view mercurial/templater.py @ 23845:0a7fd54d4e60

revset: introduce "_parsealiasdecl" to parse alias declarations strictly

This patch introduces "_parsealiasdecl" to parse alias declarations
strictly. For example, "_parsealiasdecl" can detect problems below,
which current implementation can't.

  - un-closed parenthesis causes being treated as "alias symbol"

    because all of declarations not in "func(....)" style are
    recognized as "alias symbol".

    for example, "foo($1, $2" is treated as the alias symbol.

  - alias symbol/function names aren't examined whether they are valid
    as symbol or not

    for example, "foo bar" can be treated as the alias symbol, but of
    course such invalid symbol can't be referred in revset.

  - just splitting argument list by "," causes overlooking syntax
    problems in the declaration

    for example, all of invalid declarations below are overlooked:

    - foo("bar")     => taking one argument named as '"bar"'
    - foo("unclosed) => taking one argument named as '"unclosed'
    - foo(bar::baz)  => taking one argument named as 'bar::baz'
    - foo(bar($1))   => taking one argument named as 'bar($1)'

To decrease complication of patch, current implementation for alias
declarations is replaced by "_parsealiasdecl" in the subsequent
patch. This patch just introduces it.

This patch defines "_parsealiasdecl" not as a method of "revsetalias"
class but as a one of "revset" module, because of ease of testing by
doctest.

This patch factors some helper functions for "tree" out, because:

  - direct accessing like "if tree[0] == 'func' and len(tree) > 1"
    decreases readability

  - subsequent patch (and also existing code paths, in the future) can
    use them for readability

This patch also factors "_tokenizealias" out, because it can be used
also for parsing alias definitions strictly.

# templater.py - template expansion for output
#
# 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 i18n import _
import os, re
import util, config, templatefilters, templatekw, parser, error
import revset as revsetmod
import types
import minirst

# template parsing

elements = {
    "(": (20, ("group", 1, ")"), ("func", 1, ")")),
    ",": (2, None, ("list", 2)),
    "|": (5, None, ("|", 5)),
    "%": (6, None, ("%", 6)),
    ")": (0, None, None),
    "symbol": (0, ("symbol",), None),
    "string": (0, ("string",), None),
    "rawstring": (0, ("rawstring",), None),
    "end": (0, None, None),
}

def tokenizer(data):
    program, start, end = data
    pos = start
    while pos < end:
        c = program[pos]
        if c.isspace(): # skip inter-token whitespace
            pass
        elif c in "(,)%|": # handle simple operators
            yield (c, None, pos)
        elif (c in '"\'' or c == 'r' and
              program[pos:pos + 2] in ("r'", 'r"')): # handle quoted strings
            if c == 'r':
                pos += 1
                c = program[pos]
                decode = False
            else:
                decode = True
            pos += 1
            s = pos
            while pos < end: # find closing quote
                d = program[pos]
                if decode and d == '\\': # skip over escaped characters
                    pos += 2
                    continue
                if d == c:
                    if not decode:
                        yield ('rawstring', program[s:pos], s)
                        break
                    yield ('string', program[s:pos], s)
                    break
                pos += 1
            else:
                raise error.ParseError(_("unterminated string"), s)
        elif c.isalnum() or c in '_':
            s = pos
            pos += 1
            while pos < end: # find end of symbol
                d = program[pos]
                if not (d.isalnum() or d == "_"):
                    break
                pos += 1
            sym = program[s:pos]
            yield ('symbol', sym, s)
            pos -= 1
        elif c == '}':
            pos += 1
            break
        else:
            raise error.ParseError(_("syntax error"), pos)
        pos += 1
    yield ('end', None, pos)

def compiletemplate(tmpl, context, strtoken="string"):
    parsed = []
    pos, stop = 0, len(tmpl)
    p = parser.parser(tokenizer, elements)
    while pos < stop:
        n = tmpl.find('{', pos)
        if n < 0:
            parsed.append((strtoken, tmpl[pos:]))
            break
        if n > 0 and tmpl[n - 1] == '\\':
            # escaped
            parsed.append((strtoken, (tmpl[pos:n - 1] + "{")))
            pos = n + 1
            continue
        if n > pos:
            parsed.append((strtoken, tmpl[pos:n]))

        pd = [tmpl, n + 1, stop]
        parseres, pos = p.parse(pd)
        parsed.append(parseres)

    return [compileexp(e, context) for e in parsed]

def compileexp(exp, context):
    t = exp[0]
    if t in methods:
        return methods[t](exp, context)
    raise error.ParseError(_("unknown method '%s'") % t)

# template evaluation

def getsymbol(exp):
    if exp[0] == 'symbol':
        return exp[1]
    raise error.ParseError(_("expected a symbol, got '%s'") % exp[0])

def getlist(x):
    if not x:
        return []
    if x[0] == 'list':
        return getlist(x[1]) + [x[2]]
    return [x]

def getfilter(exp, context):
    f = getsymbol(exp)
    if f not in context._filters:
        raise error.ParseError(_("unknown function '%s'") % f)
    return context._filters[f]

def gettemplate(exp, context):
    if exp[0] == 'string' or exp[0] == 'rawstring':
        return compiletemplate(exp[1], context, strtoken=exp[0])
    if exp[0] == 'symbol':
        return context._load(exp[1])
    raise error.ParseError(_("expected template specifier"))

def runstring(context, mapping, data):
    return data.decode("string-escape")

def runrawstring(context, mapping, data):
    return data

def runsymbol(context, mapping, key):
    v = mapping.get(key)
    if v is None:
        v = context._defaults.get(key)
    if v is None:
        try:
            v = context.process(key, mapping)
        except TemplateNotFound:
            v = ''
    if callable(v):
        return v(**mapping)
    if isinstance(v, types.GeneratorType):
        v = list(v)
    return v

def buildfilter(exp, context):
    func, data = compileexp(exp[1], context)
    filt = getfilter(exp[2], context)
    return (runfilter, (func, data, filt))

def runfilter(context, mapping, data):
    func, data, filt = data
    try:
        return filt(func(context, mapping, data))
    except (ValueError, AttributeError, TypeError):
        if isinstance(data, tuple):
            dt = data[1]
        else:
            dt = data
        raise util.Abort(_("template filter '%s' is not compatible with "
                           "keyword '%s'") % (filt.func_name, dt))

def buildmap(exp, context):
    func, data = compileexp(exp[1], context)
    ctmpl = gettemplate(exp[2], context)
    return (runmap, (func, data, ctmpl))

def runtemplate(context, mapping, template):
    for func, data in template:
        yield func(context, mapping, data)

def runmap(context, mapping, data):
    func, data, ctmpl = data
    d = func(context, mapping, data)
    if callable(d):
        d = d()

    lm = mapping.copy()

    for i in d:
        if isinstance(i, dict):
            lm.update(i)
            lm['originalnode'] = mapping.get('node')
            yield runtemplate(context, lm, ctmpl)
        else:
            # v is not an iterable of dicts, this happen when 'key'
            # has been fully expanded already and format is useless.
            # If so, return the expanded value.
            yield i

def buildfunc(exp, context):
    n = getsymbol(exp[1])
    args = [compileexp(x, context) for x in getlist(exp[2])]
    if n in funcs:
        f = funcs[n]
        return (f, args)
    if n in context._filters:
        if len(args) != 1:
            raise error.ParseError(_("filter %s expects one argument") % n)
        f = context._filters[n]
        return (runfilter, (args[0][0], args[0][1], f))
    raise error.ParseError(_("unknown function '%s'") % n)

def date(context, mapping, args):
    if not (1 <= len(args) <= 2):
        # i18n: "date" is a keyword
        raise error.ParseError(_("date expects one or two arguments"))

    date = args[0][0](context, mapping, args[0][1])
    if len(args) == 2:
        fmt = stringify(args[1][0](context, mapping, args[1][1]))
        return util.datestr(date, fmt)
    return util.datestr(date)

def diff(context, mapping, args):
    if len(args) > 2:
        # i18n: "diff" is a keyword
        raise error.ParseError(_("diff expects one, two or no arguments"))

