templater: remember cache key of evaluated revset

This provides a hint for caching further computation result of the given
revset. See the next patch for example.

mercurial/templatefuncs.py

@@ -1,880 +1,882
 # templatefuncs.py - common template functions
 #
 # Copyright 2005, 2006 Matt Mackall <[e-mail]>
 #
 # This software may be used and distributed according to the terms of the
 # GNU General Public License version 2 or any later version.
 
 from __future__ import absolute_import
 
 import re
 
 from .i18n import _
 from .node import (
     bin,
     wdirid,
 )
 from . import (
     color,
     diffutil,
     encoding,
     error,
     minirst,
     obsutil,
     pycompat,
     registrar,
     revset as revsetmod,
     revsetlang,
     scmutil,
     templatefilters,
     templatekw,
     templateutil,
     util,
 )
 from .utils import (
     dateutil,
     stringutil,
 )
 
 evalrawexp = templateutil.evalrawexp
 evalwrapped = templateutil.evalwrapped
 evalfuncarg = templateutil.evalfuncarg
 evalboolean = templateutil.evalboolean
 evaldate = templateutil.evaldate
 evalinteger = templateutil.evalinteger
 evalstring = templateutil.evalstring
 evalstringliteral = templateutil.evalstringliteral
 
 # dict of template built-in functions
 funcs = {}
 templatefunc = registrar.templatefunc(funcs)
 
 
 @templatefunc(b'date(date[, fmt])')
 def date(context, mapping, args):
     """Format a date. See :hg:`help dates` for formatting
     strings. The default is a Unix date format, including the timezone:
     "Mon Sep 04 15:13:13 2006 0700"."""
     if not (1 <= len(args) <= 2):
         # i18n: "date" is a keyword
         raise error.ParseError(_(b"date expects one or two arguments"))
 
     date = evaldate(
         context,
         mapping,
         args[0],
         # i18n: "date" is a keyword
         _(b"date expects a date information"),
     )
     fmt = None
     if len(args) == 2:
         fmt = evalstring(context, mapping, args[1])
     if fmt is None:
         return dateutil.datestr(date)
     else:
         return dateutil.datestr(date, fmt)
 
 
 @templatefunc(b'dict([[key=]value...])', argspec=b'*args **kwargs')
 def dict_(context, mapping, args):
     """Construct a dict from key-value pairs. A key may be omitted if
     a value expression can provide an unambiguous name."""
     data = util.sortdict()
 
     for v in args[b'args']:
         k = templateutil.findsymbolicname(v)
         if not k:
             raise error.ParseError(_(b'dict key cannot be inferred'))
         if k in data or k in args[b'kwargs']:
             raise error.ParseError(_(b"duplicated dict key '%s' inferred") % k)
         data[k] = evalfuncarg(context, mapping, v)
 
     data.update(
         (k, evalfuncarg(context, mapping, v))
         for k, v in pycompat.iteritems(args[b'kwargs'])
     )
     return templateutil.hybriddict(data)
 
 
 @templatefunc(
     b'diff([includepattern [, excludepattern]])', requires={b'ctx', b'ui'}
 )
 def diff(context, mapping, args):
     """Show a diff, optionally
     specifying files to include or exclude."""
     if len(args) > 2:
         # i18n: "diff" is a keyword
         raise error.ParseError(_(b"diff expects zero, one, or two arguments"))
 
     def getpatterns(i):
         if i < len(args):
             s = evalstring(context, mapping, args[i]).strip()
             if s:
                 return [s]
         return []
 
     ctx = context.resource(mapping, b'ctx')
     ui = context.resource(mapping, b'ui')
     diffopts = diffutil.diffallopts(ui)
     chunks = ctx.diff(
         match=ctx.match([], getpatterns(0), getpatterns(1)), opts=diffopts
     )
 
     return b''.join(chunks)
 
 
 @templatefunc(
     b'extdata(source)', argspec=b'source', requires={b'ctx', b'cache'}
 )
 def extdata(context, mapping, args):
     """Show a text read from the specified extdata source. (EXPERIMENTAL)"""
     if b'source' not in args:
         # i18n: "extdata" is a keyword
         raise error.ParseError(_(b'extdata expects one argument'))
 
     source = evalstring(context, mapping, args[b'source'])
     if not source:
         sym = templateutil.findsymbolicname(args[b'source'])
         if sym:
             raise error.ParseError(
                 _(b'empty data source specified'),
                 hint=_(b"did you mean extdata('%s')?") % sym,
             )
         else:
             raise error.ParseError(_(b'empty data source specified'))
     cache = context.resource(mapping, b'cache').setdefault(b'extdata', {})
     ctx = context.resource(mapping, b'ctx')
     if source in cache:
         data = cache[source]
     else:
         data = cache[source] = scmutil.extdatasource(ctx.repo(), source)
     return data.get(ctx.rev(), b'')
 
 
 @templatefunc(b'files(pattern)', requires={b'ctx'})
 def files(context, mapping, args):
     """All files of the current changeset matching the pattern. See
     :hg:`help patterns`."""
     if not len(args) == 1:
         # i18n: "files" is a keyword
         raise error.ParseError(_(b"files expects one argument"))
 
     raw = evalstring(context, mapping, args[0])
     ctx = context.resource(mapping, b'ctx')
     m = ctx.match([raw])
     files = list(ctx.matches(m))
     return templateutil.compatfileslist(context, mapping, b"file", files)
 
 
 @templatefunc(b'fill(text[, width[, initialident[, hangindent]]])')
 def fill(context, mapping, args):
     """Fill many
     paragraphs with optional indentation. See the "fill" filter."""
     if not (1 <= len(args) <= 4):
         # i18n: "fill" is a keyword
         raise error.ParseError(_(b"fill expects one to four arguments"))
 
     text = evalstring(context, mapping, args[0])
     width = 76
     initindent = b''
     hangindent = b''
     if 2 <= len(args) <= 4:
         width = evalinteger(
             context,
             mapping,
             args[1],
             # i18n: "fill" is a keyword
             _(b"fill expects an integer width"),
         )
         try:
             initindent = evalstring(context, mapping, args[2])
             hangindent = evalstring(context, mapping, args[3])
         except IndexError:
             pass
 
     return templatefilters.fill(text, width, initindent, hangindent)
 
 
 @templatefunc(b'filter(iterable[, expr])')
 def filter_(context, mapping, args):
     """Remove empty elements from a list or a dict. If expr specified, it's
     applied to each element to test emptiness."""
     if not (1 <= len(args) <= 2):
         # i18n: "filter" is a keyword
         raise error.ParseError(_(b"filter expects one or two arguments"))
     iterable = evalwrapped(context, mapping, args[0])
     if len(args) == 1:
 
         def select(w):
             return w.tobool(context, mapping)
 
     else:
 
         def select(w):
             if not isinstance(w, templateutil.mappable):
                 raise error.ParseError(_(b"not filterable by expression"))
             lm = context.overlaymap(mapping, w.tomap(context))
             return evalboolean(context, lm, args[1])
 
     return iterable.filter(context, mapping, select)
 
 
 @templatefunc(b'formatnode(node)', requires={b'ui'})
 def formatnode(context, mapping, args):
     """Obtain the preferred form of a changeset hash. (DEPRECATED)"""
     if len(args) != 1:
         # i18n: "formatnode" is a keyword
         raise error.ParseError(_(b"formatnode expects one argument"))
 
     ui = context.resource(mapping, b'ui')
     node = evalstring(context, mapping, args[0])
     if ui.debugflag:
         return node
     return templatefilters.short(node)
 
 
 @templatefunc(b'mailmap(author)', requires={b'repo', b'cache'})
 def mailmap(context, mapping, args):
     """Return the author, updated according to the value
     set in the .mailmap file"""
     if len(args) != 1:
         raise error.ParseError(_(b"mailmap expects one argument"))
 
     author = evalstring(context, mapping, args[0])
 
     cache = context.resource(mapping, b'cache')
     repo = context.resource(mapping, b'repo')
 
     if b'mailmap' not in cache:
         data = repo.wvfs.tryread(b'.mailmap')
         cache[b'mailmap'] = stringutil.parsemailmap(data)
 
     return stringutil.mapname(cache[b'mailmap'], author)
 
