- [enhance] add ErboutEnhancer

- [enhance] add ExpressionInterpolationEnhancer

2 files changed, 160 insertions, 8 deletions

diff --git a/doc/users-guide.html b/doc/users-guide.html
index 36a93ba..b9355b3 100644
--- a/doc/users-guide.html
+++ b/doc/users-guide.html
@@ -99,6 +99,8 @@ It has the following features.
     </li>
     <li><a href="#stringbuffer-enhancer">StringBufferEnhancer</a>
     </li>
+    <li><a href="#erbout-enhancer">ErboutEnhancer</a>
+    </li>
     <li><a href="#notext-enhancer">NoTextEnhancer</a>
     </li>
     <li><a href="#nocode-enhancer">NoCodeEnhancer</a>
@@ -111,6 +113,8 @@ It has the following features.
     </li>
     <li><a href="#headerfooter-enhancer">HeaderFooterEnhancer</a>
     </li>
+    <li><a href="#expressioninterpolation-enhancer">ExpressionInterpolationEnhancer</a>
+    </li>
   </ul>
   </li>
   <li><a href="#lang">Multi-Language</a>
@@ -998,12 +1002,17 @@ The following is an example to use some enhancers in command-line.
 <dt class="dt1">
 <a href="#arraybuffer-enhancer">ArrayBufferEnhancer</a> (only for Eruby)</dt>
 <dd class="dd1">
-	Use array buffer. This is included in Erubis::Eruby by default.
+	Use array buffer. It is a little slower than StringBufferEnhancer.
 </dd>
 <dt class="dt1">
 <a href="#stringbuffer-enhancer">StringBufferEnhancer</a> (only for Eruby)</dt>
 <dd class="dd1">
-	Use string buffer. It is a little slower than ArrayBufferEnhancer.
+	Use string buffer. This is included in Erubis::Eruby by default.
+</dd>
+<dt class="dt1">
+<a href="#erbout-enhancer">ErboutEnhancer</a> (only for Eruby)</dt>
+<dd class="dd1">
+	Set '_erbout = _buf = "";' to be compatible with ERB.
 </dd>
 <dt class="dt1">
 <a href="#notext-enhancer">NoTextEnhancer</a> (language-independent)</dt>
@@ -1035,6 +1044,11 @@ The following is an example to use some enhancers in command-line.
 <dd class="dd1">
 	[experimental] Enable you to add header and footer in eRuby script.
 </dd>
+<dt class="dt1">
+<a href="#expressioninterpolation-enhancer">ExpressionInterpolationEnhancer</a> (only for Eruby)</dt>
+<dd class="dd1">
+	[experimental] convert '&lt;p&gt;&lt;%= text %&gt;&lt;/p&gt;' into '_buf &lt;&lt; %Q`&lt;p&gt;#{text}&lt;/p&gt;`'.
+</dd>
 </dl>
 <p>If you required 'erubis/engine/enhanced', Eruby subclasses which include each enhancers are defined.
 For example, class BiPatternEruby includes BiPatternEnhancer.
@@ -1156,7 +1170,8 @@ because print() method in '&lt;% ... %&gt;' invokes not Kernel#print() but Print
 </p>
 <div class="terminal_caption">
 compiled source code</div>
-<pre class="terminal"><strong>_buf = [];</strong> _buf &lt;&lt; '&lt;div&gt;
+<pre class="terminal">$ erubis -xE Array example.eruby
+<strong>_buf = [];</strong> _buf &lt;&lt; '&lt;div&gt;
 '; for item in list 
  _buf &lt;&lt; '  &lt;p&gt;'; _buf &lt;&lt; ( item ).to_s; _buf &lt;&lt; '&lt;/p&gt;
   &lt;p&gt;'; _buf &lt;&lt; Erubis::XmlHelper.escape_xml( item ); _buf &lt;&lt; '&lt;/p&gt;
@@ -1185,7 +1200,7 @@ Array buffer is a litte slower than String buffer.
 '; end 
  _buf &lt;&lt; '&lt;/div&gt;
 ';
-<strong>_buf</strong>.join
+<strong>_buf.join</strong>
 </pre>
 <br>
 
@@ -1201,6 +1216,26 @@ Erubis::Eruby includes this enhancer by default.
 <br>
 
 
+<a name="erbout-enhancer"></a>
+<h3 class="section2">ErboutEnhancer</h3>
+<p>ErboutEnhancer makes Eruby to be compatible with ERB.
+This is useful especially for Ruby on Rails.
+</p>
+<pre class="terminal">$ erubis -xE Erbout example.eruby
+<strong>_erbout = _buf = '';</strong> _buf &lt;&lt; '&lt;div&gt;
+'; for item in list 
+ _buf &lt;&lt; '  &lt;p&gt;'; _buf &lt;&lt; ( item ).to_s; _buf &lt;&lt; '&lt;/p&gt;
+  &lt;p&gt;'; _buf &lt;&lt; Erubis::XmlHelper.escape_xml( item ); _buf &lt;&lt; '&lt;/p&gt;
+'; end 
+ _buf &lt;&lt; '&lt;/div&gt;
+';
+_buf.to_s
+</pre>
+<p>ErboutEnhancer is only for Eruby.
+</p>
+<br>
+
+
 <a name="notext-enhancer"></a>
 <h3 class="section2">NoTextEnhancer</h3>
 <p>NoTextEnhancer suppress output of text and prints only embedded code.
@@ -1471,6 +1506,40 @@ _buf.to_s
 <br>
 