    def getpatterns(i):
        if i < len(args):
            s = args[i][1].strip()
            if s:
                return [s]
        return []

    ctx = mapping['ctx']
    chunks = ctx.diff(match=ctx.match([], getpatterns(0), getpatterns(1)))

    return ''.join(chunks)

def fill(context, mapping, args):
    if not (1 <= len(args) <= 4):
        # i18n: "fill" is a keyword
        raise error.ParseError(_("fill expects one to four arguments"))

    text = stringify(args[0][0](context, mapping, args[0][1]))
    width = 76
    initindent = ''
    hangindent = ''
    if 2 <= len(args) <= 4:
        try:
            width = int(stringify(args[1][0](context, mapping, args[1][1])))
        except ValueError:
            # i18n: "fill" is a keyword
            raise error.ParseError(_("fill expects an integer width"))
        try:
            initindent = stringify(_evalifliteral(args[2], context, mapping))
            hangindent = stringify(_evalifliteral(args[3], context, mapping))
        except IndexError:
            pass

    return templatefilters.fill(text, width, initindent, hangindent)

def pad(context, mapping, args):
    """usage: pad(text, width, fillchar=' ', right=False)
    """
    if not (2 <= len(args) <= 4):
        # i18n: "pad" is a keyword
        raise error.ParseError(_("pad() expects two to four arguments"))

    width = int(args[1][1])

    text = stringify(args[0][0](context, mapping, args[0][1]))
    if args[0][0] == runstring:
        text = stringify(runtemplate(context, mapping,
            compiletemplate(text, context)))

    right = False
    fillchar = ' '
    if len(args) > 2:
        fillchar = stringify(args[2][0](context, mapping, args[2][1]))
    if len(args) > 3:
        right = util.parsebool(args[3][1])

    if right:
        return text.rjust(width, fillchar)
    else:
        return text.ljust(width, fillchar)

def get(context, mapping, args):
    if len(args) != 2:
        # i18n: "get" is a keyword
        raise error.ParseError(_("get() expects two arguments"))

    dictarg = args[0][0](context, mapping, args[0][1])
    if not util.safehasattr(dictarg, 'get'):
        # i18n: "get" is a keyword
        raise error.ParseError(_("get() expects a dict as first argument"))

    key = args[1][0](context, mapping, args[1][1])
    yield dictarg.get(key)

def _evalifliteral(arg, context, mapping):
    t = stringify(arg[0](context, mapping, arg[1]))
    if arg[0] == runstring or arg[0] == runrawstring:
        yield runtemplate(context, mapping,
                          compiletemplate(t, context, strtoken='rawstring'))
    else:
        yield t

def if_(context, mapping, args):
    if not (2 <= len(args) <= 3):
        # i18n: "if" is a keyword
        raise error.ParseError(_("if expects two or three arguments"))

    test = stringify(args[0][0](context, mapping, args[0][1]))
    if test:
        yield _evalifliteral(args[1], context, mapping)
    elif len(args) == 3:
        yield _evalifliteral(args[2], context, mapping)

def ifcontains(context, mapping, args):
    if not (3 <= len(args) <= 4):
        # i18n: "ifcontains" is a keyword
        raise error.ParseError(_("ifcontains expects three or four arguments"))

    item = stringify(args[0][0](context, mapping, args[0][1]))
    items = args[1][0](context, mapping, args[1][1])

    # Iterating over items gives a formatted string, so we iterate
    # directly over the raw values.
    if ((callable(items) and item in [i.values()[0] for i in items()]) or
        (isinstance(items, str) and item in items)):
        yield _evalifliteral(args[2], context, mapping)
    elif len(args) == 4:
        yield _evalifliteral(args[3], context, mapping)

def ifeq(context, mapping, args):
    if not (3 <= len(args) <= 4):
        # i18n: "ifeq" is a keyword
        raise error.ParseError(_("ifeq expects three or four arguments"))

