Fixing a bug in pascal-mode

Fixing a bug in pascal-mode

[Feng Li]

Hi Emacs devs,

I just fixed a small bug in pascal-mode. Here's the diff

diff --git a/lisp/progmodes/pascal.el b/lisp/progmodes/pascal.el
index a693295..4058826 100644
--- a/lisp/progmodes/pascal.el
+++ b/lisp/progmodes/pascal.el
@@ -168,7 +168,7 @@
     ;;  "record" "array" "file")
     (,(concat "\\<\\(array\\|boolean\\|c\\(har\\|onst\\)\\|file\\|"
               "integer\\|re\\(al\\|cord\\)\\|type\\|var\\)\\>")
-     font-lock-type-face)
+     . font-lock-type-face)
     ("\\<\\(label\\|external\\|forward\\)\\>" . font-lock-constant-face)
     ("\\<\\([0-9]+\\)[ \t]*:" 1 font-lock-function-name-face)
     ;; ("of" "to" "for" "if" "then" "else" "case" "while"


-- 
Feng Li

Re: Fixing a bug in pascal-mode

[Feng Li]

Feng Li <fengli@gmail.com> writes:

> Hi Emacs devs,
>
> I just fixed a small bug in pascal-mode. Here's the diff
>
> diff --git a/lisp/progmodes/pascal.el b/lisp/progmodes/pascal.el
> index a693295..4058826 100644
> --- a/lisp/progmodes/pascal.el
> +++ b/lisp/progmodes/pascal.el
> @@ -168,7 +168,7 @@
>      ;;  "record" "array" "file")
>      (,(concat "\\<\\(array\\|boolean\\|c\\(har\\|onst\\)\\|file\\|"
>                "integer\\|re\\(al\\|cord\\)\\|type\\|var\\)\\>")
> -     font-lock-type-face)
> +     . font-lock-type-face)
>      ("\\<\\(label\\|external\\|forward\\)\\>" . font-lock-constant-face)
>      ("\\<\\([0-9]+\\)[ \t]*:" 1 font-lock-function-name-face)
>      ;; ("of" "to" "for" "if" "then" "else" "case" "while"


Another one,  this fixes pascal variables that contain keywords
surrounded by '_' chars (eg. do_this):

diff --git a/lisp/progmodes/pascal.el b/lisp/progmodes/pascal.el
index 4058826..10b7619 100644
--- a/lisp/progmodes/pascal.el
+++ b/lisp/progmodes/pascal.el
@@ -166,20 +166,20 @@
      (3 font-lock-function-name-face))
     ;; ("type" "const" "real" "integer" "char" "boolean" "var"
     ;;  "record" "array" "file")
-    (,(concat "\\<\\(array\\|boolean\\|c\\(har\\|onst\\)\\|file\\|"
-              "integer\\|re\\(al\\|cord\\)\\|type\\|var\\)\\>")
+    (,(concat "\\_<\\(array\\|boolean\\|c\\(har\\|onst\\)\\|file\\|"
+              "integer\\|re\\(al\\|cord\\)\\|type\\|var\\)\\_>")
      . font-lock-type-face)
-    ("\\<\\(label\\|external\\|forward\\)\\>" . font-lock-constant-face)
-    ("\\<\\([0-9]+\\)[ \t]*:" 1 font-lock-function-name-face)
+    ("\\_<\\(label\\|external\\|forward\\)\\_>" . font-lock-constant-face)
+    ("\\_<\\([0-9]+\\)[ \t]*:" 1 font-lock-function-name-face)
     ;; ("of" "to" "for" "if" "then" "else" "case" "while"
     ;;  "do" "until" "and" "or" "not" "in" "with" "repeat" "begin" "end")
-    ,(concat "\\<\\("
+    ,(concat "\\_<\\("
              "and\\|begin\\|case\\|do\\|e\\(lse\\|nd\\)\\|for\\|i[fn]\\|"
              "not\\|o[fr]\\|repeat\\|t\\(hen\\|o\\)\\|until\\|w\\(hile\\|ith\\)"
-             "\\)\\>")
-    ("\\<\\(goto\\)\\>[ \t]*\\([0-9]+\\)?"
+             "\\)\\_>")
+    ("\\_<\\(goto\\)\\_>[ \t]*\\([0-9]+\\)?"
      1 font-lock-keyword-face)
-    ("\\<\\(goto\\)\\>[ \t]*\\([0-9]+\\)?"
+    ("\\_<\\(goto\\)\\_>[ \t]*\\([0-9]+\\)?"
      2 font-lock-keyword-face t))
   "Additional expressions to highlight in Pascal mode.")


