NULL_CHOLL FUCK

ano.rb

class NullcholFuck
    def initialize(prog)
        @program = []
        until prog.empty?
            /^(あっ|えー|あの|えっと|その|…|、|。)(.*)/ =~ prog
            raise  "文法に誤りがあります." unless $1
           @program << $1
            prog = $2
        end
    end

    def exec
        pc = pt = 0
        ary = [0]
        while @program.size > pc
            case @program[pc]
                when "あっ"
                    ary[pt+=1] ||= 0
                when "えー"
                    pt -= 1 if pt > 0
                when "あの"
                    ary[pt] += 1
                when "えっと"
                    ary[pt] -= 1
                when "その"
                    print ary[pt].chr
                when "…"
                    ary[pt] = $stdin.getc.bytes.to_a[0]
                when "、"
                    if ary[pt] == 0
                        jmp = 1
                        until jmp==0
                            pc += 1
                            jmp += 1 if @program[pc] == "、"
                            jmp -= 1 if @program[pc] == "。"
                        end
                    end
                when "。"
                    if ary[pt] != 0
                        jmp = 1
                        until jmp==0
                            pc -= 1
                            jmp += 1 if @program[pc] == "。"
                            jmp -= 1 if @program[pc] == "、"
                        end
                    end
                else
                    raise  "文法に誤りがあります."
            end
            pc += 1
        end
        ary[pc]
    end
end

begin
    file = File.open(ARGV[0])
    p = file.read.gsub(/[\n\r\s]/, '')
    file.close
rescue
    raise "ファイルが開けませんでした."
end

nf = NullcholFuck.new(p)
nf.exec