I forgot to mention that in order to be able to translate XPath to Smalltalk

I added these methods to my Smalltalk:

AbstractSequence>>

�� afterSubCollection: aSequence [ifAbsent: exceptionBlock]

������ "based on substring-after"

�� beforeSubCollection: aSequence [ifAbsent: exceptionBlock]

������ "based on substring-before"

I'm not going to display the code, which is pretty simple, because there is a

serious efficiency problem with these.�� (The Java equivalent, had there been

one, would not have had this problem, but since I think Java 7 it would too.)

Imagine that we have a string consisting of N instances of separators, and

we want to split it into pieces.

�� [s includesSubCollection: separator] whileTrue: [

�������� self process: (s beforeSubCollection: separator).

�������� s := s afterSubCollection: separator].

�� s isEmpty ifFalse: [

�������� self process: s].

Do I need to explain why this takes O(N**2) time?

However,

�� r := ReadStream on: s.

�� [r atEnd] whileFalse: [

�������� self process: (r upToAll: separator)].

is linear time (assuming an efficient #upToAll:).

My previous remarks about boundary issues apply here as well, of course.

My previous remarks about wanting to see the context do too.

On Sun, 2 Jun 2019 at 00:43, Ben Coman <btc@openinworld.com> wrote:

On Sat, 1 Jun 2019 at 18:01, Tim Mackinnon <tim@testit.works> wrote:
>
> Maybe this is a dumb question - and often I��m surprised when asking these, but why is there no way to ��find after�� a string.
>
> I find it rather boring to try and parse a string, after a known marker - thus:
> (loc := aString findString: ��marker��) > 0 ifTrue: [ loc := loc + ��marker�� size ].
>
> Is there a better way? This whole pattern seems very old and clunky and not smalltalk like?
>
> Couldn��t we have: findAfter: aString ifAbsent: aBlock ?
>
> Or is there a whole better pattern for string searching that I��m missing ?

Can your input be split into tokens using Stirng>>findTokens:
and `ReadStream on: that`.�� Then you marker will be consumed by a single #next.

cheers -ben