Re: Problem with import/export in local modules

[Gaius Mulley]

john o goyo <jog37@riddermarkfarm.ca> writes:

> Greetings, Gaius.
>
> The following module fails compilation.
>
>
> MODULE Test;
>
> PROCEDURE Double(n :CARDINAL) :CARDINAL;
> BEGIN
>     RETURN 2*n
> END Double;
>
> MODULE Inside;
>
>     EXPORT Quadruple;
>     IMPORT Double;
>
>     PROCEDURE Quadruple(k :CARDINAL) :CARDINAL;
>     BEGIN
>         RETURN Double(k) * Double(k)
>     END Quadruple;
>
> END Inside;
>
> VAR
>     d :CARDINAL;
> BEGIN
>     d := Quadruple(3)
> END Test.
>
>
> This is a minimal version of a much larger legacy module.  I believe
> the above to be valid.
>
> The following is the compilation.
>
> => gm2-git -c Test.mod
> Test.mod:12:12: warning: In inner module ": syntax warning, " missing
>    12 |     IMPORT Double;
>       |            ^~~~~~
> Test.mod:19:11: warning: In program module ": syntax warning, " missing
>    19 | END Inside;
>       |           ^
> Test.mod:1:8: error: module name at beginning " does not match the
> name at end "
>     1 | MODULE Test;
>       |        ^~~~
> Test.mod:9:8: error: In inner module â: module name at beginning "
> does not match the name at end "
>     9 | MODULE Inside;
>       |        ^~~~~~
> Test.mod:12:5: error: syntax error, found "
>    12 |     IMPORT Double;
>       |     ^~~~~~
> Test.mod:12:12: error: module name at end " does not match the name at
> beginning "
>    12 |     IMPORT Double;
>       |            ^~~~~~
> Test.mod:19:5: error: In program module ": module name at end " does
> not match the name at beginning "
>    19 | END Inside;
>       |     ^~~~~~
> Test.mod:19:11: error: syntax error, found "
>    19 | END Inside;
>       |           ^
> Test.mod:29:1: error: no scope active: compilation failed
>
> (I am also mystified by the quotation marks.)

Hi John,

ah yes - the error messages are misleading.  The bug is that the
EXPORT/IMPORT statements are in the wrong order and the error recovery
has become confused!

 IMPORT Double;
 EXPORT Quadruple;

and it compiles,

regards,
Gaius