rpl.rb/repl.rb

71 lines
1.4 KiB
Ruby

# frozen_string_literal: true
require 'readline'
require './language'
class RplRepl
def initialize
@lang = Rpl::Language.new
end
def run
Readline.completion_proc = proc do |s|
Readline::HISTORY.grep(/^#{Regexp.escape(s)}/)
end
Readline.completion_append_character = ' '
loop do
input = Readline.readline( ' ', true )
break if input.nil? || input == 'quit'
pp Readline::HISTORY if input == 'history'
input = '"rpn.rb version 0.0"' if %w[version uname].include?( input )
# Remove blank lines from history
Readline::HISTORY.pop if input.empty?
begin
@lang.run( input )
rescue ArgumentError, ZeroDivisionError => e
p e
end
print_stack
end
end
def format_element( elt )
case elt[:type]
when :numeric
prefix = case elt[:base]
when 2
'0b'
when 8
'0o'
when 10
''
when 16
'0x'
else
"0#{elt[:base]}_"
end
"#{prefix}#{elt[:value].to_s( elt[:base] )}"
when :list
"[#{elt[:value].map { |e| e[:value] }.join(', ')}]"
else
elt[:value]
end
end
def print_stack
stack_size = @lang.stack.size
@lang.stack.each_with_index do |elt, i|
puts "#{stack_size - i}: #{format_element( elt )}"
end
end
end
RplRepl.new.run