Re: code128.py
Klaas Feenstra <[email protected]>
| Newsgroups | gmane.comp.python.reportlab.user |
|---|---|
| Message-ID | <CAJcivada9SGTLV9aJHPZ82Bz-xJgQmUFPtFYNqL0Z3RBi=EmtA@mail.gmail.com> |
Robin, I made a little modification and I think this is now working
correctly.
def _trailingDigitsToC(self, l):
# Optimization: trailing digits -> set C double-digits
i = 0
nl = []
while i < len(l):
startpos = i
rl = []
savings = -1 # the TO_C costs one character
while i < len(l):
if l[i] in (['START_B','TO_A','TO_B']):
j = i
break
elif l[i] == '\xf1':
rl.append(l[i])
i += 1
continue
elif len(l[i]) == 1 and l[i] in digits \
and len(l[i+1]) == 1 and l[i+1] in digits:
rl.append(l[i] + l[i+1])
i += 2
savings += 1
continue
else:
break
ta = not (l[i]=='STOP' or j==i)
if savings > int(ta) or savings > (startpos-1): #In case of
starting with C
nl += ['TO_C']+rl
if ta:
nl.append('TO'+l[j][-2:])
nl.append(l[i])
else:
nl += l[startpos:i+1]
i += 1
return nl
On Tue, Jan 5, 2016 at 12:21 AM, Klaas Feenstra <[email protected]> wrote:
> Hi Robin,
>
> Yes, your code is working better, but is also not correct. Try the next:
> 'START_B xf1 1 2 3 4 b STOP' (8)
> should be
> 'START_B TO_C xf1 12 34 TO_B b STOP' (8), but in the function encode
>
> # Finally, replace START_X,TO_Y with START_Y
> if l[1] in tos:
> l[:2] = ['START_' + l[1][-1]]
>
> this will be transformed to
> 'START_C xf1 12 34 TO_B b STOP' (7)
>
>
>
> On Mon, Jan 4, 2016 at 3:04 PM, Robin Becker <[email protected]> wrote:
>
>> Hi Klaas,
>>
>> had a chance to look at this code and figured out you're doing a forward
>> pass over the translated sets.
>>
>> Nothing terribly wrong with the code, but I did come to the conclusion
>> that we might be missing something related to the actual optimality
>>
>>
>> I ran this code as a test
>>
>> ttdigskf.py
>>
>> rom string import digits
>>
>> def _trailingDigitsToC(self, l):
>> # Optimization: trailing digits -> set C double-digits
>>
>> i = 0
>> nl = []
>> while i < len(l):
>> startpos = i
>> rl = ['TO_C']
>> savings = -1 # the TO_C costs one character
>> while i < len(l):
>> if l[i] in (['START_B','TO_A','TO_B']):
>> set = 'TO' + l[i][-2:]
>> break
>> elif l[i] == '\xf1':
>> rl.append(l[i])
>> i += 1
>> continue
>> elif len(l[i]) == 1 and l[i] in digits \
>> and len(l[i+1]) == 1 and l[i+1] in digits:
>> rl.append(l[i] + l[i+1])
>> i += 2
>> savings += 1
>> continue
>> else:
>> break
>>
>> if savings > 0:
>> nl = nl + rl
>> if not l[i]=='STOP':
>> nl.append(set)
>> nl.append(l[i])
>> else:
>> nl = nl + l[startpos:i+1]
>> i += 1
>> return nl
>>
>> for x,l in enumerate((
>> 'START_B b b b b 1 2 3 4 5 6 b b b STOP',
>> 'START_B b b b b 1 2 3 4 5 b b b STOP',
>> 'START_B b b b b 1 2 3 4 b b b STOP',
>> 'START_B b b b b 1 2 3 b b b STOP',
>> 'START_B b b b b 1 2 b b b STOP',
>> 'START_B b b b b 1 b b b STOP',
>> 'START_B b b b b 1 2 3 4 5 6 TO_A a a STOP',
>> 'START_B b b b b 1 2 3 4 TO_A a a STOP',
>> 'START_B b b b b 1 2 3 TO_A a a STOP',
>> 'START_B b b b b 1 2 TO_A a a STOP',
>> 'START_B b b b b 1 TO_A a a STOP',
>> 'START_B b b b b 1 2 3 4 5 6 STOP',
>> 'START_B b b b b 1 2 3 4 5 STOP',
>> 'START_B b b b b 1 2 3 4 STOP',
>> 'START_B b b b b 1 2 3 STOP',
>> 'START_B b b b b 1 2 STOP',
>> 'START_B b b b b 1 STOP',
>> )):
>> l = l.split()
>> lo = _trailingDigitsToC(None, l)
>> print '%2d: %s(%d) --> %s(%d)' % (x,' '.join(l),len(l),'
>> '.join(lo),len(lo))
>>
>> result is
>>
>> C:\code\hg-repos\reportlab>tmp\ttdigskf.py
>> 0: START_B b b b b 1 2 3 4 5 6 b b b STOP(15) --> START_B b b b b TO_C
>> 12 34 56 TO_B b b b STOP(14)
>> 1: START_B b b b b 1 2 3 4 5 b b b STOP(14) --> START_B b b b b TO_C 12
>> 34 TO_B 5 b b b STOP(14)
>> 2: START_B b b b b 1 2 3 4 b b b STOP(13) --> START_B b b b b TO_C 12 34
>> TO_B b b b STOP(13)
