# frozen_string_literal: false
#
# irb.rb - irb main module
# by Keiju ISHITSUKA(keiju@ruby-lang.org)
#
require "ripper"
require "reline"
require_relative "irb/init"
require_relative "irb/context"
require_relative "irb/extend-command"
require_relative "irb/ruby-lex"
require_relative "irb/statement"
require_relative "irb/input-method"
require_relative "irb/locale"
require_relative "irb/color"
require_relative "irb/version"
require_relative "irb/easter-egg"
require_relative "irb/debug"
require_relative "irb/pager"
# == \IRB
#
# \Module \IRB ("Interactive Ruby") provides a shell-like interface
# that supports user interaction with the Ruby interpreter.
#
# It operates as a read-eval-print loop
# ({REPL}[https://en.wikipedia.org/wiki/Read%E2%80%93eval%E2%80%93print_loop])
# that:
#
# - _Reads_ each character as you type.
# You can modify the \IRB context to change the way input works.
# See {Input}[rdoc-ref:IRB@Input].
# - _Evaluates_ the code each time it has read a syntactically complete passage.
# - _Prints_ after evaluating.
# You can modify the \IRB context to change the way output works.
# See {Output}[rdoc-ref:IRB@Output].
#
# Example:
#
# $ irb
# irb(main):001> File.basename(Dir.pwd)
# => "irb"
# irb(main):002> Dir.entries('.').size
# => 25
# irb(main):003* Dir.entries('.').select do |entry|
# irb(main):004* entry.start_with?('R')
# irb(main):005> end
# => ["README.md", "Rakefile"]
#
# The typed input may also include
# {\IRB-specific commands}[rdoc-ref:IRB@IRB-Specific+Commands].
#
# As seen above, you can start \IRB by using the shell command +irb+.
#
# You can stop an \IRB session by typing command +exit+:
#
# irb(main):006> exit
# $
#
# At that point, \IRB calls any hooks found in array IRB.conf[:AT_EXIT],
# then exits.
#
# == Startup
#
# At startup, \IRB:
#
# 1. Interprets (as Ruby code) the content of the
# {configuration file}[rdoc-ref:IRB@Configuration+File] (if given).
# 1. Constructs the initial session context
# from {hash IRB.conf}[rdoc-ref:IRB@Hash+IRB.conf] and from default values;
# the hash content may have been affected
# by {command-line options}[rdoc-ref:IB@Command-Line+Options],
# and by direct assignments in the configuration file.
# 1. Assigns the context to variable +conf+.
# 1. Assigns command-line arguments to variable ARGV.
# 1. Prints the {prompt}[rdoc-ref:IRB@Prompt+and+Return+Formats].
# 1. Puts the content of the
# {initialization script}[rdoc-ref:IRB@Initialization+Script]
# onto the \IRB shell, just as if it were user-typed commands.
#
# === The Command Line
#
# On the command line, all options precede all arguments;
# the first item that is not recognized as an option is treated as an argument,
# as are all items that follow.
#
# ==== Command-Line Options
#
# Many command-line options affect entries in hash IRB.conf,
# which in turn affect the initial configuration of the \IRB session.
#
# Details of the options are described in the relevant subsections below.
#
# A cursory list of the \IRB command-line options
# may be seen in the {help message}[https://raw.githubusercontent.com/ruby/irb/master/lib/irb/lc/help-message],
# which is also displayed if you use command-line option --help.
#
# If you are interested in a specific option, consult the
# {index}[rdoc-ref:doc/irb/indexes.md@Index+of+Command-Line+Options].
#
# ==== Command-Line Arguments
#
# Command-line arguments are passed to \IRB in array +ARGV+:
#
# $ irb --noscript Foo Bar Baz
# irb(main):001> ARGV
# => ["Foo", "Bar", "Baz"]
# irb(main):002> exit
# $
#
# Command-line option -- causes everything that follows
# to be treated as arguments, even those that look like options:
#
# $ irb --noscript -- --noscript -- Foo Bar Baz
# irb(main):001> ARGV
# => ["--noscript", "--", "Foo", "Bar", "Baz"]
# irb(main):002> exit
# $
#
# === Configuration File
#
# You can initialize \IRB via a configuration file.
#
# If command-line option -f is given,
# no configuration file is looked for.
#
# Otherwise, \IRB reads and interprets a configuration file
# if one is available.
#
# The configuration file can contain any Ruby code, and can usefully include
# user code that:
#
# - Can then be debugged in \IRB.
# - Configures \IRB itself.
# - Requires or loads files.
#
# The path to the configuration file is the first found among:
#
# - The value of variable $IRBRC, if defined.
# - The value of variable $XDG_CONFIG_HOME/irb/irbrc, if defined.
# - File $HOME/.irbrc, if it exists.
# - File $HOME/.config/irb/irbrc, if it exists.
# - File +.config/irb/irbrc+ in the current directory, if it exists.
# - File +.irbrc+ in the current directory, if it exists.
# - File +irb.rc+ in the current directory, if it exists.
# - File +_irbrc+ in the current directory, if it exists.
# - File $irbrc in the current directory, if it exists.
#
# If the search fails, there is no configuration file.
#
# If the search succeeds, the configuration file is read as Ruby code,
# and so can contain any Ruby programming you like.
#
# \Method conf.rc? returns +true+ if a configuration file was read,
# +false+ otherwise.
# \Hash entry IRB.conf[:RC] also contains that value.
#
# === \Hash IRB.conf
#
# The initial entries in hash IRB.conf are determined by:
#
# - Default values.
# - Command-line options, which may override defaults.
# - Direct assignments in the configuration file.
#
# You can see the hash by typing IRB.conf.
#
# Details of the entries' meanings are described in the relevant subsections below.
#
# If you are interested in a specific entry, consult the
# {index}[rdoc-ref:doc/irb/indexes.md@Index+of+IRB.conf+Entries].
#
# === Notes on Initialization Precedence
#
# - Any conflict between an entry in hash IRB.conf and a command-line option
# is resolved in favor of the hash entry.
