mkm3u: Use `-1' throughout as a sentinel title/chapter number.

This will make it easier to integrate with statically typed systems like
databases.  It already simplifies the duration-caching machinery.

diff --git a/mkm3u b/mkm3u
index 7df1891..368546a 100755 (executable)
--- a/mkm3u
+++ b/mkm3u
@@ -141,22 +141,22 @@ class Source (object):
 
   def _duration(me, title, start_chapter, end_chapter):
     return -1
-  def url_and_duration(me, title = None,
-                       start_chapter = None, end_chapter = None):
-    if title == "-":
+
+  def url_and_duration(me, title = -1, start_chapter = -1, end_chapter = -1):
+    if title == -1:
       if me.TITLEP: raise ExpectedError("missing title number")
-      if start_chapter is not None or end_chapter is not None:
+      if start_chapter != -1 or end_chapter != -1:
         raise ExpectedError("can't specify chapter without title")
       suffix = ""
     elif not me.TITLEP:
       raise ExpectedError("can't specify title with `%s'" % me.fn)
-    elif start_chapter is None:
-      if end_chapter is not None:
+    elif start_chapter == -1:
+      if end_chapter != -1:
         raise ExpectedError("can't specify end chapter without start chapter")
       suffix = "#%d" % title
     elif not me.CHAPTERP:
       raise ExpectedError("can't specify chapter with `%s'" % me.fn)
-    elif end_chapter is None:
+    elif end_chapter == -1:
       suffix = "#%d:%d" % (title, start_chapter)
     else:
       suffix = "#%d:%d-%d:%d" % (title, start_chapter, title, end_chapter - 1)
@@ -172,8 +172,7 @@ class Source (object):
               SELECT device, inode, size, mtime,  duration FROM duration
               WHERE path = ? AND title = ? AND
                     start_chapter = ? AND end_chapter = ?
-      """, [me.fn, title, start_chapter is None and -1 or start_chapter,
-            end_chapter is None and -1 or end_chapter])
+      """, [me.fn, title, start_chapter, end_chapter])
       row = c.fetchone()
       foundp = False
       if row is None:
@@ -183,8 +182,7 @@ class Source (object):
                         (path, title, start_chapter, end_chapter,
                          device, inode, size, mtime,  duration)
                 VALUES (?, ?, ?, ?,  ?, ?, ?, ?,  ?)
-        """, [me.fn, title, start_chapter is None and -1 or start_chapter,
-              end_chapter is None and -1 or end_chapter,
+        """, [me.fn, title, start_chapter, end_chapter,
               st.st_dev, st.st_ino, st.st_size, st.st_mtime,
               duration])
       else:
@@ -199,26 +197,25 @@ class Source (object):
                   SET device = ?, inode = ?, size = ?, mtime = ?, duration = ?
                   WHERE path = ? AND title = ? AND
                         start_chapter = ? AND end_chapter = ?
-        """, [st.st_dev, st.st_dev, st.st_size, st.st_mtime,  duration,
-              me.fn, title, start_chapter is None and -1 or start_chapter,
-              end_chapter is None and -1 or end_chapter])
+          """, [st.st_dev, st.st_dev, st.st_size, st.st_mtime,  duration,
+                me.fn, title, start_chapter, end_chapter])
       DB.commit()
 
-    if end_chapter is not None:
+    if end_chapter != -1:
       keys = [(title, ch) for ch in range(start_chapter, end_chapter)]
       set = me.used_chapters
     else:
       keys, set = [title], me.used_titles
     for k in keys:
       if k in set:
-        if title == "-":
+        if title == -1:
           raise ExpectedError("`%s' already used" % me.fn)
-        elif end_chapter is None:
+        elif end_chapter == -1:
           raise ExpectedError("`%s' title %d already used" % (me.fn, title))
         else:
           raise ExpectedError("`%s' title %d chapter %d already used" %
                               (me.fn, title, k[1]))
-    if end_chapter is not None:
+    if end_chapter != -1:
       for ch in range(start_chapter, end_chapter):
         me.used_chapters.add((title, ch))
     return me.PREFIX + ROOT + urlencode(me.fn) + suffix, duration
@@ -237,11 +234,11 @@ class VideoDisc (Source):
     if not 1 <= title <= ntitle:
       raise ExpectedError("bad title %d for `%s': must be in 1 .. %d" %
                             (title, me.fn, ntitle))
-    if start_chapter is None:
+    if start_chapter == -1:
       durq = "duration:%d" % title
     else:
       nch = int(program_output(["dvd-info", path, "chapters:%d" % title]))
-      if end_chapter is None: end_chapter = nch
+      if end_chapter == -1: end_chapter = nch
       else: end_chapter -= 1
       if not 1 <= start_chapter <= end_chapter <= nch:
         raise ExpectedError("bad chapter range %d .. %d for `%s' title %d: "
@@ -407,7 +404,7 @@ class Chapter (object):
 
 class Episode (object):
   def __init__(me, season, i, neps, title, src, series_title_p = True,
-               tno = None, startch = None, endch = None):
+               tno = -1, startch = -1, endch = -1):
     me.season = season
     me.i, me.neps, me.title = i, neps, title
     me.chapters = []
@@ -732,13 +729,13 @@ class EpisodeListParser (object):
   def _process_episode(me, ww):
 
     opts = ww.nextword(); check(opts is not None, "missing title/options")
-    ti = None; sname = None; neps = 1; epi = None; loch = hich = None
+    ti = -1; sname = None; neps = 1; epi = None; loch = hich = -1
     explen, expvar, explicitlen = me._explen, me._expvar, False
     series_title_p = True
     for k, v in me._keyvals(opts):
       if k is None:
         if v.isdigit(): ti = int(v)
-        elif v == "-": ti = "-"
+        elif v == "-": ti = -1
         else: sname = v
       elif k == "s": sname = v
       elif k == "n": neps = getint(v)
@@ -751,7 +748,7 @@ class EpisodeListParser (object):
           explicitlen = True
       elif k == "ch":
         try: sep = v.index("-")
-        except ValueError: loch, hich = getint(v), None
+        except ValueError: loch, hich = getint(v), -1
         else: loch, hich = getint(v[:sep]), getint(v[sep + 1:]) + 1
       else: raise ExpectedError("unknown episode option `%s'" % k)
     check(ti is not None, "missing title number")
@@ -763,7 +760,7 @@ class EpisodeListParser (object):
     season = series.ensure_season()
     if epi is None: epi = season.ep_i
 
-    if ti == "-":
+    if ti == -1:
       check(season.implicitp or season.i is None,
             "audio source, but explicit non-movie season")
       dir = lookup(me._audirs, series.name,