>> 3: START_B b b b b 1 2 3 b b b STOP(12) --> START_B b b b b 1 2 3 b b b
>> STOP(12)
>> 4: START_B b b b b 1 2 b b b STOP(11) --> START_B b b b b 1 2 b b b
>> STOP(11)
>> 5: START_B b b b b 1 b b b STOP(10) --> START_B b b b b 1 b b b STOP(10)
>> 6: START_B b b b b 1 2 3 4 5 6 TO_A a a STOP(15) --> START_B b b b b
>> TO_C 12 34 56 TO_A TO_A a a STOP(14)
>> 7: START_B b b b b 1 2 3 4 TO_A a a STOP(13) --> START_B b b b b TO_C 12
>> 34 TO_A TO_A a a STOP(13)
>> 8: START_B b b b b 1 2 3 TO_A a a STOP(12) --> START_B b b b b 1 2 3
>> TO_A a a STOP(12)
>> 9: START_B b b b b 1 2 TO_A a a STOP(11) --> START_B b b b b 1 2 TO_A a
>> a STOP(11)
>> 10: START_B b b b b 1 TO_A a a STOP(10) --> START_B b b b b 1 TO_A a a
>> STOP(10)
>> 11: START_B b b b b 1 2 3 4 5 6 STOP(12) --> START_B b b b b TO_C 12 34
>> 56 STOP(10)
>> 12: START_B b b b b 1 2 3 4 5 STOP(11) --> START_B b b b b TO_C 12 34
>> TO_B 5 STOP(11)
>> 13: START_B b b b b 1 2 3 4 STOP(10) --> START_B b b b b TO_C 12 34
>> STOP(9)
>> 14: START_B b b b b 1 2 3 STOP(9) --> START_B b b b b 1 2 3 STOP(9)
>> 15: START_B b b b b 1 2 STOP(8) --> START_B b b b b 1 2 STOP(8)
>> 16: START_B b b b b 1 STOP(7) --> START_B b b b b 1 STOP(7)
>>
>> where clearly something is wrong with #6, #7 (TO_A duplicated) and #2,
>> #12 switches to C without a net gain (because we needed a TO_B to go back).
>>
>> I changed the algorithm slightly to avoid doing some work early and this
>> version appears to work slightly better
>>
>> def _trailingDigitsToC(self, l):
>> # Optimization: trailing digits -> set C double-digits
>>
>> i = 0
>> nl = []
>> while i < len(l):
>> startpos = i
>> rl = []
>> savings = -1 # the TO_C costs one character
>> while i < len(l):
>> if l[i] in (['START_B','TO_A','TO_B']):
>> j = i
>> break
>> elif l[i] == '\xf1':
>> rl.append(l[i])
>> i += 1
>> continue
>> elif len(l[i]) == 1 and l[i] in digits \
>> and len(l[i+1]) == 1 and l[i+1] in digits:
>> rl.append(l[i] + l[i+1])
>> i += 2
>> savings += 1
>> continue
>> else:
>> break
>>
>> ta = not (l[i]=='STOP' or j==i)
>> if savings > int(ta):
>> nl += ['TO_C']+rl
>> if ta:
>> nl.append('TO'+l[j][-2:])
>> nl.append(l[i])
>> else:
>> nl += l[startpos:i+1]
>> i += 1
>> return nl
>>
>>
>> if I use that then the tests show this
>>
>> C:\code\hg-repos\reportlab>tmp\ttdigs.py
>> 0: START_B b b b b 1 2 3 4 5 6 b b b STOP(15) --> START_B b b b b TO_C
>> 12 34 56 TO_B b b b STOP(14)
>> 1: START_B b b b b 1 2 3 4 5 b b b STOP(14) --> START_B b b b b 1 2 3 4
>> 5 b b b STOP(14)
>> 2: START_B b b b b 1 2 3 4 b b b STOP(13) --> START_B b b b b 1 2 3 4 b
>> b b STOP(13)
>> 3: START_B b b b b 1 2 3 b b b STOP(12) --> START_B b b b b 1 2 3 b b b
>> STOP(12)
>> 4: START_B b b b b 1 2 b b b STOP(11) --> START_B b b b b 1 2 b b b
>> STOP(11)
>> 5: START_B b b b b 1 b b b STOP(10) --> START_B b b b b 1 b b b STOP(10)
>> 6: START_B b b b b 1 2 3 4 5 6 TO_A a a STOP(15) --> START_B b b b b
>> TO_C 12 34 56 TO_A a a STOP(13)
>> 7: START_B b b b b 1 2 3 4 TO_A a a STOP(13) --> START_B b b b b TO_C 12
>> 34 TO_A a a STOP(12)
>> 8: START_B b b b b 1 2 3 TO_A a a STOP(12) --> START_B b b b b 1 2 3
>> TO_A a a STOP(12)
>> 9: START_B b b b b 1 2 TO_A a a STOP(11) --> START_B b b b b 1 2 TO_A a
>> a STOP(11)
>> 10: START_B b b b b 1 TO_A a a STOP(10) --> START_B b b b b 1 TO_A a a
>> STOP(10)
>> 11: START_B b b b b 1 2 3 4 5 6 STOP(12) --> START_B b b b b TO_C 12 34
>> 56 STOP(10)
>> 12: START_B b b b b 1 2 3 4 5 STOP(11) --> START_B b b b b 1 2 3 4 5
>> STOP(11)
>> 13: START_B b b b b 1 2 3 4 STOP(10) --> START_B b b b b TO_C 12 34
>> STOP(9)
>> 14: START_B b b b b 1 2 3 STOP(9) --> START_B b b b b 1 2 3 STOP(9)
>> 15: START_B b b b b 1 2 STOP(8) --> START_B b b b b 1 2 STOP(8)
>> 16: START_B b b b b 1 STOP(7) --> START_B b b b b 1 STOP(7)
>>
>> what do you think?
>> --
>> Robin Becker
>>
>
>