dagparser: use absolute_import

mercurial/dagparser.py

@@ -1,476 +1,480 b''
 # dagparser.py - parser and generator for concise description of DAGs
 #
 # Copyright 2010 Peter Arrenbrecht <[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.
 
-import re, string
-import util
-from i18n import _
+from __future__ import absolute_import
+
+import re
+import string
+
+from .i18n import _
+from . import util
 
 def parsedag(desc):
     '''parses a DAG from a concise textual description; generates events
 
     "+n" is a linear run of n nodes based on the current default parent
     "." is a single node based on the current default parent
     "$" resets the default parent to -1 (implied at the start);
         otherwise the default parent is always the last node created
     "<p" sets the default parent to the backref p
     "*p" is a fork at parent p, where p is a backref
     "*p1/p2/.../pn" is a merge of parents p1..pn, where the pi are backrefs
     "/p2/.../pn" is a merge of the preceding node and p2..pn
     ":name" defines a label for the preceding node; labels can be redefined
     "@text" emits an annotation event for text
     "!command" emits an action event for the current node
     "!!my command\n" is like "!", but to the end of the line
     "#...\n" is a comment up to the end of the line
 
     Whitespace between the above elements is ignored.
 
     A backref is either
      * a number n, which references the node curr-n, where curr is the current
        node, or
      * the name of a label you placed earlier using ":name", or
      * empty to denote the default parent.
 
     All string valued-elements are either strictly alphanumeric, or must
     be enclosed in double quotes ("..."), with "\" as escape character.
 
     Generates sequence of
 
       ('n', (id, [parentids])) for node creation
       ('l', (id, labelname)) for labels on nodes
       ('a', text) for annotations
       ('c', command) for actions (!)
       ('C', command) for line actions (!!)
 
     Examples
     --------
 
     Example of a complex graph (output not shown for brevity):
 
         >>> len(list(parsedag("""
         ...
         ... +3         # 3 nodes in linear run
         ... :forkhere  # a label for the last of the 3 nodes from above
         ... +5         # 5 more nodes on one branch
         ... :mergethis # label again
         ... <forkhere  # set default parent to labeled fork node
         ... +10        # 10 more nodes on a parallel branch
         ... @stable    # following nodes will be annotated as "stable"
         ... +5         # 5 nodes in stable
         ... !addfile   # custom command; could trigger new file in next node
         ... +2         # two more nodes
         ... /mergethis # merge last node with labeled node
         ... +4         # 4 more nodes descending from merge node
         ...
         ... """)))
         34
 
     Empty list:
 
         >>> list(parsedag(""))
         []
 
     A simple linear run:
 
         >>> list(parsedag("+3"))
         [('n', (0, [-1])), ('n', (1, [0])), ('n', (2, [1]))]
 
     Some non-standard ways to define such runs:
 
         >>> list(parsedag("+1+2"))
         [('n', (0, [-1])), ('n', (1, [0])), ('n', (2, [1]))]
 
         >>> list(parsedag("+1*1*"))
         [('n', (0, [-1])), ('n', (1, [0])), ('n', (2, [1]))]
 
         >>> list(parsedag("*"))
         [('n', (0, [-1]))]
 
         >>> list(parsedag("..."))
         [('n', (0, [-1])), ('n', (1, [0])), ('n', (2, [1]))]
 
     A fork and a join, using numeric back references:
 
         >>> list(parsedag("+2*2*/2"))
         [('n', (0, [-1])), ('n', (1, [0])), ('n', (2, [0])), ('n', (3, [2, 1]))]
 
         >>> list(parsedag("+2<2+1/2"))
         [('n', (0, [-1])), ('n', (1, [0])), ('n', (2, [0])), ('n', (3, [2, 1]))]
 
     Placing a label:
 
         >>> list(parsedag("+1 :mylabel +1"))
         [('n', (0, [-1])), ('l', (0, 'mylabel')), ('n', (1, [0]))]
 
     An empty label (silly, really):
 
         >>> list(parsedag("+1:+1"))
         [('n', (0, [-1])), ('l', (0, '')), ('n', (1, [0]))]
 
     Fork and join, but with labels instead of numeric back references:
 
         >>> list(parsedag("+1:f +1:p2 *f */p2"))
         [('n', (0, [-1])), ('l', (0, 'f')), ('n', (1, [0])), ('l', (1, 'p2')),
          ('n', (2, [0])), ('n', (3, [2, 1]))]
 
         >>> list(parsedag("+1:f +1:p2 <f +1 /p2"))
         [('n', (0, [-1])), ('l', (0, 'f')), ('n', (1, [0])), ('l', (1, 'p2')),
          ('n', (2, [0])), ('n', (3, [2, 1]))]
 
     Restarting from the root:
 
         >>> list(parsedag("+1 $ +1"))
         [('n', (0, [-1])), ('n', (1, [-1]))]
 
