class Prism::BeginNode
Represents a begin statement.
begin foo end ^^^^^
Attributes
attr_reader begin_keyword_loc
: Location
?
attr_reader else_clause
: ElseNode
?
attr_reader end_keyword_loc
: Location
?
attr_reader ensure_clause
: EnsureNode
?
attr_reader rescue_clause
: RescueNode
?
attr_reader statements: StatementsNode
?
Public Class Methods
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 1168 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
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 1294 def self.type :begin_node end
Public Instance Methods
def accept: (visitor: Visitor
) -> void
# File prism/node.rb, line 1179 def accept(visitor) visitor.visit_begin_node(self) end
def begin_keyword
: () -> String?
# File prism/node.rb, line 1229 def begin_keyword begin_keyword_loc&.slice end
def child_nodes
: () -> Array[nil | Node]
# File prism/node.rb, line 1188 def child_nodes [statements, rescue_clause, else_clause, ensure_clause] end
def comment_targets
: () -> Array[Node | Location]
# File prism/node.rb, line 1203 def comment_targets [*begin_keyword_loc, *statements, *rescue_clause, *else_clause, *ensure_clause, *end_keyword_loc] end
def compact_child_nodes
: () -> Array
# File prism/node.rb, line 1193 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
def copy: (**params) -> BeginNode
# File prism/node.rb, line 1208 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
def deconstruct_keys
: (keys: Array) -> Hash[Symbol, nil | Node
| Array | String | Token
| Array | Location]
# File prism/node.rb, line 1224 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
def end_keyword
: () -> String?
# File prism/node.rb, line 1234 def end_keyword end_keyword_loc&.slice end
def inspect(inspector: NodeInspector) -> String
# File prism/node.rb, line 1239 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
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 1284 def type :begin_node end