node.rb, line 8452 def if_keyword if_keyword_loc&.slice end
attr_reader if_keyword_loc
: Location
?
# File lib/prism/node.rb, line 8403 def if_keyword_loc location = @if_keyword_loc case location when nil nil when Location location else @if_keyword_loc = Location.new(source, location >> 32, location & 0xFFFFFFFF) end end
def inspect(NodeInspector inspector) -> String
# File lib/prism/node.rb, line 8467 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
def then_keyword
: () -> String
?
# File lib/prism/node.rb, line 8457 def then_keyword then_keyword_loc&.slice end
attr_reader then_keyword_loc
: Location
?
# File lib/prism/node.rb, line 8419 def then_keyword_loc location = @then_keyword_loc case location when nil nil when Location location else @then_keyword_loc = Location.new(source, location >> 32, location & 0xFFFFFFFF) end end
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 8503 def type :if_node end