Add :if/:elseif/:else/:endif contiditionals. Also add comment help tag.

--HG--
extra : rebase_source : 6b6e15157d2fae436aa812df2db94a36a5e7ce79

common/locale/en-US/eval.xml

@@ -24,6 +24,8 @@
     along with paren matching and syntax error highlighting.
 </p>
 
+<h2 tag="javascript-evaluation">JavaScript evaluation</h2>
+
 <item>
     <tags>:ec :echo</tags>
     <spec>:ec<oa>ho</oa> <a>expr</a></spec>
@@ -134,6 +136,8 @@
     </description>
 </item>
 
+<h2 tag="global-variables">Global Variables</h2>
+
 <item>
     <tags>:let</tags>
     <spec>:let <a>var-name</a> [+-.]= <a>expr1</a></spec>
@@ -166,6 +170,55 @@
     </description>
 </item>
 
+<h2 tag="conditionals">Conditionals</h2>
+
+<item>
+    <tags>:if</tags>
+    <spec>:if <a>expr</a></spec>
+    <description>
+        <p>
+            Execute commands until the next <ex>:elseif</ex>, <ex>:else</ex>,
+            or <ex>:endif</ex> only if the JavaScript expression <a>expr</a>
+            evaluates to a true value.
+        </p>
+    </description>
+</item>
+
+<item>
+    <tags>:endif :en :fi</tags>
+    <spec>:en<oa>dif</oa></spec>
+    <description>
+        <p>
+            Ends a string of <ex>:if</ex>/<ex>:elseif</ex>/<ex>:else</ex>
+            conditionals.
+        </p>
+    </description>
+</item>
+
+
+<item>
+    <tags>:elseif :elsei :elif</tags>
+    <spec>:elsei<oa>f</oa> <a>expr</a></spec>
+    <description>
+        <p>
+            Execute commands until the next <ex>:elseif</ex>, <ex>:else</ex>,
+            or <ex>:endif</ex> only if the JavaScript expression <a>expr</a>
+            evaluates to a true value.
+        </p>
+    </description>
+</item>
+
+<item>
+    <tags>:else :el</tags>
+    <spec>:el<oa>se</oa></spec>
+    <description>
+        <p>
+            Execute commands until the next <ex>:endif</ex> only if the
+            previous conditionals were not executed.
+        </p>
+    </description>
+</item>
+
 </document>
 
 <!-- vim:se sts=4 sw=4 et: -->

common/locale/en-US/index.xml

@@ -242,7 +242,10 @@ This file contains a list of all available commands, mappings and options.
     <dt><ex>:echo</ex></dt> <dd>Echo the expression</dd>
     <dt><ex>:echoerr</ex></dt> <dd>Echo the expression as an error message</dd>
     <dt><ex>:echomsg</ex></dt> <dd>Echo the expression as an informational message</dd>
+    <dt><ex>:else</ex></dt> <dd>Execute commands until the next <ex>:endif</ex> only if the previous conditionals were not executed</dd>
+    <dt><ex>:elseif</ex></dt> <dd>Execute commands until the next :elseif, <ex>:else</ex>, or :endif only if the argument returns true</dd>
     <dt><ex>:emenu</ex></dt> <dd>Execute the specified menu item from the command line</dd>
+    <dt><ex>:endif</ex></dt> <dd>Ends a string of <ex>:if</ex>/<ex>:elseif</ex>/<ex>:else</ex> conditionals</dd>
     <dt><ex>:execute</ex></dt> <dd>Execute the argument as an Ex command</dd>
     <dt><ex>:extadd</ex></dt> <dd>Install an extension</dd>
     <dt><ex>:extdelete</ex></dt> <dd>Uninstall an extension</dd>
@@ -262,6 +265,7 @@ This file contains a list of all available commands, mappings and options.
     <dt><ex>:history</ex></dt> <dd>Show recently visited URLs</dd>
     <dt><ex>:iabbrev</ex></dt> <dd>Abbreviate a key sequence in Insert mode</dd>
     <dt><ex>:iabclear</ex></dt> <dd>Remove all abbreviations in Insert mode</dd>
+    <dt><ex>:if</ex></dt> <dd>Execute commands until the next <ex>:elseif</ex>, <ex>:else</ex>, or <ex>:endif</ex> only if the argument returns true</dd>
     <dt><ex>:imap</ex></dt> <dd>Map a key sequence in Insert mode</dd>
     <dt><ex>:imapclear</ex></dt> <dd>Remove all mappings in Insert mode</dd>
     <dt><ex>:inoremap</ex></dt> <dd>Map a key sequence without remapping keys in Insert mode</dd>

common/locale/en-US/repeat.xml

@@ -169,6 +169,8 @@
             on a single line, you can use
         </p>
 
+        <p>See also <t>ex-scripts</t> below.</p>
+
         <code><ex>:js</ex> &lt;&lt;<em>EOF</em>
 <hl key="Object">var</hl> hello = <hl key="Key">function</hl> () {
     alert(<str>Hello world</str>);
@@ -228,6 +230,54 @@
     </description>
 </item>
 
+<h3 tag="ex-scripts">Ex Command Scripts</h3>
+
+<p>
+    Ex command scripts are similar to both entering commands on the
+    <link topic="command-line">command line</link> and to Vim
+    scripts, but with some notable differences.
+</p>
+
+<p tag="multiline-commands">
+    Commands in Ex command scripts can span multiple lines by
+    prefixing the second and further lines with a <em>\</em>
+    character. For instance, the following all define commands whose
+    definitions span multiple lines.
+</p>
+
+<code><ex>:command!</ex> <em>foo</em>
+        \ <em>-description</em> <str>A command that frobs bars</str>
+        \ <ex>:javascript</ex> frob(content.bar)</code>
+
+<code><ex>:style</ex> <em>-name</em> <str>foo</str>
+     \ <str delim="'">foobar.com</str>
+     \ p:first-line { <em>font-variant:</em> <str delim="">small-caps</str>; }
+     \ div#side-bar > :first-child { <em>display</em>: <str delim="">none</str>; }</code>
+
+<code><ex>:command</ex> <em>do-some-stuff</em>
+        \ <em>-description</em> <str>A command does some stuff in JavaScript</str>
+        \ <ex>:javascript</ex> &lt;&lt;<em>EOF</em>
+        \     window.do(<str>some</str>);
+        \     window.do(<str>stuff</str>);
+        \<em>EOF</em></code>
+
+<code><ex>:command</ex> <em>do-some-stuff</em>
+        \ <em>-description</em> <str>A command does some stuff in JavaScript</str>
+        \ <ex>:javascript</ex>
+        \\    window.do(<str>some</str>);
+        \\    window.do(<str>stuff</str>);</code>
+
+<p tag="comments">
+    Lines may be commented out by prefixing them with a <em>"</em>
+    character.
+</p>
+
+<code>    <html:span style="color: #444">        " This is a comment</html:span>
+    foo bar <html:span style="color: #444">" This is a comment</html:span>
+            <str> This is not a comment</str>
+    foo bar <str> This is not a cumment</str>
+</code>
+
 <h2 tag="profile profiling">Profiling</h2>
 
 <item>