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|
# frozen_string_literal: true
require "ripper"
module Prism
# Note: This integration is not finished, and therefore still has many
# inconsistencies with Ripper. If you'd like to help out, pull requests would
# be greatly appreciated!
#
# This class is meant to provide a compatibility layer between prism and
# Ripper. It functions by parsing the entire tree first and then walking it
# and executing each of the Ripper callbacks as it goes.
#
# This class is going to necessarily be slower than the native Ripper API. It
# is meant as a stopgap until developers migrate to using prism. It is also
# meant as a test harness for the prism parser.
#
# To use this class, you treat `Prism::RipperCompat` effectively as you would
# treat the `Ripper` class.
class RipperCompat < Visitor
# This class mirrors the ::Ripper::SexpBuilder subclass of ::Ripper that
# returns the arrays of [type, *children].
class SexpBuilder < RipperCompat
private
Ripper::PARSER_EVENTS.each do |event|
define_method(:"on_#{event}") do |*args|
[event, *args]
end
end
Ripper::SCANNER_EVENTS.each do |event|
define_method(:"on_#{event}") do |value|
[:"@#{event}", value, [lineno, column]]
end
end
end
# This class mirrors the ::Ripper::SexpBuilderPP subclass of ::Ripper that
# returns the same values as ::Ripper::SexpBuilder except with a couple of
# niceties that flatten linked lists into arrays.
class SexpBuilderPP < SexpBuilder
private
def _dispatch_event_new # :nodoc:
[]
end
def _dispatch_event_push(list, item) # :nodoc:
list << item
list
end
Ripper::PARSER_EVENT_TABLE.each do |event, arity|
case event
when /_new\z/
alias_method :"on_#{event}", :_dispatch_event_new if arity == 0
when /_add\z/
alias_method :"on_#{event}", :_dispatch_event_push
end
end
end
# The source that is being parsed.
attr_reader :source
# The current line number of the parser.
attr_reader :lineno
# The current column number of the parser.
attr_reader :column
# Create a new RipperCompat object with the given source.
def initialize(source)
@source = source
@result = nil
@lineno = nil
@column = nil
end
############################################################################
# Public interface
############################################################################
# True if the parser encountered an error during parsing.
def error?
result.failure?
end
# Parse the source and return the result.
def parse
result.magic_comments.each do |magic_comment|
on_magic_comment(magic_comment.key, magic_comment.value)
end
if error?
result.errors.each do |error|
on_parse_error(error.message)
end
else
result.value.accept(self)
end
end
############################################################################
# Visitor methods
############################################################################
# Visit a CallNode node.
def visit_call_node(node)
if !node.message.match?(/^[[:alpha:]_]/) && node.opening_loc.nil? && node.arguments&.arguments&.length == 1
left = visit(node.receiver)
right = visit(node.arguments.arguments.first)
bounds(node.location)
on_binary(left, node.name, right)
else
raise NotImplementedError
end
end
# Visit a FloatNode node.
def visit_float_node(node)
bounds(node.location)
on_float(node.slice)
end
# Visit a ImaginaryNode node.
def visit_imaginary_node(node)
bounds(node.location)
on_imaginary(node.slice)
end
# Visit an IntegerNode node.
def visit_integer_node(node)
bounds(node.location)
on_int(node.slice)
end
# Visit a RationalNode node.
def visit_rational_node(node)
bounds(node.location)
on_rational(node.slice)
end
# Visit a StatementsNode node.
def visit_statements_node(node)
bounds(node.location)
node.body.inject(on_stmts_new) do |stmts, stmt|
on_stmts_add(stmts, visit(stmt))
end
end
# Visit a ProgramNode node.
def visit_program_node(node)
statements = visit(node.statements)
bounds(node.location)
on_program(statements)
end
############################################################################
# Entrypoints for subclasses
############################################################################
# This is a convenience method that runs the SexpBuilder subclass parser.
def self.sexp_raw(source)
SexpBuilder.new(source).parse
end
# This is a convenience method that runs the SexpBuilderPP subclass parser.
def self.sexp(source)
SexpBuilderPP.new(source).parse
end
private
# This method is responsible for updating lineno and column information
# to reflect the current node.
#
# This method could be drastically improved with some caching on the start
# of every line, but for now it's good enough.
def bounds(location)
@lineno = location.start_line
@column = location.start_column
end
# Lazily initialize the parse result.
def result
@result ||= Prism.parse(source)
end
def _dispatch0; end # :nodoc:
def _dispatch1(_); end # :nodoc:
def _dispatch2(_, _); end # :nodoc:
def _dispatch3(_, _, _); end # :nodoc:
def _dispatch4(_, _, _, _); end # :nodoc:
def _dispatch5(_, _, _, _, _); end # :nodoc:
def _dispatch7(_, _, _, _, _, _, _); end # :nodoc:
alias_method :on_parse_error, :_dispatch1
alias_method :on_magic_comment, :_dispatch2
(Ripper::SCANNER_EVENT_TABLE.merge(Ripper::PARSER_EVENT_TABLE)).each do |event, arity|
alias_method :"on_#{event}", :"_dispatch#{arity}"
end
end
end
|
