World: r3wp

So essential in cases where the middle bit is truly unpredictable

Yes

Now we can change the parse rule to work with 3/. 4 and  /12:


> parse/all inp [ any [copy range [["2/" | "3/" | "4/" | "12/"]  
some digit]  (print range) | skip ]]                             
              
2/2
2/4
2/33
== true

the 2/ part can be any number from 1 to 13

Do you want to capture all of them?

absolutely

one-to-thirteen: ["1" digit | non-zero-digit]

Then we can come up with a pattern for them:

digit opt digit "/"

could we use 1 2 digit #"/"   ?

at-most-three: [#"0" - #"3"]
non-zero-digit: [#"1" - #"9"]

one-to-thirteen: ["1" at-most-three | non-zero-digit]

I'm presuming that the only possible values are 1 to 13.

they are, but there will never be a 0/  or 22/ that we want to avoid 
in this case

Ladislav's will select values 1 to 13 from any numbers and so is 
more correct.

This is the amended rule:

>> parse/all inp [ any [copy range [[digit opt digit "/"]  some digit] 
 (print range) | skip ]]                                         
                       
2/2
2/4

2/33

== true

Oops I've lost the range again:


>> parse/all inp [ any [copy range [[digit opt digit "/"]  [some 
digit "-" some digit]]  (print range) | skip ]]                  
                             
2/4-6
2/33-37

== true

To be more lecturable, perhaps you could deal with named sub-rules

yes, we should describe the structure using named parts like:


record: [random-part whitespace repeated-part any ["," repeated-part]]

mhinson, does the structure I described correspond to what you need?

That's a good idea but I was being lazy partly because it's such 
a pain to copy and paste in AltME (it strips out all line endings).

Here's the big rule now fixed :


>> parse/all inp [ any [copy range [[digit opt digit "/"]  [some 
digit opt ["-" some digit]]]  (print range) | skip ]]            
                             
2/2
2/4-6
2/33-37
== true

Ladislav, that's my understanding

rewrote Peter's with named sub-rules

prefix: [digit opt digit]
sufix: [some digit opt ["-" some digit]]
target: [prefix #"/" sufix]

parse/all inp [any [copy range target (print range) | skip]]

Thanks, Steeve

sorry the phone rang

So now we can capture all the ranges:

>> all-ranges: copy []

== []

 >> parse/all inp [any [copy range target (insert tail all-ranges 
 range) | skip]]

== true
>> all-ranges
== ["2/2" "2/4-6" "2/33-37"]

prefix can be:
prefix: [1 2 digit]

Once we've captured all-ranges, we can process them in a second step 
:

Ladislav, I am not sure I understand your terminology. record: [random-part 
whitespace repeated-part any ["," repeated-part]]
random-part may be absent
repeated-part is a number between 1 & 13 followed by "/" 
any is the bit we want and will be a number or a range
,
 is not present at the end of the line

repeated-part  is the same as above, but will not be the last thing 
on the line.

I need to go now but your in good hands.

mhinson: OK, let's proceed further

so you are saying, that random-part may be a-word a-number or absent. 
This is it:

random-part: [a-word | a-number | none]

is this understood?

Thanks for your help Peter.  I am taking notes & understanding it 
I think.

Yes, that sounds a good description of the random part.

fine, we need to describe further, what is a-word:

a-word: [some alpha]

, is this adequate?

alpha: charset [#"a" - #"z" #"A" - #"Z"]

yes

fine, now for the a-number part. how big a number can it be?

1 to 2000 will cover it

a-number: [one-to-two 3 digit | non-zero-digit 0 2 digit]

hum..
a-number: [1 4 digit]
is that not enough ?

that allows for 0

as well as for 9999

that would be fine

ok then, you pick what is appropriate

yep but it's an average limit that mhinson gave

no need to be strict here, i think

repeated-part will not be the last thing on the line
: fine, what will be the last thing on the line?

(except for the newline character, of course)