     Annotations, which are meant to introduce sticky state for subsequent nodes:
 
         >>> list(parsedag("+1 @ann +1"))
         [('n', (0, [-1])), ('a', 'ann'), ('n', (1, [0]))]
 
         >>> list(parsedag('+1 @"my annotation" +1'))
         [('n', (0, [-1])), ('a', 'my annotation'), ('n', (1, [0]))]
 
     Commands, which are meant to operate on the most recently created node:
 
         >>> list(parsedag("+1 !cmd +1"))
         [('n', (0, [-1])), ('c', 'cmd'), ('n', (1, [0]))]
 
         >>> list(parsedag('+1 !"my command" +1'))
         [('n', (0, [-1])), ('c', 'my command'), ('n', (1, [0]))]
 
         >>> list(parsedag('+1 !!my command line\\n +1'))
         [('n', (0, [-1])), ('C', 'my command line'), ('n', (1, [0]))]
 
     Comments, which extend to the end of the line:
 
         >>> list(parsedag('+1 # comment\\n+1'))
         [('n', (0, [-1])), ('n', (1, [0]))]
 
     Error:
 
         >>> try: list(parsedag('+1 bad'))
         ... except Exception, e: print e
         invalid character in dag description: bad...
 
     '''
     if not desc:
         return
 
     wordchars = string.ascii_letters + string.digits
 
     labels = {}
     p1 = -1
     r = 0
 
     def resolve(ref):
         if not ref:
             return p1
         elif ref[0] in string.digits:
             return r - int(ref)
         else:
             return labels[ref]
 
     chiter = (c for c in desc)
 
     def nextch():
         return next(chiter, '\0')
 
     def nextrun(c, allow):
         s = ''
         while c in allow:
             s += c
             c = nextch()
         return c, s
 
     def nextdelimited(c, limit, escape):
         s = ''
         while c != limit:
             if c == escape:
                 c = nextch()
             s += c
             c = nextch()
         return nextch(), s
 
     def nextstring(c):
         if c == '"':
             return nextdelimited(nextch(), '"', '\\')
         else:
             return nextrun(c, wordchars)
 
     c = nextch()
     while c != '\0':
         while c in string.whitespace:
             c = nextch()
         if c == '.':
             yield 'n', (r, [p1])
             p1 = r
             r += 1
             c = nextch()
         elif c == '+':
             c, digs = nextrun(nextch(), string.digits)
             n = int(digs)
             for i in xrange(0, n):
                 yield 'n', (r, [p1])
                 p1 = r
                 r += 1
         elif c in '*/':
             if c == '*':
                 c = nextch()
             c, pref = nextstring(c)
             prefs = [pref]
             while c == '/':
                 c, pref = nextstring(nextch())
                 prefs.append(pref)
             ps = [resolve(ref) for ref in prefs]
             yield 'n', (r, ps)
             p1 = r
             r += 1
         elif c == '<':
             c, ref = nextstring(nextch())
             p1 = resolve(ref)
         elif c == ':':
             c, name = nextstring(nextch())
             labels[name] = p1
             yield 'l', (p1, name)
         elif c == '@':
             c, text = nextstring(nextch())
             yield 'a', text
         elif c == '!':
             c = nextch()
             if c == '!':
                 cmd = ''
                 c = nextch()
                 while c not in '\n\r\0':
                     cmd += c
                     c = nextch()
                 yield 'C', cmd
             else:
                 c, cmd = nextstring(c)
                 yield 'c', cmd
         elif c == '#':
             while c not in '\n\r\0':
                 c = nextch()
         elif c == '$':
             p1 = -1
             c = nextch()
         elif c == '\0':
             return # in case it was preceded by whitespace
         else:
             s = ''
             i = 0
             while c != '\0' and i < 10:
                 s += c
                 i += 1
                 c = nextch()
             raise util.Abort(_('invalid character in dag description: '
                                '%s...') % s)
 
 def dagtextlines(events,
                  addspaces=True,
                  wraplabels=False,
                  wrapannotations=False,
                  wrapcommands=False,
                  wrapnonlinear=False,
                  usedots=False,
                  maxlinewidth=70):
     '''generates single lines for dagtext()'''
 
     def wrapstring(text):
         if re.match("^[0-9a-z]*$", text):
             return text
         return '"' + text.replace('\\', '\\\\').replace('"', '\"') + '"'
 
     def gen():
         labels = {}
         run = 0
         wantr = 0
         needroot = False
         for kind, data in events:
             if kind == 'n':
                 r, ps = data
 
                 # sanity check
                 if r != wantr:
                     raise util.Abort(_("expected id %i, got %i") % (wantr, r))
                 if not ps:
                     ps = [-1]
                 else:
                     for p in ps:
                         if p >= r:
                             raise util.Abort(_("parent id %i is larger than "
                                                "current id %i") % (p, r))
                 wantr += 1
 