    test = stringify(args[0][0](context, mapping, args[0][1]))
    match = stringify(args[1][0](context, mapping, args[1][1]))
    if test == match:
        yield _evalifliteral(args[2], context, mapping)
    elif len(args) == 4:
        yield _evalifliteral(args[3], context, mapping)

def join(context, mapping, args):
    if not (1 <= len(args) <= 2):
        # i18n: "join" is a keyword
        raise error.ParseError(_("join expects one or two arguments"))

    joinset = args[0][0](context, mapping, args[0][1])
    if callable(joinset):
        jf = joinset.joinfmt
        joinset = [jf(x) for x in joinset()]

    joiner = " "
    if len(args) > 1:
        joiner = stringify(args[1][0](context, mapping, args[1][1]))

    first = True
    for x in joinset:
        if first:
            first = False
        else:
            yield joiner
        yield x

def label(context, mapping, args):
    if len(args) != 2:
        # i18n: "label" is a keyword
        raise error.ParseError(_("label expects two arguments"))

    # ignore args[0] (the label string) since this is supposed to be a a no-op
    yield _evalifliteral(args[1], context, mapping)

def revset(context, mapping, args):
    """usage: revset(query[, formatargs...])
    """
    if not len(args) > 0:
        # i18n: "revset" is a keyword
        raise error.ParseError(_("revset expects one or more arguments"))

    raw = args[0][1]
    ctx = mapping['ctx']
    repo = ctx._repo

    def query(expr):
        m = revsetmod.match(repo.ui, expr)
        return m(repo, revsetmod.spanset(repo))

    if len(args) > 1:
        formatargs = list([a[0](context, mapping, a[1]) for a in args[1:]])
        revs = query(revsetmod.formatspec(raw, *formatargs))
        revs = list([str(r) for r in revs])
    else:
        revsetcache = mapping['cache'].setdefault("revsetcache", {})
        if raw in revsetcache:
            revs = revsetcache[raw]
        else:
            revs = query(raw)
            revs = list([str(r) for r in revs])
            revsetcache[raw] = revs

    return templatekw.showlist("revision", revs, **mapping)

def rstdoc(context, mapping, args):
    if len(args) != 2:
        # i18n: "rstdoc" is a keyword
        raise error.ParseError(_("rstdoc expects two arguments"))

    text = stringify(args[0][0](context, mapping, args[0][1]))
    style = stringify(args[1][0](context, mapping, args[1][1]))

    return minirst.format(text, style=style, keep=['verbose'])

def shortest(context, mapping, args):
    """usage: shortest(node, minlength=4)
    """
    if not (1 <= len(args) <= 2):
        # i18n: "shortest" is a keyword
        raise error.ParseError(_("shortest() expects one or two arguments"))

    node = stringify(args[0][0](context, mapping, args[0][1]))

    minlength = 4
    if len(args) > 1:
        minlength = int(args[1][1])

    cl = mapping['ctx']._repo.changelog
    def isvalid(test):
        try:
            try:
                cl.index.partialmatch(test)
            except AttributeError:
                # Pure mercurial doesn't support partialmatch on the index.
                # Fallback to the slow way.
                if cl._partialmatch(test) is None:
                    return False

            try:
                i = int(test)
                # if we are a pure int, then starting with zero will not be
                # confused as a rev; or, obviously, if the int is larger than
                # the value of the tip rev
                if test[0] == '0' or i > len(cl):
                    return True
                return False
            except ValueError:
                return True
        except error.RevlogError:
            return False

    shortest = node
    startlength = max(6, minlength)
    length = startlength
    while True:
        test = node[:length]
        if isvalid(test):
            shortest = test
            if length == minlength or length > startlength:
                return shortest
            length -= 1
        else:
            length += 1
            if len(shortest) <= length:
                return shortest

def strip(context, mapping, args):
    if not (1 <= len(args) <= 2):
        # i18n: "strip" is a keyword
        raise error.ParseError(_("strip expects one or two arguments"))

    text = stringify(args[0][0](context, mapping, args[0][1]))
    if len(args) == 2:
        chars = stringify(args[1][0](context, mapping, args[1][1]))
        return text.strip(chars)
    return text.strip()

