Site updated: 2017-03-30 16:10:22

Author: nameoverflow

2017/03/03/使用-Parsec-处理左递归/index.html

@@ -74,6 +74,7 @@ <h1>使用 Parsec 处理左递归</h1>
  Apply &amp; \rightarrow  Factor  (  Exprs  )
 \end{aligned}</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="strut" style="height:6.849999999999999em;"></span><span class="strut bottom" style="height:13.2em;vertical-align:-6.35em;"></span><span class="base displaystyle textstyle uncramped"><span class="mord"><span class="mtable"><span class="col-align-r"><span class="vlist"><span style="top:-6.009999999999999em;"><span class="fontsize-ensurer reset-size5 size5"><span style="font-size:0em;">​</span></span><span class="mord displaystyle textstyle uncramped"><span class="mord mathit" style="margin-right:0.05764em;">E</span><span class="mord mathit">x</span><span class="mord mathit">p</span><span class="mord mathit" style="margin-right:0.02778em;">r</span></span></span><span style="top:-4.809999999999999em;"><span class="fontsize-ensurer reset-size5 size5"><span style="font-size:0em;">​</span></span><span class="mord displaystyle textstyle uncramped"></span></span><span style="top:-3.609999999999998em;"><span class="fontsize-ensurer reset-size5 size5"><span style="font-size:0em;">​</span></span><span class="mord displaystyle textstyle uncramped"><span class="mord mathit" style="margin-right:0.05764em;">E</span><span class="mord mathit">x</span><span class="mord mathit">p</span><span class="mord mathit" style="margin-right:0.02778em;">r</span><span class="mord mathit">s</span></span></span><span style="top:-2.409999999999998em;"><span class="fontsize-ensurer reset-size5 size5"><span style="font-size:0em;">​</span></span><span class="mord displaystyle textstyle uncramped"></span></span><span style="top:-1.209999999999998em;"><span class="fontsize-ensurer reset-size5 size5"><span style="font-size:0em;">​</span></span><span class="mord displaystyle textstyle uncramped"><span class="mord mathit" style="margin-right:0.13889em;">F</span><span class="mord mathit">a</span><span class="mord mathit">c</span><span class="mord mathit">t</span><span class="mord mathit">o</span><span class="mord mathit" style="margin-right:0.02778em;">r</span></span></span><span style="top:-0.009999999999997733em;"><span class="fontsize-ensurer reset-size5 size5"><span style="font-size:0em;">​</span></span><span class="mord displaystyle textstyle uncramped"></span></span><span style="top:1.1900000000000024em;"><span class="fontsize-ensurer reset-size5 size5"><span style="font-size:0em;">​</span></span><span class="mord displaystyle textstyle uncramped"><span class="mord mathit" style="margin-right:0.07847em;">I</span><span class="mord mathit">n</span><span class="mord mathit">t</span><span class="mord mathit">e</span><span class="mord mathit" style="margin-right:0.03588em;">g</span><span class="mord mathit">e</span><span class="mord mathit" style="margin-right:0.02778em;">r</span></span></span><span style="top:2.390000000000002em;"><span class="fontsize-ensurer reset-size5 size5"><span style="font-size:0em;">​</span></span><span class="mord displaystyle textstyle uncramped"></span></span><span style="top:3.590000000000001em;"><span class="fontsize-ensurer reset-size5 size5"><span style="font-size:0em;">​</span></span><span class="mord displaystyle textstyle uncramped"><span class="mord mathrm">.</span><span class="mord mathrm">.</span><span class="mord mathrm">.</span></span></span><span style="top:4.79em;"><span class="fontsize-ensurer reset-size5 size5"><span style="font-size:0em;">​</span></span><span class="mord displaystyle textstyle uncramped"></span></span><span style="top:5.989999999999999em;"><span class="fontsize-ensurer reset-size5 size5"><span style="font-size:0em;">​</span></span><span class="mord displaystyle textstyle uncramped"><span class="mord mathit">A</span><span class="mord mathit">p</span><span class="mord mathit">p</span><span class="mord mathit" style="margin-right:0.01968em;">l</span><span class="mord mathit" style="margin-right:0.03588em;">y</span></span></span><span class="baseline-fix"><span class="fontsize-ensurer reset-size5 size5"><span style="font-size:0em;">​</span></span>​</span></span></span><span class="col-align-l"><span class="vlist"><span style="top:-6.009999999999999em;"><span class="fontsize-ensurer reset-size5 size5"><span style="font-size:0em;">​</span></span><span class="mord displaystyle textstyle uncramped"><span class="mord displaystyle textstyle uncramped"></span><span class="mrel">→</span><span class="mord mathit" style="margin-right:0.13889em;">F</span><span class="mord mathit">a</span><span class="mord mathit">c</span><span class="mord mathit">t</span><span class="mord mathit">o</span><span class="mord mathit" style="margin-right:0.02778em;">r</span><span class="mord mathrm">.