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author | timeless@mozdev.org |
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date | Fri, 17 Aug 2012 13:58:18 -0700 |
parents | 525fdb738975 |
children | 8ac8db8dc346 |
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# dagparser.py - parser and generator for concise description of DAGs # # Copyright 2010 Peter Arrenbrecht <peter@arrenbrecht.ch> # # 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 _ 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 labelled 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 labelled 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(): try: return chiter.next() except StopIteration: return '\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))