-- 
Feng Li

Re: Fixing a bug in pascal-mode

[Daniel Colascione]

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On 04/06/2014 03:40 AM, Feng Li wrote:
> Feng Li <fengli@gmail.com> writes:
> 
>> Hi Emacs devs,
>>
>> I just fixed a small bug in pascal-mode. Here's the diff
>>

Can you write a testcase?


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Re: Fixing a bug in pascal-mode

[Feng Li]

Daniel Colascione <dancol <at> dancol.org> writes:

> 
> On 04/06/2014 03:40 AM, Feng Li wrote:
> > Feng Li <fengli <at> gmail.com> writes:
> > 
> >> Hi Emacs devs,
> >>
> >> I just fixed a small bug in pascal-mode. Here's the diff
> >>
> 
> Can you write a testcase?
> 
> 

Hi Daniel,

I'm not sure what kind of testcase do you want. I had a brief look in the
source tree and didn't see any Pascal (or other languages) syntax
highlighting testcases under the 'test' directory, which I could use as
examples to write my testcases for these bugs.

I could describe the nature of the 2 bugs though as they are really quite
straightforward. So if you know how to write testcases probably you could help?

The first bug actually prevents any syntax highlighting rules after it to
run because that slot, if it's a list, then it should be a function rather
than a font lock class. Emacs prints out errors like "function is void:
font-lock-type-face" to the messages buffer.  If there is any existing
Pascal mode syntax highlighting testcases then most of them should already fail.

The second bug is that in the syntax table the '_' character is considered a
symbol delimiter but not a word delimiter. Therefore the regexps would match
sub-strings inside a symbol. For example, the variable 'value_to_rgb' would
have the 'to' matched as a keyword and the 'to' gets highlighted.

Hopefully this helps. 

--
Feng Li

Re: Fixing a bug in pascal-mode

[Stefan Monnier]

> I'm not sure what kind of testcase do you want. I had a brief look in the
> source tree and didn't see any Pascal (or other languages) syntax
> highlighting testcases under the 'test' directory, which I could use as
> examples to write my testcases for these bugs.

Just add to test/indent/pascal.pas a sample piece of Pascal code
where the bug shows up.


        Stefan

Re: Fixing a bug in pascal-mode

[Feng Li]

Here you go.

Note that there are 2 bugs and this is just a test case for the second
one.

This is because the first bug actually stops font lock from completing
so you'll only see very little syntax highlighting in the test
file. There is no need to add a test case for this as the entire file is
a test case.

Once the first bug is fixed then the syntax highlighting becomes much
richer and then you'll be able to see the second bug.

--->8------>8------>8------>8------>8------>8------>8------>8---

diff --git a/test/indent/pascal.pas b/test/indent/pascal.pas
index 4b3be7c..0005b95 100644
--- a/test/indent/pascal.pas
+++ b/test/indent/pascal.pas
@@ -29,6 +29,7 @@ by the GNU General Public License. }
 // Free-pascal style comment.
 var x:Char = 12 /* 45;   // This /* does not start a comment.
 var x:Char = (/ 4);      // This (/ does not start a comment.
+var a_to_b : integer;    // 'to' should not be highlighted
 
 program CRTDemo;




Stefan Monnier <monnier@IRO.UMontreal.CA> writes:

>> I'm not sure what kind of testcase do you want. I had a brief look in the
>> source tree and didn't see any Pascal (or other languages) syntax
>> highlighting testcases under the 'test' directory, which I could use as
>> examples to write my testcases for these bugs.
>
> Just add to test/indent/pascal.pas a sample piece of Pascal code
> where the bug shows up.
>
>
>         Stefan
>
>

-- 
Feng Li

Re: Fixing a bug in pascal-mode

[Stefan Monnier]

> Here you go.
> Note that there are 2 bugs and this is just a test case for the second
> one.

Cool, thanks, installed in emacs-24.


        Stefan