 
 @templatefunc(
     b'pad(text, width[, fillchar=\' \'[, left=False[, truncate=False]]])',
     argspec=b'text width fillchar left truncate',
 )
 def pad(context, mapping, args):
     """Pad text with a
     fill character."""
     if b'text' not in args or b'width' not in args:
         # i18n: "pad" is a keyword
         raise error.ParseError(_(b"pad() expects two to four arguments"))
 
     width = evalinteger(
         context,
         mapping,
         args[b'width'],
         # i18n: "pad" is a keyword
         _(b"pad() expects an integer width"),
     )
 
     text = evalstring(context, mapping, args[b'text'])
 
     truncate = False
     left = False
     fillchar = b' '
     if b'fillchar' in args:
         fillchar = evalstring(context, mapping, args[b'fillchar'])
         if len(color.stripeffects(fillchar)) != 1:
             # i18n: "pad" is a keyword
             raise error.ParseError(_(b"pad() expects a single fill character"))
     if b'left' in args:
         left = evalboolean(context, mapping, args[b'left'])
     if b'truncate' in args:
         truncate = evalboolean(context, mapping, args[b'truncate'])
 
     fillwidth = width - encoding.colwidth(color.stripeffects(text))
     if fillwidth < 0 and truncate:
         return encoding.trim(color.stripeffects(text), width, leftside=left)
     if fillwidth <= 0:
         return text
     if left:
         return fillchar * fillwidth + text
     else:
         return text + fillchar * fillwidth
 
 
 @templatefunc(b'indent(text, indentchars[, firstline])')
 def indent(context, mapping, args):
     """Indents all non-empty lines
     with the characters given in the indentchars string. An optional
     third parameter will override the indent for the first line only
     if present."""
     if not (2 <= len(args) <= 3):
         # i18n: "indent" is a keyword
         raise error.ParseError(_(b"indent() expects two or three arguments"))
 
     text = evalstring(context, mapping, args[0])
     indent = evalstring(context, mapping, args[1])
 
     firstline = indent
     if len(args) == 3:
         firstline = evalstring(context, mapping, args[2])
 
     return templatefilters.indent(text, indent, firstline=firstline)
 
 
 @templatefunc(b'get(dict, key)')
 def get(context, mapping, args):
     """Get an attribute/key from an object. Some keywords
     are complex types. This function allows you to obtain the value of an
     attribute on these types."""
     if len(args) != 2:
         # i18n: "get" is a keyword
         raise error.ParseError(_(b"get() expects two arguments"))
 
     dictarg = evalwrapped(context, mapping, args[0])
     key = evalrawexp(context, mapping, args[1])
     try:
         return dictarg.getmember(context, mapping, key)
     except error.ParseError as err:
         # i18n: "get" is a keyword
         hint = _(b"get() expects a dict as first argument")
         raise error.ParseError(bytes(err), hint=hint)
 
 
 @templatefunc(b'config(section, name[, default])', requires={b'ui'})
 def config(context, mapping, args):
     """Returns the requested hgrc config option as a string."""
     fn = context.resource(mapping, b'ui').config
     return _config(context, mapping, args, fn, evalstring)
 
 
 @templatefunc(b'configbool(section, name[, default])', requires={b'ui'})
 def configbool(context, mapping, args):
     """Returns the requested hgrc config option as a boolean."""
     fn = context.resource(mapping, b'ui').configbool
     return _config(context, mapping, args, fn, evalboolean)
 
 
 @templatefunc(b'configint(section, name[, default])', requires={b'ui'})
 def configint(context, mapping, args):
     """Returns the requested hgrc config option as an integer."""
     fn = context.resource(mapping, b'ui').configint
     return _config(context, mapping, args, fn, evalinteger)
 
 
 def _config(context, mapping, args, configfn, defaultfn):
     if not (2 <= len(args) <= 3):
         raise error.ParseError(_(b"config expects two or three arguments"))
 
     # The config option can come from any section, though we specifically
     # reserve the [templateconfig] section for dynamically defining options
     # for this function without also requiring an extension.
     section = evalstringliteral(context, mapping, args[0])
     name = evalstringliteral(context, mapping, args[1])
     if len(args) == 3:
         default = defaultfn(context, mapping, args[2])
         return configfn(section, name, default)
     else:
         return configfn(section, name)
 
 
 @templatefunc(b'if(expr, then[, else])')
 def if_(context, mapping, args):
     """Conditionally execute based on the result of
     an expression."""
     if not (2 <= len(args) <= 3):
         # i18n: "if" is a keyword
         raise error.ParseError(_(b"if expects two or three arguments"))
 
     test = evalboolean(context, mapping, args[0])
     if test:
         return evalrawexp(context, mapping, args[1])
     elif len(args) == 3:
         return evalrawexp(context, mapping, args[2])
 
 
 @templatefunc(b'ifcontains(needle, haystack, then[, else])')
 def ifcontains(context, mapping, args):
     """Conditionally execute based
     on whether the item "needle" is in "haystack"."""
     if not (3 <= len(args) <= 4):
         # i18n: "ifcontains" is a keyword
         raise error.ParseError(_(b"ifcontains expects three or four arguments"))
 
     haystack = evalwrapped(context, mapping, args[1])
     try:
         needle = evalrawexp(context, mapping, args[0])
         found = haystack.contains(context, mapping, needle)
     except error.ParseError:
         found = False
 
     if found:
         return evalrawexp(context, mapping, args[2])
     elif len(args) == 4:
         return evalrawexp(context, mapping, args[3])
 
 
 @templatefunc(b'ifeq(expr1, expr2, then[, else])')
 def ifeq(context, mapping, args):
     """Conditionally execute based on
     whether 2 items are equivalent."""
     if not (3 <= len(args) <= 4):
         # i18n: "ifeq" is a keyword
         raise error.ParseError(_(b"ifeq expects three or four arguments"))
 
     test = evalstring(context, mapping, args[0])
     match = evalstring(context, mapping, args[1])
     if test == match:
         return evalrawexp(context, mapping, args[2])
     elif len(args) == 4:
         return evalrawexp(context, mapping, args[3])
 
 
 @templatefunc(b'join(list, sep)')
 def join(context, mapping, args):
     """Join items in a list with a delimiter."""
     if not (1 <= len(args) <= 2):
         # i18n: "join" is a keyword
         raise error.ParseError(_(b"join expects one or two arguments"))
 
     joinset = evalwrapped(context, mapping, args[0])
     joiner = b" "
     if len(args) > 1:
         joiner = evalstring(context, mapping, args[1])
     return joinset.join(context, mapping, joiner)
 
 
 @templatefunc(b'label(label, expr)', requires={b'ui'})
 def label(context, mapping, args):
     """Apply a label to generated content. Content with
     a label applied can result in additional post-processing, such as
     automatic colorization."""
     if len(args) != 2:
         # i18n: "label" is a keyword
         raise error.ParseError(_(b"label expects two arguments"))
 
     ui = context.resource(mapping, b'ui')
     thing = evalstring(context, mapping, args[1])
     # preserve unknown symbol as literal so effects like 'red', 'bold',
     # etc. don't need to be quoted
     label = evalstringliteral(context, mapping, args[0])
 
     return ui.label(thing, label)
 
 
 @templatefunc(b'latesttag([pattern])')
 def latesttag(context, mapping, args):
     """The global tags matching the given pattern on the
     most recent globally tagged ancestor of this changeset.
     If no such tags exist, the "{tag}" template resolves to
     the string "null". See :hg:`help revisions.patterns` for the pattern
     syntax.
     """
     if len(args) > 1:
         # i18n: "latesttag" is a keyword
         raise error.ParseError(_(b"latesttag expects at most one argument"))
 
     pattern = None
     if len(args) == 1:
         pattern = evalstring(context, mapping, args[0])
     return templatekw.showlatesttags(context, mapping, pattern)
 
 
 @templatefunc(b'localdate(date[, tz])')
 def localdate(context, mapping, args):
     """Converts a date to the specified timezone.
     The default is local date."""
     if not (1 <= len(args) <= 2):
         # i18n: "localdate" is a keyword
         raise error.ParseError(_(b"localdate expects one or two arguments"))
 
     date = evaldate(
         context,
         mapping,
         args[0],
         # i18n: "localdate" is a keyword
         _(b"localdate expects a date information"),
     )
     if len(args) >= 2:
         tzoffset = None
         tz = evalfuncarg(context, mapping, args[1])
         if isinstance(tz, bytes):
             tzoffset, remainder = dateutil.parsetimezone(tz)
             if remainder:
                 tzoffset = None
         if tzoffset is None:
             try:
                 tzoffset = int(tz)
             except (TypeError, ValueError):
                 # i18n: "localdate" is a keyword
                 raise error.ParseError(_(b"localdate expects a timezone"))
     else:
         tzoffset = dateutil.makedate()[1]
     return templateutil.date((date[0], tzoffset))
 
 
 @templatefunc(b'max(iterable)')
 def max_(context, mapping, args, **kwargs):
     """Return the max of an iterable"""
     if len(args) != 1:
         # i18n: "max" is a keyword
         raise error.ParseError(_(b"max expects one argument"))
 
     iterable = evalwrapped(context, mapping, args[0])
     try:
         return iterable.getmax(context, mapping)
     except error.ParseError as err:
         # i18n: "max" is a keyword
         hint = _(b"max first argument should be an iterable")
         raise error.ParseError(bytes(err), hint=hint)
 
 
 @templatefunc(b'min(iterable)')
 def min_(context, mapping, args, **kwargs):
     """Return the min of an iterable"""
     if len(args) != 1:
         # i18n: "min" is a keyword
         raise error.ParseError(_(b"min expects one argument"))
 
     iterable = evalwrapped(context, mapping, args[0])
     try:
         return iterable.getmin(context, mapping)
     except error.ParseError as err:
         # i18n: "min" is a keyword
         hint = _(b"min first argument should be an iterable")
         raise error.ParseError(bytes(err), hint=hint)
 
 
 @templatefunc(b'mod(a, b)')
 def mod(context, mapping, args):
     """Calculate a mod b such that a / b + a mod b == a"""
     if not len(args) == 2:
         # i18n: "mod" is a keyword
         raise error.ParseError(_(b"mod expects two arguments"))
 
     func = lambda a, b: a % b
     return templateutil.runarithmetic(
         context, mapping, (func, args[0], args[1])
     )
 
 
 @templatefunc(b'obsfateoperations(markers)')
 def obsfateoperations(context, mapping, args):
     """Compute obsfate related information based on markers (EXPERIMENTAL)"""
     if len(args) != 1:
         # i18n: "obsfateoperations" is a keyword
         raise error.ParseError(_(b"obsfateoperations expects one argument"))
 
     markers = evalfuncarg(context, mapping, args[0])
 
     try:
         data = obsutil.markersoperations(markers)
         return templateutil.hybridlist(data, name=b'operation')
     except (TypeError, KeyError):
         # i18n: "obsfateoperations" is a keyword
         errmsg = _(b"obsfateoperations first argument should be an iterable")
         raise error.ParseError(errmsg)
 
 
 @templatefunc(b'obsfatedate(markers)')
 def obsfatedate(context, mapping, args):
     """Compute obsfate related information based on markers (EXPERIMENTAL)"""
     if len(args) != 1:
         # i18n: "obsfatedate" is a keyword
         raise error.ParseError(_(b"obsfatedate expects one argument"))
 
     markers = evalfuncarg(context, mapping, args[0])
 
     try:
         # TODO: maybe this has to be a wrapped list of date wrappers?
         data = obsutil.markersdates(markers)
         return templateutil.hybridlist(data, name=b'date', fmt=b'%d %d')
     except (TypeError, KeyError):
         # i18n: "obsfatedate" is a keyword
         errmsg = _(b"obsfatedate first argument should be an iterable")
         raise error.ParseError(errmsg)
 
 
 @templatefunc(b'obsfateusers(markers)')
 def obsfateusers(context, mapping, args):
     """Compute obsfate related information based on markers (EXPERIMENTAL)"""
     if len(args) != 1:
         # i18n: "obsfateusers" is a keyword
         raise error.ParseError(_(b"obsfateusers expects one argument"))
 
     markers = evalfuncarg(context, mapping, args[0])
 
     try:
         data = obsutil.markersusers(markers)
         return templateutil.hybridlist(data, name=b'user')
     except (TypeError, KeyError, ValueError):
         # i18n: "obsfateusers" is a keyword
         msg = _(
             b"obsfateusers first argument should be an iterable of "
             b"obsmakers"
         )
         raise error.ParseError(msg)
 
 
 @templatefunc(b'obsfateverb(successors, markers)')
 def obsfateverb(context, mapping, args):
     """Compute obsfate related information based on successors (EXPERIMENTAL)"""
     if len(args) != 2:
         # i18n: "obsfateverb" is a keyword
         raise error.ParseError(_(b"obsfateverb expects two arguments"))
 
     successors = evalfuncarg(context, mapping, args[0])
     markers = evalfuncarg(context, mapping, args[1])
 
     try:
         return obsutil.obsfateverb(successors, markers)
     except TypeError:
         # i18n: "obsfateverb" is a keyword
         errmsg = _(b"obsfateverb first argument should be countable")
         raise error.ParseError(errmsg)
 
 
 @templatefunc(b'relpath(path)', requires={b'repo'})
 def relpath(context, mapping, args):
     """Convert a repository-absolute path into a filesystem path relative to
     the current working directory."""
     if len(args) != 1:
         # i18n: "relpath" is a keyword
         raise error.ParseError(_(b"relpath expects one argument"))
 
     repo = context.resource(mapping, b'repo')
     path = evalstring(context, mapping, args[0])
     return repo.pathto(path)
 
 
 @templatefunc(b'revset(query[, formatargs...])', requires={b'repo', b'cache'})
 def revset(context, mapping, args):
     """Execute a revision set query. See
     :hg:`help revset`."""
     if not len(args) > 0:
         # i18n: "revset" is a keyword
         raise error.ParseError(_(b"revset expects one or more arguments"))
 
     raw = evalstring(context, mapping, args[0])
     repo = context.resource(mapping, b'repo')
 
     def query(expr):
         m = revsetmod.match(repo.ui, expr, lookup=revsetmod.lookupfn(repo))
         return m(repo)
 
     if len(args) > 1:
+        key = None  # dynamically-created revs shouldn't be cached
         formatargs = [evalfuncarg(context, mapping, a) for a in args[1:]]
         revs = query(revsetlang.formatspec(raw, *formatargs))
     else:
         cache = context.resource(mapping, b'cache')
         revsetcache = cache.setdefault(b"revsetcache", {})
-        if raw in revsetcache:
-            revs = revsetcache[raw]
+        key = raw
+        if key in revsetcache:
+            revs = revsetcache[key]
         else:
             revs = query(raw)
-            revsetcache[raw] = revs
-    return templateutil.revslist(repo, revs, name=b'revision')
+            revsetcache[key] = revs
+    return templateutil.revslist(repo, revs, name=b'revision', cachekey=key)
 
 
 @templatefunc(b'rstdoc(text, style)')
 def rstdoc(context, mapping, args):
     """Format reStructuredText."""
     if len(args) != 2:
         # i18n: "rstdoc" is a keyword
         raise error.ParseError(_(b"rstdoc expects two arguments"))
 
     text = evalstring(context, mapping, args[0])
     style = evalstring(context, mapping, args[1])
 
     return minirst.format(text, style=style, keep=[b'verbose'])
 
 
 @templatefunc(b'search(pattern, text)')
 def search(context, mapping, args):
     """Look for the first text matching the regular expression pattern.
     Groups are accessible as ``{1}``, ``{2}``, ... in %-mapped template."""
     if len(args) != 2:
         # i18n: "search" is a keyword
         raise error.ParseError(_(b'search expects two arguments'))
 
     pat = evalstring(context, mapping, args[0])
     src = evalstring(context, mapping, args[1])
     try:
         patre = re.compile(pat)
     except re.error:
         # i18n: "search" is a keyword
         raise error.ParseError(_(b'search got an invalid pattern: %s') % pat)
     # named groups shouldn't shadow *reserved* resource keywords
     badgroups = context.knownresourcekeys() & set(
         pycompat.byteskwargs(patre.groupindex)
     )
     if badgroups:
         raise error.ParseError(
             # i18n: "search" is a keyword
             _(b'invalid group %(group)s in search pattern: %(pat)s')
             % {
                 b'group': b', '.join(b"'%s'" % g for g in sorted(badgroups)),
                 b'pat': pat,
             }
         )
 
     match = patre.search(src)
     if not match:
         return templateutil.mappingnone()
 
     lm = {b'0': match.group(0)}
     lm.update((b'%d' % i, v) for i, v in enumerate(match.groups(), 1))
     lm.update(pycompat.byteskwargs(match.groupdict()))
     return templateutil.mappingdict(lm, tmpl=b'{0}')
 
 
 @templatefunc(b'separate(sep, args...)', argspec=b'sep *args')
 def separate(context, mapping, args):
     """Add a separator between non-empty arguments."""
     if b'sep' not in args:
         # i18n: "separate" is a keyword
         raise error.ParseError(_(b"separate expects at least one argument"))
 
     sep = evalstring(context, mapping, args[b'sep'])
     first = True
     for arg in args[b'args']:
         argstr = evalstring(context, mapping, arg)
         if not argstr:
             continue
         if first:
             first = False
         else:
             yield sep
         yield argstr
 
 
 @templatefunc(b'shortest(node, minlength=4)', requires={b'repo', b'cache'})
 def shortest(context, mapping, args):
     """Obtain the shortest representation of
     a node."""
     if not (1 <= len(args) <= 2):
         # i18n: "shortest" is a keyword
         raise error.ParseError(_(b"shortest() expects one or two arguments"))
 
     hexnode = evalstring(context, mapping, args[0])
 
     minlength = 4
     if len(args) > 1:
         minlength = evalinteger(
             context,
             mapping,
             args[1],
             # i18n: "shortest" is a keyword
             _(b"shortest() expects an integer minlength"),
         )
 
     repo = context.resource(mapping, b'repo')
     if len(hexnode) > 40:
         return hexnode
     elif len(hexnode) == 40:
         try:
             node = bin(hexnode)
         except TypeError:
             return hexnode
     else:
         try:
             node = scmutil.resolvehexnodeidprefix(repo, hexnode)
         except error.WdirUnsupported:
             node = wdirid
         except error.LookupError:
             return hexnode
         if not node:
             return hexnode
     cache = context.resource(mapping, b'cache')
     try:
         return scmutil.shortesthexnodeidprefix(repo, node, minlength, cache)
     except error.RepoLookupError:
         return hexnode
 
 
 @templatefunc(b'strip(text[, chars])')
 def strip(context, mapping, args):
     """Strip characters from a string. By default,
     strips all leading and trailing whitespace."""
     if not (1 <= len(args) <= 2):
         # i18n: "strip" is a keyword
         raise error.ParseError(_(b"strip expects one or two arguments"))
 
     text = evalstring(context, mapping, args[0])
     if len(args) == 2:
         chars = evalstring(context, mapping, args[1])
         return text.strip(chars)
     return text.strip()
 
 
 @templatefunc(b'sub(pattern, replacement, expression)')
 def sub(context, mapping, args):
     """Perform text substitution
     using regular expressions."""
     if len(args) != 3:
         # i18n: "sub" is a keyword
         raise error.ParseError(_(b"sub expects three arguments"))
 
     pat = evalstring(context, mapping, args[0])
     rpl = evalstring(context, mapping, args[1])
     src = evalstring(context, mapping, args[2])
     try:
         patre = re.compile(pat)
     except re.error:
         # i18n: "sub" is a keyword
         raise error.ParseError(_(b"sub got an invalid pattern: %s") % pat)
     try:
         yield patre.sub(rpl, src)
     except re.error:
         # i18n: "sub" is a keyword
         raise error.ParseError(_(b"sub got an invalid replacement: %s") % rpl)
 
 
 @templatefunc(b'startswith(pattern, text)')
 def startswith(context, mapping, args):
     """Returns the value from the "text" argument
     if it begins with the content from the "pattern" argument."""
     if len(args) != 2:
         # i18n: "startswith" is a keyword
         raise error.ParseError(_(b"startswith expects two arguments"))
 
     patn = evalstring(context, mapping, args[0])
     text = evalstring(context, mapping, args[1])
     if text.startswith(patn):
         return text
     return b''
 
 
 @templatefunc(b'word(number, text[, separator])')
 def word(context, mapping, args):
     """Return the nth word from a string."""
     if not (2 <= len(args) <= 3):
         # i18n: "word" is a keyword
         raise error.ParseError(
             _(b"word expects two or three arguments, got %d") % len(args)
         )
 
     num = evalinteger(
         context,
         mapping,
         args[0],
         # i18n: "word" is a keyword
         _(b"word expects an integer index"),
     )
     text = evalstring(context, mapping, args[1])
     if len(args) == 3:
         splitter = evalstring(context, mapping, args[2])
     else:
         splitter = None
 
     tokens = text.split(splitter)
     if num >= len(tokens) or num < -len(tokens):
         return b''
     else:
         return tokens[num]
 
 
 def loadfunction(ui, extname, registrarobj):
     """Load template function from specified registrarobj
     """
     for name, func in pycompat.iteritems(registrarobj._table):
         funcs[name] = func
 
 
 # tell hggettext to extract docstrings from these functions:
 i18nfunctions = funcs.values()

mercurial/templateutil.py

@@ -1,1165 +1,1170
 # templateutil.py - utility for template evaluation
 #
 # Copyright 2005, 2006 Matt Mackall <[e-mail]>
 #
 # This software may be used and distributed according to the terms of the
 # GNU General Public License version 2 or any later version.
 
 from __future__ import absolute_import
 
 import abc
 import types
 
 from .i18n import _
 from .pycompat import getattr
 from . import (
     error,
     pycompat,
     smartset,
     util,
 )
 from .utils import (
     dateutil,
     stringutil,
 )
 
 
 class ResourceUnavailable(error.Abort):
     pass
 
 
 class TemplateNotFound(error.Abort):
     pass
 
 
 class wrapped(object):  # pytype: disable=ignored-metaclass
     """Object requiring extra conversion prior to displaying or processing
     as value
 
     Use unwrapvalue() or unwrapastype() to obtain the inner object.
     """
 
     __metaclass__ = abc.ABCMeta
 
     @abc.abstractmethod
     def contains(self, context, mapping, item):
         """Test if the specified item is in self
 
         The item argument may be a wrapped object.
         """
 
     @abc.abstractmethod
     def getmember(self, context, mapping, key):
         """Return a member item for the specified key
 
         The key argument may be a wrapped object.
         A returned object may be either a wrapped object or a pure value
         depending on the self type.
         """
 
     @abc.abstractmethod
     def getmin(self, context, mapping):
         """Return the smallest item, which may be either a wrapped or a pure
         value depending on the self type"""
 
     @abc.abstractmethod
     def getmax(self, context, mapping):
         """Return the largest item, which may be either a wrapped or a pure
         value depending on the self type"""
 
     @abc.abstractmethod
     def filter(self, context, mapping, select):
         """Return new container of the same type which includes only the
         selected elements
 
         select() takes each item as a wrapped object and returns True/False.
         """
 
     @abc.abstractmethod
     def itermaps(self, context):
         """Yield each template mapping"""
 
     @abc.abstractmethod
     def join(self, context, mapping, sep):
         """Join items with the separator; Returns a bytes or (possibly nested)
         generator of bytes
 
         A pre-configured template may be rendered per item if this container
         holds unprintable items.
         """
 
