issue 165: hashes after curly brackets should not be treated as a line comment in bash/perl

Author: mikesamuel@gmail.com

js-modules/prettify.js

@@ -469,7 +469,7 @@ var prettyPrint;
         } else {
           // Stop C preprocessor declarations at an unclosed open comment
           shortcutStylePatterns.push(
-              [PR_COMMENT, /^#(?:(?:define|elif|else|endif|error|ifdef|include|ifndef|line|pragma|undef|warning)\b|[^\r\n]*)/,
+              [PR_COMMENT, /^#(?:(?:define|e(?:l|nd)if|else|error|ifn?def|include|line|pragma|undef|warning)\b|[^\r\n]*)/,
                null, '#']);
         }
         // #include <stdio.h>
@@ -523,6 +523,45 @@ var prettyPrint;
     }
 
     shortcutStylePatterns.push([PR_PLAIN,       /^\s+/, null, ' \r\n\t\xA0']);
+
+    var punctuation =
+      // The Bash man page says
+
+      // A word is a sequence of characters considered as a single
+      // unit by GRUB. Words are separated by metacharacters,
+      // which are the following plus space, tab, and newline: { }
+      // | & $ ; < >
+      // ...
+      
+      // A word beginning with # causes that word and all remaining
+      // characters on that line to be ignored.
+
+      // which means that only a '#' after /(?:^|[{}|&$;<>\s])/ starts a
+      // comment but empirically
+      // $ echo {#}
+      // {#}
+      // $ echo \$#
+      // $#
+      // $ echo }#
+      // }#
+
+      // so /(?:^|[|&;<>\s])/ is more appropriate.
+
+      // http://gcc.gnu.org/onlinedocs/gcc-2.95.3/cpp_1.html#SEC3
+      // suggests that this definition is compatible with a
+      // default mode that tries to use a single token definition
+      // to recognize both bash/python style comments and C
+      // preprocessor directives.
+
+      // This definition of punctuation does not include # in the list of
+      // follow-on exclusions, so # will not be broken before if preceeded
+      // by a punctuation character.  We could try to exclude # after
+      // [|&;<>] but that doesn't seem to cause many major problems.
+      // If that does turn out to be a problem, we should change the below
+      // when hc is truthy to include # in the run of punctuation characters
+      // only when not followint [|&;<>].
+      /^.[^\s\w\.$@\'\"\`\/\\]*/;
+
     fallthroughStylePatterns.push(
         // TODO(mikesamuel): recognize non-latin letters and numerals in idents
         [PR_LITERAL,     /^@[a-z_$][a-z_$@0-9]*/i, null],
@@ -543,7 +582,7 @@ var prettyPrint;
          null, '0123456789'],
         // Don't treat escaped quotes in bash as starting strings.  See issue 144.
         [PR_PLAIN,       /^\\[\s\S]?/, null],
-        [PR_PUNCTUATION, /^.[^\s\w\.$@\'\"\`\/\#\\]*/, null]);
+        [PR_PUNCTUATION, punctuation, null]);
 
     return createSimpleLexer(shortcutStylePatterns, fallthroughStylePatterns);
   }

src/prettify.js

@@ -829,7 +829,7 @@ var REGEXP_PRECEDER_PATTERN = '(?:^^\\.?|[+-]|[!=]=?=?|\\#|%=?|&&?=?|\\(|\\*=?|[
         } else {
           // Stop C preprocessor declarations at an unclosed open comment
           shortcutStylePatterns.push(
-              [PR_COMMENT, /^#(?:(?:define|elif|else|endif|error|ifdef|include|ifndef|line|pragma|undef|warning)\b|[^\r\n]*)/,
+              [PR_COMMENT, /^#(?:(?:define|e(?:l|nd)if|else|error|ifn?def|include|line|pragma|undef|warning)\b|[^\r\n]*)/,
                null, '#']);
         }
         // #include <stdio.h>
@@ -883,6 +883,45 @@ var REGEXP_PRECEDER_PATTERN = '(?:^^\\.?|[+-]|[!=]=?=?|\\#|%=?|&&?=?|\\(|\\*=?|[
     }
 
