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authorJohn MacFarlane <jgm@berkeley.edu>2015-01-10 08:37:31 -0800
committerJohn MacFarlane <jgm@berkeley.edu>2015-01-10 08:37:31 -0800
commit64ee8123152b4c2696bacbe6ad3a274c933a2835 (patch)
tree7169bde70b9b3a082e7abb39dd001c6b67132f0a
parentee502421b239bc1c8e74d0578d9615a641b5cc81 (diff)
Regex optimizations in blocks.js.
-rw-r--r--js/lib/blocks.js55
1 files changed, 42 insertions, 13 deletions
diff --git a/js/lib/blocks.js b/js/lib/blocks.js
index c6e5d75..afc5ea9 100644
--- a/js/lib/blocks.js
+++ b/js/lib/blocks.js
@@ -10,7 +10,7 @@ var unescapeString = new InlineParser().unescapeString;
// Returns true if string contains only space characters.
var isBlank = function(s) {
"use strict";
- return /^\s*$/.test(s);
+ return !(reNonSpace.test(s));
};
// Convert tabs to spaces on each line using a 4-space tab stop.
@@ -51,6 +51,34 @@ var reHtmlBlockOpen = new RegExp('^' + HTMLBLOCKOPEN, 'i');
var reHrule = /^(?:(?:\* *){3,}|(?:_ *){3,}|(?:- *){3,}) *$/;
+var reMaybeSpecial = /^[ #`~*+_=<>0-9-]/;
+
+var reNonSpace = /[^ \t\n]/;
+
+var reBulletListMarker = /^[*+-]( +|$)/;
+
+var reOrderedListMarker = /^(\d+)([.)])( +|$)/;
+
+var reATXHeaderMarker = /^#{1,6}(?: +|$)/;
+
+var reCodeFence = /^`{3,}(?!.*`)|^~{3,}(?!.*~)/;
+
+var reClosingCodeFence = /^(?:`{3,}|~{3,})(?= *$)/;
+
+var reSetextHeaderLine = /^(?:=+|-+) *$/;
+
+var reFinalNewlines = /(?:\n *)+$/;
+
+var reLineEnding = /\r\n|\n|\r/;
+
+// destructively trip final blank lines in an array of strings
+var stripFinalBlankLines = function(lns) {
+ var i = lns.length - 1;
+ while (!reNonSpace.test(lns[i])) {
+ lns.pop();
+ i--;
+ }
+};
// DOC PARSER
@@ -160,12 +188,12 @@ var parseListMarker = function(ln, offset) {
if (rest.match(reHrule)) {
return null;
}
- if ((match = rest.match(/^[*+-]( +|$)/))) {
+ if ((match = rest.match(reBulletListMarker))) {
spaces_after_marker = match[1].length;
data.type = 'Bullet';
data.bullet_char = match[0][0];
- } else if ((match = rest.match(/^(\d+)([.)])( +|$)/))) {
+ } else if ((match = rest.match(reOrderedListMarker))) {
spaces_after_marker = match[3].length;
data.type = 'Ordered';
data.start = parseInt(match[1]);
@@ -226,7 +254,7 @@ var incorporateLine = function(ln, line_number) {
}
container = container.lastChild;
- match = matchAt(/[^ ]/, ln, offset);
+ match = matchAt(reNonSpace, ln, offset);
if (match === -1) {
first_nonspace = ln.length;
blank = true;
@@ -339,9 +367,9 @@ var incorporateLine = function(ln, line_number) {
container.t !== 'IndentedCode' &&
container.t !== 'HtmlBlock' &&
// this is a little performance optimization:
- matchAt(/^[ #`~*+_=<>0-9-]/, ln, offset) !== -1) {
+ matchAt(reMaybeSpecial, ln, offset) !== -1) {
- match = matchAt(/[^ ]/, ln, offset);
+ match = matchAt(reNonSpace, ln, offset);
if (match === -1) {
first_nonspace = ln.length;
blank = true;
@@ -371,7 +399,7 @@ var incorporateLine = function(ln, line_number) {
closeUnmatchedBlocks(this);
container = this.addChild('BlockQuote', line_number, offset);
- } else if ((match = ln.slice(first_nonspace).match(/^#{1,6}(?: +|$)/))) {
+ } else if ((match = ln.slice(first_nonspace).match(reATXHeaderMarker))) {
// ATX header
offset = first_nonspace + match[0].length;
closeUnmatchedBlocks(this);
@@ -382,7 +410,7 @@ var incorporateLine = function(ln, line_number) {
[ln.slice(offset).replace(/^ *#+ *$/, '').replace(/ +#+ *$/, '')];
break;
- } else if ((match = ln.slice(first_nonspace).match(/^`{3,}(?!.*`)|^~{3,}(?!.*~)/))) {
+ } else if ((match = ln.slice(first_nonspace).match(reCodeFence))) {
// fenced code block
var fence_length = match[0].length;
closeUnmatchedBlocks(this);
@@ -402,7 +430,7 @@ var incorporateLine = function(ln, line_number) {
} else if (container.t === 'Paragraph' &&
container.strings.length === 1 &&
- ((match = ln.slice(first_nonspace).match(/^(?:=+|-+) *$/)))) {
+ ((match = ln.slice(first_nonspace).match(reSetextHeaderLine)))) {
// setext header line
closeUnmatchedBlocks(this);
container.t = 'Header'; // convert Paragraph to SetextHeader
@@ -447,7 +475,7 @@ var incorporateLine = function(ln, line_number) {
// What remains at the offset is a text line. Add the text to the
// appropriate container.
- match = matchAt(/[^ ]/, ln, offset);
+ match = matchAt(reNonSpace, ln, offset);
if (match === -1) {
first_nonspace = ln.length;
blank = true;
@@ -500,7 +528,7 @@ var incorporateLine = function(ln, line_number) {
// check for closing code fence:
match = (indent <= 3 &&
ln.charAt(first_nonspace) === container.fence_char &&
- ln.slice(first_nonspace).match(/^(?:`{3,}|~{3,})(?= *$)/));
+ ln.slice(first_nonspace).match(reClosingCodeFence));
if (match && match[0].length >= container.fence_length) {
// don't add closing fence to container; instead, close it:
this.finalize(container, line_number);
@@ -569,7 +597,8 @@ var finalize = function(block, line_number) {
break;
case 'IndentedCode':
- block.literal = block.strings.join('\n').replace(/(\n *)*$/, '\n');
+ stripFinalBlankLines(block.strings);
+ block.literal = block.strings.join('\n') + '\n';
block.t = 'CodeBlock';
break;
@@ -644,7 +673,7 @@ var parse = function(input) {
this.doc = Document();
this.tip = this.doc;
this.refmap = {};
- var lines = input.replace(/\n$/, '').split(/\r\n|\n|\r/);
+ var lines = input.replace(/\n$/, '').split(reLineEnding);
var len = lines.length;
for (var i = 0; i < len; i++) {
this.incorporateLine(lines[i], i + 1);