--- a/mercurial/fileset.py	Sat Jul 21 15:23:56 2018 +0900
+++ b/mercurial/fileset.py	Sun Jul 22 15:50:45 2018 +0900
@@ -13,9 +13,9 @@
 from .i18n import _
 from . import (
     error,
+    filesetlang,
     match as matchmod,
     merge,
-    parser,
     pycompat,
     registrar,
     scmutil,
@@ -25,120 +25,12 @@
     stringutil,
 )
 
-elements = {
-    # token-type: binding-strength, primary, prefix, infix, suffix
-    "(": (20, None, ("group", 1, ")"), ("func", 1, ")"), None),
-    ":": (15, None, None, ("kindpat", 15), None),
-    "-": (5, None, ("negate", 19), ("minus", 5), None),
-    "not": (10, None, ("not", 10), None, None),
-    "!": (10, None, ("not", 10), None, None),
-    "and": (5, None, None, ("and", 5), None),
-    "&": (5, None, None, ("and", 5), None),
-    "or": (4, None, None, ("or", 4), None),
-    "|": (4, None, None, ("or", 4), None),
-    "+": (4, None, None, ("or", 4), None),
-    ",": (2, None, None, ("list", 2), None),
-    ")": (0, None, None, None, None),
-    "symbol": (0, "symbol", None, None, None),
-    "string": (0, "string", None, None, None),
-    "end": (0, None, None, None, None),
-}
-
-keywords = {'and', 'or', 'not'}
-
-globchars = ".*{}[]?/\\_"
-
-def tokenize(program):
-    pos, l = 0, len(program)
-    program = pycompat.bytestr(program)
-    while pos < l:
-        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 = lambda x: x
-            else:
-                decode = parser.unescapestr
-            pos += 1
-            s = pos
-            while pos < l: # find closing quote
-                d = program[pos]
-                if d == '\\': # skip over escaped characters
-                    pos += 2
-                    continue
-                if d == c:
-                    yield ('string', decode(program[s:pos]), s)
-                    break
-                pos += 1
-            else:
-                raise error.ParseError(_("unterminated string"), s)
-        elif c.isalnum() or c in globchars or ord(c) > 127:
-            # gather up a symbol/keyword
-            s = pos
-            pos += 1
-            while pos < l: # find end of symbol
-                d = program[pos]
-                if not (d.isalnum() or d in globchars or ord(d) > 127):
-                    break
-                pos += 1
-            sym = program[s:pos]
-            if sym in keywords: # operator keywords
-                yield (sym, None, s)
-            else:
-                yield ('symbol', sym, s)
-            pos -= 1
-        else:
-            raise error.ParseError(_("syntax error"), pos)
-        pos += 1
-    yield ('end', None, pos)
-
-def parse(expr):
-    p = parser.parser(elements)
-    tree, pos = p.parse(tokenize(expr))
-    if pos != len(expr):
-        raise error.ParseError(_("invalid token"), pos)
-    return parser.simplifyinfixops(tree, {'list', 'or'})
-
-def getsymbol(x):
-    if x and x[0] == 'symbol':
-        return x[1]
-    raise error.ParseError(_('not a symbol'))
-
-def getstring(x, err):
-    if x and (x[0] == 'string' or x[0] == 'symbol'):
-        return x[1]
-    raise error.ParseError(err)
-
-def _getkindpat(x, y, allkinds, err):
-    kind = getsymbol(x)
-    pat = getstring(y, err)
-    if kind not in allkinds:
-        raise error.ParseError(_("invalid pattern kind: %s") % kind)
-    return '%s:%s' % (kind, pat)
-
-def getpattern(x, allkinds, err):
-    if x and x[0] == 'kindpat':
-        return _getkindpat(x[1], x[2], allkinds, err)
-    return getstring(x, err)
-
-def getlist(x):
-    if not x:
-        return []
-    if x[0] == 'list':
-        return list(x[1:])
-    return [x]
-
-def getargs(x, min, max, err):
-    l = getlist(x)
-    if len(l) < min or len(l) > max:
-        raise error.ParseError(err)
-    return l
+# helpers for processing parsed tree
+getsymbol = filesetlang.getsymbol
+getstring = filesetlang.getstring
+_getkindpat = filesetlang.getkindpat
+getpattern = filesetlang.getpattern
+getargs = filesetlang.getargs
 
 def getmatch(mctx, x):
     if not x:
@@ -192,7 +84,7 @@
 # with:
 #  mctx - current matchctx instance
 #  x - argument in tree form
-symbols = {}
+symbols = filesetlang.symbols
 
 # filesets using matchctx.status()
 _statuscallers = set()
@@ -635,7 +527,7 @@
 
 def match(ctx, expr, badfn=None):
     """Create a matcher for a single fileset expression"""
-    tree = parse(expr)
+    tree = filesetlang.parse(expr)
     mctx = matchctx(ctx, _buildstatus(ctx, tree), badfn=badfn)
     return getmatch(mctx, tree)
 
@@ -653,9 +545,6 @@
     else:
         return None
 
-def prettyformat(tree):
-    return parser.prettyformat(tree, ('string', 'symbol'))
-
 def loadpredicate(ui, extname, registrarobj):
     """Load fileset predicates from specified registrarobj
     """