# - \Hash IRB.conf affects the context only once,
# when the configuration file is interpreted;
# any subsequent changes to it do not affect the context
# and are therefore essentially meaningless.
#
# === Initialization Script
#
# By default, the first command-line argument (after any options)
# is the path to a Ruby initialization script.
#
# \IRB reads the initialization script and puts its content onto the \IRB shell,
# just as if it were user-typed commands.
#
# Command-line option --noscript causes the first command-line argument
# to be treated as an ordinary argument (instead of an initialization script);
# --script is the default.
#
# == Input
#
# This section describes the features that allow you to change
# the way \IRB input works;
# see also {Input and Output}[rdoc-ref:IRB@Input+and+Output].
#
# === Input Command History
#
# By default, \IRB stores a history of up to 1000 input commands
# in file ~/.irb_history
# (or, if a {configuration file}[rdoc-ref:IRB@Configuration+File]
# is found, in file +.irb_history+
# inin the same directory as that file).
#
# A new \IRB session creates the history file if it does not exist,
# and appends to the file if it does exist.
#
# You can change the filepath by adding to your configuration file:
# IRB.conf[:HISTORY_FILE] = _filepath_,
# where _filepath_ is a string filepath.
#
# During the session, method conf.history_file returns the filepath,
# and method conf.history_file = new_filepath
# copies the history to the file at new_filepath,
# which becomes the history file for the session.
#
# You can change the number of commands saved by adding to your configuration file:
# IRB.conf[:SAVE_HISTORY] = _n_,
# where _n_ is one of:
#
# - Positive integer: the number of commands to be saved,
# - Zero: all commands are to be saved.
# - +nil+: no commands are to be saved,.
#
# During the session, you can use
# methods conf.save_history or conf.save_history=
# to retrieve or change the count.
#
# === Command Aliases
#
# By default, \IRB defines several command aliases:
#
# irb(main):001> conf.command_aliases
# => {:"$"=>:show_source, :"@"=>:whereami}
#
# You can change the initial aliases in the configuration file with:
#
# IRB.conf[:COMMAND_ALIASES] = {foo: :show_source, bar: :whereami}
#
# You can replace the current aliases at any time
# with configuration method conf.command_aliases=;
# Because conf.command_aliases is a hash,
# you can modify it.
#
# === End-of-File
#
# By default, IRB.conf[:IGNORE_EOF] is +false+,
# which means that typing the end-of-file character Ctrl-D
# causes the session to exit.
#
# You can reverse that behavior by adding IRB.conf[:IGNORE_EOF] = true
# to the configuration file.
#
# During the session, method conf.ignore_eof? returns the setting,
# and method conf.ignore_eof = _boolean_ sets it.
#
# === SIGINT
#
# By default, IRB.conf[:IGNORE_SIGINT] is +true+,
# which means that typing the interrupt character Ctrl-C
# causes the session to exit.
#
# You can reverse that behavior by adding IRB.conf[:IGNORE_SIGING] = false
# to the configuration file.
#
# During the session, method conf.ignore_siging? returns the setting,
# and method conf.ignore_sigint = _boolean_ sets it.
#
# === Automatic Completion
#
# By default, \IRB enables
# {automatic completion}[https://en.wikipedia.org/wiki/Autocomplete#In_command-line_interpreters]:
#
# You can disable it by either of these:
#
# - Adding IRB.conf[:USE_AUTOCOMPLETE] = false to the configuration file.
# - Giving command-line option --noautocomplete
# (--autocomplete is the default).
#
# \Method conf.use_autocomplete? returns +true+
# if automatic completion is enabled, +false+ otherwise.
#
# The setting may not be changed during the session.
#
# === Automatic Indentation
#
# By default, \IRB automatically indents lines of code to show structure
# (e.g., it indent the contents of a block).
#
# The current setting is returned
# by the configuration method conf.auto_indent_mode.
#
# The default initial setting is +true+:
#
# irb(main):001> conf.auto_indent_mode
# => true
# irb(main):002* Dir.entries('.').select do |entry|
# irb(main):003* entry.start_with?('R')
# irb(main):004> end
# => ["README.md", "Rakefile"]
#
# You can change the initial setting in the
# configuration file with:
#
# IRB.conf[:AUTO_INDENT] = false
#
# Note that the _current_ setting may not be changed in the \IRB session.
#
# === Input \Method
#
# The \IRB input method determines how command input is to be read;
# by default, the input method for a session is IRB::RelineInputMethod.
#
# You can set the input method by:
#
# - Adding to the configuration file:
#
# - IRB.conf[:USE_SINGLELINE] = true
# or IRB.conf[:USE_MULTILINE]= false
# sets the input method to IRB::ReadlineInputMethod.
# - IRB.conf[:USE_SINGLELINE] = false
# or IRB.conf[:USE_MULTILINE] = true
# sets the input method to IRB::RelineInputMethod.
#
# - Giving command-line options:
#
# - --singleline
# or --nomultiline
# sets the input method to IRB::ReadlineInputMethod.
# - --nosingleline
# or --multiline/tt>
# sets the input method to IRB::RelineInputMethod.
#
# \Method conf.use_multiline?
# and its synonym conf.use_reline return:
#
# - +true+ if option --multiline was given.
# - +false+ if option --nomultiline was given.
# - +nil+ if neither was given.
#
# \Method conf.use_singleline?
# and its synonym conf.use_readline return:
#
# - +true+ if option --singleline was given.
# - +false+ if option --nosingleline was given.
# - +nil+ if neither was given.
#
# == Output
#
# This section describes the features that allow you to change
# the way \IRB output works;
# see also {Input and Output}[rdoc-ref:IRB@Input+and+Output].
