class Prism::BeginNode

Represents a begin statement.

begin
  foo
end
^^^^^

Attributes

else_clause[R]

attr_reader else_clause: ElseNode?

ensure_clause[R]

attr_reader ensure_clause: EnsureNode?

rescue_clause[R]

attr_reader rescue_clause: RescueNode?

statements[R]

attr_reader statements: StatementsNode?

Public Class Methods

new(source, begin_keyword_loc, statements, rescue_clause, else_clause, ensure_clause, end_keyword_loc, location) click to toggle source

def initialize: (Location? begin_keyword_loc, StatementsNode? statements, RescueNode? rescue_clause, ElseNode? else_clause, EnsureNode? ensure_clause, Location? end_keyword_loc, Location location) -> void

# File prism/node.rb, line 1392
def initialize(source, begin_keyword_loc, statements, rescue_clause, else_clause, ensure_clause, end_keyword_loc, location)
  @source = source
  @location = location
  @begin_keyword_loc = begin_keyword_loc
  @statements = statements
  @rescue_clause = rescue_clause
  @else_clause = else_clause
  @ensure_clause = ensure_clause
  @end_keyword_loc = end_keyword_loc
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 prism/node.rb, line 1518
def self.type
  :begin_node
end

Public Instance Methods

===(other) click to toggle source

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

# File prism/node.rb, line 1524
def ===(other)
  other.is_a?(BeginNode) &&
    (begin_keyword_loc.nil? == other.begin_keyword_loc.nil?) &&
    (statements === other.statements) &&
    (rescue_clause === other.rescue_clause) &&
    (else_clause === other.else_clause) &&
    (ensure_clause === other.ensure_clause) &&
    (end_keyword_loc.nil? == other.end_keyword_loc.nil?)
end

accept(visitor) click to toggle source

def accept: (Visitor visitor) -> void

# File prism/node.rb, line 1404
def accept(visitor)
  visitor.visit_begin_node(self)
end

begin_keyword() click to toggle source

def begin_keyword: () -> String?

# File prism/node.rb, line 1480
def begin_keyword
  begin_keyword_loc&.slice
end

begin_keyword_loc() click to toggle source

attr_reader begin_keyword_loc: Location?

# File prism/node.rb, line 1442
def begin_keyword_loc
  location = @begin_keyword_loc
  case location
  when nil
    nil
  when Location
    location
  else
    @begin_keyword_loc = Location.new(source, location >> 32, location & 0xFFFFFFFF)
  end
end

child_nodes() click to toggle source

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

# File prism/node.rb, line 1409
def child_nodes
  [statements, rescue_clause, else_clause, ensure_clause]
end

Also aliased as: deconstruct

comment_targets() click to toggle source

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

# File prism/node.rb, line 1424
def comment_targets
  [*begin_keyword_loc, *statements, *rescue_clause, *else_clause, *ensure_clause, *end_keyword_loc] #: Array[Prism::node | Location]
end

compact_child_nodes() click to toggle source

def compact_child_nodes: () -> Array

# File prism/node.rb, line 1414
def compact_child_nodes
  compact = [] #: Array[Prism::node]
  compact << statements if statements
  compact << rescue_clause if rescue_clause
  compact << else_clause if else_clause
  compact << ensure_clause if ensure_clause
  compact
end

copy(begin_keyword_loc: self.begin_keyword_loc, statements: self.statements, rescue_clause: self.rescue_clause, else_clause: self.else_clause, ensure_clause: self.ensure_clause, end_keyword_loc: self.end_keyword_loc, location: self.location) click to toggle source

def copy: (?begin_keyword_loc: Location?, ?statements: StatementsNode?, ?rescue_clause: RescueNode?, ?else_clause: ElseNode?, ?ensure_clause: EnsureNode?, ?end_keyword_loc: Location?, ?location: Location) -> BeginNode

# File prism/node.rb, line 1429
def copy(begin_keyword_loc: self.begin_keyword_loc, statements: self.statements, rescue_clause: self.rescue_clause, else_clause: self.else_clause, ensure_clause: self.ensure_clause, end_keyword_loc: self.end_keyword_loc, location: self.location)
  BeginNode.new(source, begin_keyword_loc, statements, rescue_clause, else_clause, ensure_clause, end_keyword_loc, location)
end

deconstruct()

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

Alias for: child_nodes

deconstruct_keys(keys) click to toggle source

def deconstruct_keys: (Array keys) -> { begin_keyword_loc: Location?, statements: StatementsNode?, rescue_clause: RescueNode?, else_clause: ElseNode?, ensure_clause: EnsureNode?, end_keyword_loc: Location?, location: Location }

# File prism/node.rb, line 1437
def deconstruct_keys(keys)
  { begin_keyword_loc: begin_keyword_loc, statements: statements, rescue_clause: rescue_clause, else_clause: else_clause, ensure_clause: ensure_clause, end_keyword_loc: end_keyword_loc, location: location }
end

end_keyword() click to toggle source

def end_keyword: () -> String?

# File prism/node.rb, line 1485
def end_keyword
  end_keyword_loc&.slice
end

end_keyword_loc() click to toggle source

attr_reader end_keyword_loc: Location?

# File prism/node.rb, line 1467
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

inspect() click to toggle source

def inspect -> String

# File prism/node.rb, line 1490
def inspect
  InspectVisitor.compose(self)
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 prism/node.rb, line 1508
def type
  :begin_node
end