help: populate template functions via docstrings

We do this for revsets, template keywrods, and template filters. Now we
do it for template functions as well.

mercurial/help.py

@@ -9,6 +9,7 b' from i18n import gettext, _'
 import itertools, os, textwrap
 import error
 import extensions, revset, fileset, templatekw, templatefilters, filemerge
+import templater
 import encoding, util, minirst
 import cmdutil
 import hgweb.webcommands as webcommands
@@ -209,6 +210,7 b" addtopicsymbols('merge-tools', '.. inter"
 addtopicsymbols('revsets', '.. predicatesmarker', revset.symbols)
 addtopicsymbols('templates', '.. keywordsmarker', templatekw.dockeywords)
 addtopicsymbols('templates', '.. filtersmarker', templatefilters.filters)
+addtopicsymbols('templates', '.. functionsmarker', templater.funcs)
 addtopicsymbols('hgweb', '.. webcommandsmarker', webcommands.commands,
                 dedent=True)
 

mercurial/help/templates.txt

@@ -41,39 +41,7 b' Note that a filter is nothing more than '
 
 In addition to filters, there are some basic built-in functions:
 
-- date(date[, fmt])
-
-- diff([includepattern [, excludepattern]])
-
-- fill(text[, width])
-
-- get(dict, key)
-
-- if(expr, then[, else])
-
-- ifcontains(expr, expr, then[, else])
-
-- ifeq(expr, expr, then[, else])
-
-- join(list, sep)
-
-- label(label, expr)
-
-- pad(text, width[, fillchar, right])
-
-- revset(query[, formatargs])
-
-- rstdoc(text, style)
-
-- shortest(node)
-
-- startswith(string, text)
-
-- strip(text[, chars])
-
-- sub(pat, repl, expr)
-
-- word(number, text[, separator])
+.. functionsmarker
 
 Also, for any expression that returns a list, there is a list operator: