1 files changed, 65 insertions, 0 deletions
diff --git a/dns/grange.py b/dns/grange.py
new file mode 100644
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--- /dev/null
+++ b/dns/grange.py
@@ -0,0 +1,65 @@
+# Copyright (C) 2003-2007, 2009-2011 Nominum, Inc.
+#
+# Permission to use, copy, modify, and distribute this software and its
+# documentation for any purpose with or without fee is hereby granted,
+# provided that the above copyright notice and this permission notice
+# appear in all copies.
+#
+# THE SOFTWARE IS PROVIDED "AS IS" AND NOMINUM DISCLAIMS ALL WARRANTIES
+# WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+# MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL NOMINUM BE LIABLE FOR
+# ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+# WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+# ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
+# OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+
+"""DNS GENERATE range conversion."""
+
+import dns
+
+def from_text(text):
+    """Convert the text form of a range in a GENERATE statement to an
+    integer.
+
+    @param text: the textual range
+    @type text: string
+    @return range: The start, stop and step values.
+    @type range: tuple
+    """
+    # TODO, figure out the bounds on start, stop and step.
+
+    import pdb
+    step = 1
+    cur = ''
+    state = 0
+    # state   0 1 2 3 4
+    #         x - y / z
+    for c in text:
+        if c == '-' and state == 0:
+            start = int(cur)
+            cur = ''
+            state = 2
+        elif c == '/':
+            stop = int(cur)
+            cur = ''
+            state = 4
+        elif c.isdigit():
+            cur += c
+        else:
+            raise dns.exception.SyntaxError("Could not parse %s" % (c))
+
+    if state in (1, 3):
+        raise dns.exception.SyntaxError
+
+    if state == 2:
+        stop = int(cur)
+
+    if state == 4:
+        step = int(cur)
+
+    assert step >= 1
+    assert start >= 0
+    assert start <= stop
+    # TODO, can start == stop?
+
+    return (start, stop, step)