     @abc.abstractmethod
     def show(self, context, mapping):
         """Return a bytes or (possibly nested) generator of bytes representing
         the underlying object
 
         A pre-configured template may be rendered if the underlying object is
         not printable.
         """
 
     @abc.abstractmethod
     def tobool(self, context, mapping):
         """Return a boolean representation of the inner value"""
 
     @abc.abstractmethod
     def tovalue(self, context, mapping):
         """Move the inner value object out or create a value representation
 
         A returned value must be serializable by templaterfilters.json().
         """
 
 
 class mappable(object):  # pytype: disable=ignored-metaclass
     """Object which can be converted to a single template mapping"""
 
     __metaclass__ = abc.ABCMeta
 
     def itermaps(self, context):
         yield self.tomap(context)
 
     @abc.abstractmethod
     def tomap(self, context):
         """Create a single template mapping representing this"""
 
 
 class wrappedbytes(wrapped):
     """Wrapper for byte string"""
 
     def __init__(self, value):
         self._value = value
 
     def contains(self, context, mapping, item):
         item = stringify(context, mapping, item)
         return item in self._value
 
     def getmember(self, context, mapping, key):
         raise error.ParseError(
             _(b'%r is not a dictionary') % pycompat.bytestr(self._value)
         )
 
     def getmin(self, context, mapping):
         return self._getby(context, mapping, min)
 
     def getmax(self, context, mapping):
         return self._getby(context, mapping, max)
 
     def _getby(self, context, mapping, func):
         if not self._value:
             raise error.ParseError(_(b'empty string'))
         return func(pycompat.iterbytestr(self._value))
 
     def filter(self, context, mapping, select):
         raise error.ParseError(
             _(b'%r is not filterable') % pycompat.bytestr(self._value)
         )
 
     def itermaps(self, context):
         raise error.ParseError(
             _(b'%r is not iterable of mappings') % pycompat.bytestr(self._value)
         )
 
     def join(self, context, mapping, sep):
         return joinitems(pycompat.iterbytestr(self._value), sep)
 
     def show(self, context, mapping):
         return self._value
 
     def tobool(self, context, mapping):
         return bool(self._value)
 
     def tovalue(self, context, mapping):
         return self._value
 
 
 class wrappedvalue(wrapped):
     """Generic wrapper for pure non-list/dict/bytes value"""
 
     def __init__(self, value):
         self._value = value
 
     def contains(self, context, mapping, item):
         raise error.ParseError(_(b"%r is not iterable") % self._value)
 
     def getmember(self, context, mapping, key):
         raise error.ParseError(_(b'%r is not a dictionary') % self._value)
 
     def getmin(self, context, mapping):
         raise error.ParseError(_(b"%r is not iterable") % self._value)
 
     def getmax(self, context, mapping):
         raise error.ParseError(_(b"%r is not iterable") % self._value)
 
     def filter(self, context, mapping, select):
         raise error.ParseError(_(b"%r is not iterable") % self._value)
 
     def itermaps(self, context):
         raise error.ParseError(
             _(b'%r is not iterable of mappings') % self._value
         )
 
     def join(self, context, mapping, sep):
         raise error.ParseError(_(b'%r is not iterable') % self._value)
 
     def show(self, context, mapping):
         if self._value is None:
             return b''
         return pycompat.bytestr(self._value)
 
     def tobool(self, context, mapping):
         if self._value is None:
             return False
         if isinstance(self._value, bool):
             return self._value
         # otherwise evaluate as string, which means 0 is True
         return bool(pycompat.bytestr(self._value))
 
     def tovalue(self, context, mapping):
         return self._value
 
 
 class date(mappable, wrapped):
     """Wrapper for date tuple"""
 
     def __init__(self, value, showfmt=b'%d %d'):
         # value may be (float, int), but public interface shouldn't support
         # floating-point timestamp
         self._unixtime, self._tzoffset = map(int, value)
         self._showfmt = showfmt
 
     def contains(self, context, mapping, item):
         raise error.ParseError(_(b'date is not iterable'))
 
     def getmember(self, context, mapping, key):
         raise error.ParseError(_(b'date is not a dictionary'))
 
     def getmin(self, context, mapping):
         raise error.ParseError(_(b'date is not iterable'))
 
     def getmax(self, context, mapping):
         raise error.ParseError(_(b'date is not iterable'))
 
     def filter(self, context, mapping, select):
         raise error.ParseError(_(b'date is not iterable'))
 
     def join(self, context, mapping, sep):
         raise error.ParseError(_(b"date is not iterable"))
 
     def show(self, context, mapping):
         return self._showfmt % (self._unixtime, self._tzoffset)
 
     def tomap(self, context):
         return {b'unixtime': self._unixtime, b'tzoffset': self._tzoffset}
 
     def tobool(self, context, mapping):
         return True
 
     def tovalue(self, context, mapping):
         return (self._unixtime, self._tzoffset)
 
 
 class hybrid(wrapped):
     """Wrapper for list or dict to support legacy template
 
     This class allows us to handle both:
     - "{files}" (legacy command-line-specific list hack) and
     - "{files % '{file}\n'}" (hgweb-style with inlining and function support)
     and to access raw values:
     - "{ifcontains(file, files, ...)}", "{ifcontains(key, extras, ...)}"
     - "{get(extras, key)}"
     - "{files|json}"
     """
 
     def __init__(self, gen, values, makemap, joinfmt, keytype=None):
         self._gen = gen  # generator or function returning generator
         self._values = values
         self._makemap = makemap
         self._joinfmt = joinfmt
         self._keytype = keytype  # hint for 'x in y' where type(x) is unresolved
 
     def contains(self, context, mapping, item):
         item = unwrapastype(context, mapping, item, self._keytype)
         return item in self._values
 
     def getmember(self, context, mapping, key):
         # TODO: maybe split hybrid list/dict types?
         if not util.safehasattr(self._values, b'get'):
             raise error.ParseError(_(b'not a dictionary'))
         key = unwrapastype(context, mapping, key, self._keytype)
         return self._wrapvalue(key, self._values.get(key))
 
     def getmin(self, context, mapping):
         return self._getby(context, mapping, min)
 
     def getmax(self, context, mapping):
         return self._getby(context, mapping, max)
 
     def _getby(self, context, mapping, func):
         if not self._values:
             raise error.ParseError(_(b'empty sequence'))
         val = func(self._values)
         return self._wrapvalue(val, val)
 
     def _wrapvalue(self, key, val):
         if val is None:
             return
         if util.safehasattr(val, b'_makemap'):
             # a nested hybrid list/dict, which has its own way of map operation
             return val
         return hybriditem(None, key, val, self._makemap)
 
     def filter(self, context, mapping, select):
         if util.safehasattr(self._values, b'get'):
             values = {
                 k: v
                 for k, v in pycompat.iteritems(self._values)
                 if select(self._wrapvalue(k, v))
             }
         else:
             values = [v for v in self._values if select(self._wrapvalue(v, v))]
         return hybrid(None, values, self._makemap, self._joinfmt, self._keytype)
 
     def itermaps(self, context):
         makemap = self._makemap
         for x in self._values:
             yield makemap(x)
 
     def join(self, context, mapping, sep):
         # TODO: switch gen to (context, mapping) API?
         return joinitems((self._joinfmt(x) for x in self._values), sep)
 
     def show(self, context, mapping):
         # TODO: switch gen to (context, mapping) API?
         gen = self._gen
         if gen is None:
             return self.join(context, mapping, b' ')
         if callable(gen):
             return gen()
         return gen
 
     def tobool(self, context, mapping):
         return bool(self._values)
 
     def tovalue(self, context, mapping):
         # TODO: make it non-recursive for trivial lists/dicts
         xs = self._values
         if util.safehasattr(xs, b'get'):
             return {
                 k: unwrapvalue(context, mapping, v)
                 for k, v in pycompat.iteritems(xs)
             }
         return [unwrapvalue(context, mapping, x) for x in xs]
 
 
 class hybriditem(mappable, wrapped):
     """Wrapper for non-list/dict object to support map operation
 
