class Prism::BeginNode

Represents a begin statement.

begin
  foo
end
^^^^^

Attributes

begin_keyword_loc[R]

attr_reader begin_keyword_loc: Location?

else_clause[R]

attr_reader else_clause: ElseNode?

end_keyword_loc[R]

attr_reader end_keyword_loc: Location?

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

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

# File prism/node.rb, line 1156
def initialize(begin_keyword_loc, statements, rescue_clause, else_clause, ensure_clause, end_keyword_loc, 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
  @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 prism/node.rb, line 1282
def self.type
  :begin_node
end

Public Instance Methods

accept(visitor) click to toggle source

def accept: (visitor: Visitor) -> void

# File prism/node.rb, line 1167
def accept(visitor)
  visitor.visit_begin_node(self)
end

begin_keyword() click to toggle source

def begin_keyword: () -> String?

# File prism/node.rb, line 1217
def begin_keyword
  begin_keyword_loc&.slice
end

child_nodes() click to toggle source

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

# File prism/node.rb, line 1176
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 1191
def comment_targets
  [*begin_keyword_loc, *statements, *rescue_clause, *else_clause, *ensure_clause, *end_keyword_loc]
end

compact_child_nodes() click to toggle source

def compact_child_nodes: () -> Array

# File prism/node.rb, line 1181
def compact_child_nodes
  compact = []
  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(**params) click to toggle source

def copy: (**params) -> BeginNode

# File prism/node.rb, line 1196
def copy(**params)
  BeginNode.new(
    params.fetch(:begin_keyword_loc) { begin_keyword_loc },
    params.fetch(:statements) { statements },
    params.fetch(:rescue_clause) { rescue_clause },
    params.fetch(:else_clause) { else_clause },
    params.fetch(:ensure_clause) { ensure_clause },
    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 prism/node.rb, line 1212
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 1222
def end_keyword
  end_keyword_loc&.slice
end

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

def inspect(inspector: NodeInspector) -> String

# File prism/node.rb, line 1227
def inspect(inspector = NodeInspector.new)
  inspector << inspector.header(self)
  inspector << "├── begin_keyword_loc: #{inspector.location(begin_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 (rescue_clause = self.rescue_clause).nil?
    inspector << "├── rescue_clause: ∅\n"
  else
    inspector << "├── rescue_clause:\n"
    inspector << rescue_clause.inspect(inspector.child_inspector("│   ")).delete_prefix(inspector.prefix)
  end
  if (else_clause = self.else_clause).nil?
    inspector << "├── else_clause: ∅\n"
  else
    inspector << "├── else_clause:\n"
    inspector << else_clause.inspect(inspector.child_inspector("│   ")).delete_prefix(inspector.prefix)
  end
  if (ensure_clause = self.ensure_clause).nil?
    inspector << "├── ensure_clause: ∅\n"
  else
    inspector << "├── ensure_clause:\n"
    inspector << ensure_clause.inspect(inspector.child_inspector("│   ")).delete_prefix(inspector.prefix)
  end
  inspector << "└── end_keyword_loc: #{inspector.location(end_keyword_loc)}\n"
  inspector.to_str
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 1272
def type
  :begin_node
end