Parse issue when using Change command (Rebol2) - parsing

Question

I have the following parse issue. In the first sample text below, the parse will hit the two command blocks as it finds the parts in the text.
Give the below a try (Rebol 2).
sample-text: {deferred member}
remove-anchors: func [sample-text][
parse sample-text[
some [
to {<a href="javascript:gotoURL('displayContent.aspx?contentID=9}
begin:
thru {);">}
ending:
(print "Command 1 executed" )
to "<"
begin:
thru ">"
ending:
(print "Command 2 executed" )
]
]
return sample-text
]
Result:
remove-anchors sample-text
Command 1 executed
Command 2 executed
However, if I insert the change/part portion of the command, which is expected to remove the text it finds, the first change/part executes but it appears the second portion of the parse command stops as the second execution block doesn't trigger.
sample-text: {deferred member}
remove-anchors: func [sample-text][
parse sample-text[
some [
to {<a href="javascript:gotoURL('displayContent.aspx?contentID=9}
begin:
thru {);">}
ending:
(print "Command 1 executed" change/part begin "" ending) ;<<----- change
to "<"
begin:
thru ">"
ending:
(print "Command 2 executed" change/part begin "" ending) ;<<----- change
]
]
return sample-text
]
Result:
remove-anchors sample-text
Command 1 executed
== "deferred member</a>"
Note the second command didn't seem to execute both by the Print not executing and the parse not completing.
Since I have multiple different types of links in the texts I'm trying to remove these pieces of HTML from, and multiple occurrences in the same text, I figured PARSE was the right solution.
Can anyone see what I am doing wrong?

Answer 1

Your function should work if you use this
remove-anchors: func [sample-text][
parse sample-text[
some [
to {<a href="javascript:gotoURL('displayContent.aspx?contentID=9}
begin:
thru {);">}
ending:
(print "Command 1 executed" change/part begin "" ending)
:begin ; note this
to "<"
begin:
thru ">"
ending:
(print "Command 2 executed" change/part begin "" ending)
]
]
return sample-text
]
Explanation:
The internal parse pointer is at an internal numeric index of 95 after {);">}. After the change command the index is still at 95, but the sample-text is now much shorter and your parse pointer after your second search text "to "<", probably already after the end. You can see that if you use this line
(print "Command 1 executed" change/part begin "" ending print ending) ;<<----- change
in your function, giving you following error
** Script Error: Out of range or past end
** Where: remove-anchors
** Near: print ending
So you have to set back your parse index / pointer to the beginning of the point, where you changed/deleted your text. This you get with :begin after your alteration.
Best advice is to set back / initialize your internal parse pointer anew, if you modified your parse input: After deletion you should go back to the start of your deletion and after insertion / modification you should go first to the start and then to the end of the new item.