     This class allows us to handle both:
     - "{manifest}"
     - "{manifest % '{rev}:{node}'}"
     - "{manifest.rev}"
     """
 
     def __init__(self, gen, key, value, makemap):
         self._gen = gen  # generator or function returning generator
         self._key = key
         self._value = value  # may be generator of strings
         self._makemap = makemap
 
     def tomap(self, context):
         return self._makemap(self._key)
 
     def contains(self, context, mapping, item):
         w = makewrapped(context, mapping, self._value)
         return w.contains(context, mapping, item)
 
     def getmember(self, context, mapping, key):
         w = makewrapped(context, mapping, self._value)
         return w.getmember(context, mapping, key)
 
     def getmin(self, context, mapping):
         w = makewrapped(context, mapping, self._value)
         return w.getmin(context, mapping)
 
     def getmax(self, context, mapping):
         w = makewrapped(context, mapping, self._value)
         return w.getmax(context, mapping)
 
     def filter(self, context, mapping, select):
         w = makewrapped(context, mapping, self._value)
         return w.filter(context, mapping, select)
 
     def join(self, context, mapping, sep):
         w = makewrapped(context, mapping, self._value)
         return w.join(context, mapping, sep)
 
     def show(self, context, mapping):
         # TODO: switch gen to (context, mapping) API?
         gen = self._gen
         if gen is None:
             return pycompat.bytestr(self._value)
         if callable(gen):
             return gen()
         return gen
 
     def tobool(self, context, mapping):
         w = makewrapped(context, mapping, self._value)
         return w.tobool(context, mapping)
 
     def tovalue(self, context, mapping):
         return _unthunk(context, mapping, self._value)
 
 
 class revslist(wrapped):
     """Wrapper for a smartset (a list/set of revision numbers)
 
     If name specified, the revs will be rendered with the old-style list
     template of the given name by default.
+
+    The cachekey provides a hint to cache further computation on this
+    smartset. If the underlying smartset is dynamically created, the cachekey
+    should be None.
     """
 
-    def __init__(self, repo, revs, name=None):
+    def __init__(self, repo, revs, name=None, cachekey=None):
         assert isinstance(revs, smartset.abstractsmartset)
         self._repo = repo
         self._revs = revs
         self._name = name
+        self.cachekey = cachekey
 
     def contains(self, context, mapping, item):
         rev = unwrapinteger(context, mapping, item)
         return rev in self._revs
 
     def getmember(self, context, mapping, key):
         raise error.ParseError(_(b'not a dictionary'))
 
     def getmin(self, context, mapping):
         makehybriditem = self._makehybriditemfunc()
         return makehybriditem(self._revs.min())
 
     def getmax(self, context, mapping):
         makehybriditem = self._makehybriditemfunc()
         return makehybriditem(self._revs.max())
 
     def filter(self, context, mapping, select):
         makehybriditem = self._makehybriditemfunc()
         frevs = self._revs.filter(lambda r: select(makehybriditem(r)))
         # once filtered, no need to support old-style list template
         return revslist(self._repo, frevs, name=None)
 
     def itermaps(self, context):
         makemap = self._makemapfunc()
         for r in self._revs:
             yield makemap(r)
 
     def _makehybriditemfunc(self):
         makemap = self._makemapfunc()
         return lambda r: hybriditem(None, r, r, makemap)
 
     def _makemapfunc(self):
         repo = self._repo
         name = self._name
         if name:
             return lambda r: {name: r, b'ctx': repo[r]}
         else:
             return lambda r: {b'ctx': repo[r]}
 
     def join(self, context, mapping, sep):
         return joinitems(self._revs, sep)
 
     def show(self, context, mapping):
         if self._name:
             srevs = [b'%d' % r for r in self._revs]
             return _showcompatlist(context, mapping, self._name, srevs)
         else:
             return self.join(context, mapping, b' ')
 
     def tobool(self, context, mapping):
         return bool(self._revs)
 
     def tovalue(self, context, mapping):
         return self._revs
 
 
 class _mappingsequence(wrapped):
     """Wrapper for sequence of template mappings
 
     This represents an inner template structure (i.e. a list of dicts),
     which can also be rendered by the specified named/literal template.
 
     Template mappings may be nested.
     """
 
     def __init__(self, name=None, tmpl=None, sep=b''):
         if name is not None and tmpl is not None:
             raise error.ProgrammingError(
                 b'name and tmpl are mutually exclusive'
             )
         self._name = name
         self._tmpl = tmpl
         self._defaultsep = sep
 
     def contains(self, context, mapping, item):
         raise error.ParseError(_(b'not comparable'))
 
     def getmember(self, context, mapping, key):
         raise error.ParseError(_(b'not a dictionary'))
 
     def getmin(self, context, mapping):
         raise error.ParseError(_(b'not comparable'))
 
     def getmax(self, context, mapping):
         raise error.ParseError(_(b'not comparable'))
 
     def filter(self, context, mapping, select):
         # implement if necessary; we'll need a wrapped type for a mapping dict
         raise error.ParseError(_(b'not filterable without template'))
 
     def join(self, context, mapping, sep):
         mapsiter = _iteroverlaymaps(context, mapping, self.itermaps(context))
         if self._name:
             itemiter = (context.process(self._name, m) for m in mapsiter)
         elif self._tmpl:
             itemiter = (context.expand(self._tmpl, m) for m in mapsiter)
         else:
             raise error.ParseError(_(b'not displayable without template'))
         return joinitems(itemiter, sep)
 
     def show(self, context, mapping):
         return self.join(context, mapping, self._defaultsep)
 
     def tovalue(self, context, mapping):
         knownres = context.knownresourcekeys()
         items = []
         for nm in self.itermaps(context):
             # drop internal resources (recursively) which shouldn't be displayed
             lm = context.overlaymap(mapping, nm)
             items.append(
                 {
                     k: unwrapvalue(context, lm, v)
                     for k, v in pycompat.iteritems(nm)
                     if k not in knownres
                 }
             )
         return items
 
 
 class mappinggenerator(_mappingsequence):
     """Wrapper for generator of template mappings
 
     The function ``make(context, *args)`` should return a generator of
     mapping dicts.
     """
 
     def __init__(self, make, args=(), name=None, tmpl=None, sep=b''):
         super(mappinggenerator, self).__init__(name, tmpl, sep)
         self._make = make
         self._args = args
 
     def itermaps(self, context):
         return self._make(context, *self._args)
 
     def tobool(self, context, mapping):
         return _nonempty(self.itermaps(context))
 
 
 class mappinglist(_mappingsequence):
     """Wrapper for list of template mappings"""
 
     def __init__(self, mappings, name=None, tmpl=None, sep=b''):
         super(mappinglist, self).__init__(name, tmpl, sep)
         self._mappings = mappings
 
     def itermaps(self, context):
         return iter(self._mappings)
 
     def tobool(self, context, mapping):
         return bool(self._mappings)
 
 
 class mappingdict(mappable, _mappingsequence):
     """Wrapper for a single template mapping
 
     This isn't a sequence in a way that the underlying dict won't be iterated
     as a dict, but shares most of the _mappingsequence functions.
     """
 
     def __init__(self, mapping, name=None, tmpl=None):
         super(mappingdict, self).__init__(name, tmpl)
         self._mapping = mapping
 
     def tomap(self, context):
         return self._mapping
 
     def tobool(self, context, mapping):
         # no idea when a template mapping should be considered an empty, but
         # a mapping dict should have at least one item in practice, so always
         # mark this as non-empty.
         return True
 
     def tovalue(self, context, mapping):
         return super(mappingdict, self).tovalue(context, mapping)[0]
 
 
 class mappingnone(wrappedvalue):
     """Wrapper for None, but supports map operation
 
     This represents None of Optional[mappable]. It's similar to
     mapplinglist([]), but the underlying value is not [], but None.
     """
 
     def __init__(self):
         super(mappingnone, self).__init__(None)
 
     def itermaps(self, context):
         return iter([])
 
 
 class mappedgenerator(wrapped):
     """Wrapper for generator of strings which acts as a list
 
