##language:zh
'''
含有章节索引的中文 文章模板
'''

-- 218.4.189.4 [<<DateTime(2005-01-15T02:55:42Z)>>]
<<TableOfContents>>
= Python 上的Prolog解释器 =
''简述''
== WAM虚拟机 ==
第一步, WAM虚拟机. 解释执行gprolog产生的wam代码

=== 分析wam代码 ===
prolog代码:
{{{
appen([],L,L).
appen([H|T],Y,[H|Z]):-appen(T,Y,Z).

go:- appen([1],[1,2],[2,3]).

:- initialization(
    go
).
}}}

 wam代码形如:
{{{
% compiler: GNU Prolog 1.2.16 (Sep 19 2002)
% file    : t3.pl
% date    : 1 14 2005
% time    : 21:47:24


file_name('G:\\MYPRO~1\\projects\\PUREPR~1\\current\\test\\t3.pl').


predicate(appen/3,1,static,private,user,[
    switch_on_term(1,2,fail,4,fail),

label(1),
    try_me_else(3),

label(2),
    get_nil(0),
    get_value(x(2),1),
    proceed,

label(3),
    trust_me_else_fail,

label(4),
    get_list(0),
    unify_variable(x(3)),
    unify_variable(x(0)),
    get_list(2),
    unify_value(x(3)),
    unify_variable(x(2)),
    execute(appen/3)]).


predicate(go/0,4,static,private,user,[
    put_list(0),
    unify_integer(1),
    unify_nil,
    put_list(1),
    unify_integer(1),
    unify_list,
    unify_integer(2),
    unify_nil,
    put_list(2),
    unify_integer(2),
    unify_list,
    unify_integer(3),
    unify_nil,
    execute(appen/3)]).


directive(6,user,[
    execute(go/0)]).
}}}

分析代码, 结果是一个代码树:
{{{
#!python
import re

rerem = r"\%.*$"
statment = r""
refilename = r"\w*file_name\('(?P<filename>.*)'\).\w*$"
st  = { '"':r'^"([^"]|(\\"))*?"',
        "'":r"^'([^']|(\\'))*?'"
        }
refn = re.compile(refilename)

tb = {
    'start':[(lambda s, c: c in lable,
              'lable',  )
             ],
    '':()
    }


class tock:
    def __init__(self):
        pass
    def setbuf(self, f):
        self.buf = f
    def parser(self):
        d = ''
        w = ' \n\t'
        nl = 0
        for rl in self.buf:
            nl +=1
            l = re.sub(rerem, '', rl)
            while l:
                if l[0] in "'\"":
                    mc = re.match(st[l[0]], l)
                    if not mc:
                        print 'string error', rl, 'line', nl
                    d =  mc.group()
                    yield ('l', d, rl, nl)
                    l = l[mc.end():]
                    d = ''
                if l[0] in '()[],.':
                    if d:
                        yield ('l', d.strip(w), rl, nl)
                        d = ''
                    yield ('s', l[0], rl, nl)
                    l = l[1:]
                else:
                    d += l[0]
                    l = l[1:]
                 
class parser:
    def __init__(self):
        pass
    def setbuf(self, tocker):
        self.tocker = tocker
    def parse(self):
        import pprint
        pp = pprint.PrettyPrinter(indent=4)
 
        t = self.tocker.parser()
        ast = ('start',list())
        p = [ast]
        for k, v, rl, nl in t:
            if k == 'l':
                p[-1][1].append(v)
            if v == '(':
                p[-1][1][-1] = (p[-1][1][-1],list())
                p.append(p[-1][1][-1])
            if v in ')]':
                p.pop()
            if v == '[':
                p[-1][1].append(('^list', list()))
                p.append(p[-1][1][-1])
            if v == ',':
                if p[-1][0] == 'start':
                    print 'stock error', rl, 'line', nl
            if v == '.':
                if p[-1][0] != 'start':
                    print 'stock error', rl, 'line', nl
            
        pp.pprint(ast)
        
def main(fn):
    t = tock()
    f = open(fn, 'r')
    t.setbuf(f)
    p = parser()
    p.setbuf(t)
    p.parse()


if __name__ == '__main__':
    from sys import argv
    main(argv[1])

}}}