ruby--ruby/ext/ripper/lib/ripper.rb

# frozen_string_literal: true
require 'ripper/core'
require 'ripper/lexer'
require 'ripper/filter'
require 'ripper/sexp'

# Ripper is a Ruby script parser.
#
# You can get information from the parser with event-based style.
# Information such as abstract syntax trees or simple lexical analysis of the
# Ruby program.
#
# == Usage
#
# Ripper provides an easy interface for parsing your program into a symbolic
# expression tree (or S-expression).
#
# Understanding the output of the parser may come as a challenge, it's
# recommended you use PP to format the output for legibility.
#
#   require 'ripper'
#   require 'pp'
#
#   pp Ripper.sexp('def hello(world) "Hello, #{world}!"; end')
#     #=> [:program,
#          [[:def,
#            [:@ident, "hello", [1, 4]],
#            [:paren,
#             [:params, [[:@ident, "world", [1, 10]]], nil, nil, nil, nil, nil, nil]],
#            [:bodystmt,
#             [[:string_literal,
#               [:string_content,
#                [:@tstring_content, "Hello, ", [1, 18]],
#                [:string_embexpr, [[:var_ref, [:@ident, "world", [1, 27]]]]],
#                [:@tstring_content, "!", [1, 33]]]]],
#             nil,
#             nil,
#             nil]]]]
#
# You can see in the example above, the expression starts with +:program+.
#
# From here, a method definition at +:def+, followed by the method's identifier
# <code>:@ident</code>. After the method's identifier comes the parentheses
# +:paren+ and the method parameters under +:params+.
#
# Next is the method body, starting at +:bodystmt+ (+stmt+ meaning statement),
# which contains the full definition of the method.
#
# In our case, we're simply returning a String, so next we have the
# +:string_literal+ expression.
#
# Within our +:string_literal+ you'll notice two <code>@tstring_content</code>,
# this is the literal part for <code>Hello, </code> and <code>!</code>. Between
# the two <code>@tstring_content</code> statements is a +:string_embexpr+,
# where _embexpr_ is an embedded expression. Our expression consists of a local
# variable, or +var_ref+, with the identifier (<code>@ident</code>) of +world+.
#
# == Resources
#
# * {Ruby Inside}[http://www.rubyinside.com/using-ripper-to-see-how-ruby-is-parsing-your-code-5270.html]
#
# == Requirements
#
# * ruby 1.9 (support CVS HEAD only)
# * bison 1.28 or later (Other yaccs do not work)
#
# == License
#
# Ruby License.
#
# - Minero Aoki
# - aamine@loveruby.net
# - http://i.loveruby.net
class Ripper; end