I believe I have finally vanquished the Demons of Derval Byslexia...
What I posted:
_______________
I ......I
IV .....V.
V .....V.
VI .....VI
IX ....X..
X ....X..
XI ....X.I
XIV ....XV.
XV ....XV.
XVI ....XVI
XIX ....X.I
X ....X..
XL ....X.. WRONG Should be: ...L...
LX ...LX..
XC ....X.. WRONG Should be: ..C....
CLXIX ..CLX.I
CDXLVI .D..XVI WRONG Should be: .D.L.VI
MCMXCVI M.C.XVI
MDCLI MDCL..I
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Here's more on what I want to do, and why:
1 2 3 4 5 6 7
Simple Rule: M D C L X V I
Input String: IV
Character: I
Desired position: 7
Next char: V (Desired position: 6)
I>V
7>6
Discard I; take V (Output: .......)
Character: V
Desired position: 6
Next char: NONE
V<NONE
Keep V (Output: .....V.)
End of Input; Output: .....V. (Agrees with Posted)
---
Input String: VI
Character: V
Desired position: 6
Next char: I (Desired position: 7)
V<I
6<7
Keep V; consider I (Output: .....V.)
Character: I
Desired position: 7
Next char: NONE
I<NONE
Keep I (Output: .....VI)
End of Input; Output: .....VI (Agrees with Posted)
---
IX ....X.. for the same reason IV .....V.
XI ....X.I for the same reason VI .....VI
---
Input String: XIV
Character: X
Desired position: 5
Next char: I (Desired position: 7)
X<I
5<7
Keep X; consider I (Output: ....X..)
Character: I
Desired position: 7
Next char: V (Desired position: 6)
I>V
7>6
Discard I; consider V (Output: ....X..)
Character: V
Desired position: 6
Next char: NONE
V<NONE
Keep V (Output: ....XV.)
End of Input; Output: ....XV. (Agrees with Posted)
---
XIX ....X.I
(Special case because we already "saw" X - See MCMXCVI M.C.XVI for a complete discussion.)
CLXIX ..CLX.I
for the same reason XIX ....X.I
---
Input String: XL
Character: X
Desired position: 5
Next char: L (Desired position: 4)
X>L
5>4
Discard X; consider L (Output: .......)
Character: L
Desired position: 4
Next char: NONE
L<NONE
Keep L (Output: ...L...)
End of Input; Output: ...L... (DOES NOT Agree with Posted)
---
Input String: LX
Character: L
Desired position: 4
Next char: X (Desired position: 5)
L<X
4<5
Keep L; consider X (Output: ...L...)
Character: X
Desired position: 5
Next char: NONE
X<NONE
Keep X (Output: ...LX..)
End of Input; Output: ...LX.. (Agrees with Posted)
---
XC ..C.... for the same reason XL ...L... (DOES NOT Agree with
+ Posted)
---
Input String: CDXLVI
Character: C
Desired position: 3
Next char: D (Desired position: 2)
C>D
3>2
Discard C; consider D (Output: .......)
Character: D
Desired position: 2
Next char: X (Desired position: 5)
D<X
2<5
Keep D; consider X (Output: .D.....)
Character: X
Desired position: 5
Next char: L (Desired position: 4)
X>L
5>4
Discard X; consider L (Output: .D.....)
Character: L
Desired position: 4
Next char: V (Desired position: 6)
L<V
4<6
Keep L; consider V (Output: .D.L...)
Character: V
Desired position: 6
Next char: I (Desired position: 7)
V<I
6<7
Keep V; consider I (Output: .D.L.V.)
Character: I
Desired position: 7
Next char: NONE
I<NONE
Keep I (Output: .D.L.VI)
End of Input; Output: .D.L.VI (DOES NOT Agree with Posted)
---
Input String: MCMXCVI
Character: M
Desired position: 1
Next char: C (Desired position: 3)
M<C
1<3
Keep M; consider C (Output: M......)
Character: C
Desired position: 3
Next char: M (Desired position: 1)
C>M
3>1 BUT... we've already "seen" M...
Keep C; discard second M; consider X (Output: M.C....)
Character: X
Desired position: 5
Next char: C (Desired position: 3)
X>C
5>3 BUT... we've already "seen" C...
Keep X; discard second C; consider V (Output: M.C.X..)
Character: V
Desired position: 6
Next char: I (Desired position: 7)
V<I
6<7
Keep V; consider I (Output: M.C.XV.)
Character: I
Desired position: 7
Next char: NONE
I<NONE
Keep I (Output: M.C.XVI)
End of Input; Output: M.C.XVI (By some miracle, Agrees with Posted)
Complex Rule: Discard an earlier, one character match in favor of a longer, later match. In real data, earlier, one
character matches also occur and should be discarded, because a longer match is probably on the way. Similarly, we probably
want to get rid of characters we've already seen, unless... Unless those characters are SUPPOSED to also occur later,
which is why I used the character classes in the regex in the code I posted... Arg.
Revised
Desired Output:
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I ......I
IV .....V.
V .....V.
VI .....VI
IX ....X..
X ....X..
XI ....X.I
XIV ....XV.
XV ....XV.
XVI ....XVI
XIX ....X.I
X ....X..
XL ...L...
LX ...LX..
XC ..C....
CLXIX ..CLX.I
CDXLVI .D.L.VI
MCMXCVI M.C.XVI
MDCLI MDCL..I
_______________
Now for me to figure out which monk-contributed code works with the revised output... I'm blind now, so...
Updated: Fixed two relatively minor typos.