feat: add \REPEAT+\UNTIL{<cond>}

Author: ZJUGuoShuai

src/Parser.js

@@ -23,13 +23,14 @@
  *     <block>         :== ( <control> | <function> | <statement> |
  *                           <comment> )[0..n]
  *
- *     <control>       :== <if> | <for> | <while>
+ *     <control>       :== <if> | <for> | <while> | <repeat>
  *     <if>            :== \IF{<cond>} + <block>
  *                         + ( \ELIF{<cond>} <block> )[0..n]
  *                         + ( \ELSE <block> )[0..1]
  *                         + \ENDIF
  *     <for>           :== \FOR{<cond>} + <block> + \ENDFOR
  *     <while>         :== \WHILE{<cond>} + <block> + \ENDWHILE
+ *     <repeat>        :== \REPEAT + <block> + \UNTIL{<cond>}
  *
  *     <function>      :== \FUNCTION{<name>}{<params>} <block> \ENDFUNCTION
  *                         (same for <procedure>)
@@ -251,6 +252,7 @@ Parser.prototype._parseControl = function() {
     var controlNode;
     if ((controlNode = this._parseIf())) return controlNode;
     if ((controlNode = this._parseLoop())) return controlNode;
+    if ((controlNode = this._parseRepeat())) return controlNode;
 };
 
 Parser.prototype._parseFunction = function() {
@@ -331,6 +333,26 @@ Parser.prototype._parseLoop = function() {
     return loopNode;
 };
 
+Parser.prototype._parseRepeat = function() {
+    if (!this._lexer.accept('func', ['REPEAT'])) return null;
+
+    var repeatName = this._lexer.get().text.toLowerCase();
+    var repeatNode = new ParseNode('repeat', repeatName);
+
+    // <block>
+    repeatNode.addChild(this._parseBlock());
+
+    // \UNTIL
+    this._lexer.expect('func', 'until');
+
+    // {<cond>}
+    this._lexer.expect('open');
+    repeatNode.addChild(this._parseCond());
+    this._lexer.expect('close');
+
+    return repeatNode;
+};
+
 var INPUTS_OUTPUTS_COMMANDS = ['ensure', 'require'];
 var STATEMENT_COMMANDS = ['state', 'print', 'return'];
 Parser.prototype._parseCommand = function(acceptCommands) {

src/Renderer.js

@@ -736,6 +736,32 @@ Renderer.prototype._buildTree = function(node) {
                 this._typeKeyword(endLoopName);
             }
             break;
+        case 'repeat':
+            // \REPEAT
+            // ==>
+            // <p class="ps-line">
+            //     <span class="ps-keyword">repeat</span>
+            // </p>
+            this._newLine();
+            this._typeKeyword('repeat');
+
+            // block
+            var repeatBlock = node.children[0];
+            this._buildCommentsFromBlock(repeatBlock);
+            this._buildTree(repeatBlock);
+
+            if (!this._options.noEnd) {
+                // \UNTIL{<cond>}
+                // ==>
+                // <p class="ps-line">
+                //     <span class="ps-keyword">until</span>
+                // </p>
+                this._newLine();
+                this._typeKeyword('until ');
+                var repeatCond = node.children[1];
+                this._buildTree(repeatCond);
+            }
+            break;
         // ------------------- Lines -------------------
         case 'command':
             // commands: \STATE, \ENSURE, \PRINT, \RETURN, etc.

static/samples.html.template

@@ -84,6 +84,13 @@
                 \STATE $i \gets i + 1$
             \ENDWHILE
         \ENDPROCEDURE
+        \PROCEDURE{Test-Repeat}{$n$}
+            \STATE $i \gets 0$
+            \REPEAT
+                \PRINT $i$
+                \STATE $i \gets i + 1$
+            \UNTIL{$i>n$}
+        \ENDPROCEDURE
         \end{algorithmic}
         \end{algorithm}
         \begin{algorithm}