 
+<a name="expressioninterpolation-enhancer"></a>
+<h3 class="section2">ExpressionInterpolationEnhancer</h3>
+<p>[experimental]
+</p>
+<p>ExpressionInterpolationEnhancer converts "&lt;h1&gt;&lt;%= title %&gt;&lt;/h1&gt;" into
+"_buf &lt;&lt; %Q`&lt;h1&gt;#{ title }&lt;/h1&gt;`".
+This makes Eruby a litter faster because method call of String#&lt;&lt; are eliminated
+by expression interpolations.
+</p>
+<div class="program_caption">
+ExpressionInterpolationEnhancer elmininates method call of String#&lt;&lt;.</div>
+<pre class="program">## Assume that input is '&lt;a href="&lt;%=url%&gt;"&gt;&lt;%=name%&gt;&lt;/a&gt;'.
+## Eruby convert input into the following code.  String#&lt;&lt; is called 5 times.
+_buf &lt;&lt; '&lt;a href="'; _buf &lt;&lt; (url).to_s; _buf &lt;&lt; '"&gt;'; _buf &lt;&lt; (name).to_s; _buf &lt;&lt; '&lt;/a&gt;';
+
+## If ExpressionInterpolationEnhancer is used, String#&lt;&lt; is called only once.
+_buf &lt;&lt; %Q`&lt;a href="#{url}"&gt;#{name}&lt;/a&gt;`;
+</pre>
+<div class="terminal_caption">
+compiled source code</div>
+<pre class="terminal">$ erubis -xE ExpressionInterpolation example.eruby
+_buf = ''; _buf &lt;&lt; <strong>%Q`</strong>&lt;div&gt;\n<strong>`</strong>
+ for item in list 
+ _buf &lt;&lt; <strong>%Q`</strong>  &lt;p&gt;<strong>#{ item }</strong>&lt;/p&gt;
+  &lt;p&gt;<strong>#{Erubis::XmlHelper.escape_xml( item )}</strong>&lt;/p&gt;\n<strong>`</strong>
+ end 
+ _buf &lt;&lt; <strong>%Q`</strong>&lt;/div&gt;\n<strong>`</strong>
+_buf.to_s
+</pre>
+<p>ExpressionInterpolationEnhancer is only for Eruby.
+</p>
+<br>
+
+
 <br>
 
 
diff --git a/doc/users-guide.txt b/doc/users-guide.txt
index fd766d0..e129044 100644
--- a/doc/users-guide.txt
+++ b/doc/users-guide.txt
@@ -735,9 +735,11 @@ The following is the list of enhancers.
 .: {{<ArrayEnhancer|#array-enhancer>}} (only for Eruby)
 	Return array of string instead of returning string.
 .: {{<ArrayBufferEnhancer|#arraybuffer-enhancer>}} (only for Eruby)
-	Use array buffer. This is included in Erubis::Eruby by default.
+	Use array buffer. It is a little slower than StringBufferEnhancer.
 .: {{<StringBufferEnhancer|#stringbuffer-enhancer>}} (only for Eruby)
-	Use string buffer. It is a little slower than ArrayBufferEnhancer.
+	Use string buffer. This is included in Erubis::Eruby by default.
+.: {{<ErboutEnhancer|#erbout-enhancer>}} (only for Eruby)
+	Set '_erbout = _buf = "";' to be compatible with ERB.
 .: {{<NoTextEnhancer|#notext-enhancer>}} (language-independent)
 	Print embedded code only and ignore normal text.
 .: {{<NoCodeEnhancer|#nocode-enhancer>}} (language-independent)
@@ -750,6 +752,8 @@ The following is the list of enhancers.
 	Regard lines starting with '%' as Ruby code. This is for compatibility with eruby and ERB.
 .: {{<HeaderFooterEnhancer|#headerfooter-enhancer>}} (language-independent)
 	[experimental] Enable you to add header and footer in eRuby script.
+.: {{<ExpressionInterpolationEnhancer|#expressioninterpolation-enhancer>}} (only for Eruby)
+	[experimental] convert '<p><%= text %></p>' into '_buf << %Q`<p>#{text}</p>`'.
 
 
 If you required 'erubis/engine/enhanced', Eruby subclasses which include each enhancers are defined.
@@ -926,6 +930,7 @@ ArrayEnhancer makes Eruby to return an array of strings.
 
