class RuboCop::AST::NodePattern::Builder

Responsible to build the AST nodes for `NodePattern`

Doc on how this fits in the compiling process:

/docs/modules/ROOT/pages/node_pattern.adoc

Public Instance Methods

emit_atom(type, value) click to toggle source
# File lib/rubocop/ast/node_pattern/builder.rb, line 17
def emit_atom(type, value)
  n(type, [value])
end
emit_call(type, selector, args = nil) click to toggle source
# File lib/rubocop/ast/node_pattern/builder.rb, line 29
def emit_call(type, selector, args = nil)
  _begin_t, arg_nodes, _end_t = args
  n(type, [selector, *arg_nodes])
end
emit_capture(capture_token, node) click to toggle source
# File lib/rubocop/ast/node_pattern/builder.rb, line 11
def emit_capture(capture_token, node)
  return node if capture_token.nil?

  emit_unary_op(:capture, capture_token, node)
end
emit_list(type, _begin, children, _end) click to toggle source
# File lib/rubocop/ast/node_pattern/builder.rb, line 25
def emit_list(type, _begin, children, _end)
  n(type, children)
end
emit_subsequence(node_list) click to toggle source
# File lib/rubocop/ast/node_pattern/builder.rb, line 41
def emit_subsequence(node_list)
  return node_list.first if node_list.size == 1 # Don't put a single child in a subsequence

  emit_list(:subsequence, nil, node_list, nil)
end
emit_unary_op(type, _operator = nil, *children) click to toggle source
# File lib/rubocop/ast/node_pattern/builder.rb, line 21
def emit_unary_op(type, _operator = nil, *children)
  n(type, children)
end
emit_union(begin_t, pattern_lists, end_t) click to toggle source
# File lib/rubocop/ast/node_pattern/builder.rb, line 34
def emit_union(begin_t, pattern_lists, end_t)
  children = union_children(pattern_lists)

  type = optimizable_as_set?(children) ? :set : :union
  emit_list(type, begin_t, children, end_t)
end

Private Instance Methods

n(type, *args) click to toggle source
# File lib/rubocop/ast/node_pattern/builder.rb, line 53
def n(type, *args)
  Node::MAP[type].new(type, *args)
end
optimizable_as_set?(children) click to toggle source
# File lib/rubocop/ast/node_pattern/builder.rb, line 49
def optimizable_as_set?(children)
  children.all?(&:matches_within_set?)
end
union_children(pattern_lists) click to toggle source
# File lib/rubocop/ast/node_pattern/builder.rb, line 57
def union_children(pattern_lists)
  if pattern_lists.size == 1 # {a b c} => [[a, b, c]] => [a, b, c]
    children = pattern_lists.first
    raise NodePattern::Invalid, 'A union can not be empty' if children.empty?

    children
  else # { a b | c } => [[a, b], [c]] => [s(:subsequence, a, b), c]
    pattern_lists.map do |list|
      emit_subsequence(list)
    end
  end
end