[Gm2] Use of functions in expressions

[Scott Robinson]

Hi all,

I have another Modula-2 language question about function results and  
using them in expressions.  Specifically, it seems that the language  
allows you to return an array or a pointer but apparently (at least  
according to the GM2 compiler) does not allow you to turn around and  
use an array subscript to access a particular element of the array  
within an expression.  The pointer dereference operator '^' also  
appears to be illegal after a call to a function.

A specific example:

MODULE test1;

FROM InOut IMPORT WriteString, Write, WriteLn;

TYPE
 tArr = ARRAY [0..9] OF CHAR;

VAR
 temp : tArr;

PROCEDURE tester() : tArr;
BEGIN
 RETURN "testing";
END tester;

BEGIN

 (* This works *)
 WriteString("The 5th character returned is ");
 temp := tester();
 Write(temp[4]);
 WriteLn;

 (* This does not work *)
 WriteString("The 5th character returned is ");
 Write(tester()[4]);
 WriteLn;

END test1.

GM2 gives the following for the above:

# gm2 -c test1.mod
test1.mod:26:3: error: syntax error, found `['
test1.mod:30:1: error: compilation failed

I'm wondering if the Modula-2 ISO standard specifically disallows that  
syntax?  And, if anyone has access to other Modula-2 compilers, do  
those compilers accept the above?

Thanks,
Scott