kaitai: adjustments and rearrangements for python2/3 compat

1 files changed, 110 insertions, 0 deletions

diff --git a/python/examples/kaitai/bcd.py b/python/examples/kaitai/bcd.py
new file mode 100644
index 00000000..3f2afb80
--- /dev/null
+++ b/python/examples/kaitai/bcd.py
@@ -0,0 +1,110 @@
+# This is a generated file! Please edit source .ksy file and use kaitai-struct-compiler to rebuild
+
+from pkg_resources import parse_version
+from .kaitaistruct import __version__ as ks_version, KaitaiStruct, KaitaiStream, BytesIO
+import collections
+
+
+if parse_version(ks_version) < parse_version('0.7'):
+    raise Exception("Incompatible Kaitai Struct Python API: 0.7 or later is required, but you have %s" % (ks_version))
+
+class Bcd(KaitaiStruct):
+    """BCD (Binary Coded Decimals) is a common way to encode integer
+    numbers in a way that makes human-readable output somewhat
+    simpler. In this encoding scheme, every decimal digit is encoded as
+    either a single byte (8 bits), or a nibble (half of a byte, 4
+    bits). This obviously wastes a lot of bits, but it makes translation
+    into human-readable string much easier than traditional
+    binary-to-decimal conversion process, which includes lots of
+    divisions by 10.
+    
+    For example, encoding integer 31337 in 8-digit, 8 bits per digit,
+    big endian order of digits BCD format yields
+    
+    ```
+    00 00 00 03 01 03 03 07
+    ```
+    
+    Encoding the same integer as 8-digit, 4 bits per digit, little
+    endian order BCD format would yield:
+    
+    ```
+    73 31 30 00
+    ```
+    
+    Using this type of encoding in Kaitai Struct is pretty
+    straightforward: one calls for this type, specifying desired
+    encoding parameters, and gets result using either `as_int` or
+    `as_str` attributes.
+    """
+    SEQ_FIELDS = ["digits"]
+    def __init__(self, num_digits, bits_per_digit, is_le, _io, _parent=None, _root=None):
+        self._io = _io
+        self._parent = _parent
+        self._root = _root if _root else self
+        self.num_digits = num_digits
+        self.bits_per_digit = bits_per_digit
+        self.is_le = is_le
+        self._debug = collections.defaultdict(dict)
+
+    def _read(self):
+        self._debug['digits']['start'] = self._io.pos()
+        self.digits = [None] * (self.num_digits)
+        for i in range(self.num_digits):
+            if not 'arr' in self._debug['digits']:
+                self._debug['digits']['arr'] = []
+            self._debug['digits']['arr'].append({'start': self._io.pos()})
+            _on = self.bits_per_digit
+            if _on == 4:
+                if not 'arr' in self._debug['digits']:
+                    self._debug['digits']['arr'] = []
+                self._debug['digits']['arr'].append({'start': self._io.pos()})
+                self.digits[i] = self._io.read_bits_int(4)
+                self._debug['digits']['arr'][i]['end'] = self._io.pos()
+            elif _on == 8:
+                if not 'arr' in self._debug['digits']:
+                    self._debug['digits']['arr'] = []
+                self._debug['digits']['arr'].append({'start': self._io.pos()})
+                self.digits[i] = self._io.read_u1()
+                self._debug['digits']['arr'][i]['end'] = self._io.pos()
+            self._debug['digits']['arr'][i]['end'] = self._io.pos()
+
+        self._debug['digits']['end'] = self._io.pos()
+
+    @property
+    def as_int(self):
+        """Value of this BCD number as integer. Endianness would be selected based on `is_le` parameter given."""
+        if hasattr(self, '_m_as_int'):
+            return self._m_as_int if hasattr(self, '_m_as_int') else None
+
+        self._m_as_int = (self.as_int_le if self.is_le else self.as_int_be)
+        return self._m_as_int if hasattr(self, '_m_as_int') else None
+
+    @property
+    def as_int_le(self):
+        """Value of this BCD number as integer (treating digit order as little-endian)."""
+        if hasattr(self, '_m_as_int_le'):
+            return self._m_as_int_le if hasattr(self, '_m_as_int_le') else None
+
+        self._m_as_int_le = (self.digits[0] + (0 if self.num_digits < 2 else ((self.digits[1] * 10) + (0 if self.num_digits < 3 else ((self.digits[2] * 100) + (0 if self.num_digits < 4 else ((self.digits[3] * 1000) + (0 if self.num_digits < 5 else ((self.digits[4] * 10000) + (0 if self.num_digits < 6 else ((self.digits[5] * 100000) + (0 if self.num_digits < 7 else ((self.digits[6] * 1000000) + (0 if self.num_digits < 8 else (self.digits[7] * 10000000)))))))))))))))
+        return self._m_as_int_le if hasattr(self, '_m_as_int_le') else None
+
+    @property
+    def last_idx(self):
+        """Index of last digit (0-based)."""
+        if hasattr(self, '_m_last_idx'):
+            return self._m_last_idx if hasattr(self, '_m_last_idx') else None
+
+        self._m_last_idx = (self.num_digits - 1)
+        return self._m_last_idx if hasattr(self, '_m_last_idx') else None
+
+    @property
+    def as_int_be(self):
+        """Value of this BCD number as integer (treating digit order as big-endian)."""
+        if hasattr(self, '_m_as_int_be'):
+            return self._m_as_int_be if hasattr(self, '_m_as_int_be') else None
+
+        self._m_as_int_be = (self.digits[self.last_idx] + (0 if self.num_digits < 2 else ((self.digits[(self.last_idx - 1)] * 10) + (0 if self.num_digits < 3 else ((self.digits[(self.last_idx - 2)] * 100) + (0 if self.num_digits < 4 else ((self.digits[(self.last_idx - 3)] * 1000) + (0 if self.num_digits < 5 else ((self.digits[(self.last_idx - 4)] * 10000) + (0 if self.num_digits < 6 else ((self.digits[(self.last_idx - 5)] * 100000) + (0 if self.num_digits < 7 else ((self.digits[(self.last_idx - 6)] * 1000000) + (0 if self.num_digits < 8 else (self.digits[(self.last_idx - 7)] * 10000000)))))))))))))))
+        return self._m_as_int_be if hasattr(self, '_m_as_int_be') else None
+
+