Represents the use of the ‘if` keyword, either in the block form or the modifier form, or a ternary expression.
bar if foo ^^^^^^^^^^ if foo then bar end ^^^^^^^^^^^^^^^^^^^ foo ? bar : baz ^^^^^^^^^^^^^^^
The node for the condition the ‘IfNode` is testing.
if foo
^^^
bar
end
bar if foo
^^^
foo ? bar : baz
^^^
Represents the body of statements that will be executed when the predicate is evaluated as truthy. Will be ‘nil` when no body is provided.
if foo bar ^^^ baz ^^^ end
Represents an ‘ElseNode` or an `IfNode` when there is an `else` or an `elsif` in the `if` statement.
if foo
bar
elsif baz
^^^^^^^^^
qux
^^^
end
^^^
if foo then bar else baz end
^^^^^^^^^^^^
# File tmp/rubies/ruby-3.4.0-preview1/lib/prism/node.rb, line 8472
def initialize(source, if_keyword_loc, predicate, then_keyword_loc, statements, consequent, end_keyword_loc, location)
@source = source
@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
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 tmp/rubies/ruby-3.4.0-preview1/lib/prism/node.rb, line 8658
def self.type
:if_node
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 tmp/rubies/ruby-3.4.0-preview1/lib/prism/node.rb, line 8664
def ===(other)
other.is_a?(IfNode) &&
(if_keyword_loc.nil? == other.if_keyword_loc.nil?) &&
(predicate === other.predicate) &&
(then_keyword_loc.nil? == other.then_keyword_loc.nil?) &&
(statements === other.statements) &&
(consequent === other.consequent) &&
(end_keyword_loc.nil? == other.end_keyword_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.
# File tmp/rubies/ruby-3.4.0-preview1/lib/prism/node.rb, line 8484
def accept(visitor)
visitor.visit_if_node(self)
end
def accept: (Visitor visitor) -> void
# File tmp/rubies/ruby-3.4.0-preview1/lib/prism/node.rb, line 8489
def child_nodes
[predicate, statements, consequent]
end
def child_nodes: () -> Array[nil | Node]
# File tmp/rubies/ruby-3.4.0-preview1/lib/prism/node.rb, line 8503
def comment_targets
[*if_keyword_loc, predicate, *then_keyword_loc, *statements, *consequent, *end_keyword_loc] #: Array[Prism::node | Location]
end
def comment_targets: () -> Array[Node | Location]
# File tmp/rubies/ruby-3.4.0-preview1/lib/prism/node.rb, line 8494
def compact_child_nodes
compact = [] #: Array[Prism::node]
compact << predicate
compact << statements if statements
compact << consequent if consequent
compact
end
def compact_child_nodes: () -> Array
# File tmp/rubies/ruby-3.4.0-preview1/lib/prism/node.rb, line 8508
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
# File tmp/rubies/ruby-3.4.0-preview1/lib/prism/node.rb, line 8516
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 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 tmp/rubies/ruby-3.4.0-preview1/lib/prism/node.rb, line 8625
def end_keyword
end_keyword_loc&.slice
end
def end_keyword: () -> String?
# File tmp/rubies/ruby-3.4.0-preview1/lib/prism/node.rb, line 8602
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
The location of the ‘end` keyword if present, `nil` otherwise.
if foo bar end ^^^
# File tmp/rubies/ruby-3.4.0-preview1/lib/prism/node.rb, line 8615
def if_keyword
if_keyword_loc&.slice
end
def if_keyword: () -> String?
# File tmp/rubies/ruby-3.4.0-preview1/lib/prism/node.rb, line 8526
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
The location of the ‘if` keyword if present.
bar if foo
^^
The ‘if_keyword_loc` field will be `nil` when the `IfNode` represents a ternary expression.
# File tmp/rubies/ruby-3.4.0-preview1/lib/prism/node.rb, line 8630
def inspect
InspectVisitor.compose(self)
end
def inspect -> String
# File tmp/rubies/ruby-3.4.0-preview1/lib/prism/node.rb, line 8620
def then_keyword
then_keyword_loc&.slice
end
def then_keyword: () -> String?
# File tmp/rubies/ruby-3.4.0-preview1/lib/prism/node.rb, line 8559
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
The location of the ‘then` keyword (if present) or the `?` in a ternary expression, `nil` otherwise.
if foo then bar end
^^^^
a ? b : c
^
# File tmp/rubies/ruby-3.4.0-preview1/lib/prism/node.rb, line 8648
def type
:if_node
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