#
# Enable saving of expression history across runs of irb, just like in ghci
#
require 'irb/ext/save-history'
# History configuration
IRB.conf[:SAVE_HISTORY] = 500
IRB.conf[:HISTORY_FILE] = "#{ENV['HOME']}/.irb-save-history"

#
# Makes "it" work like in ghci.  (But _ works, too.)
def it
    IRB.CurrentContext.last_value
end

def rv
    RUBY_VERSION
end

def show_match(s, re)
    if s =~ re then
        "#{$`}<<#{$&}>>#{$'}"
    else
        "no match"
    end
end

alias sm show_match

def smg(s, re)
    if s =~ re then
        groups = ""
        sep = ""
        1.upto(20) { |n| 
            if $~[n]
                groups += "#{sep}$#{n} = <<#{$~[n]}>>"
                sep = ", "
            end
            }
        p "#{$`}<<#{$&}>>#{$'}"
        puts groups if !groups.empty?
		true
    else
        puts "no match"
		false
    end
end

alias l load

#
# Some handy globals for assignments 4 and 5
$lg="longest.rb"
$sw="seqwords.rb"
$mm="minmax.rb"
$xf="xfield.rb"
$nz="nzip.rb"
$vr="vrepl.rb"
$mr="mirror.rb"
$cc="calc.rb"
$sd="switched.rb"
$pk="pancakes.rb"

#
# mainthing simply PRINTS A LINE to remind you how the unless modifier can be used
# to prevent starting main when a file is loaded with irb -r.
#
def maintrick
    puts 'main unless $0 == "irb"'
end
alias mainthing maintrick