     The function ``make(context, *args)`` should return a generator of
     byte strings, or a generator of (possibly nested) generators of byte
     strings (i.e. a generator for a list of byte strings.)
     """
 
     def __init__(self, make, args=()):
         self._make = make
         self._args = args
 
     def contains(self, context, mapping, item):
         item = stringify(context, mapping, item)
         return item in self.tovalue(context, mapping)
 
     def _gen(self, context):
         return self._make(context, *self._args)
 
     def getmember(self, context, mapping, key):
         raise error.ParseError(_(b'not a dictionary'))
 
     def getmin(self, context, mapping):
         return self._getby(context, mapping, min)
 
     def getmax(self, context, mapping):
         return self._getby(context, mapping, max)
 
     def _getby(self, context, mapping, func):
         xs = self.tovalue(context, mapping)
         if not xs:
             raise error.ParseError(_(b'empty sequence'))
         return func(xs)
 
     @staticmethod
     def _filteredgen(context, mapping, make, args, select):
         for x in make(context, *args):
             s = stringify(context, mapping, x)
             if select(wrappedbytes(s)):
                 yield s
 
     def filter(self, context, mapping, select):
         args = (mapping, self._make, self._args, select)
         return mappedgenerator(self._filteredgen, args)
 
     def itermaps(self, context):
         raise error.ParseError(_(b'list of strings is not mappable'))
 
     def join(self, context, mapping, sep):
         return joinitems(self._gen(context), sep)
 
     def show(self, context, mapping):
         return self.join(context, mapping, b'')
 
     def tobool(self, context, mapping):
         return _nonempty(self._gen(context))
 
     def tovalue(self, context, mapping):
         return [stringify(context, mapping, x) for x in self._gen(context)]
 
 
 def hybriddict(data, key=b'key', value=b'value', fmt=None, gen=None):
     """Wrap data to support both dict-like and string-like operations"""
     prefmt = pycompat.identity
     if fmt is None:
         fmt = b'%s=%s'
         prefmt = pycompat.bytestr
     return hybrid(
         gen,
         data,
         lambda k: {key: k, value: data[k]},
         lambda k: fmt % (prefmt(k), prefmt(data[k])),
     )
 
 
 def hybridlist(data, name, fmt=None, gen=None):
     """Wrap data to support both list-like and string-like operations"""
     prefmt = pycompat.identity
     if fmt is None:
         fmt = b'%s'
         prefmt = pycompat.bytestr
     return hybrid(gen, data, lambda x: {name: x}, lambda x: fmt % prefmt(x))
 
 
 def compatdict(
     context,
     mapping,
     name,
     data,
     key=b'key',
     value=b'value',
     fmt=None,
     plural=None,
     separator=b' ',
 ):
     """Wrap data like hybriddict(), but also supports old-style list template
 
     This exists for backward compatibility with the old-style template. Use
     hybriddict() for new template keywords.
     """
     c = [{key: k, value: v} for k, v in pycompat.iteritems(data)]
     f = _showcompatlist(context, mapping, name, c, plural, separator)
     return hybriddict(data, key=key, value=value, fmt=fmt, gen=f)
 
 
 def compatlist(
     context,
     mapping,
     name,
     data,
     element=None,
     fmt=None,
     plural=None,
     separator=b' ',
 ):
     """Wrap data like hybridlist(), but also supports old-style list template
 
     This exists for backward compatibility with the old-style template. Use
     hybridlist() for new template keywords.
     """
     f = _showcompatlist(context, mapping, name, data, plural, separator)
     return hybridlist(data, name=element or name, fmt=fmt, gen=f)
 
 
 def compatfilecopiesdict(context, mapping, name, copies):
     """Wrap list of (dest, source) file names to support old-style list
     template and field names
 
     This exists for backward compatibility. Use hybriddict for new template
     keywords.
     """
     # no need to provide {path} to old-style list template
     c = [{b'name': k, b'source': v} for k, v in copies]
     f = _showcompatlist(context, mapping, name, c, plural=b'file_copies')
     copies = util.sortdict(copies)
     return hybrid(
         f,
         copies,
         lambda k: {b'name': k, b'path': k, b'source': copies[k]},
         lambda k: b'%s (%s)' % (k, copies[k]),
     )
 
 
 def compatfileslist(context, mapping, name, files):
     """Wrap list of file names to support old-style list template and field
     names
 
     This exists for backward compatibility. Use hybridlist for new template
     keywords.
     """
     f = _showcompatlist(context, mapping, name, files)
     return hybrid(
         f, files, lambda x: {b'file': x, b'path': x}, pycompat.identity
     )
 
 
 def _showcompatlist(
     context, mapping, name, values, plural=None, separator=b' '
 ):
     """Return a generator that renders old-style list template
 
     name is name of key in template map.
     values is list of strings or dicts.
     plural is plural of name, if not simply name + 's'.
     separator is used to join values as a string
 
     expansion works like this, given name 'foo'.
 
     if values is empty, expand 'no_foos'.
 
     if 'foo' not in template map, return values as a string,
     joined by 'separator'.
 
     expand 'start_foos'.
 
     for each value, expand 'foo'. if 'last_foo' in template
     map, expand it instead of 'foo' for last key.
 
     expand 'end_foos'.
     """
     if not plural:
         plural = name + b's'
     if not values:
         noname = b'no_' + plural
         if context.preload(noname):
             yield context.process(noname, mapping)
         return
     if not context.preload(name):
         if isinstance(values[0], bytes):
             yield separator.join(values)
         else:
             for v in values:
                 r = dict(v)
                 r.update(mapping)
                 yield r
         return
     startname = b'start_' + plural
     if context.preload(startname):
         yield context.process(startname, mapping)
 
     def one(v, tag=name):
         vmapping = {}
         try:
             vmapping.update(v)
         # Python 2 raises ValueError if the type of v is wrong. Python
         # 3 raises TypeError.
         except (AttributeError, TypeError, ValueError):
             try:
                 # Python 2 raises ValueError trying to destructure an e.g.
                 # bytes. Python 3 raises TypeError.
                 for a, b in v:
                     vmapping[a] = b
             except (TypeError, ValueError):
                 vmapping[name] = v
         vmapping = context.overlaymap(mapping, vmapping)
         return context.process(tag, vmapping)
 
     lastname = b'last_' + name
     if context.preload(lastname):
         last = values.pop()
     else:
         last = None
     for v in values:
         yield one(v)
     if last is not None:
         yield one(last, tag=lastname)
     endname = b'end_' + plural
     if context.preload(endname):
         yield context.process(endname, mapping)
 
 
 def flatten(context, mapping, thing):
     """Yield a single stream from a possibly nested set of iterators"""
     if isinstance(thing, wrapped):
         thing = thing.show(context, mapping)
     if isinstance(thing, bytes):
         yield thing
     elif isinstance(thing, str):
         # We can only hit this on Python 3, and it's here to guard
         # against infinite recursion.
         raise error.ProgrammingError(
             b'Mercurial IO including templates is done'
             b' with bytes, not strings, got %r' % thing
         )
     elif thing is None:
         pass
     elif not util.safehasattr(thing, b'__iter__'):
         yield pycompat.bytestr(thing)
     else:
         for i in thing:
             if isinstance(i, wrapped):
                 i = i.show(context, mapping)
             if isinstance(i, bytes):
                 yield i
             elif i is None:
                 pass
             elif not util.safehasattr(i, b'__iter__'):
                 yield pycompat.bytestr(i)
             else:
                 for j in flatten(context, mapping, i):
                     yield j
 
 
 def stringify(context, mapping, thing):
     """Turn values into bytes by converting into text and concatenating them"""
     if isinstance(thing, bytes):
         return thing  # retain localstr to be round-tripped
     return b''.join(flatten(context, mapping, thing))
 
 
 def findsymbolicname(arg):
     """Find symbolic name for the given compiled expression; returns None
     if nothing found reliably"""
     while True:
         func, data = arg
         if func is runsymbol:
             return data
         elif func is runfilter:
             arg = data[0]
         else:
             return None
 