                 # new root?
                 p1 = r - 1
                 if len(ps) == 1 and ps[0] == -1:
                     if needroot:
                         if run:
                             yield '+' + str(run)
                             run = 0
                         if wrapnonlinear:
                             yield '\n'
                         yield '$'
                         p1 = -1
                     else:
                         needroot = True
                 if len(ps) == 1 and ps[0] == p1:
                     if usedots:
                         yield "."
                     else:
                         run += 1
                 else:
                     if run:
                         yield '+' + str(run)
                         run = 0
                     if wrapnonlinear:
                         yield '\n'
                     prefs = []
                     for p in ps:
                         if p == p1:
                             prefs.append('')
                         elif p in labels:
                             prefs.append(labels[p])
                         else:
                             prefs.append(str(r - p))
                     yield '*' + '/'.join(prefs)
             else:
                 if run:
                     yield '+' + str(run)
                     run = 0
                 if kind == 'l':
                     rid, name = data
                     labels[rid] = name
                     yield ':' + name
                     if wraplabels:
                         yield '\n'
                 elif kind == 'c':
                     yield '!' + wrapstring(data)
                     if wrapcommands:
                         yield '\n'
                 elif kind == 'C':
                     yield '!!' + data
                     yield '\n'
                 elif kind == 'a':
                     if wrapannotations:
                         yield '\n'
                     yield '@' + wrapstring(data)
                 elif kind == '#':
                     yield '#' + data
                     yield '\n'
                 else:
                     raise util.Abort(_("invalid event type in dag: %s")
                                      % str((type, data)))
         if run:
             yield '+' + str(run)
 
     line = ''
     for part in gen():
         if part == '\n':
             if line:
                 yield line
                 line = ''
         else:
             if len(line) + len(part) >= maxlinewidth:
                 yield line
                 line = ''
             elif addspaces and line and part != '.':
                 line += ' '
             line += part
     if line:
         yield line
 
 def dagtext(dag,
             addspaces=True,
             wraplabels=False,
             wrapannotations=False,
             wrapcommands=False,
             wrapnonlinear=False,
             usedots=False,
             maxlinewidth=70):
     '''generates lines of a textual representation for a dag event stream
 
     events should generate what parsedag() does, so:
 
       ('n', (id, [parentids])) for node creation
       ('l', (id, labelname)) for labels on nodes
       ('a', text) for annotations
       ('c', text) for commands
       ('C', text) for line commands ('!!')
       ('#', text) for comment lines
 
     Parent nodes must come before child nodes.
 
     Examples
     --------
 
     Linear run:
 
         >>> dagtext([('n', (0, [-1])), ('n', (1, [0]))])
         '+2'
 
     Two roots:
 
         >>> dagtext([('n', (0, [-1])), ('n', (1, [-1]))])
         '+1 $ +1'
 
     Fork and join:
 
         >>> dagtext([('n', (0, [-1])), ('n', (1, [0])), ('n', (2, [0])),
         ...          ('n', (3, [2, 1]))])
         '+2 *2 */2'
 
     Fork and join with labels:
 
         >>> dagtext([('n', (0, [-1])), ('l', (0, 'f')), ('n', (1, [0])),
         ...          ('l', (1, 'p2')), ('n', (2, [0])), ('n', (3, [2, 1]))])
         '+1 :f +1 :p2 *f */p2'
 
     Annotations:
 
         >>> dagtext([('n', (0, [-1])), ('a', 'ann'), ('n', (1, [0]))])
         '+1 @ann +1'
 
         >>> dagtext([('n', (0, [-1])),
         ...          ('a', 'my annotation'),
         ...          ('n', (1, [0]))])
         '+1 @"my annotation" +1'
 
     Commands:
 
         >>> dagtext([('n', (0, [-1])), ('c', 'cmd'), ('n', (1, [0]))])
         '+1 !cmd +1'
 
         >>> dagtext([('n', (0, [-1])), ('c', 'my command'), ('n', (1, [0]))])
         '+1 !"my command" +1'
 
         >>> dagtext([('n', (0, [-1])),
         ...          ('C', 'my command line'),
         ...          ('n', (1, [0]))])
         '+1 !!my command line\\n+1'
 
     Comments:
 
         >>> dagtext([('n', (0, [-1])), ('#', ' comment'), ('n', (1, [0]))])
         '+1 # comment\\n+1'
 
         >>> dagtext([])
         ''
 
     Combining parsedag and dagtext:
 
         >>> dagtext(parsedag('+1 :f +1 :p2 *f */p2'))
         '+1 :f +1 :p2 *f */p2'
 
     '''
     return "\n".join(dagtextlines(dag,
                                   addspaces,
                                   wraplabels,
                                   wrapannotations,
                                   wrapcommands,
                                   wrapnonlinear,
                                   usedots,
                                   maxlinewidth))