     shortcutStylePatterns.push([PR_PLAIN,       /^\s+/, null, ' \r\n\t\xA0']);
+
+    var punctuation =
+      // The Bash man page says
+
+      // A word is a sequence of characters considered as a single
+      // unit by GRUB. Words are separated by metacharacters,
+      // which are the following plus space, tab, and newline: { }
+      // | & $ ; < >
+      // ...
+      
+      // A word beginning with # causes that word and all remaining
+      // characters on that line to be ignored.
+
+      // which means that only a '#' after /(?:^|[{}|&$;<>\s])/ starts a
+      // comment but empirically
+      // $ echo {#}
+      // {#}
+      // $ echo \$#
+      // $#
+      // $ echo }#
+      // }#
+
+      // so /(?:^|[|&;<>\s])/ is more appropriate.
+
+      // http://gcc.gnu.org/onlinedocs/gcc-2.95.3/cpp_1.html#SEC3
+      // suggests that this definition is compatible with a
+      // default mode that tries to use a single token definition
+      // to recognize both bash/python style comments and C
+      // preprocessor directives.
+
+      // This definition of punctuation does not include # in the list of
+      // follow-on exclusions, so # will not be broken before if preceeded
+      // by a punctuation character.  We could try to exclude # after
+      // [|&;<>] but that doesn't seem to cause many major problems.
+      // If that does turn out to be a problem, we should change the below
+      // when hc is truthy to include # in the run of punctuation characters
+      // only when not followint [|&;<>].
+      /^.[^\s\w\.$@\'\"\`\/\\]*/;
+
     fallthroughStylePatterns.push(
         // TODO(mikesamuel): recognize non-latin letters and numerals in idents
         [PR_LITERAL,     /^@[a-z_$][a-z_$@0-9]*/i, null],
@@ -903,7 +942,7 @@ var REGEXP_PRECEDER_PATTERN = '(?:^^\\.?|[+-]|[!=]=?=?|\\#|%=?|&&?=?|\\(|\\*=?|[
          null, '0123456789'],
         // Don't treat escaped quotes in bash as starting strings.  See issue 144.
         [PR_PLAIN,       /^\\[\s\S]?/, null],
-        [PR_PUNCTUATION, /^.[^\s\w\.$@\'\"\`\/\#\\]*/, null]);
+        [PR_PUNCTUATION, punctuation, null]);
 
     return createSimpleLexer(shortcutStylePatterns, fallthroughStylePatterns);
   }

tests/prettify_test.html

@@ -87,6 +87,11 @@ <h1>Bash w/ language specified</h1>
 fib | /usr/bin/*head -10 | tail -1
 </pre>
 
+<h1>Issue 165</h1>
+<pre class="prettyprint lang-sh" id="issue_165"># Comment
+local $x = ${#x[@]}  # Previous is not a comment
+# A comment</pre>
+
 <h1>C</h1>
 
 <pre class="prettyprint" id="C">
@@ -1368,7 +1373,12 @@ <h1>Go mode</h1>
       '`#6`PLNfib `END`PUN|`END`PLN `END`PUN/`END`PLNusr`END`PUN/`END`PLNbin`END' +
           '`PUN/*`END`PLNhead `END`PUN-`END`LIT10`END`PLN `END`PUN|`END' +
           '`PLN tail `END`PUN-`END`LIT1`END</li></ol>'),
-  C: (
+  issue_165: (
+      '`COM# Comment`END`PLN\n' +
+      '`END`KWDlocal`END`PLN $x `END`PUN=`END`PLN $`END`PUN{#`END`PLNx`END`PUN[@]}`END`PLN  `END'
+          + '`COM# Previous is not a comment`END`PLN\n' +
+      '`END`COM# A comment`END'),
+ C: (
       '`COM#include`END`PLN `END`STR&lt;stdio.h&gt;`END`PLN\n' +
       '\n' +
       '`END`COM/* the n-th fibonacci number.\n' +