def sub(context, mapping, args):
    if len(args) != 3:
        # i18n: "sub" is a keyword
        raise error.ParseError(_("sub expects three arguments"))

    pat = stringify(args[0][0](context, mapping, args[0][1]))
    rpl = stringify(args[1][0](context, mapping, args[1][1]))
    src = stringify(_evalifliteral(args[2], context, mapping))
    yield re.sub(pat, rpl, src)

def startswith(context, mapping, args):
    if len(args) != 2:
        # i18n: "startswith" is a keyword
        raise error.ParseError(_("startswith expects two arguments"))

    patn = stringify(args[0][0](context, mapping, args[0][1]))
    text = stringify(args[1][0](context, mapping, args[1][1]))
    if text.startswith(patn):
        return text
    return ''


def word(context, mapping, args):
    """return nth word from a string"""
    if not (2 <= len(args) <= 3):
        # i18n: "word" is a keyword
        raise error.ParseError(_("word expects two or three arguments, got %d")
                               % len(args))

    num = int(stringify(args[0][0](context, mapping, args[0][1])))
    text = stringify(args[1][0](context, mapping, args[1][1]))
    if len(args) == 3:
        splitter = stringify(args[2][0](context, mapping, args[2][1]))
    else:
        splitter = None

    tokens = text.split(splitter)
    if num >= len(tokens):
        return ''
    else:
        return tokens[num]

methods = {
    "string": lambda e, c: (runstring, e[1]),
    "rawstring": lambda e, c: (runrawstring, e[1]),
    "symbol": lambda e, c: (runsymbol, e[1]),
    "group": lambda e, c: compileexp(e[1], c),
#    ".": buildmember,
    "|": buildfilter,
    "%": buildmap,
    "func": buildfunc,
    }

funcs = {
    "date": date,
    "diff": diff,
    "fill": fill,
    "get": get,
    "if": if_,
    "ifcontains": ifcontains,
    "ifeq": ifeq,
    "join": join,
    "label": label,
    "pad": pad,
    "revset": revset,
    "rstdoc": rstdoc,
    "shortest": shortest,
    "startswith": startswith,
    "strip": strip,
    "sub": sub,
    "word": word,
}

# template engine

stringify = templatefilters.stringify

def _flatten(thing):
    '''yield a single stream from a possibly nested set of iterators'''
    if isinstance(thing, str):
        yield thing
    elif not util.safehasattr(thing, '__iter__'):
        if thing is not None:
            yield str(thing)
    else:
        for i in thing:
            if isinstance(i, str):
                yield i
            elif not util.safehasattr(i, '__iter__'):
                if i is not None:
                    yield str(i)
            elif i is not None:
                for j in _flatten(i):
                    yield j

def parsestring(s, quoted=True):
    '''parse a string using simple c-like syntax.
    string must be in quotes if quoted is True.'''
    if quoted:
        if len(s) < 2 or s[0] != s[-1]:
            raise SyntaxError(_('unmatched quotes'))
        return s[1:-1].decode('string_escape')

    return s.decode('string_escape')

class engine(object):
    '''template expansion engine.

    template expansion works like this. a map file contains key=value
    pairs. if value is quoted, it is treated as string. otherwise, it
    is treated as name of template file.

    templater is asked to expand a key in map. it looks up key, and
    looks for strings like this: {foo}. it expands {foo} by looking up
    foo in map, and substituting it. expansion is recursive: it stops
    when there is no more {foo} to replace.

    expansion also allows formatting and filtering.

    format uses key to expand each item in list. syntax is
    {key%format}.

    filter uses function to transform value. syntax is
    {key|filter1|filter2|...}.'''

