Commit
14b997d9350b3ee3f6d67fb12b470bf406d4a31b Parent
b34e19cd2f32342fafd6ae76de4e537240784f71 Author
John MacFarlane <jgm@berkeley.edu >
Date
Sun, 18 Jan 2015 10:41:54 -0800
Changed rule for `_` emphasis and strong emphasis.
To prevent intra-word emphasis, we used to check to see if
the delimiter was followed/preceded by an ASCII alphanumeric.
We now do something more elegant: whereas an opening `*` must
be left-flanking, an opening `_` must be left-flanking *and not
right-flanking*. And so on for the other cases.
All the original tests passed except some tests with Russian
text with internal `_`, which formerly created emphasis but no
longer do with the new rule. These tests have been adjusted.
A few new test cases have been added to illustrate the rule.
The C and JS implementations have both been updated.
diff --git a/js/lib/inlines.js b/js/lib/inlines.js
@@ -87,8 +87,6 @@ var reFinalSpace = / *$/;
var reInitialSpace = /^ */;
-var reAsciiAlnum = /[a-z0-9]/i;
-
var reLinkLabel = /^\[(?:[^\\\[\]]|\\[\[\]]){0,1000}\]/;
// Matches a string of non-special characters.
@@ -238,6 +236,7 @@ var scanDelims = function(cc) {
var numdelims = 0;
var char_before, char_after, cc_after;
var startpos = this.pos;
+ var left_flanking, right_flanking, can_open, can_close;
char_before = this.pos === 0 ? '\n' :
this.subject.charAt(this.pos - 1);
@@ -254,17 +253,22 @@ var scanDelims = function(cc) {
char_after = fromCodePoint(cc_after);
}
- var can_open = numdelims > 0 && !(reWhitespaceChar.test(char_after)) &&
+ left_flanking = numdelims > 0 &&
+ !(reWhitespaceChar.test(char_after)) &&
!(rePunctuation.test(char_after) &&
!(/\s/.test(char_before)) &&
!(rePunctuation.test(char_before)));
- var can_close = numdelims > 0 && !(reWhitespaceChar.test(char_before)) &&
+ right_flanking = numdelims > 0 &&
+ !(reWhitespaceChar.test(char_before)) &&
!(rePunctuation.test(char_before) &&
!(reWhitespaceChar.test(char_after)) &&
!(rePunctuation.test(char_after)));
if (cc === C_UNDERSCORE) {
- can_open = can_open && !((reAsciiAlnum).test(char_before));
- can_close = can_close && !((reAsciiAlnum).test(char_after));
+ can_open = left_flanking && !right_flanking;
+ can_close = right_flanking && !left_flanking;
+ } else {
+ can_open = left_flanking;
+ can_close = right_flanking;
}
this.pos = startpos;
return { numdelims: numdelims,
diff --git a/spec.txt b/spec.txt
@@ -4547,28 +4547,28 @@ The following rules define emphasis and strong emphasis:
2. A single `_` character [can open emphasis] iff
it is part of a [left-flanking delimiter run]
- and is not preceded by an ASCII alphanumeric character.
+ and not part of a [right-flanking delimiter run].
3. A single `*` character [can close emphasis](@can-close-emphasis)
iff it is part of a [right-flanking delimiter run].
4. A single `_` character [can close emphasis]
- iff it is part of a [right-flanking delimiter run].
- and it is not followed by an ASCII alphanumeric character.
+ iff it is part of a [right-flanking delimiter run]
+ and not part of a [left-flanking delimiter run].
5. A double `**` [can open strong emphasis](@can-open-strong-emphasis)
iff it is part of a [left-flanking delimiter run].
6. A double `__` [can open strong emphasis]
iff it is part of a [left-flanking delimiter run]
- and is not preceded by an ASCII alphanumeric character.
+ and not part of a [right-flanking delimiter run].
7. A double `**` [can close strong emphasis](@can-close-strong-emphasis)
iff it is part of a [right-flanking delimiter run].
8. A double `__` [can close strong emphasis]
iff it is part of a [right-flanking delimiter run]
- and is not followed by an ASCII alphanumeric character.
+ and not part of a [left-flanking delimiter run].
9. Emphasis begins with a delimiter that [can open emphasis] and ends
with a delimiter that [can close emphasis], and that uses the same
@@ -4701,7 +4701,7 @@ a_"foo"_
<p>a_"foo"_</p>
.
-Emphasis with `_` is not allowed inside ASCII words:
+Emphasis with `_` is not allowed inside words:
.
foo_bar_
@@ -4715,12 +4715,28 @@ foo_bar_
<p>5_6_78</p>
.
-But it is permitted inside non-ASCII words:
-
.
пристаням_стремятся_
.
-<p>пристаням<em>стремятся</em></p>
+<p>пристаням_стремятся_</p>
+.
+
+Here `_` does not generate emphasis, because the first delimiter run
+is right-flanking and the second left-flanking:
+
+.
+aa_"bb"_cc
+.
+<p>aa_"bb"_cc</p>
+.
+
+Here there is no emphasis, because the delimiter runs are
+both left- and right-flanking:
+
+.
+"aa"_"bb"_"cc"
+.
+<p>"aa"_"bb"_"cc"</p>
.
Rule 3:
@@ -4810,7 +4826,7 @@ _foo_bar
.
_пристаням_стремятся
.
-<p><em>пристаням</em>стремятся</p>
+<p>_пристаням_стремятся</p>
.
.
@@ -4897,7 +4913,7 @@ foo__bar__
.
пристаням__стремятся__
.
-<p>пристаням<strong>стремятся</strong></p>
+<p>пристаням__стремятся__</p>
.
.
@@ -5000,7 +5016,7 @@ __foo__bar
.
__пристаням__стремятся
.
-<p><strong>пристаням</strong>стремятся</p>
+<p>__пристаням__стремятся</p>
.
.