第一个小目标，完成一个最简单的解析器

[guonaihong]

完成最基本的解析器

package main

import (
    "fmt"
    "github.com/guonaihong/clop"
)

func main() {

     type cat struct {
        NumberNonblank bool `clop:"-b;--number-nonblank"
                            usage:"number nonempty output lines, overrides"`

        ShowEnds bool `clop:"-E;--show-ends"
                            usage:"display $ at end of each line"`

        Number bool `clop:"-n;--number"
                            usage:"number all output lines"`

        SqueezeBlank bool `clop:"-s;--squeeze-blank"
                            usage:"suppress repeated empty output lines"`

        ShowTab bool `clop:"-T;--show-tabs"
                            usage:"display TAB characters as ^I"`

        ShowNonprinting bool `clop:"-v;--show-nonprinting"
                            usage:"use ^ and M- notation, except for LFD and TAB" `
    }   
    c := cat{}
    clop.Bind(&c)
}