</span><span class="mord mathrm">.</span><span class="mord mathrm">.</span></span></span><span style="top:-3.6099999999999985em;"><span class="fontsize-ensurer reset-size5 size5"><span style="font-size:0em;">​</span></span><span class="mord displaystyle textstyle uncramped"><span class="mord displaystyle textstyle uncramped"></span><span class="mrel">→</span><span class="mord mathit" style="margin-right:0.05764em;">E</span><span class="mord mathit">x</span><span class="mord mathit">p</span><span class="mord mathit" style="margin-right:0.02778em;">r</span><span class="mpunct">,</span><span class="mord mathit" style="margin-right:0.05764em;">E</span><span class="mord mathit">x</span><span class="mord mathit">p</span><span class="mord mathit" style="margin-right:0.02778em;">r</span><span class="mord mathit">s</span></span></span><span style="top:-1.2099999999999989em;"><span class="fontsize-ensurer reset-size5 size5"><span style="font-size:0em;">​</span></span><span class="mord displaystyle textstyle uncramped"><span class="mord displaystyle textstyle uncramped"></span><span class="mrel">→</span><span class="mord mathit" style="margin-right:0.07847em;">I</span><span class="mord mathit">n</span><span class="mord mathit">t</span><span class="mord mathit">e</span><span class="mord mathit" style="margin-right:0.03588em;">g</span><span class="mord mathit">e</span><span class="mord mathit" style="margin-right:0.02778em;">r</span><span class="mord mathrm">∣</span><span class="mord mathit">A</span><span class="mord mathit">p</span><span class="mord mathit">p</span><span class="mord mathit" style="margin-right:0.01968em;">l</span><span class="mord mathit" style="margin-right:0.03588em;">y</span><span class="mord mathrm">∣</span><span class="mord mathit" style="margin-right:0.07847em;">I</span><span class="mord mathit">d</span><span class="mord mathit">e</span><span class="mord mathit">n</span><span class="mord mathit">t</span><span class="mord mathit">i</span><span class="mord mathit" style="margin-right:0.10764em;">f</span><span class="mord mathit" style="margin-right:0.03588em;">y</span><span class="mord mathrm">∣</span><span class="mord mathrm">.</span><span class="mord mathrm">.</span><span class="mord mathrm">.</span><span class="mord mathrm">∣</span><span class="mord displaystyle textstyle uncramped"><span class="mopen">(</span></span><span class="mord displaystyle textstyle uncramped"><span class="mord mathit" style="margin-right:0.05764em;">E</span><span class="mord mathit">x</span><span class="mord mathit">p</span><span class="mord mathit" style="margin-right:0.02778em;">r</span></span><span class="mord displaystyle textstyle uncramped"><span class="mclose">)</span></span></span></span><span style="top:1.1900000000000015em;"><span class="fontsize-ensurer reset-size5 size5"><span style="font-size:0em;">​</span></span><span class="mord displaystyle textstyle uncramped"><span class="mord displaystyle textstyle uncramped"></span><span class="mrel">→</span><span class="mord mathrm">.</span><span class="mord mathrm">.</span><span class="mord mathrm">.</span></span></span><span style="top:5.989999999999999em;"><span class="fontsize-ensurer reset-size5 size5"><span style="font-size:0em;">​</span></span><span class="mord displaystyle textstyle uncramped"><span class="mord displaystyle textstyle uncramped"></span><span class="mrel">→</span><span class="mord mathit" style="margin-right:0.13889em;">F</span><span class="mord mathit">a</span><span class="mord mathit">c</span><span class="mord mathit">t</span><span class="mord mathit">o</span><span class="mord mathit" style="margin-right:0.02778em;">r</span><span class="mopen">(</span><span class="mord mathit" style="margin-right:0.05764em;">E</span><span class="mord mathit">x</span><span class="mord mathit">p</span><span class="mord mathit" style="margin-right:0.02778em;">r</span><span class="mord mathit">s</span><span class="mclose">)</span></span></span><span class="baseline-fix"><span class="fontsize-ensurer reset-size5 size5"><span style="font-size:0em;">​</span></span>​</span></span></span></span></span></span></span></span></span>