#
# === Return-Value Printing (Echoing)
#
# By default, \IRB prints (echoes) the values returned by all input commands.
#
# You can change the initial behavior and suppress all echoing by:
#
# - Adding to the configuration file: IRB.conf[:ECHO] = false.
# (The default value for this entry is +niL+, which means the same as +true+.)
# - Giving command-line option --noecho.
# (The default is --echo.)
#
# During the session, you can change the current setting
# with configuration method conf.echo= (set to +true+ or +false+).
#
# As stated above, by default \IRB prints the values returned by all input commands;
# but \IRB offers special treatment for values returned by assignment statements,
# which may be:
#
# - Printed with truncation (to fit on a single line of output),
# which is the default;
# an ellipsis (... is suffixed, to indicate the truncation):
#
# irb(main):001> x = 'abc' * 100
# => "abcabcabcabcabcabcabcabcabcabcabcabcabcabcabcabcabcabcabcabcabcabcabcabcabc...
#
# - Printed in full (regardless of the length).
# - Suppressed (not printed at all)
#
# You can change the initial behavior by:
#
# - Adding to the configuration file: IRB.conf[:ECHO_ON_ASSIGNMENT] = false.
# (The default value for this entry is +niL+, which means the same as +:truncate+.)
# - Giving command-line option --noecho-on-assignment
# or --echo-on-assignment.
# (The default is --truncate-echo-on-assigment.)
#
# During the session, you can change the current setting
# with configuration method conf.echo_on_assignment=
# (set to +true+, +false+, or +:truncate+).
#
# By default, \IRB formats returned values by calling method +inspect+.
#
# You can change the initial behavior by:
#
# - Adding to the configuration file: IRB.conf[:INSPECT_MODE] = false.
# (The default value for this entry is +true+.)
# - Giving command-line option --noinspect.
# (The default is --inspect.)
#
# During the session, you can change the setting using method conf.inspect_mode=.
#
# === Multiline Output
#
# By default, \IRB prefixes a newline to a multiline response.
#
# You can change the initial default value by adding to the configuation file:
#
# IRB.conf[:NEWLINE_BEFORE_MULTILINE_OUTPUT] = false
#
# During a session, you can retrieve or set the value using
# methods conf.newline_before_multiline_output?
# and conf.newline_before_multiline_output=.
#
# Examples:
#
# irb(main):001> conf.inspect_mode = false
# => false
# irb(main):002> "foo\nbar"
# =>
# foo
# bar
# irb(main):003> conf.newline_before_multiline_output = false
# => false
# irb(main):004> "foo\nbar"
# => foo
# bar
#
# === Evaluation History
#
# By default, \IRB saves no history of evaluations (returned values),
# and the related methods conf.eval_history, _,
# and __ are undefined.
#
# You can turn on that history, and set the maximum number of evaluations to be stored:
#
# - In the configuration file: add IRB.conf[:EVAL_HISTORY] = _n_.
# (Examples below assume that we've added IRB.conf[:EVAL_HISTORY] = 5.)
# - In the session (at any time): conf.eval_history = _n_.
#
# If +n+ is zero, all evaluation history is stored.
#
# Doing either of the above:
#
# - Sets the maximum size of the evaluation history;
# defines method conf.eval_history,
# which returns the maximum size +n+ of the evaluation history:
#
# irb(main):001> conf.eval_history = 5
# => 5
# irb(main):002> conf.eval_history
# => 5
#
# - Defines variable _, which contains the most recent evaluation,
# or +nil+ if none; same as method conf.last_value:
#
# irb(main):003> _
# => 5
# irb(main):004> :foo
# => :foo
# irb(main):005> :bar
# => :bar
# irb(main):006> _
# => :bar
# irb(main):007> _
# => :bar
#
# - Defines variable __:
#
# - __ unadorned: contains all evaluation history:
#
# irb(main):008> :foo
# => :foo
# irb(main):009> :bar
# => :bar
# irb(main):010> :baz
# => :baz
# irb(main):011> :bat
# => :bat
# irb(main):012> :bam
# => :bam
# irb(main):013> __
# =>
# 9 :bar
# 10 :baz
# 11 :bat
# 12 :bam
# irb(main):014> __
# =>
# 10 :baz
# 11 :bat
# 12 :bam
# 13 ...self-history...
#
# Note that when the evaluation is multiline, it is displayed differently.
#
# - __[_m_]:
#
# - Positive _m_: contains the evaluation for the given line number,
# or +nil+ if that line number is not in the evaluation history:
#
# irb(main):015> __[12]
# => :bam
# irb(main):016> __[1]
# => nil
#
# - Negative _m_: contains the +mth+-from-end evaluation,
# or +nil+ if that evaluation is not in the evaluation history:
#
# irb(main):017> __[-3]
# => :bam
# irb(main):018> __[-13]
# => nil
#
# - Zero _m_: contains +nil+:
#
# irb(main):019> __[0]
# => nil
#
# === Prompt and Return Formats
#
# By default, \IRB uses the prompt and return value formats
# defined in its +:DEFAULT+ prompt mode.
#
# ==== The Default Prompt and Return Format
#
# The default prompt and return values look like this:
#
# irb(main):001> 1 + 1
# => 2
# irb(main):002> 2 + 2
# => 4
#
# The prompt includes:
#
# - The name of the running program (irb);
# see {IRB Name}[rdoc-ref:IRB@IRB+Name].
# - The name of the current session (main);
# See {IRB Sessions}[rdoc-ref:IRB@IRB+Sessions].
# - A 3-digit line number (1-based).
#
# The default prompt actually defines three formats:
#
# - One for most situations (as above):
#
# irb(main):003> Dir
# => Dir
#
# - One for when the typed command is a statement continuation (adds trailing asterisk):
#
# irb(main):004* Dir.
#
# - One for when the typed command is a string continuation (adds trailing single-quote):
#
# irb(main):005' Dir.entries('.
#
# You can see the prompt change as you type the characters in the following:
#
# irb(main):001* Dir.entries('.').select do |entry|
# irb(main):002* entry.start_with?