 
 def _nonempty(xiter):
     try:
         next(xiter)
         return True
     except StopIteration:
         return False
 
 
 def _unthunk(context, mapping, thing):
     """Evaluate a lazy byte string into value"""
     if not isinstance(thing, types.GeneratorType):
         return thing
     return stringify(context, mapping, thing)
 
 
 def evalrawexp(context, mapping, arg):
     """Evaluate given argument as a bare template object which may require
     further processing (such as folding generator of strings)"""
     func, data = arg
     return func(context, mapping, data)
 
 
 def evalwrapped(context, mapping, arg):
     """Evaluate given argument to wrapped object"""
     thing = evalrawexp(context, mapping, arg)
     return makewrapped(context, mapping, thing)
 
 
 def makewrapped(context, mapping, thing):
     """Lift object to a wrapped type"""
     if isinstance(thing, wrapped):
         return thing
     thing = _unthunk(context, mapping, thing)
     if isinstance(thing, bytes):
         return wrappedbytes(thing)
     return wrappedvalue(thing)
 
 
 def evalfuncarg(context, mapping, arg):
     """Evaluate given argument as value type"""
     return unwrapvalue(context, mapping, evalrawexp(context, mapping, arg))
 
 
 def unwrapvalue(context, mapping, thing):
     """Move the inner value object out of the wrapper"""
     if isinstance(thing, wrapped):
         return thing.tovalue(context, mapping)
     # evalrawexp() may return string, generator of strings or arbitrary object
     # such as date tuple, but filter does not want generator.
     return _unthunk(context, mapping, thing)
 
 
 def evalboolean(context, mapping, arg):
     """Evaluate given argument as boolean, but also takes boolean literals"""
     func, data = arg
     if func is runsymbol:
         thing = func(context, mapping, data, default=None)
         if thing is None:
             # not a template keyword, takes as a boolean literal
             thing = stringutil.parsebool(data)
     else:
         thing = func(context, mapping, data)
     return makewrapped(context, mapping, thing).tobool(context, mapping)
 
 
 def evaldate(context, mapping, arg, err=None):
     """Evaluate given argument as a date tuple or a date string; returns
     a (unixtime, offset) tuple"""
     thing = evalrawexp(context, mapping, arg)
     return unwrapdate(context, mapping, thing, err)
 
 
 def unwrapdate(context, mapping, thing, err=None):
     if isinstance(thing, date):
         return thing.tovalue(context, mapping)
     # TODO: update hgweb to not return bare tuple; then just stringify 'thing'
     thing = unwrapvalue(context, mapping, thing)
     try:
         return dateutil.parsedate(thing)
     except AttributeError:
         raise error.ParseError(err or _(b'not a date tuple nor a string'))
     except error.ParseError:
         if not err:
             raise
         raise error.ParseError(err)
 
 
 def evalinteger(context, mapping, arg, err=None):
     thing = evalrawexp(context, mapping, arg)
     return unwrapinteger(context, mapping, thing, err)
 
 
 def unwrapinteger(context, mapping, thing, err=None):
     thing = unwrapvalue(context, mapping, thing)
     try:
         return int(thing)
     except (TypeError, ValueError):
         raise error.ParseError(err or _(b'not an integer'))
 
 
 def evalstring(context, mapping, arg):
     return stringify(context, mapping, evalrawexp(context, mapping, arg))
 
 
 def evalstringliteral(context, mapping, arg):
     """Evaluate given argument as string template, but returns symbol name
     if it is unknown"""
     func, data = arg
     if func is runsymbol:
         thing = func(context, mapping, data, default=data)
     else:
         thing = func(context, mapping, data)
     return stringify(context, mapping, thing)
 
 
 _unwrapfuncbytype = {
     None: unwrapvalue,
     bytes: stringify,
     date: unwrapdate,
     int: unwrapinteger,
 }
 
 
 def unwrapastype(context, mapping, thing, typ):
     """Move the inner value object out of the wrapper and coerce its type"""
     try:
         f = _unwrapfuncbytype[typ]
     except KeyError:
         raise error.ProgrammingError(b'invalid type specified: %r' % typ)
     return f(context, mapping, thing)
 
 
 def runinteger(context, mapping, data):
     return int(data)
 
 
 def runstring(context, mapping, data):
     return data
 
 
 def _recursivesymbolblocker(key):
     def showrecursion(context, mapping):
         raise error.Abort(_(b"recursive reference '%s' in template") % key)
 
     return showrecursion
 
 
 def runsymbol(context, mapping, key, default=b''):
     v = context.symbol(mapping, key)
     if v is None:
         # put poison to cut recursion. we can't move this to parsing phase
         # because "x = {x}" is allowed if "x" is a keyword. (issue4758)
         safemapping = mapping.copy()
         safemapping[key] = _recursivesymbolblocker(key)
         try:
             v = context.process(key, safemapping)
         except TemplateNotFound:
             v = default
     if callable(v):
         # new templatekw
         try:
             return v(context, mapping)
         except ResourceUnavailable:
             # unsupported keyword is mapped to empty just like unknown keyword
             return None
     return v
 
 
 def runtemplate(context, mapping, template):
     for arg in template:
         yield evalrawexp(context, mapping, arg)
 
 
 def runfilter(context, mapping, data):
     arg, filt = data
     thing = evalrawexp(context, mapping, arg)
     intype = getattr(filt, '_intype', None)
     try:
         thing = unwrapastype(context, mapping, thing, intype)
         return filt(thing)
     except error.ParseError as e:
         raise error.ParseError(bytes(e), hint=_formatfiltererror(arg, filt))
 
 
 def _formatfiltererror(arg, filt):
     fn = pycompat.sysbytes(filt.__name__)
     sym = findsymbolicname(arg)
     if not sym:
         return _(b"incompatible use of template filter '%s'") % fn
     return _(b"template filter '%s' is not compatible with keyword '%s'") % (
         fn,
         sym,
     )
 
 
 def _iteroverlaymaps(context, origmapping, newmappings):
     """Generate combined mappings from the original mapping and an iterable
     of partial mappings to override the original"""
     for i, nm in enumerate(newmappings):
         lm = context.overlaymap(origmapping, nm)
         lm[b'index'] = i
         yield lm
 
 
 def _applymap(context, mapping, d, darg, targ):
     try:
         diter = d.itermaps(context)
     except error.ParseError as err:
         sym = findsymbolicname(darg)
         if not sym:
             raise
         hint = _(b"keyword '%s' does not support map operation") % sym
         raise error.ParseError(bytes(err), hint=hint)
     for lm in _iteroverlaymaps(context, mapping, diter):
         yield evalrawexp(context, lm, targ)
 
 
 def runmap(context, mapping, data):
     darg, targ = data
     d = evalwrapped(context, mapping, darg)
     return mappedgenerator(_applymap, args=(mapping, d, darg, targ))
 
 
 def runmember(context, mapping, data):
     darg, memb = data
     d = evalwrapped(context, mapping, darg)
     if isinstance(d, mappable):
         lm = context.overlaymap(mapping, d.tomap(context))
         return runsymbol(context, lm, memb)
     try:
         return d.getmember(context, mapping, memb)
     except error.ParseError as err:
         sym = findsymbolicname(darg)
         if not sym:
             raise
         hint = _(b"keyword '%s' does not support member operation") % sym
         raise error.ParseError(bytes(err), hint=hint)
 
 
 def runnegate(context, mapping, data):
     data = evalinteger(
         context, mapping, data, _(b'negation needs an integer argument')
     )
     return -data
 
 
 def runarithmetic(context, mapping, data):
     func, left, right = data
     left = evalinteger(
         context, mapping, left, _(b'arithmetic only defined on integers')
     )
     right = evalinteger(
         context, mapping, right, _(b'arithmetic only defined on integers')
     )
     try:
         return func(left, right)
     except ZeroDivisionError:
         raise error.Abort(_(b'division by zero is not defined'))
 
 
 def joinitems(itemiter, sep):
     """Join items with the separator; Returns generator of bytes"""
     first = True
     for x in itemiter:
         if first:
             first = False
         elif sep:
             yield sep
         yield x