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alangr · Posted: Wed Dec 13, 2023 9:10 am Post subject: non-writable expression

I have a problem with the following:

0095) READ(5,500) II, JJ, (VIEW(I, J, K),K=1,4)
*** Non-writable expression in READ statement
*** Compilation abandoned

I can find no reference to explain the problem here. The odd thing is that this error has only now appeared having been no problem before. I wondered if I had amended a compiler option somehow but again could find nothing to explain what was happening and why and so found no help to resolve the code.

What is happening here? Any suggestions?
_________________
Alan

PaulLaidler · Posted: Wed Dec 13, 2023 10:18 am Post subject:

This error report is produced by FTN95 when there is something wrong with one of the variables in the list.

How are II, JJ, and VIEW defined?

alangr · Posted: Wed Dec 13, 2023 10:33 am Post subject:

The definitions are as below

INTEGER IOS, I, J, II, JJ

CHARACTER VIEW(20, 20, 4)*40

The latter is in a common block and the integers are local variables.

Thanks for your comments; does the above help?
_________________
Alan

PaulLaidler · Posted: Wed Dec 13, 2023 11:20 am Post subject:

Can you post a small program with all the necessary features to reproduce the error?

alangr · Posted: Wed Dec 13, 2023 11:53 am Post subject:

The first line of code in my initial post delivered the two lines of comment that followed.

I have even tried the following 'program' with no declarations at all

READ(5,500) (VIEW(I, J, K),K=1,4)
*
END

and get the same results.

I am using code which appeared to be compiled OK yesterday morning that suddenly flagged this error and would not compile (I have other similar cases). Could I have inadvertently changed something in the settings....?

Thank you for your help - I am at a loss to understand the error.
_________________
Alan

PaulLaidler · Posted: Wed Dec 13, 2023 12:08 pm Post subject:

Yes but the compiler does not know that VIEW is an array.

mecej4 · Joined: 31 Oct 2006 Posts: 1886

My guess is that the character array VIEW, which is in a common block, is used in more than one subprogram, and one of those subprograms does not contain the COMMON declaration. Absent a type declaration for VIEW, the expression VIEW(I,J,K) would be regarded as a function invocation with arguments I, J, K.

alangr · Posted: Wed Dec 13, 2023 1:11 pm Post subject:

That's it.

In editing files yesterday I inadvertently removed the include file that held all the declarations and common statements - and, more importantly, the 'implicit none'. So compilation seemed OK.....

Thank you Paul for tour help and thank you mecej4 for the help with the common block.

I am most grateful for your help.
_________________
Alan