 <p>显然，non-terminal <span class="katex"><span class="katex-mathml"><math><semantics><mrow><mi>A</mi><mi>p</mi><mi>p</mi><mi>l</mi><mi>y</mi></mrow><annotation encoding="application/x-tex">Apply</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="strut" style="height:0.69444em;"></span><span class="strut bottom" style="height:0.8888799999999999em;vertical-align:-0.19444em;"></span><span class="base textstyle uncramped"><span class="mord mathit">A</span><span class="mord mathit">p</span><span class="mord mathit">p</span><span class="mord mathit" style="margin-right:0.01968em;">l</span><span class="mord mathit" style="margin-right:0.03588em;">y</span></span></span></span> 的派生最左端会进入  <span class="katex"><span class="katex-mathml"><math><semantics><mrow><mi>F</mi><mi>a</mi><mi>c</mi><mi>t</mi><mi>o</mi><mi>r</mi></mrow><annotation encoding="application/x-tex">Factor</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="strut" style="height:0.68333em;"></span><span class="strut bottom" style="height:0.68333em;vertical-align:0em;"></span><span class="base textstyle uncramped"><span class="mord mathit" style="margin-right:0.13889em;">F</span><span class="mord mathit">a</span><span class="mord mathit">c</span><span class="mord mathit">t</span><span class="mord mathit">o</span><span class="mord mathit" style="margin-right:0.02778em;">r</span></span></span></span> ，之后又会回到 <span class="katex"><span class="katex-mathml"><math><semantics><mrow><mi>A</mi><mi>p</mi><mi>p</mi><mi>l</mi><mi>y</mi></mrow><annotation encoding="application/x-tex">Apply</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="strut" style="height:0.69444em;"></span><span class="strut bottom" style="height:0.8888799999999999em;vertical-align:-0.19444em;"></span><span class="base textstyle uncramped"><span class="mord mathit">A</span><span class="mord mathit">p</span><span class="mord mathit">p</span><span class="mord mathit" style="margin-right:0.01968em;">l</span><span class="mord mathit" style="margin-right:0.03588em;">y</span></span></span></span> 。教科书式的左递归。</p>
+<a id="more"></a>
 <p>龙书中告诉我们，左递归可以通过提取出一个产生式来消除。</p>
 <p>对于</p>
 <span class="katex-display"><span class="katex"><span class="katex-mathml"><math><semantics><mrow><mi>A</mi><mo>→</mo><mi>A</mi><msub><mi>α</mi><mn>1</mn></msub><mi mathvariant="normal">∣</mi><mi>A</mi><msub><mi>α</mi><mn>2</mn></msub><mi mathvariant="normal">∣</mi><mi mathvariant="normal">.</mi><mi mathvariant="normal">.</mi><mi mathvariant="normal">.</mi><mi mathvariant="normal">∣</mi><mi>β</mi><mi mathvariant="normal">.</mi><mi mathvariant="normal">.</mi></mrow><annotation encoding="application/x-tex">A \rightarrow A \alpha_1|A \alpha_2|...|\beta..</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="strut" style="height:0.75em;"></span><span class="strut bottom" style="height:1em;vertical-align:-0.25em;"></span><span class="base displaystyle textstyle uncramped"><span class="mord mathit">A</span><span class="mrel">→</span><span class="mord mathit">A</span><span class="mord"><span class="mord mathit" style="margin-right:0.0037em;">α</span><span class="vlist"><span style="top:0.15em;margin-right:0.05em;margin-left:-0.0037em;"><span class="fontsize-ensurer reset-size5 size5"><span style="font-size:0em;">​</span></span><span class="reset-textstyle scriptstyle cramped"><span class="mord mathrm">1</span></span></span><span class="baseline-fix"><span class="fontsize-ensurer reset-size5 size5"><span style="font-size:0em;">​</span></span>​</span></span></span><span class="mord mathrm">∣</span><span class="mord mathit">A</span><span class="mord"><span class="mord mathit" style="margin-right:0.0037em;">α</span><span class="vlist"><span style="top:0.15em;margin-right:0.05em;margin-left:-0.0037em;"><span class="fontsize-ensurer reset-size5 size5"><span style="font-size:0em;">​</span></span><span class="reset-textstyle scriptstyle cramped"><span class="mord mathrm">2</span></span></span><span class="baseline-fix"><span class="fontsize-ensurer reset-size5 size5"><span style="font-size:0em;">​</span></span>​</span></span></span><span class="mord mathrm">∣</span><span class="mord mathrm">.</span><span class="mord mathrm">.</span><span class="mord mathrm">.</span><span class="mord mathrm">∣</span><span class="mord mathit" style="margin-right:0.05278em;">β</span><span class="mord mathrm">.</span><span class="mord mathrm">.</span></span></span></span></span>