('R')
# irb(main):003> end
# => ["README.md", "Rakefile"]
#
# ==== Pre-Defined Prompts
#
# \IRB has several pre-defined prompts, stored in hash IRB.conf[:PROMPT]:
#
# irb(main):001> IRB.conf[:PROMPT].keys
# => [:NULL, :DEFAULT, :CLASSIC, :SIMPLE, :INF_RUBY, :XMP]
#
# To see the full data for these, type IRB.conf[:PROMPT].
#
# Most of these prompt definitions include specifiers that represent
# values like the \IRB name, session name, and line number;
# see {Prompt Specifiers}[rdoc-ref:IRB@Prompt+Specifiers].
#
# You can change the initial prompt and return format by:
#
# - Adding to the configuration file: IRB.conf[:PROMPT] = _mode_
# where _mode_ is the symbol name of a prompt mode.
# - Giving a command-line option:
#
# - --prompt _mode_: sets the prompt mode to _mode_.
# where _mode_ is the symbol name of a prompt mode.
# - --simple-prompt or --sample-book-mode:
# sets the prompt mode to +:SIMPLE+.
# - --inf-ruby-mode: sets the prompt mode to +:INF_RUBY+
# and suppresses both --multiline and --singleline.
# - --noprompt: suppresses prompting; does not affect echoing.
#
# You can retrieve or set the current prompt mode with methods
#
# conf.prompt_mode and conf.prompt_mode=.
#
# If you're interested in prompts and return formats other than the defaults,
# you might experiment by trying some of the others.
#
# ==== Custom Prompts
#
# You can also define custom prompts and return formats,
# which may be done either in an \IRB session or in the configuration file.
#
# A prompt in \IRB actually defines three prompts, as seen above.
# For simple custom data, we'll make all three the same:
#
# irb(main):001* IRB.conf[:PROMPT][:MY_PROMPT] = {
# irb(main):002* PROMPT_I: ': ',
# irb(main):003* PROMPT_C: ': ',
# irb(main):004* PROMPT_S: ': ',
# irb(main):005* RETURN: '=> '
# irb(main):006> }
# => {:PROMPT_I=>": ", :PROMPT_C=>": ", :PROMPT_S=>": ", :RETURN=>"=> "}
#
# If you define the custom prompt in the configuration file,
# you can also make it the current prompt by adding:
#
# IRB.conf[:PROMPT_MODE] = :MY_PROMPT
#
# Regardless of where it's defined, you can make it the current prompt in a session:
#
# conf.prompt_mode = :MY_PROMPT
#
# You can view or modify the current prompt data with various configuration methods:
#
# - conf.prompt_mode, conf.prompt_mode=.
# - conf.prompt_c, conf.c=.
# - conf.prompt_i, conf.i=.
# - conf.prompt_s, conf.s=.
# - conf.return_format, return_format=.
#
# ==== Prompt Specifiers
#
# A prompt's definition can include specifiers for which certain values are substituted:
#
# - %N: the name of the running program.
# - %m: the value of self.to_s.
# - %M: the value of self.inspect.
# - %l: an indication of the type of string;
# one of ", ', /, ].
# - NNi: Indentation level.
# - NNn: Line number.
# - %%: Literal %.
#
# === Verbosity
#
# By default, \IRB verbosity is disabled, which means that output is smaller
# rather than larger.
#
# You can enable verbosity by:
#
# - Adding to the configuration file: IRB.conf[:VERBOSE] = true
# (the default is +nil+).
# - Giving command-line options --verbose
# (the default is --noverbose).
#
# During a session, you can retrieve or set verbosity with methods
# conf.verbose and conf.verbose=.
#
# === Help
#
# Command-line option --version causes \IRB to print its help text
# and exit.
#
# === Version
#
# Command-line option --version causes \IRB to print its version text
# and exit.
#
# == Input and Output
#
# === \Color Highlighting
#
# By default, \IRB color highlighting is enabled, and is used for both:
#
# - Input: As you type, \IRB reads the typed characters and highlights
# elements that it recognizes;
# it also highlights errors such as mismatched parentheses.
# - Output: \IRB highlights syntactical elements.
#
# You can disable color highlighting by:
#
# - Adding to the configuration file: IRB.conf[:USE_COLORIZE] = false
# (the default value is +true+).
# - Giving command-line option --nocolorize
#
# == Debugging
#
# Command-line option -d sets variables $VERBOSE
# and $DEBUG to +true+;
# these have no effect on \IRB output.
#
# === Warnings
#
# Command-line option -w suppresses warnings.
#
# Command-line option -W[_level_]
# sets warning level; 0=silence, 1=medium, 2=verbose.
#
# :stopdoc:
# === Performance Measurement
#
# IRB.conf[:MEASURE] IRB.conf[:MEASURE_CALLBACKS] IRB.conf[:MEASURE_PROC]
# :startdoc:
#
# == Other Features
#
# === Load Modules
#
# You can specify the names of modules that are to be required at startup.
#
# \Array conf.load_modules determines the modules (if any)
# that are to be required during session startup.
# The array is used only during session startup,
# so the initial value is the only one that counts.
#
# The default initial value is [] (load no modules):
#
# irb(main):001> conf.load_modules
# => []
#
# You can set the default initial value via:
#
# - Command-line option -r
#
# $ irb -r csv -r json
# irb(main):001> conf.load_modules
# => ["csv", "json"]
#
# - \Hash entry IRB.conf[:LOAD_MODULES] = _array_:
#
# IRB.conf[:LOAD_MODULES] = %w[csv, json]
#
# Note that the configuration file entry overrides the command-line options.
#
# === RI Documentation Directories
#
# You can specify the paths to RI documentation directories
# that are to be loaded (in addition to the default directories) at startup;
# see details about RI by typing ri --help.
#
# \Array conf.extra_doc_dirs determines the directories (if any)
# that are to be loaded during session startup.
# The array is used only during session startup,
# so the initial value is the only one that counts.
