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对编译原理有兴趣的进解决方法

时间:2021-07-01 10:21:17 帮助过:24人阅读

对编译原理有兴趣的进
本帖最后由 xuzuning 于 2012-08-27 16:40:33 编辑

最近尝试做了文法分析的东东,问题较多。
请提建议。代码放不下,分两页。下载地址 http://download.csdn.net/detail/xuzuning/4529066
include 'ttrie.php';

class Rule extends TTrie {
public $rule = array();
public $savematch = 0;

function __construct($s='') {
$this->set( array(
' ' => 'Separated',
"\r\n" => 'set_rule',
"\n" => 'set_rule',
"\t" => 'Separated',
'->' => 'Separated',
'→' => 'Separated',
'|' => 'set_parallel_rule',
));
$this->match($s);
if($this->rule[0][0] == $this->rule[0][1]) {
if(count($this->rule[0]) == 2) $this->rule[0][0] .= "'";
else array_unshift($this->rule, array($this->rule[0][0]."'", $this->rule[0][0]));
}else {
$c = $this->rule[0][0];
$n = 0;
foreach($this->rule as $r) if($r[0] == $c) $n++;
if($n > 1) array_unshift($this->rule, array($this->rule[0][0]."'", $this->rule[0][0]));
}
}
function Separated() {
}
function set_rule() {
$this->rule[] = $this->buffer;
$this->buffer = array();
}
function set_parallel_rule() {
$t = $this->buffer[0];
$this->set_rule();
$this->buffer[] = $t;
}
}


class Grammar {
var $closure = array();
var $first = array();
var $follow = array();
var $rule = array();
var $identifier = array();
var $leay = array();
var $forecast = array();
var $stack = array();
var $ll = 'LL(0)';
var $lr = 'LR(0)';

function __construct($s='') {
$p = new Rule($s);
$this->rule = $p->rule;
$this->set_grammar();
}

function set_grammar() {
foreach($this->rule as $rule) {
if(! in_array($rule[0], $this->identifier)) $this->identifier[] = $rule[0];
}
foreach($this->rule as $rule) {
foreach($rule as $v)
if(! in_array($v, $this->identifier) && ! in_array($v, $this->leay))
$this->leay[] = $v;
}
$this->set_first();
$this->set_follow();
$this->set_closure();
$this->set_select();
$this->set_forecast();
}
function set_first() {
foreach($this->rule as $rule) $this->first[$rule[0]] = array();
//直接收取 形如U->a…的产生式(其中a是终结符),把a收入到First(U)中
foreach($this->rule as $v) {
if(in_array($v[1], $this->leay)) $this->first[$v[0]][] = $v[1];
}
//反复传递 形入U->P1P2P3…Pn的产生式(其中P是非终结符),应先把First(P1)中的全部内容传送到First(U)中,如果P1中有ε,把First(P2)中的内容传送到First(U)中,类推直到Pi中无ε
do {
$t = serialize($this->first);
foreach($this->rule as $rule) {
for($i=1; $i $v = $rule[$i];
if(in_array($v, $this->identifier)) {
$this->first[$rule[0]] = array_unique(array_merge($this->first[$rule[0]], $this->first[$v]));
if(! in_array('#', $this->first[$v])) break;
}else break;
}
}
}while($t != serialize($this->first));
}
function set_follow() {
foreach($this->rule as $rule) $this->follow[$rule[0]] = array();
//直接收取 形如 …Ua… 的,把a直接收入到Follow(U)中
foreach($this->rule as $rule) {
for($i=1; $i if(in_array($rule[$i], $this->identifier) && in_array($rule[$i+1], $this->leay))
$this->follow[$rule[$i]][] = $rule[$i+1];
}
if(in_array($rule[$i], $this->identifier)) $this->follow[$rule[$i]][] = '#';
}
foreach($this->follow as &$v) if(! $v) $v[] = '#';
//直接收取 形如 …UP…(P是非终结符)的,把First(P)中非ε收入到Follow(U)中
foreach($this->rule as $rule) {
for($i=1; $i if(in_array($rule[$i], $this->identifier) && in_array($rule[$i+1], $this->identifier)) {
$this->follow[$rule[$i]] = array_unique(array_merge($this->follow[$rule[$i]], array_diff($this->first[$rule[$i+1]], array('#'))));
}
}
}
//反复传递 形如U->aP的(P是非终结符)或U->aPQ(P,Q为非终结符且Q中含ε),应把Follow(U)中的全部内容传送到Follow(P)中
do {
$t = serialize($this->follow);
foreach($this->rule as $rule) {
$s = $rule[0];
$d = end($rule);
if(in_array($d, $this->leay)) continue;

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