Bring pipe escape algorithm in tables closer to gfm

close #689
close #697

lib/rules_block/table.js

@@ -1,4 +1,4 @@
-// GFM table, non-standard
+// GFM table, https://github.github.com/gfm/#tables-extension-
 
 'use strict';
 
@@ -17,56 +17,42 @@ function escapedSplit(str) {
       pos = 0,
       max = str.length,
       ch,
-      escapes = 0,
+      isEscaped = false,
       lastPos = 0,
-      backTicked = false,
-      lastBackTick = 0;
+      current = '';
 
   ch  = str.charCodeAt(pos);
 
   while (pos < max) {
-    if (ch === 0x60/* ` */) {
-      if (backTicked) {
-        // make \` close code sequence, but not open it;
-        // the reason is: `\` is correct code block
-        backTicked = false;
-        lastBackTick = pos;
-      } else if (escapes % 2 === 0) {
-        backTicked = true;
-        lastBackTick = pos;
+    if (ch === 0x7c/* | */) {
+      if (!isEscaped) {
+        // pipe separating cells, '|'
+        result.push(current + str.substring(lastPos, pos));
+        current = '';
+        lastPos = pos + 1;
+      } else {
+        // escaped pipe, '\|'
+        current += str.substring(lastPos, pos - 1);
+        lastPos = pos;
       }
-    } else if (ch === 0x7c/* | */ && (escapes % 2 === 0) && !backTicked) {
-      result.push(str.substring(lastPos, pos));
-      lastPos = pos + 1;
-    }
-
-    if (ch === 0x5c/* \ */) {
-      escapes++;
-    } else {
-      escapes = 0;
     }
 
+    isEscaped = (ch === 0x5c/* \ */);
     pos++;
 
-    // If there was an un-closed backtick, go back to just after
-    // the last backtick, but as if it was a normal character
-    if (pos === max && backTicked) {
-      backTicked = false;
-      pos = lastBackTick + 1;
-    }
-
     ch = str.charCodeAt(pos);
   }
 
-  result.push(str.substring(lastPos));
+  result.push(current + str.substring(lastPos));
 
   return result;
 }
 
 
 module.exports = function table(state, startLine, endLine, silent) {
-  var ch, lineText, pos, i, nextLine, columns, columnCount, token,
-      aligns, t, tableLines, tbodyLines;
+  var ch, lineText, pos, i, l, nextLine, columns, columnCount, token,
+      aligns, t, tableLines, tbodyLines, oldParentType, terminate,
+      terminatorRules;
 
   // should have at least two lines
   if (startLine + 2 > endLine) { return false; }
@@ -125,15 +111,24 @@ module.exports = function table(state, startLine, endLine, silent) {
   lineText = getLine(state, startLine).trim();
   if (lineText.indexOf('|') === -1) { return false; }
   if (state.sCount[startLine] - state.blkIndent >= 4) { return false; }
-  columns = escapedSplit(lineText.replace(/^\||\|$/g, ''));
+  columns = escapedSplit(lineText);
+  if (columns.length && columns[0] === '') columns.shift();
+  if (columns.length && columns[columns.length - 1] === '') columns.pop();
 
   // header row will define an amount of columns in the entire table,
-  // and align row shouldn't be smaller than that (the rest of the rows can)
+  // and align row should be exactly the same (the rest of the rows can differ)
   columnCount = columns.length;
-  if (columnCount > aligns.length) { return false; }
+  if (columnCount !== aligns.length) { return false; }
 
   if (silent) { return true; }
 
+  oldParentType = state.parentType;
+  state.parentType = 'table';
+
+  // use 'blockquote' lists for termination because it's
+  // the most similar to tables
+  terminatorRules = state.md.block.ruler.getRules('blockquote');
+
   token     = state.push('table_open', 'table', 1);
   token.map = tableLines = [ startLine, 0 ];
 
@@ -161,16 +156,29 @@ module.exports = function table(state, startLine, endLine, silent) {
   token     = state.push('tr_close', 'tr', -1);
   token     = state.push('thead_close', 'thead', -1);
 
-  token     = state.push('tbody_open', 'tbody', 1);
-  token.map = tbodyLines = [ startLine + 2, 0 ];
-
   for (nextLine = startLine + 2; nextLine < endLine; nextLine++) {
     if (state.sCount[nextLine] < state.blkIndent) { break; }
 
+    terminate = false;
+    for (i = 0, l = terminatorRules.length; i < l; i++) {
+      if (terminatorRules[i](state, nextLine, endLine, true)) {
+        terminate = true;
+        break;
+      }
+    }
+
+    if (terminate) { break; }
     lineText = getLine(state, nextLine).trim();
-    if (lineText.indexOf('|') === -1) { break; }
+    if (!lineText) { break; }
     if (state.sCount[nextLine] - state.blkIndent >= 4) { break; }
-    columns = escapedSplit(lineText.replace(/^\||\|$/g, ''));
+    columns = escapedSplit(lineText);
+    if (columns.length && columns[0] === '') columns.shift();
+    if (columns.length && columns[columns.length - 1] === '') columns.pop();
+
+    if (nextLine === startLine + 2) {
+      token     = state.push('tbody_open', 'tbody', 1);
+      token.map = tbodyLines = [ startLine + 2, 0 ];
+    }
 
     token = state.push('tr_open', 'tr', 1);
     for (i = 0; i < columnCount; i++) {
@@ -189,10 +197,16 @@ module.exports = function table(state, startLine, endLine, silent) {
     }
     token = state.push('tr_close', 'tr', -1);
   }
-  token = state.push('tbody_close', 'tbody', -1);
+
+  if (tbodyLines) {
+    token = state.push('tbody_close', 'tbody', -1);
+    tbodyLines[1] = nextLine;
+  }
+
   token = state.push('table_close', 'table', -1);
+  tableLines[1] = nextLine;
 
-  tableLines[1] = tbodyLines[1] = nextLine;
+  state.parentType = oldParentType;
   state.line = nextLine;
   return true;
 };