#
# The default initial value is [] (load no extra documentation):
#
# irb(main):001> conf.extra_doc_dirs
# => []
#
# You can set the default initial value via:
#
# - Command-line option --extra_doc_dir
#
# $ irb --extra-doc-dir your_doc_dir --extra-doc-dir my_doc_dir
# irb(main):001> conf.extra_doc_dirs
# => ["your_doc_dir", "my_doc_dir"]
#
# - \Hash entry IRB.conf[:EXTRA_DOC_DIRS] = _array_:
#
# IRB.conf[:EXTRA_DOC_DIRS] = %w[your_doc_dir my_doc_dir]
#
# Note that the configuration file entry overrides the command-line options.
#
# :stopdoc:
# === \Context Mode
#
# IRB.conf[:CONTEXT_MODE]
# :startdoc:
#
# === \IRB Name
#
# You can specify a name for \IRB.
#
# The default initial value is 'irb':
#
# irb(main):001> conf.irb_name
# => "irb"
#
# You can set the default initial value
# via hash entry IRB.conf[:IRB_NAME] = _string_:
#
# IRB.conf[:IRB_NAME] = 'foo'
#
# === Application Name
#
# You can specify an application name for the \IRB session.
#
# The default initial value is 'irb':
#
# irb(main):001> conf.ap_name
# => "irb"
#
# You can set the default initial value
# via hash entry IRB.conf[:AP_NAME] = _string_:
#
# IRB.conf[:AP_NAME] = 'my_ap_name'
#
# === Configuration Monitor
#
# You can monitor changes to the configuration by assigning a proc
# to IRB.conf[:IRB_RC] in the configuration file:
#
# IRB.conf[:IRB_RC] = proc {|conf| puts conf.class }
#
# Each time the configuration is changed,
# that proc is called with argument +conf+:
#
# :stopdoc:
# === \Locale
#
# IRB.conf[:LC_MESSAGES]
# :startdoc:
#
# === Encodings
#
# Command-line option -E _ex_[:_in_]
# sets initial external (ex) and internal (in) encodings.
#
# Command-line option -U sets both to UTF-8.
#
# === Commands
#
# Please use the `show_cmds` command to see the list of available commands.
#
# === IRB Sessions
#
# IRB has a special feature, that allows you to manage many sessions at once.
#
# You can create new sessions with Irb.irb, and get a list of current sessions
# with the +jobs+ command in the prompt.
#
# ==== Configuration
#
# The command line options, or IRB.conf, specify the default behavior of
# Irb.irb.
#
# On the other hand, each conf in IRB@Command-Line+Options is used to
# individually configure IRB.irb.
#
# If a proc is set for IRB.conf[:IRB_RC], its will be invoked after execution
# of that proc with the context of the current session as its argument. Each
# session can be configured using this mechanism.
#
# ==== Session variables
#
# There are a few variables in every Irb session that can come in handy:
#
# _::
# The value command executed, as a local variable
# __::
# The history of evaluated commands. Available only if
# IRB.conf[:EVAL_HISTORY] is not +nil+ (which is the default).
# See also IRB::Context#eval_history= and IRB::History.
# __[line_no]::
# Returns the evaluation value at the given line number, +line_no+.
# If +line_no+ is a negative, the return value +line_no+ many lines before
# the most recent return value.
#
# == Restrictions
#
# Ruby code typed into \IRB behaves the same as Ruby code in a file, except that:
#
# - Because \IRB evaluates input immediately after it is syntactically complete,
# some results may be slightly different.
# - Forking may not be well behaved.
#
module IRB
# An exception raised by IRB.irb_abort
class Abort < Exception;end
# The current IRB::Context of the session, see IRB.conf
#
# irb
# irb(main):001:0> IRB.CurrentContext.irb_name = "foo"
# foo(main):002:0> IRB.conf[:MAIN_CONTEXT].irb_name #=> "foo"
def IRB.CurrentContext
IRB.conf[:MAIN_CONTEXT]
end
# Initializes IRB and creates a new Irb.irb object at the +TOPLEVEL_BINDING+
def IRB.start(ap_path = nil)
STDOUT.sync = true
$0 = File::basename(ap_path, ".rb") if ap_path
IRB.setup(ap_path)
if @CONF[:SCRIPT]
irb = Irb.new(nil, @CONF[:SCRIPT])
else
irb = Irb.new
end
irb.run(@CONF)
end
# Quits irb
def IRB.irb_exit(irb, ret)
throw :IRB_EXIT, ret
end
# Aborts then interrupts irb.
#
# Will raise an Abort exception, or the given +exception+.
def IRB.irb_abort(irb, exception = Abort)
irb.context.thread.raise exception, "abort then interrupt!"
end
class Irb
# Note: instance and index assignment expressions could also be written like:
# "foo.bar=(1)" and "foo.[]=(1, bar)", when expressed that way, the former
# be parsed as :assign and echo will be suppressed, but the latter is
# parsed as a :method_add_arg and the output won't be suppressed
PROMPT_MAIN_TRUNCATE_LENGTH = 32
PROMPT_MAIN_TRUNCATE_OMISSION = '...'.freeze
CONTROL_CHARACTERS_PATTERN = "\x00-\x1F".freeze
# Returns the current context of this irb session
attr_reader :context
# The lexer used by this irb session
attr_accessor :scanner
# Creates a new irb session
def initialize(workspace = nil, input_method = nil)
@context = Context.new(self, workspace, input_method)
@context.workspace.load_commands_to_main
@signal_status = :IN_IRB
@scanner = RubyLex.new
@line_no = 1
end
# A hook point for `debug` command's breakpoint after :IRB_EXIT as well as its clean-up
def debug_break
# it means the debug integration has been activated
if defined?(DEBUGGER__) && DEBUGGER__.respond_to?(:capture_frames_without_irb)
# after leaving this initial breakpoint, revert the capture_frames patch
DEBUGGER__.singleton_class.send(:alias_method, :capture_frames, :capture_frames_without_irb)
# and remove the redundant method
DEBUGGER__.singleton_class.send(:undef_method, :capture_frames_without_irb)
end
end
def debug_readline(binding)
workspace = IRB::WorkSpace.new(binding)
context.workspace = workspace
context.workspace.load_commands_to_main
@line_no += 1
# When users run:
# 1. Debugging commands, like `step 2`
# 2. Any input that's not irb-command, like `foo = 123`
#
# Irb#eval_input will simply return the input, and we need to pass it to the debugger.
input = if IRB.conf[:SAVE_HISTORY] && context.io.support_history_saving?
