Is REXX awful ? Or lack of knowledge ?

XOpen · New User Joined: 19 Mar 2008 Posts: 24 Location: Russia

Greetings. Did I miss something ? Could you guide me with next items comparing with C/C++?

1. Stem is not like a structure in C++. You can't copy stem to stem by one command, you must do it member by member in cycle.
2. You can't pass stem to function/subroutine. In one source file, you can use EXPOSE to use global stem, but no way at all to pass it to the external function/subroutine. Funny, you have to create a big string from stem and then parse it again.
3. REXX counts DO TO cycle once at the beginning. It doesn't check that last value can be changed.(as C++ does)
4. You can't do BIT operations with HEX values. Better say, there is no HEX variables, it just a string again looks like hex. And decimal=string also. To sum 2 simple bytes, you must call C2D() for both, then sum them, call D2C() and write 1 byte back.

And reading REXX you can't skip any function, because each of them can change everything. Each of them can create new "global" variables.

Do you beleive you can write big programs on REXX ?

enrico-sorichetti

be careful before offending rexx

YES You missed almost everyithing about IT

points:
1 - stems are associative arrays ,
the thing after the dot can be anything with any number of dots

2 - yes, thats the only problem with stems, but external function are available
to store/retrieve variables (stems included ) in data spaces

3 - c++ behavior is IRRELEVANT
clarify Your doubts
if the initial limit checking is false the loop will not executed

4 - Yes You can ( check the builtin functions bit... )

Yes You can ( done it )
clarify the meaning of big...
complex certainly YES
check this sample ( it will RECEIVE ) on any platform ( windows,linux,mac osx) a file created by tso IDTF ( xmit )

XOpen · New User Joined: 19 Mar 2008 Posts: 24 Location: Russia

Good. Thanks for the answer. Let's clarify some items(one by one)

1. stem - array ?
How it can be an array, if I can't work with it as with array ?
I said I can't easy create a copy of stem. Correct ? In C++ I can memcpy either array or structure, without bothering of member names inside.

That's why, in real, stem is just a set of separate variables. And only good thing that you can limit them by setting variable value between dots in name.

Correct ?

enrico-sorichetti

You missed one word - associative

stems tokens are not limited to numerics

XOpen · New User Joined: 19 Mar 2008 Posts: 24 Location: Russia

stem.AAA="bbb"

associative = set of separate variables. So I guess I am correct.

Real situation: Load file into stem, then remove 1 line by condition. Then again process original stem and remove 1 lines by another condition.

Is there a way instead of creating 2 new stem and coping all lines - 1 to both?(coping one by one line)
Or call execio twice for different stems ? (disk operations are slow)

btw, I see REXX "execio * diskw" writes all stem without checking .0 member. So I must call it only as "execio "num" diskw"
Why it use .0 at diskr time(fill it), but not at diskw time ?

enrico-sorichetti

"EXECIO * DISKW" should stop writing when encountering a non existent stem entry

execio * diskr ... (stem stemvar.

suppose it reads 100 rcords

drop "STEMVAR.8"

a diskw * will write 7 records

for heavy stem manipulation the best thing is to look for external function packages

stemadd stemdelete stemsort

XOpen · New User Joined: 19 Mar 2008 Posts: 24 Location: Russia

I see, I have just changed middle record with last one and decreased .0

Don't see in REXX Reference anything about stemadd, so guess can't use it.(can't install anything)

Now, I would like to go to the 2nd point:
Could you give me a link or example of using dataspace from REXX ? (can't find in reference)

From my knowledge, I used dataspace in C++ to have data more than 2GB, but it's obsolete now, as we can use AMODE 64. It was like a big file, so can't imagine how you can store to it stems like stem.AAA and stem.BBB.

enrico-sorichetti

all of these are not standard functions, they are implemented as rexx externals functions

I wrote them for my personal use many ( too many ) years ago

I' ll dig around and see if I can find them

the function implemented are

rxclip write/read a stem to a named dataspace used for ISPF cut/paste before data spaces were available on the standard ISPF

stemsort the name tells

stemdelete same ...

stemadd same ...

rxvars return all the variables with a certain prefix

rxvsam for vsam access

rxpds read/write pds/pdse with ispf integrity

rxsql name tells before it was available on the official db2 distribution

XOpen · New User Joined: 19 Mar 2008 Posts: 24 Location: Russia

ok. So in general I am correct for point 2 also. I can use stack with same result. Main idea was - there is no normal way.

point 3. Agree, REXX can have his behavior. Good point, that you can change TO variable inside without problems. REXX already counted how many times execute the cycle. (just was a surprise for me)

ps: see you tomorrow for point 4. It can be big discussion...

XOpen · New User Joined: 19 Mar 2008 Posts: 24 Location: Russia

Hi again. Let's see next example

XOpen · New User Joined: 19 Mar 2008 Posts: 24 Location: Russia

yes - and it's awful, especially that there is no BIT functions work with HEX-STRING...

No problem, as you see, I can survive. The project is already set up on REXX, so it's not a good idea to use C++ for changes. (yes - I am crying)

And before I supported another REXX project for 2 year without any problems. Troubleshooting and bug fixing... but only now I realised how difficult to write on REXX(not support).

enrico-sorichetti

You are the first person i find that complains, without any reason, about REXX

show an example of what You are trying to achieve please

XOpen · New User Joined: 19 Mar 2008 Posts: 24 Location: Russia

Relax, In this topic I complain about REXX behavior, not about something that I don't know how to do. All reasons above. No one can help me here, it happens in real life. Thanks for participating.

enrico-sorichetti

again...
show an example of what You are trying to achieve please

XOpen · New User Joined: 19 Mar 2008 Posts: 24 Location: Russia

I would like that REXX has real data types, structures, memory pointers... Am I asking too much?

In near topic, I am tring to create one more function, that will allow REXX programmers start remote replications. Not DB2, but disk.(SRDF on symmetrix) We already have REXX api to some functions, but don't have their sources. So I am going to extend it. And as there can be a lot of disks, it's resonable to get stem as a parameter to this my new function.