Utility to output a single symbol from a design

Hi Jim,

Nice utility. Great example of the usefulness of Skill.

I'm curious about the reason for putting functions inside functions. It's unusual to me but probable stems from your experience with other programming languages? If you do this you should avoid the duplicate use of variable names (SymForm).

The statements putd('jmWriteOneSym nil) etc. are unnecessary I think. I am curious as to why you have done this. Is it regarded as good practice?

A little known feature in 16.6 is the ability to create a form using a string. This would avoid the need to create a form file that you need to delete later.

Cheers,
Dave

Hi Dave,

Thanks for the feedback and I'm glad you like it.

In fact the style comes from my inexperience and the the fact that I sometimes have had problems passing multiple returning values from functions to a calling function. I figure I can use one let() command to cover a group of functions and play happily with all of the variables without leaking globals. Probably not good practice but it seems to work. This gives just one warning in sklint but no errors so I was happy to stick with it. I think that as I get to grips with skill I will probably change to a more conventional style.

The putd statements are just something I copied from another program from the forum assuming that they were useful. They probably are useless so if I create a version 1.1 I will delete them.

Creating a form from a string is a better method. Do you know where I can read about this?

Cheers,
Jim

A simple example for a string form:

p = nil
sprintf(p "FILE_TYPE=FORM_DEFN VERSION=2\tFORM\tFIXED\tPORT 50 10\tHEADER \"TITLE_OF_FORM\"\tTILE")
sprintf(p "%s\tTEXT \"HELLO\" \tTLOC 2 1\t\tENDTEXT" p)
sprintf(p "%s\tENDTILE\tENDFORM" p)
defvar(fw_test nil)
axlFormCreate( 'fw_test list("test_form" list(p)) '("CENTER" ) 'fw_callback t)
axlFormDisplay(fw_test)

basically you need to make 1 long string that contains the form. New lines need to be \t (tab), not \n or \r.
Then you need to call axlFormCreate with this : list("test_form" list(p)) the "test_form" can be any string you like.
The rest of the form function, creation, handling etc is equal to the file-based form.

To return multiple variables you can or return a list like list( result_a result_b) and then use car() and cadr() to extract the results returned from the function
Another way is to use a global.
First you need to generate a global with defvar() and then at the end use var_name = 'unbind. The last statement unbinds/removes the global variable.
Don't put this global variable into the let(), otherwise it won't work.

A hint, you can use the form variable to store return values like;
axlFormCreate( 'fw_test ....
fw_test->test = "hello"

and then you can recall the value by simply using 'fw_test->test'.
Since in the above example the fw_test is a global, you can access it anywhere in your functions.

Bram

Thanks Bram, good info.