# Previous IRB session's history has been saved when `Irb#run` is exited
# We need to make sure the saved history is not saved again by reseting the counter
context.io.reset_history_counter
begin
eval_input
ensure
context.io.save_history
end
else
eval_input
end
if input&.include?("\n")
@line_no += input.count("\n") - 1
end
input
end
def run(conf = IRB.conf)
in_nested_session = !!conf[:MAIN_CONTEXT]
conf[:IRB_RC].call(context) if conf[:IRB_RC]
conf[:MAIN_CONTEXT] = context
save_history = !in_nested_session && conf[:SAVE_HISTORY] && context.io.support_history_saving?
if save_history
context.io.load_history
end
prev_trap = trap("SIGINT") do
signal_handle
end
begin
catch(:IRB_EXIT) do
eval_input
end
ensure
trap("SIGINT", prev_trap)
conf[:AT_EXIT].each{|hook| hook.call}
context.io.save_history if save_history
end
end
# Evaluates input for this session.
def eval_input
configure_io
each_top_level_statement do |statement, line_no|
signal_status(:IN_EVAL) do
begin
# If the integration with debugger is activated, we return certain input if it should be dealt with by debugger
if @context.with_debugger && statement.should_be_handled_by_debugger?
return statement.code
end
@context.evaluate(statement.evaluable_code, line_no)
if @context.echo? && !statement.suppresses_echo?
if statement.is_assignment?
if @context.echo_on_assignment?
output_value(@context.echo_on_assignment? == :truncate)
end
else
output_value
end
end
rescue SystemExit, SignalException
raise
rescue Interrupt, Exception => exc
handle_exception(exc)
@context.workspace.local_variable_set(:_, exc)
end
end
end
end
def read_input(prompt)
signal_status(:IN_INPUT) do
@context.io.prompt = prompt
if l = @context.io.gets
print l if @context.verbose?
else
if @context.ignore_eof? and @context.io.readable_after_eof?
l = "\n"
if @context.verbose?
printf "Use \"exit\" to leave %s\n", @context.ap_name
end
else
print "\n" if @context.prompting?
end
end
l
end
end
def readmultiline
prompt = generate_prompt([], false, 0)
# multiline
return read_input(prompt) if @context.io.respond_to?(:check_termination)
# nomultiline
code = ''
line_offset = 0
loop do
line = read_input(prompt)
unless line
return code.empty? ? nil : code
end
code << line
# Accept any single-line input for symbol aliases or commands that transform args
return code if single_line_command?(code)
tokens, opens, terminated = @scanner.check_code_state(code, local_variables: @context.local_variables)
return code if terminated
line_offset += 1
continue = @scanner.should_continue?(tokens)
prompt = generate_prompt(opens, continue, line_offset)
end
end
def each_top_level_statement
loop do
code = readmultiline
break unless code
if code != "\n"
yield build_statement(code), @line_no
end
@line_no += code.count("\n")
rescue RubyLex::TerminateLineInput
end
end
def build_statement(code)
code.force_encoding(@context.io.encoding)
command_or_alias, arg = code.split(/\s/, 2)
# Transform a non-identifier alias (@, $) or keywords (next, break)
command_name = @context.command_aliases[command_or_alias.to_sym]
command = command_name || command_or_alias
command_class = ExtendCommandBundle.load_command(command)
if command_class
Statement::Command.new(code, command, arg, command_class)
else
is_assignment_expression = @scanner.assignment_expression?(code, local_variables: @context.local_variables)
Statement::Expression.new(code, is_assignment_expression)
end
end
def single_line_command?(code)
command = code.split(/\s/, 2).first
@context.symbol_alias?(command) || @context.transform_args?(command)
end
def configure_io
if @context.io.respond_to?(:check_termination)
@context.io.check_termination do |code|
if Reline::IOGate.in_pasting?
rest = @scanner.check_termination_in_prev_line(code, local_variables: @context.local_variables)
if rest
Reline.delete_text
rest.bytes.reverse_each do |c|
Reline.ungetc(c)
end
true
else
false
end
else
# Accept any single-line input for symbol aliases or commands that transform args
next true if single_line_command?(code)
_tokens, _opens, terminated = @scanner.check_code_state(code, local_variables: @context.local_variables)
terminated
end
end
end
if @context.io.respond_to?(:dynamic_prompt)
@context.io.dynamic_prompt do |lines|
lines << '' if lines.empty?