archives/2015/01/index.html

@@ -572,29 +572,6 @@ <h2>用上了instantclick</h2>
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-                <h2>撸了个node的微型web server</h2>
-            </a>
-            <div class='ListMeta'>
-  <time datetime="2015-08-02T17:16:00.000Z" itemprop="datePublished">
-    2015-08-03
-  </time>
-  
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-  { <a href="/tags/nodejs/">nodejs</a> }
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 </div>
@@ -631,6 +608,29 @@ <h2>新版博客上线</h2>
   </li>
 
 
+  </ul>
+  
+</div>
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+        </li>
+      
+        <li>
+            <a href="/2015/08/03/撸了个node的微型web-server/">
+                <h2>撸了个node的微型web server</h2>
+            </a>
+            <div class='ListMeta'>
+  <time datetime="2015-08-02T17:16:00.000Z" itemprop="datePublished">
+    2015-08-03
+  </time>
+  
+  | 
+  <ul>
+    
+  <li class="meta-text">
+  { <a href="/tags/nodejs/">nodejs</a> }
+  </li>
+
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@@ -814,19 +814,19 @@ <h2>千年弦歌网络工作室html编码规范</h2>
         </li>
 
         <li>
-            <a href="/2015/09/08/关于程序设计报告/">
-                <h2>关于程序设计报告</h2>
+            <a href="/2015/06/06/前端面试-将嵌套的js数组转化为一维数组的许多种办法/">
+                <h2>前端面试：将嵌套的js数组转化为一维数组的许多种办法</h2>
             </a>
             <div class='ListMeta'>
-  <time datetime="2015-09-08T15:16:58.000Z" itemprop="datePublished">
-    2015-09-08
+  <time datetime="2015-06-06T00:49:21.000Z" itemprop="datePublished">
+    2015-06-06
   </time>
 
