Thanks. I confirm that this works, but I have 2 follow-up issues with
this patch:
1. It adds tags for some identifiers that AFAUI are actually
keywords, and shouldn't be in the TAGS tables. Examples:
"interface" (e.g., on line 146 of accumulator.m) and
"implementation" (e.g., on line 166). I guess this is unintended?
If so, how to fix it?
This is intended. I commented this in the commit message (one-word declarations).
I confirm that
':- implementation' and ':-interface' are formally declarations in Mercury as all others are.
They were not included in the previous version bercause of an incomplete switch.
It is quite useful from a practical point of view to add them to the tag base. When interfaces are big (they can reach a couple of thousand lines in real-world programming) it is sometimes useful to have a bookmark to jump to the start of the implementation section and back. I used to create an ad-hoc emacs bookmark for this. Tagging removes the need for this. Simply strike M-. at a blank line an select the interface/implementation tag.
In the C family this is the same as striking M-. on an header include declaration and jumping to the header file and back. Some IDEs use F4 for this. Think of Mercury interfaces as C headers.
2. It always produces "explicitly named" tags, which I think is
unnecessary. AFAICT, this is related to the following snippet from
mercury_pr:
> + /* Left-trim type definitions. */
> +
> + while (pos > namelength + offset
> + && c_isspace (s[pos - namelength - offset]))
> + --offset;
> +
> + /* There is no need to correct namelength or call notinname. */
> + s[pos - offset - 1] = '\0';
> +
> + make_tag (s + pos - namelength - offset, namelength, true, s, pos, lineno, linecharno);
> + return pos;
I don't understand why you need to overwrite s[pos - offset -1]
with the null byte: the same effect could be obtained by adjusting
the POS argument passed to make_tag. Also, you in effect chop off
the last character of NAME, but don't adjust NAMELENGTH
accordingly. These factors together cause make_tag to decide that
an explicitly-named tag is in order, because name[namelength-1] is
a null byte, which is rejected as being "not-a-name" character.
To fix this second issue, I propose the change below, which should
be applied on top of your patches:
diff --git a/lib-src/etags.c b/lib-src/etags.c
index 370e825..2b0288e 100644
--- a/lib-src/etags.c
+++ b/lib-src/etags.c
@@ -6585,10 +6585,8 @@ mercury_pr (char *s, char *last, ptrdiff_t lastlen)
&& c_isspace (s[pos - namelength - offset]))
--offset;
- /* There is no need to correct namelength or call notinname. */
- s[pos - offset - 1] = '\0';
-
- make_tag (s + pos - namelength - offset, namelength, true, s, pos, lineno, linecharno);
+ make_tag (s + pos - namelength - offset, namelength - 1, true,
+ s, pos - offset - 1, lineno, linecharno);
return pos;
}
I've verified that etags after this change still produces the correct
TAGS file, including for the file univ.m you sent up-thread.
Do you agree with the changes I propose? If not, could you please
explain what I miss here?
OK, this is another way of achieving an equivalent result. Please leave me until tomorrow to perform more tests so that I can formally confirm that this is fine.
Best
Fabrice