Hi,
discovered a strange behaviour of the split function for Strings:
A very natural application is to read in a CSV file and get as many
Strings - possibly empty ones - as the number of occurencies of the
splitting character indicates (+1):
However:
(1) -> line := "A;B;;C;;"
(1) "A;B;;C;;"
Type:
String
(2) -> c := char ";"
(2) ;
Type:
Character
(3) -> split(line, c)
(3) ["A","B","C"]
Type:
List(String)
This is not what I expect. Here is a fix in IndexedString:
split(s, c) ==
n := maxIndex s
--for i in mn..n while s.i = c repeat 0
i := mn
l := empty()$List(%)
j : Integer -- j is conditionally intialized
while i <= n and (j := position(c, s, i)) >= mn repeat
l := concat(s(i..j-1), l)
--for i in j..n while s.i = c repeat 0
i := j+1
--if i <= n then l := concat(s(i..n), l)
l := concat(s(i..n), l)
reverse! l
split(s, cc) ==
n := maxIndex s
--for i in mn..n while member?(s.i, cc) repeat 0
l := empty()$List(%)
i := mn
j : Integer -- j is conditionally intialized
while i <= n and (j := position(cc, s, i)) >= mn repeat
l := concat(s(i..j-1), l)
--for i in j..n while member?(s.i, cc) repeat 0
i := j+1
--if i <= n then l := concat(s(i..n), l)
l := concat(s(i..n), l)
reverse! l
and now:
(28) -> split(line, c)
(28) ["A","B","","C","",""]
as desired and expected
If there are good reasons - would like to know - for the current
implementation, then I would suggest to add a second a pair of split
functions of this behaviour, otherwise I would suggest to switch to this
interpretation.
--
Mit freundlichen Grüßen
Johannes Grabmeier
Prof. Dr. Johannes Grabmeier
Köckstraße 1, D-94469 Deggendorf
Tel. +49-(0)-991-2979584, Tel. +49-(0)-151-681-70756
Tel. +49-(0)-991-3615-141 (d), Fax: +49-(0)-3224-192688
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