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-  { <a href="/tags/computer-science/">computer science</a> }
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@@ -837,19 +837,19 @@ <h2>关于程序设计报告</h2>
         </li>
 
         <li>
-            <a href="/2015/06/06/前端面试-将嵌套的js数组转化为一维数组的许多种办法/">
-                <h2>前端面试：将嵌套的js数组转化为一维数组的许多种办法</h2>
+            <a href="/2015/09/08/关于程序设计报告/">
+                <h2>关于程序设计报告</h2>
             </a>
             <div class='ListMeta'>
-  <time datetime="2015-06-06T00:49:21.000Z" itemprop="datePublished">
-    2015-06-06
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+    2015-09-08
   </time>
 
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   <li class="meta-text">
-  { <a href="/tags/javascript/">javascript</a> }
+  { <a href="/tags/computer-science/">computer science</a> }
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archives/2015/02/index.html

@@ -572,29 +572,6 @@ <h2>用上了instantclick</h2>
   </li>
 
 
-  </ul>
-  
-</div>
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-        </li>
-      
-        <li>
-            <a href="/2015/08/03/撸了个node的微型web-server/">
-                <h2>撸了个node的微型web server</h2>
-            </a>
-            <div class='ListMeta'>
-  <time datetime="2015-08-02T17:16:00.000Z" itemprop="datePublished">
-    2015-08-03
-  </time>
-  
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-  { <a href="/tags/nodejs/">nodejs</a> }
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 </div>
@@ -631,6 +608,29 @@ <h2>新版博客上线</h2>
   </li>
 
 
+  </ul>
+  
+</div>
+
+        </li>
+      
+        <li>
+            <a href="/2015/08/03/撸了个node的微型web-server/">
+                <h2>撸了个node的微型web server</h2>
+            </a>
+            <div class='ListMeta'>
+  <time datetime="2015-08-02T17:16:00.000Z" itemprop="datePublished">
+    2015-08-03
+  </time>
+  
+  | 
+  <ul>
+    
+  <li class="meta-text">
+  { <a href="/tags/nodejs/">nodejs</a> }
+  </li>
+
+
   </ul>
 
 </div>
@@ -814,19 +814,19 @@ <h2>千年弦歌网络工作室html编码规范</h2>
         </li>
 
         <li>
-            <a href="/2015/09/08/关于程序设计报告/">
-                <h2>关于程序设计报告</h2>
+            <a href="/2015/06/06/前端面试-将嵌套的js数组转化为一维数组的许多种办法/">
+                <h2>前端面试：将嵌套的js数组转化为一维数组的许多种办法</h2>
             </a>
             <div class='ListMeta'>
-  <time datetime="2015-09-08T15:16:58.000Z" itemprop="datePublished">
-    2015-09-08
+  <time datetime="2015-06-06T00:49:21.000Z" itemprop="datePublished">
+    2015-06-06
   </time>
 
   | 
   <ul>
 
   <li class="meta-text">
-  { <a href="/tags/computer-science/">computer science</a> }
+  { <a href="/tags/javascript/">javascript</a> }
   </li>
 
 
@@ -837,19 +837,19 @@ <h2>关于程序设计报告</h2>
         </li>
 
         <li>
-            <a href="/2015/06/06/前端面试-将嵌套的js数组转化为一维数组的许多种办法/">
-                <h2>前端面试：将嵌套的js数组转化为一维数组的许多种办法</h2>
+            <a href="/2015/09/08/关于程序设计报告/">
+                <h2>关于程序设计报告</h2>
             </a>
             <div class='ListMeta'>
-  <time datetime="2015-06-06T00:49:21.000Z" itemprop="datePublished">
-    2015-06-06
+  <time datetime="2015-09-08T15:16:58.000Z" itemprop="datePublished">
+    2015-09-08
   </time>
 
   | 
   <ul>
 
   <li class="meta-text">
-  { <a href="/tags/javascript/">javascript</a> }
+  { <a href="/tags/computer-science/">computer science</a> }
   </li>