[Issue 2179] New: import inside class works but is not in spec

[d-bugmail at puremagic.com]

http://d.puremagic.com/issues/show_bug.cgi?id=2179

           Summary: import inside class works but is not in spec
           Product: D
           Version: 1.028
          Platform: PC
        OS/Version: Windows
            Status: NEW
          Keywords: spec
          Severity: normal
          Priority: P2
         Component: DMD
        AssignedTo: bugzilla at digitalmars.com
        ReportedBy: wbaxter at gmail.com


DMD accepts imports placed inside of class scopes. This is useful for template
mixins because it means you can put the imports needed by the mixin into the
template itself.

However it doesn't seem to be allowed by the grammar in the spec.  It is
useful, and it works, and therefore I think the grammar should be updated to
reflect this.

Here's the test case:
----
module miximport;
import std.stdio;

class Foo {
    import miximport_imp;
    this() {
        writefln("Hi there from Inner - magic value: %s", magic_value);
    }
}

void main() { new Foo; }
----

Running dmd -v gives this, which includes miximport_imp in the list of imports:
----
F:\bax\Code\d\play>dmd -v miximport.d
parse     miximport
semantic  miximport
import    object        (f:\usr\pkg\d\dmd\bin\..\import\tango\object.di)
import    std.stdio     (f:\usr\pkg\d\dmd\bin\..\import\tangobos\std\stdio.d)
import    std.compat    (f:\usr\pkg\d\dmd\bin\..\import\tangobos\std\compat.d)
import    tango.stdc.stdio     
(f:\usr\pkg\d\dmd\bin\..\import\tango\tango\stdc\stdio.d)
import    tango.stdc.stdarg    
(f:\usr\pkg\d\dmd\bin\..\import\tango\tango\stdc\stdarg.d)
import    tango.stdc.stddef    
(f:\usr\pkg\d\dmd\bin\..\import\tango\tango\stdc\stddef.d)
import    tango.stdc.config    
(f:\usr\pkg\d\dmd\bin\..\import\tango\tango\stdc\config.d)
import    std.c.stdio   (f:\usr\pkg\d\dmd\bin\..\import\tangobos\std\c\stdio.d)
import    std.format    (f:\usr\pkg\d\dmd\bin\..\import\tangobos\std\format.d)
import    std.stdarg    (f:\usr\pkg\d\dmd\bin\..\import\tangobos\std\stdarg.d)
import    tango.core.Vararg    
(f:\usr\pkg\d\dmd\bin\..\import\tango\tango\core\Vararg.d)
import    std.c.stdarg 
(f:\usr\pkg\d\dmd\bin\..\import\tangobos\std\c\stdarg.d)
import    std.utf       (f:\usr\pkg\d\dmd\bin\..\import\tangobos\std\utf.d)
import    std.c.stdlib 
(f:\usr\pkg\d\dmd\bin\..\import\tangobos\std\c\stdlib.d)
import    std.stdint    (f:\usr\pkg\d\dmd\bin\..\import\tangobos\std\stdint.d)
import    std.c.stddef 
(f:\usr\pkg\d\dmd\bin\..\import\tangobos\std\c\stddef.d)
import    tango.stdc.errno     
(f:\usr\pkg\d\dmd\bin\..\import\tango\tango\stdc\errno.d)
import    std.c.string 
(f:\usr\pkg\d\dmd\bin\..\import\tangobos\std\c\string.d)
import    std.string    (f:\usr\pkg\d\dmd\bin\..\import\tangobos\std\string.d)
import    std.uni       (f:\usr\pkg\d\dmd\bin\..\import\tangobos\std\uni.d)
import    std.array     (f:\usr\pkg\d\dmd\bin\..\import\tangobos\std\array.d)
import    tango.core.Exception 
(f:\usr\pkg\d\dmd\bin\..\import\tango\tango\core\Exception.di)
import    std.ctype     (f:\usr\pkg\d\dmd\bin\..\import\tangobos\std\ctype.d)
import    std.gc        (f:\usr\pkg\d\dmd\bin\..\import\tangobos\std\gc.d)
import    tango.core.Memory    
(f:\usr\pkg\d\dmd\bin\..\import\tango\tango\core\Memory.di)
import    miximport_imp (miximport_imp.d)
semantic2 miximport
semantic3 miximport
code      miximport
function  this
function  main
----

The spec could be fixed, by for instance sticking ImportDeclaration under
ClassBodyDeclaration.

A similar issue may pertain to structs, but I haven't tried that.

Relevant discussions of this elsewhere include:
* http://www.dsource.org/projects/dsss/ticket/193
* http://www.dsource.org/forums/viewtopic.php?p=20054#20054

If it is decided that the spec is correct, and this is not legal, then it
should be made an error.  But I will note that there are libraries in existence
that depend on this behavior (namely doost,
http://www.dsource.org/projects/doost).  There maybe be others, but that's the
one where I ran across it.


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