    def __init__(self, loader, filters={}, defaults={}):
        self._loader = loader
        self._filters = filters
        self._defaults = defaults
        self._cache = {}

    def _load(self, t):
        '''load, parse, and cache a template'''
        if t not in self._cache:
            self._cache[t] = compiletemplate(self._loader(t), self)
        return self._cache[t]

    def process(self, t, mapping):
        '''Perform expansion. t is name of map element to expand.
        mapping contains added elements for use during expansion. Is a
        generator.'''
        return _flatten(runtemplate(self, mapping, self._load(t)))

engines = {'default': engine}

def stylelist():
    paths = templatepaths()
    if not paths:
        return _('no templates found, try `hg debuginstall` for more info')
    dirlist =  os.listdir(paths[0])
    stylelist = []
    for file in dirlist:
        split = file.split(".")
        if split[0] == "map-cmdline":
            stylelist.append(split[1])
    return ", ".join(sorted(stylelist))

class TemplateNotFound(util.Abort):
    pass

class templater(object):

    def __init__(self, mapfile, filters={}, defaults={}, cache={},
                 minchunk=1024, maxchunk=65536):
        '''set up template engine.
        mapfile is name of file to read map definitions from.
        filters is dict of functions. each transforms a value into another.
        defaults is dict of default map definitions.'''
        self.mapfile = mapfile or 'template'
        self.cache = cache.copy()
        self.map = {}
        self.base = (mapfile and os.path.dirname(mapfile)) or ''
        self.filters = templatefilters.filters.copy()
        self.filters.update(filters)
        self.defaults = defaults
        self.minchunk, self.maxchunk = minchunk, maxchunk
        self.ecache = {}

        if not mapfile:
            return
        if not os.path.exists(mapfile):
            raise util.Abort(_("style '%s' not found") % mapfile,
                             hint=_("available styles: %s") % stylelist())

        conf = config.config()
        conf.read(mapfile)

        for key, val in conf[''].items():
            if not val:
                raise SyntaxError(_('%s: missing value') % conf.source('', key))
            if val[0] in "'\"":
                try:
                    self.cache[key] = parsestring(val)
                except SyntaxError, inst:
                    raise SyntaxError('%s: %s' %
                                      (conf.source('', key), inst.args[0]))
            else:
                val = 'default', val
                if ':' in val[1]:
                    val = val[1].split(':', 1)
                self.map[key] = val[0], os.path.join(self.base, val[1])

    def __contains__(self, key):
        return key in self.cache or key in self.map

    def load(self, t):
        '''Get the template for the given template name. Use a local cache.'''
        if t not in self.cache:
            try:
                self.cache[t] = util.readfile(self.map[t][1])
            except KeyError, inst:
                raise TemplateNotFound(_('"%s" not in template map') %
                                       inst.args[0])
            except IOError, inst:
                raise IOError(inst.args[0], _('template file %s: %s') %
                              (self.map[t][1], inst.args[1]))
        return self.cache[t]

    def __call__(self, t, **mapping):
        ttype = t in self.map and self.map[t][0] or 'default'
        if ttype not in self.ecache:
            self.ecache[ttype] = engines[ttype](self.load,
                                                 self.filters, self.defaults)
        proc = self.ecache[ttype]

        stream = proc.process(t, mapping)
        if self.minchunk:
            stream = util.increasingchunks(stream, min=self.minchunk,
                                           max=self.maxchunk)
        return stream

def templatepaths():
    '''return locations used for template files.'''
    pathsrel = ['templates']
    paths = [os.path.normpath(os.path.join(util.datapath, f))
             for f in pathsrel]
    return [p for p in paths if os.path.isdir(p)]

def templatepath(name):
    '''return location of template file. returns None if not found.'''
    for p in templatepaths():
        f = os.path.join(p, name)
        if os.path.exists(f):
            return f
    return None

def stylemap(styles, paths=None):
    """Return path to mapfile for a given style.

    Searches mapfile in the following locations:
    1. templatepath/style/map
    2. templatepath/map-style
    3. templatepath/map
    """

    if paths is None:
        paths = templatepaths()
    elif isinstance(paths, str):
        paths = [paths]

    if isinstance(styles, str):
        styles = [styles]

    for style in styles:
        if not style:
            continue
        locations = [os.path.join(style, 'map'), 'map-' + style]
        locations.append('map')

        for path in paths:
            for location in locations:
                mapfile = os.path.join(path, location)
                if os.path.isfile(mapfile):
                    return style, mapfile

    raise RuntimeError("No hgweb templates found in %r" % paths)