tokens = RubyLex.ripper_lex_without_warning(lines.map{ |l| l + "\n" }.join, local_variables: @context.local_variables)
line_results = IRB::NestingParser.parse_by_line(tokens)
tokens_until_line = []
line_results.map.with_index do |(line_tokens, _prev_opens, next_opens, _min_depth), line_num_offset|
line_tokens.each do |token, _s|
# Avoid appending duplicated token. Tokens that include "\n" like multiline tstring_content can exist in multiple lines.
tokens_until_line << token if token != tokens_until_line.last
end
continue = @scanner.should_continue?(tokens_until_line)
generate_prompt(next_opens, continue, line_num_offset)
end
end
end
if @context.io.respond_to?(:auto_indent) and @context.auto_indent_mode
@context.io.auto_indent do |lines, line_index, byte_pointer, is_newline|
next nil if lines == [nil] # Workaround for exit IRB with CTRL+d
next nil if !is_newline && lines[line_index]&.byteslice(0, byte_pointer)&.match?(/\A\s*\z/)
code = lines[0..line_index].map { |l| "#{l}\n" }.join
tokens = RubyLex.ripper_lex_without_warning(code, local_variables: @context.local_variables)
@scanner.process_indent_level(tokens, lines, line_index, is_newline)
end
end
end
def convert_invalid_byte_sequence(str, enc)
str.force_encoding(enc)
str.scrub { |c|
c.bytes.map{ |b| "\\x#{b.to_s(16).upcase}" }.join
}
end
def encode_with_invalid_byte_sequence(str, enc)
conv = Encoding::Converter.new(str.encoding, enc)
dst = String.new
begin
ret = conv.primitive_convert(str, dst)
case ret
when :invalid_byte_sequence
conv.insert_output(conv.primitive_errinfo[3].dump[1..-2])
redo
when :undefined_conversion
c = conv.primitive_errinfo[3].dup.force_encoding(conv.primitive_errinfo[1])
conv.insert_output(c.dump[1..-2])
redo
when :incomplete_input
conv.insert_output(conv.primitive_errinfo[3].dump[1..-2])
when :finished
end
break
end while nil
dst
end
def handle_exception(exc)
if exc.backtrace[0] =~ /\/irb(2)?(\/.*|-.*|\.rb)?:/ && exc.class.to_s !~ /^IRB/ &&
!(SyntaxError === exc) && !(EncodingError === exc)
# The backtrace of invalid encoding hash (ex. {"\xAE": 1}) raises EncodingError without lineno.
irb_bug = true
else
irb_bug = false
end
if RUBY_VERSION < '3.0.0'
if STDOUT.tty?
message = exc.full_message(order: :bottom)
order = :bottom
else
message = exc.full_message(order: :top)
order = :top
end
else # '3.0.0' <= RUBY_VERSION
message = exc.full_message(order: :top)
order = :top
end
message = convert_invalid_byte_sequence(message, exc.message.encoding)
message = encode_with_invalid_byte_sequence(message, IRB.conf[:LC_MESSAGES].encoding) unless message.encoding.to_s.casecmp?(IRB.conf[:LC_MESSAGES].encoding.to_s)
message = message.gsub(/((?:^\t.+$\n)+)/) { |m|
case order
when :top
lines = m.split("\n")
when :bottom
lines = m.split("\n").reverse
end
unless irb_bug
lines = lines.map { |l| @context.workspace.filter_backtrace(l) }.compact
if lines.size > @context.back_trace_limit
omit = lines.size - @context.back_trace_limit
lines = lines[0..(@context.back_trace_limit - 1)]
lines << "\t... %d levels..." % omit
end
end
lines = lines.reverse if order == :bottom
lines.map{ |l| l + "\n" }.join
}
# The "" in "(irb)" may be the top level of IRB so imitate the main object.
message = message.gsub(/\(irb\):(?\d+):in `<(?top \(required\))>'/) { "(irb):#{$~[:num]}:in `'" }
puts message
puts 'Maybe IRB bug!' if irb_bug
rescue Exception => handler_exc
begin
puts exc.inspect
puts "backtraces are hidden because #{handler_exc} was raised when processing them"
rescue Exception
puts 'Uninspectable exception occurred'
end
end
# Evaluates the given block using the given +path+ as the Context#irb_path
# and +name+ as the Context#irb_name.
#
# Used by the irb command +source+, see IRB@IRB+Sessions for more
# information.
def suspend_name(path = nil, name = nil)
@context.irb_path, back_path = path, @context.irb_path if path
@context.irb_name, back_name = name, @context.irb_name if name
begin
yield back_path, back_name
ensure
@context.irb_path = back_path if path
@context.irb_name = back_name if name
end
end
# Evaluates the given block using the given +workspace+ as the
# Context#workspace.
#
# Used by the irb command +irb_load+, see IRB@IRB+Sessions for more
# information.
def suspend_workspace(workspace)
@context.workspace, back_workspace = workspace, @context.workspace
begin
yield back_workspace
ensure
@context.workspace = back_workspace
end
end
# Evaluates the given block using the given +input_method+ as the
# Context#io.
#
# Used by the irb commands +source+ and +irb_load+, see IRB@IRB+Sessions
# for more information.
def suspend_input_method(input_method)
back_io = @context.io
@context.instance_eval{@io = input_method}
begin
yield back_io
ensure
@context.instance_eval{@io = back_io}
end
end
# Handler for the signal SIGINT, see Kernel#trap for more information.
def signal_handle
unless @context.ignore_sigint?
print "\nabort!\n" if @context.verbose?
exit
end
case @signal_status
when :IN_INPUT
print "^C\n"
raise RubyLex::TerminateLineInput
when :IN_EVAL
IRB.irb_abort(self)
when :IN_LOAD
IRB.irb_abort(self, LoadAbort)
when :IN_IRB
# ignore
else
# ignore other cases as well
end
end
# Evaluates the given block using the given +status+.
def signal_status(status)
return yield if @signal_status == :IN_LOAD
signal_status_back = @signal_status
@signal_status = status
begin
yield
ensure
@signal_status = signal_status_back
end
end
def output_value(omit = false) # :nodoc:
str = @context.inspect_last_value
multiline_p = str.include?("\n")
if omit
winwidth = @context.io.winsize.last
if multiline_p
first_line = str.split("\n").first
result = @context.newline_before_multiline_output? ? (@context.return_format % first_line) : first_line
output_width = Reline::Unicode.calculate_width(result, true)
diff_size = output_width - Reline::Unicode.calculate_width(first_line, true)
if diff_size.positive? and output_width > winwidth
lines, _ = Reline::Unicode.split_by_width(first_line, winwidth - diff_size - 3)
str = "%s..." % lines.first
str += "\e[0m" if Color.colorable?
multiline_p = false
else
str = str.gsub(/(\A.*?\n).*/m, "\\1...")
str += "\e[0m" if Color.colorable?
end
else
output_width = Reline::Unicode.calculate_width(@context.return_format % str, true)
diff_size = output_width - Reline::Unicode.calculate_width(str, true)
if diff_size.positive? and output_width > winwidth
lines, _ = Reline::Unicode.split_by_width(str, winwidth - diff_size - 3)
str = "%s..." % lines.first
str += "\e[0m" if Color.colorable?
end
end
end
if multiline_p && @context.newline_before_multiline_output?
str = "\n" + str
end
Pager.page_content(format(@context.return_format, str), retain_content: true)
end
# Outputs the local variables to this current session, including
# #signal_status and #context, using IRB::Locale.
def inspect
ary = []
for iv in instance_variables
case (iv = iv.to_s)
when "@signal_status"
ary.push format("%s=:%s", iv, @signal_status.id2name)
when "@context"
ary.push format("%s=%s", iv, eval(iv).__to_s__)
else
ary.push format("%s=%s", iv, eval(iv))
end
end
format("#<%s: %s>", self.class, ary.join(", "))
end
private
def generate_prompt(opens, continue, line_offset)
ltype = @scanner.ltype_from_open_tokens(opens)
indent = @scanner.calc_indent_level(opens)
continue = opens.any? || continue
line_no = @line_no + line_offset
if ltype
f = @context.prompt_s
elsif continue
f = @context.prompt_c
else
f = @context.prompt_i
end
f = "" unless f
if @context.prompting?
p = format_prompt(f, ltype, indent, line_no)
else
p = ""
end
if @context.auto_indent_mode and !@context.io.respond_to?(:auto_indent)
unless ltype
prompt_i = @context.prompt_i.nil? ? "" : @context.prompt_i
ind = format_prompt(prompt_i, ltype, indent, line_no)[/.*\z/].size +
indent * 2 - p.size
p += " " * ind if ind > 0
end
end
p
end
def truncate_prompt_main(str) # :nodoc:
str = str.tr(CONTROL_CHARACTERS_PATTERN, ' ')
if str.size <= PROMPT_MAIN_TRUNCATE_LENGTH
str
else
str[0, PROMPT_MAIN_TRUNCATE_LENGTH - PROMPT_MAIN_TRUNCATE_OMISSION.size] + PROMPT_MAIN_TRUNCATE_OMISSION
end
end
def format_prompt(format, ltype, indent, line_no) # :nodoc:
format.gsub(/%([0-9]+)?([a-zA-Z])/) do
case $2
when "N"
@context.irb_name
when "m"
main_str = @context.main.to_s rescue "!#{$!.class}"
truncate_prompt_main(main_str)
when "M"
main_str = @context.main.inspect rescue "!#{$!.class}"
truncate_prompt_main(main_str)
when "l"
ltype
when "i"
if indent < 0
if $1
"-".rjust($1.to_i)
else
"-"
end
else
if $1
format("%" + $1 + "d", indent)
else
indent.to_s
end
end
when "n"
if $1
format("%" + $1 + "d", line_no)
else
line_no.to_s
end
when "%"
"%"
end
end
end
end
end
class Binding
# Opens an IRB session where +binding.irb+ is called which allows for
# interactive debugging. You can call any methods or variables available in
# the current scope, and mutate state if you need to.
#
#
# Given a Ruby file called +potato.rb+ containing the following code:
#
# class Potato
# def initialize
# @cooked = false
# binding.irb
# puts "Cooked potato: #{@cooked}"
# end
# end
#
# Potato.new
#
# Running ruby potato.rb will open an IRB session where
# +binding.irb+ is called, and you will see the following:
#
# $ ruby potato.rb
#
# From: potato.rb @ line 4 :
#
# 1: class Potato
# 2: def initialize
# 3: @cooked = false
# => 4: binding.irb
# 5: puts "Cooked potato: #{@cooked}"
# 6: end
# 7: end
# 8:
# 9: Potato.new
#
# irb(#):001:0>
#
# You can type any valid Ruby code and it will be evaluated in the current
# context. This allows you to debug without having to run your code repeatedly:
#
# irb(#):001:0> @cooked
# => false
# irb(#):002:0> self.class
# => Potato
# irb(#):003:0> caller.first
# => ".../2.5.1/lib/ruby/2.5.0/irb/workspace.rb:85:in `eval'"
# irb(#):004:0> @cooked = true
# => true
#
# You can exit the IRB session with the +exit+ command. Note that exiting will
# resume execution where +binding.irb+ had paused it, as you can see from the
# output printed to standard output in this example:
#
# irb(#):005:0> exit
# Cooked potato: true
#
# See IRB for more information.
def irb(show_code: true)
# Setup IRB with the current file's path and no command line arguments
IRB.setup(source_location[0], argv: [])
# Create a new workspace using the current binding
workspace = IRB::WorkSpace.new(self)
# Print the code around the binding if show_code is true
STDOUT.print(workspace.code_around_binding) if show_code
# Get the original IRB instance
debugger_irb = IRB.instance_variable_get(:@debugger_irb)
irb_path = File.expand_path(source_location[0])
if debugger_irb
# If we're already in a debugger session, set the workspace and irb_path for the original IRB instance
debugger_irb.context.workspace = workspace
debugger_irb.context.irb_path = irb_path
# If we've started a debugger session and hit another binding.irb, we don't want to start an IRB session
# instead, we want to resume the irb:rdbg session.
IRB::Debug.setup(debugger_irb)
IRB::Debug.insert_debug_break
debugger_irb.debug_break
else
# If we're not in a debugger session, create a new IRB instance with the current workspace
binding_irb = IRB::Irb.new(workspace)
binding_irb.context.irb_path = irb_path
binding_irb.run(IRB.conf)
binding_irb.debug_break
end
end
end