I want to change [%a/b] to [%a/c].
Basically, the same as Change path or refinement, but with file! instead:
I want to change the
a/binside a block toa/c
test: [a/b]
In this case, either change next test/1 'c or test/1/2: 'c works.
But not when test is a file!:
>> test: [%a/b]
== [%a/b]
>> test/1
== %a/b
>> test/1/2 ; can't access 2nd value
== %a/b/2
>> next first test ; not quite what you expect
== %/b
Trying to change it gives not something you'd expect:
>> change next test/1 'c
== %b
>> test
== [%acb]
You are confusing path! and file! series, they can look similar, but their nature are very different.
A path! is a collection of values (often word! values) separated by a slash symbol, a file! is a collection of char! values. Slash characters in file! series are just characters, so file! has no knowledge about any sub-structures. It has (mostly) the semantics of string! series, while path! has the semantics of a block! series.
Now that this is cleared, about the test/1/2 result, path notation on a file! series has a different behavior than on string!, it will do a smart concatenation instead of acting as an accessor. It's called smart because it will nicely handle extra slash characters present in left and right parts. For example:
>> file: %/index.html
== %/index.html
>> path: %www/
== %www/
>> path/file
== %www/file
>> path/:file
== %www/index.html
Same path notation rule applies to url! series too:
>> url: http://red-lang.org
== http://red-lang.org
>> url/index.html
== http://red-lang.org/index.html
>> file: %/index.html
== %/index.html
>> url/:file
== http://red-lang.org/index.html
So for changing the nested content of test: [%a/b], as file! behaves basically as string!, you can use any available method for strings to modify it. For example:
>> test: [%a/b]
== [%a/b]
>> change skip test/1 2 %c
== %""
>> test
== [%a/c]
>> change next find test/1 slash "d"
== %""
>> test
== [%a/d]
>> parse test/1 [thru slash change skip "e"]
== true
>> test
== [%a/e]