Better algorithm for parsing block quotes

lib/lexer_block.js

@@ -4,7 +4,6 @@
 'use strict';
 
 
-var isEmpty = require('./helpers').isEmpty;
 var skipEmptyLines  = require('./helpers').skipEmptyLines;
 
 
@@ -140,15 +139,7 @@ LexerBlock.prototype.tokenize = function (state, startLine, endLine) {
     if (line === state.line) {
       throw new Error('None of rules updated state.line');
     }
-
     line = state.line;
-    if (isEmpty(state, line)) {
-      hasEmptyLines = true;
-      line++;
-
-      // two empty lines should stop the parser
-      if (isEmpty(state, line + 1)) { break; }
-    }
   }
 
   state.tight = !hasEmptyLines;

lib/lexer_block/blockquote.js

@@ -3,13 +3,12 @@
 'use strict';
 
 
-var skipSpaces      = require('../helpers').skipSpaces;
-var getLines        = require('../helpers').getLines;
+var getLines = require('../helpers').getLines;
+var isEmpty  = require('../helpers').isEmpty;
 
 
 module.exports = function blockquote(state, startLine, endLine, silent) {
-  var nextLine, lastLineEmpty, subState,
-      rules_named = state.lexerBlock.rules_named,
+  var nextLine, subState, insideLines, lineMax,
       pos = state.bMarks[startLine] + state.tShift[startLine],
       max = state.eMarks[startLine];
 
@@ -25,63 +24,37 @@ module.exports = function blockquote(state, startLine, endLine, silent) {
   // so no point trying to find the end of it in silent mode
   if (silent) { return true; }
 
-  // check if we have an empty blockquote
-  pos = pos < max ? skipSpaces(state, pos) : pos;
-  lastLineEmpty = pos >= max;
-
-  // Search the end of the block
-  //
-  // Block ends with either:
-  //  1. an empty line outside:
-  //     ```
-  //     > test
-  //
-  //     ```
-  //  2. an empty line inside:
-  //     ```
-  //     >
-  //     test
-  //     ```
-  //  3. another tag
-  //     ```
-  //     > test
-  //      - - -
-  //     ```
-  for (nextLine = startLine + 1; nextLine < endLine; nextLine++) {
+  lineMax = state.lineMax;
+  insideLines = 1;
+  state.tokens.push({ type: 'blockquote_open' });
+  for (nextLine = startLine + 1; nextLine < lineMax; ) {
     pos = state.bMarks[nextLine] + state.tShift[nextLine];
     max = state.eMarks[nextLine];
 
-    if (pos >= max) {
-      // Case 1: line is not inside the blockquote, and this line is empty.
-      break;
+    if (pos < max && state.src.charCodeAt(pos++) === 0x3E/* > */) {
+      if (nextLine < endLine) {
+        nextLine++;
+        insideLines++;
+        continue;
+      } else {
+        break;
+      }
     }
 
-    if (state.src.charCodeAt(pos++) === 0x3E/* > */) {
-      // This line is inside the blockquote.
-      pos = pos < max ? skipSpaces(state, pos) : pos;
-      lastLineEmpty = pos >= max;
-      continue;
+    if (insideLines === 0) {
+      break;
     }
 
-    // Case 2: line is not inside the blockquote, and the last line was empty.
-    if (lastLineEmpty) { break; }
-
-    // Case 3: another tag found.
-    if (rules_named.fences(state, nextLine, endLine, true)) { break; }
-    if (rules_named.hr(state, nextLine, endLine, true)) { break; }
-    if (rules_named.list(state, nextLine, endLine, true)) { break; }
-    if (rules_named.heading(state, nextLine, endLine, true)) { break; }
-    if (rules_named.lheading(state, nextLine, endLine, true)) { break; }
-    if (rules_named.table(state, nextLine, endLine, true)) { break; }
-    //if (rules_named.tag(state, nextLine, endLine, true)) { break; }
-    //if (rules_named.def(state, nextLine, endLine, true)) { break; }
+    while (nextLine < lineMax) {
+      if (isEmpty(state, nextLine)) { break; }
+      nextLine++;
+    }
+    subState = state.clone(getLines(state, startLine, nextLine, true)
+                                  .replace(/^ {0,3}> ?/mg, ''));
+    state.lexerBlock.tokenize(subState, 0, insideLines);
+    nextLine = startLine = subState.line + startLine;
+    insideLines = 0;
   }
-
-  state.tokens.push({ type: 'blockquote_open' });
-
-  subState = state.clone(getLines(state, startLine, nextLine, true).replace(/^ {0,3}> ?/mg, ''));
-  state.lexerBlock.tokenize(subState, 0, subState.lineMax);
-
   state.tokens.push({ type: 'blockquote_close' });
 
   state.line = nextLine;

lib/lexer_block/fences.js

@@ -40,9 +40,7 @@ module.exports = function fences(state, startLine, endLine, silent) {
   nextLine = startLine;
 
   for (;;) {
-    nextLine++;
-
-    if (nextLine >= endLine) {
+    if (nextLine + 1 >= endLine) {
       // unclosed block should be autoclosed by end of document.
       // also block seems to be autoclosed by end of parent
       /*if (state.blkLevel === 0) {
@@ -52,6 +50,8 @@ module.exports = function fences(state, startLine, endLine, silent) {
       break;
     }
 
+    nextLine++;
+
     pos = mem = state.bMarks[nextLine] + state.tShift[nextLine];
     max = state.eMarks[nextLine];
 

lib/lexer_block/lheading.js

@@ -12,7 +12,7 @@ module.exports = function lheading(state, startLine, endLine, silent) {
   var marker, pos, max,
       next = startLine + 1;
 
-  if (next >= state.lineMax) { return false; }
+  if (next >= endLine) { return false; }
 
   // Scan next line
   if (state.tShift[next] > 3) { return false; }

lib/lexer_block/paragraph.js

@@ -6,10 +6,13 @@
 var isEmpty = require('../helpers').isEmpty;
 
 
-module.exports = function paragraph(state, startLine, endLine) {
-  var nextLine = startLine + 1,
+module.exports = function paragraph(state, startLine/*, endLine*/) {
+  var endLine,
+      nextLine = startLine + 1,
       rules_named = state.lexerBlock.rules_named;
 
+  endLine = state.lineMax;
+
   // jump line-by-line until empty one or EOF
   while (nextLine < endLine && !isEmpty(state, nextLine)) {
     // Some tags can terminate paragraph without empty line.

lib/parser.js

@@ -74,9 +74,7 @@ Parser.prototype.render = function (src) {
     this.options
   );
 
-  while (state.line < state.lineMax) {
-    state.lexerBlock.tokenize(state, state.line, state.lineMax);
-  }
+  state.lexerBlock.tokenize(state, state.line, state.lineMax);
 
   return this.renderer.render(state);
 };