Added double and triple colon ligations. Fixes #100.

glyphs/symbol-punctuation.ptl

@@ -168,11 +168,19 @@ export : define [apply] : begin
 		include glyphs.period
 		include glyphs.xhdot
 		save 'colon' ':'
+		save 'colon.dmid'
 
-		apply-transform : Upright
-		apply-transform : Translate 0 (parenMid - XH / 2)
-		apply-transform : Italify
-		save 'colon.mid'
+		branch
+			apply-transform : Upright
+			apply-transform : Translate 0 (parenMid - XH / 2)
+			apply-transform : Italify
+			save 'colon.mid'
+		branch
+			local delta : Math.max 0 : WIDTH / 2 - (XH - PERIODSIZE) / 2
+			apply-transform : Translate delta 0
+			save 'colon.dright'
+			apply-transform : Translate (-2 * delta) 0
+			save 'colon.dleft'
 
 	sketch # semicolon
 		include glyphs.comma

meta/features.ptl

@@ -219,6 +219,11 @@ export : define [apply para glyphList] : begin
 					chain-rule ({'colon'} ~> {'colon.mid'}) ({'colon'} ~> {'colon.mid'}) {'greater' 'less' 'hyphen' 'equal' 'plus' 'colon.mid'} # ::> ::- ::= ::< ::+
 					chain-rule ({'colon'} ~> {'colon.mid'}) ({'colon'} ~> {'colon.mid'}) ({'colon'} ~> {'colon.mid'}) {'greater' 'less' 'hyphen' 'equal' 'plus' 'colon.mid'} # :::> :::- :::= :::< :::+
 					chain-rule {'greater' 'less' 'hyphen' 'equal' 'plus' 'colon.mid'} ({'colon'} ~> {'colon.mid'}) # <: >: -: =: +:
+
+					# Colon chains
+					chain-rule {'colon.dright' 'colon.dmid'} ({'colon'} ~> {'colon.dmid'}) {'colon'}
+					chain-rule {'colon.dright' 'colon.dmid'} ({'colon'} ~> {'colon.dleft'})
+					chain-rule ({'colon'} ~> {'colon.dright'}) {'colon'}
 		
 		#opbd
 		local fwclose {'fwlcloseDoubleQuote' 'fwlcloseSingleQuote' 'dwlcjkSingleQuoteRight' 'dwlcjkDoubleQuoteRight' 'dwlparenRight'}

snapshot/index.html

@@ -314,13 +314,13 @@
 		<tr class="first"><th>Feature Tags</th><th>Designed For</th><th>Sample</th></tr>
 		<tr><td><i>No Ligation</i></td><td>&nbsp;</td><td class="nolig"><pre>-&lt;&lt; -&lt; &lt;-- &lt;&lt;- &lt;- -&gt; -&gt;&gt; --&gt; &gt;- &gt;&gt;- &lt;-&gt; &lt;--&gt; &lt;!--
 =&lt;&lt; =&lt; &lt;== &lt;&lt;= &lt;= =&gt; =&gt;&gt; ==&gt; &gt;= &gt;&gt;= &lt;=&gt; &lt;==&gt;
-:= :- :+ :&lt; :&gt;     &lt;: &gt;: +: -: =:</pre></td></tr>
+:= :- :+ :&lt; :&gt;   &lt;: &gt;: +: -: =:   a:b a::b a:::b</pre></td></tr>
 		<tr><td>calt</td><td><i>Default setting in editors</i></td><td><pre><s>-&lt;&lt;</s> <s>-&lt;</s> &lt;-- <s>&lt;&lt;-</s> &lt;- -&gt; <s>-&gt;&gt;</s> --&gt; <s>&gt;-</s> <s>&gt;&gt;-</s> &lt;-&gt; &lt;--&gt; &lt;!--
 <s>=&lt;&lt;</s> <s>=&lt;</s> &lt;== <s>&lt;&lt;=</s> <s>&lt;=</s> =&gt; <s>=&gt;&gt;</s> ==&gt; <s>&gt;=</s> <s>&gt;&gt;=</s> &lt;=&gt; &lt;==&gt;
-:= :- :+ :&lt; :&gt;     &lt;: &gt;: +: -: =:</pre></td></tr>
+:= :- :+ :&lt; :&gt;   &lt;: &gt;: +: -: =:   a:b a::b a:::b</pre></td></tr>
 		<tr><td>XHS_, XPTL</td><td>Haskell, PatEL</td><td style="font-feature-settings: &quot;XHS_&quot; 1"><pre>-&lt;&lt; -&lt; &lt;-- &lt;&lt;- &lt;- -&gt; -&gt;&gt; --&gt; &gt;- &gt;&gt;- &lt;-&gt; &lt;--&gt; &lt;!--
 =&lt;&lt; =&lt; &lt;== &lt;&lt;= <s>&lt;=</s> =&gt; =&gt;&gt; ==&gt; <s>&gt;=</s> &gt;&gt;= &lt;=&gt; &lt;==&gt;
-:= :- :+ :&lt; :&gt;     &lt;: &gt;: +: -: =:</pre></td></tr>
+:= :- :+ :&lt; :&gt;   &lt;: &gt;: +: -: =:   a:b a::b a:::b</pre></td></tr>
 	</table>
 </section>