module RuboCop::NodePattern::Macros
Helpers for defining methods based on a pattern string
Public Instance Methods
def_node_matcher(method_name, pattern_str)
click to toggle source
Define a method which applies a pattern to an AST
node
The new method will return nil if the node does not match If the node matches, and a block is provided, the new method will yield to the block (passing any captures as block arguments). If the node matches, and no block is provided, the new method will return the captures, or `true` if there were none.
# File lib/rubocop/node_pattern.rb, line 489 def def_node_matcher(method_name, pattern_str) compiler = Compiler.new(pattern_str, 'node') src = "def #{method_name}(node = self" \ "#{compiler.emit_trailing_params});" \ "#{compiler.emit_guard_clause}" \ "#{compiler.emit_method_code};end" location = caller_locations(1, 1).first class_eval(src, location.path, location.lineno) end
def_node_search(method_name, pattern_str)
click to toggle source
Define a method which recurses over the descendants of an AST
node, checking whether any of them match the provided pattern
If the method name ends with '?', the new method will return `true` as soon as it finds a descendant which matches. Otherwise, it will yield all descendants which match.
# File lib/rubocop/node_pattern.rb, line 506 def def_node_search(method_name, pattern_str) compiler = Compiler.new(pattern_str, 'node') called_from = caller(1..1).first.split(':') if method_name.to_s.end_with?('?') node_search_first(method_name, compiler, called_from) else node_search_all(method_name, compiler, called_from) end end
node_search(method_name, compiler, on_match, prelude, called_from)
click to toggle source
# File lib/rubocop/node_pattern.rb, line 531 def node_search(method_name, compiler, on_match, prelude, called_from) src = node_search_body(method_name, compiler.emit_trailing_params, prelude, compiler.match_code, on_match) filename, lineno = *called_from class_eval(src, filename, lineno.to_i) end
node_search_all(method_name, compiler, called_from)
click to toggle source
# File lib/rubocop/node_pattern.rb, line 521 def node_search_all(method_name, compiler, called_from) yieldval = compiler.emit_capture_list yieldval = 'node' if yieldval.empty? prelude = "return enum_for(:#{method_name}, node0" \ "#{compiler.emit_trailing_params}) unless block_given?" node_search(method_name, compiler, "yield(#{yieldval})", prelude, called_from) end
node_search_body(method_name, trailing_params, prelude, match_code, on_match)
click to toggle source
# File lib/rubocop/node_pattern.rb, line 538 def node_search_body(method_name, trailing_params, prelude, match_code, on_match) <<-RUBY def #{method_name}(node0#{trailing_params}) #{prelude} node0.each_node do |node| if #{match_code} #{on_match} end end nil end RUBY end
node_search_first(method_name, compiler, called_from)
click to toggle source
# File lib/rubocop/node_pattern.rb, line 517 def node_search_first(method_name, compiler, called_from) node_search(method_name, compiler, 'return true', '', called_from) end