The home of 'Abort' is 'error' not 'util' however, a lot of code seems to be
confused about that and gives all the credit to 'util' instead of the
hardworking 'error'. In a spirit of equity, we break the cycle of injustice and
give back to 'error' the respect it deserves. And screw that 'util' poser.
For great justice.
It was introduced by 236440938a03, but the important code was removed by
fcf2407610f4. So there was no positive effect other than exhausting memory.
The problem spotted by 236440938a03 is that you can't use a generator keyword
more than once. For example, in hgweb template, "{child} {child}" doesn't work
because the first "{child}" consumes the generator. But as fcf2407610f4 says,
the fix was wrong because it could overwrite a callable keyword that returns
a generator. Also the fix didn't work for a generator of generator such as
"{diff}" keyword. So, the proper fix for that problem would be to not put
a generator in a keyword table. Instead, it should be a factory of a generator.
Note that this should fix the memory issue in hgweb, but my firefox killed by
OOM in place. Be careful to not use a modern web browser to test the issue4868.
This allows the latest class of tag to be found, such as a release candidate or
final build, instead of just the absolute latest.
It doesn't appear that the existing keyword can be given an optional argument.
There is a keyword, function and filter for 'date', so it doesn't seem harmful
to introduce a new function with the same name as an existing keyword. Most
functions are pretty Mercurial agnostic, but there is {revset()} as precedent.
Even though templatekw.getlatesttags() returns a single tuple, one entry of
which is a list, it is simplest to present this as a list of tags instead of a
single item, with each tag having a distance and change count attribute. It is
also closer to how {latesttag} returns a list of tags, and how this function
works when not given a '%' operator.
Because revset() function generates a list of revisions, it seems sensible
to switch the ctx as well where a list expression will be evaluated. I think
"{revset(...) % "..."}" expression wasn't considered well when it was
introduced at 45e0e191755f.
The keyword extension uses "utcdate" for a different function, so we can't
add new "utcdate" filter or function. Instead, this patch extends "localdate"
to a general timezone converter.
This will allow us to define both a primary expression, ":", and a prefix
operator, ":y". The ambiguity will be resolved by the next patch.
Prefix actions in elements table are adjusted as follows:
original prefix primary prefix
----------------- -------- -----------------
("group", 1, ")") -> n/a ("group", 1, ")")
("negate", 19) -> n/a ("negate", 19)
("symbol",) -> "symbol" n/a
"rawstring" was introduced by cd1b50e99ed8, but it's no longer necessary
because 4f14a9644001 and e99f4f59d2e9 changed the way of processing string
literals.
This patch moves string decoding to the parsing phase as it was before:
('rawstring', s) -> ('string', s)
('string', s) -> ('string', s.decode('string-escape'))
Instead of re-parsing quoted strings as templates, the tokenizer can delegate
the parsing of nested template strings to the parser. It has two benefits:
1. syntax errors can be reported with absolute positions
2. nested template can use quotes just like shell: "{"{rev}"}"
It doesn't sound nice that the tokenizer recurses into the parser. We could
instead make the tokenize itself recursive, but it would be much more
complicated because we would have to adjust binding strengths carefully and
put dummy infix operators to concatenate template fragments.
Now "string" token without r"" never appears. It will be removed by the next
patch.
This patch backs out 297d563e92af which should no longer be needed.
The test for '{\"invalid\"}' is removed because the parser is permissive for
\"...\" literal.
As of Mercurial 3.4, there were several syntax rules to process nested
template strings. Unfortunately, they were inconsistent and conflicted
each other.
a. buildmap() rule
- template string is _parsed_ as string, and parsed as template
- <\"> is not allowed in nested template:
{xs % "{f(\"{x}\")}"} -> parse error
- template escaping <\{> is handled consistently:
{xs % "\{x}"} -> escaped
b. _evalifliteral() rule
- template string is _interpreted_ as string, and parsed as template
in crafted environment to avoid double processing of escape sequences
- <\"> is allowed in nested template:
{if(x, "{f(\"{x}\")}")}
- <\{> and escape sequences in string literal in nested template are not
handled well
c. pad() rule
- template string is first interpreted as string, and parsed as template,
which means escape sequences are processed twice
- <\"> is allowed in nested template:
{pad("{xs % \"{x}\"}', 10)}
Because of the issue of template escaping, issue4714, 56e0b66a4c27 (in stable)
unified the rule (b) to (a). Then, 41e044cfb1ef (in default) unified the rule
(c) to (b) = (a). But they disabled the following syntax that was somewhat
considered valid.