 .? compiled source code
 .====================
+$ erubis -xE Array example.eruby
 .<<<:! erubis -xE Array guide.d/example.eruby | ruby -pe 'sub! /^_buf( = \[\];)?/, "{{*\\&*}}"'
 .====================
 
@@ -942,7 +947,7 @@ ArrayBufferEnhancer is only for Eruby.
 
 .====================
 $ erubis -xE ArrayBuffer example.eruby
-.<<<:! erubis -xE ArrayBuffer guide.d/example.eruby | ruby -pe 'sub!(/^_buf( = ..;|\.to_s)?/,"{{*\\&*}}")'
+.<<<:! erubis -xE ArrayBuffer guide.d/example.eruby | ruby -pe 'sub!(/^_buf( = .*?;|\.join)?/,"{{*\\&*}}")'
 .====================
 
 
@@ -972,7 +977,7 @@ Erubis::Eruby includes this enhancer by default.
 
 .#.====================
 .#$ erubis -xE StringBuffer example.eruby
-.#.<<<:! erubis -xE StringBuffer guide.d/example.eruby | ruby -pe 'sub!(/^_buf( = ..;)?/,"{{*\\&*}}")'
+.#.<<<:! erubis -xE StringBuffer guide.d/example.eruby | ruby -pe 'sub!(/^_buf( = .*?;)?/,"{{*\\&*}}")'
 .#.====================
 
 
@@ -980,6 +985,37 @@ StringBufferEnhancer is only for Eruby.
 
 
 
+.$$ ErboutEnhancer | erbout-enhancer
+
+ErboutEnhancer makes Eruby to be compatible with ERB.
+This is useful especially for Ruby on Rails.
+
+.#.? erbout-example.rb
+.#.-------------------- erbout-example.rb
+.#require 'erubis'
+.#class ErboutEruby < Erubis::Eruby
+.#  include Erubis::ErboutEnhancer
+.#end
+.#eruby = ErboutEruby.new(File.read('example.eruby'))
+.#print eruby.src
+.#.--------------------
+.#
+.#.? compiled source code
+.#.====================
+.#$ ruby erbout-example.rb
+.#.<<<:! (cd guide.d; ruby erbout-example.rb)
+.#.====================
+
+.====================
+$ erubis -xE Erbout example.eruby
+.<<<:! erubis -xE Erbout guide.d/example.eruby | ruby -pe 'sub! /^_erbout = _buf = .*?;/,"{{*\\&*}}"'
+.====================
+
+
+ErboutEnhancer is only for Eruby.
+
+
+
 .$$ NoTextEnhancer	| notext-enhancer
 
 NoTextEnhancer suppress output of text and prints only embedded code.
@@ -1269,6 +1305,53 @@ HeaderFooterEnhancer is experimental and is language-independent.
 
 
 
+.$$ ExpressionInterpolationEnhancer | expressioninterpolation-enhancer
+
+[experimental]
+
+ExpressionInterpolationEnhancer converts "<h1><%= title %></h1>" into
+"_buf << %Q`<h1>#{ title }</h1>`".
+This makes Eruby a litter faster because method call of String#<< are eliminated
+by expression interpolations.
+
+.? ExpressionInterpolationEnhancer elmininates method call of String#<<.
+.--------------------
+## Assume that input is '<a href="<%=url%>"><%=name%></a>'.
+## Eruby convert input into the following code.  String#<< is called 5 times.
+_buf << '<a href="'; _buf << (url).to_s; _buf << '">'; _buf << (name).to_s; _buf << '</a>';
+
+## If ExpressionInterpolationEnhancer is used, String#<< is called only once.
+_buf << %Q`<a href="#{url}">#{name}</a>`;
+.--------------------
+
+.#.? expressioninterpolation-example.rb
+.#.-------------------- expressioninterpolation-example.rb
+.#require 'erubis'
+.#class ExpressionInterpolationEruby < Erubis::Eruby
+.#  include Erubis::ExpressionInterpolationEnhancer
+.#end
+.#eruby = ExpressionInterpolationEruby.new(File.read('example.eruby'))
+.### or
+.##eruby = Erubis::FastEruby.new(File.read('example.eruby'))
+.#print eruby.src
+.#.--------------------
+.#
+.#.? compiled source code
+.#.====================
+.#$ ruby expressioninterpolation-example.rb
+.#.<<<:! (cd guide.d; ruby expressioninterpolation-example.rb)
+.#.====================
+
+.? compiled source code
+.====================
+$ erubis -xE ExpressionInterpolation example.eruby
+.<<<:! erubis -xE ExpressionInterpolation guide.d/example.eruby | ruby -pe 'gsub! /(%Q`|`|\#\{.*?\})/, "{{*\\&*}}"'
+.====================
+
+ExpressionInterpolationEnhancer is only for Eruby.
+
+
+
 .$ Multi-Language	| lang
 
 Erubis supports the following language currently: