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#
# xmp.rb - irb version of gotoken xmp
# $Release Version: 0.9$
# $Revision: 47266 $
# by Keiju ISHITSUKA(Nippon Rational Inc.)
#
# --
#
#
#
require "irb"
require "irb/frame"
# An example printer for irb.
#
# It's much like the standard library PrettyPrint, that shows the value of each
# expression as it runs.
#
# In order to use this library, you must first require it:
#
# require 'irb/xmp'
#
# Now, you can take advantage of the Object#xmp convenience method.
#
# xmp <<END
# foo = "bar"
# baz = 42
# END
# #=> foo = "bar"
# #==>"bar"
# #=> baz = 42
# #==>42
#
# You can also create an XMP object, with an optional binding to print
# expressions in the given binding:
#
# ctx = binding
# x = XMP.new ctx
# x.puts
# #=> today = "a good day"
# #==>"a good day"
# ctx.eval 'today # is what?'
# #=> "a good day"
class XMP
# Creates a new XMP object.
#
# The top-level binding or, optional +bind+ parameter will be used when
# creating the workspace. See WorkSpace.new for more information.
#
# This uses the +:XMP+ prompt mode, see IRB@Customizing+the+IRB+Prompt for
# full detail.
def initialize(bind = nil)
IRB.init_config(nil)
IRB.conf[:PROMPT_MODE] = :XMP
bind = IRB::Frame.top(1) unless bind
ws = IRB::WorkSpace.new(bind)
@io = StringInputMethod.new
@irb = IRB::Irb.new(ws, @io)
@irb.context.ignore_sigint = false
IRB.conf[:MAIN_CONTEXT] = @irb.context
end
# Evaluates the given +exps+, for example:
#
# require 'irb/xmp'
# x = XMP.new
#
# x.puts '{:a => 1, :b => 2, :c => 3}'
# #=> {:a => 1, :b => 2, :c => 3}
# # ==>{:a=>1, :b=>2, :c=>3}
# x.puts 'foo = "bar"'
# # => foo = "bar"
# # ==>"bar"
def puts(exps)
@io.puts exps
if @irb.context.ignore_sigint
begin
trap_proc_b = trap("SIGINT"){@irb.signal_handle}
catch(:IRB_EXIT) do
@irb.eval_input
end
ensure
trap("SIGINT", trap_proc_b)
end
else
catch(:IRB_EXIT) do
@irb.eval_input
end
end
end
# A custom InputMethod class used by XMP for evaluating string io.
class StringInputMethod < IRB::InputMethod
# Creates a new StringInputMethod object
def initialize
super
@exps = []
end
# Whether there are any expressions left in this printer.
def eof?
@exps.empty?
end
# Reads the next expression from this printer.
#
# See IO#gets for more information.
def gets
while l = @exps.shift
next if /^\s+$/ =~ l
l.concat "\n"
print @prompt, l
break
end
l
end
# Concatenates all expressions in this printer, separated by newlines.
#
# An Encoding::CompatibilityError is raised of the given +exps+'s encoding
# doesn't match the previous expression evaluated.
def puts(exps)
if @encoding and exps.encoding != @encoding
enc = Encoding.compatible?(@exps.join("\n"), exps)
if enc.nil?
raise Encoding::CompatibilityError, "Encoding in which the passed expression is encoded is not compatible to the preceding's one"
else
@encoding = enc
end
else
@encoding = exps.encoding
end
@exps.concat exps.split(/\n/)
end
# Returns the encoding of last expression printed by #puts.
attr_reader :encoding
end
end
# A convenience method that's only available when the you require the IRB::XMP standard library.
#
# Creates a new XMP object, using the given expressions as the +exps+
# parameter, and optional binding as +bind+ or uses the top-level binding. Then
# evaluates the given expressions using the +:XMP+ prompt mode.
#
# For example:
#
# require 'irb/xmp'
# ctx = binding
# xmp 'foo = "bar"', ctx
# #=> foo = "bar"
# #==>"bar"
# ctx.eval 'foo'
# #=> "bar"
#
# See XMP.new for more information.
def xmp(exps, bind = nil)
bind = IRB::Frame.top(1) unless bind
xmp = XMP.new(bind)
xmp.puts exps
xmp
end
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