{if(rev, "{if(rev, \"{rev}\")}")}
{pad("{files % \"{file}\"}", 10)}
So, this patch introduces \"...\" literal to work around the escaped-quoted
nested template strings. Because this parsing rule exists only for the backward
compatibility, it is designed to copy the behavior of old _evalifliteral() as
possible.
Future patches will introduce a better parsing rule similar to a command
substitution of POSIX shells or a string interpolation of Ruby, where extra
escapes won't be necessary at all.
{pad("{files % "{file}"}", 10)}
~~~~~~~~~~~~~~~~~~
parsed as a template, not as a string
Because <\> character wasn't allowed in a template fragment, this patch won't
introduce more breakages. But the syntax of nested templates are interpreted
differently by people, there might be unknown issues. So if we want, we could
instead remove e926f2ef639a, 72be08a15d8d and 56e0b66a4c27 from the stable
branch as the bug fixed by these patches existed for longer periods.
554d6fcc3c8, "strip single backslash before quotation mark in quoted template",
should be superseded by this patch. I'll remove it later.
Python 2.6 introduced the "except type as instance" syntax, replacing
the "except type, instance" syntax that came before. Python 3 dropped
support for the latter syntax. Since we no longer support Python 2.4 or
2.5, we have no need to continue supporting the "except type, instance".
This patch mass rewrites the exception syntax to be Python 2.6+ and
Python 3 compatible.
This patch was produced by running `2to3 -f except -w -n .`.
The backslash character should start escape sequences no matter if a string is
prefixed with 'r'. They are just not interpreted as escape sequences in raw
strings. revset.tokenize() handles them correctly, but templater didn't.
https://docs.python.org/2/reference/lexical_analysis.html#string-literals
This can simplify the interface of parse() function. Our tokenizer tends to
have optional arguments other than the message to be parsed.
Before this patch, the "lookup" argument existed only for the revset, and the
templater had to pack [program, start, end] to be passed to its tokenizer.
The problem was spotted at cd1b50e99ed8, that says "this patch invokes it
with "strtoken='rawstring'" in "_evalifliteral()", because "t" is the result
of "arg" evaluation and it should be "string-escape"-ed if "arg" is "string"
expression." This workaround is no longer valid since 72be08a15d8d introduced
strict parsing of '\{'.
Instead, we should interpret bare token as "string" or "rawstring" template.
This is what buildmap() does at parsing phase.
Because double backslashes are processed as a string escape sequence, '\\{'
should start the template syntax. On the other hand, r'' disables any sort
of \-escapes, so r'\{' can go either way, never start the template syntax
or always start it. I simply chose the latter, which means r'\{' is the same
as '\\{'.
This patch brings back pre-2.8.1 behavior.
The result of parsestring() is stored in templater's cache, t.cache, and then
it is parsed as a template string by compiletemplate(). So t.cache should keep
an unparsed string no matter if it is sourced from config value. Otherwise
backslashes would be processed twice.
The test vector is borrowed from 83ff877959a6.
The content of "hg help templating" is largely derived from docstrings
on functions providing functionality. Template functions are the long
holdout.
Prepare for generating them dynamically by defining docstrings for all
template functions.
There are numerous ways these docs could be improved. Right now, the
help output simply shows function names and arguments. So literally
any accurate data is better than what is there now.
I've tried to unify gettemplate() with buildtemplate(), but it didn't go well
because gettemplate() have to bypass mapping dict.
For example, web templates have '{tags%changelogtag}' and 'changelogtag' is
defined in both mapping, the default, and context.cache, sourced from map file.
In general, mapping shadows context variables, but gettemplate() have to pick
it from context.cache.
