bug#259: delphi-mode does not properly format interface definitions

bug#259: delphi-mode does not properly format interface definitions

[Simon South]

delphi-mode doesn't properly indent interface definition, things like
this:

type
   IHelloWorld = interface(IInvokable)
     ['{D613A992-AB12-0978-80D1-02B40DF72551}']
     function HelloWorld: String; stdcall;
   end;

This is because it doesn't distinguish between the "interface" keyword
used as a unit separator (i.e., as opposed to "implementation") and
used like a class declaration, as above.

As a result, delphi-mode will incorrectly indent the above code this
way:

type
   IHelloWorld = interface(IInvokable)
['{D613A992-AB12-0978-80D1-02B40DF72551}']
function HelloWorld: String; stdcall;
end;

I've taken a stab at updating delphi.el to distinguish between these
cases and support "dispinterface" properly as well (patch below) but I
don't understand the existing code well enough yet to finish it.  (I
suspect more changes need to be made to the delphi-enclosing-indent-of
function.)  Perhaps someone more familiar with this sort of thing
could help me complete it?

In GNU Emacs 22.1.1 (i386-mingw-nt5.1.2600)
  of 2007-06-02 on RELEASE
Windowing system distributor `Microsoft Corp.', version 5.1.2600
configured using `configure --with-gcc (3.4) --cflags -Ic:/gnuwin32/include'

*** delphi.el.orig	Thu May 15 17:57:29 2008
--- delphi.el	Fri May 16 12:07:37 2008
***************
*** 262,271 ****
   (defconst delphi-decl-sections '(type const var label resourcestring)
     "Denotes the start of a declaration section.")

   (defconst delphi-class-types '(class object)
     "Class types.")

! (defconst delphi-composite-types `(,@delphi-class-types record)
     "Types that contain declarations within them.")

   (defconst delphi-unit-sections
--- 262,275 ----
   (defconst delphi-decl-sections '(type const var label resourcestring)
     "Denotes the start of a declaration section.")

+ (defconst delphi-interface-types '(dispinterface interface)
+   "Interface types.")
+
   (defconst delphi-class-types '(class object)
     "Class types.")

! (defconst delphi-composite-types
!   `(,@delphi-class-types ,@delphi-interface-types record)
     "Types that contain declarations within them.")

   (defconst delphi-unit-sections
***************
*** 859,866 ****
         (delphi-stmt-line-indent-of token delphi-indent-level))))

   (defun delphi-composite-type-start (token last-token)
!   ;; Returns true (actually the last-token) if the pair equals (= 
class) or (=
!   ;; record), and nil otherwise.
     (if (and (eq 'equals (delphi-token-kind token))
              (delphi-is (delphi-token-kind last-token) 
delphi-composite-types))
         last-token))
--- 863,870 ----
         (delphi-stmt-line-indent-of token delphi-indent-level))))

   (defun delphi-composite-type-start (token last-token)
!   ;; Returns true (actually the last-token) if the pair equals (= 
class), (=
!   ;; interface), or (= record), and nil otherwise.
     (if (and (eq 'equals (delphi-token-kind token))
              (delphi-is (delphi-token-kind last-token) 
delphi-composite-types))
         last-token))
***************
*** 1252,1258 ****
             (throw 'done (delphi-line-indent-of token 0)))

            ;; Unit statements mean we indent right to the left.
!          ((delphi-is token-kind delphi-unit-statements) (throw 'done 0))
            )
           (unless (delphi-is token-kind delphi-whitespace)
              (setq last-token token))
--- 1256,1264 ----
             (throw 'done (delphi-line-indent-of token 0)))

            ;; Unit statements mean we indent right to the left.
!          ((and (delphi-is token-kind delphi-unit-statements)
!                (not (delphi-composite-type-start token last-token)))
!           (throw 'done 0))
            )
           (unless (delphi-is token-kind delphi-whitespace)
              (setq last-token token))
***************
*** 1351,1357 ****
                                            delphi-indent-level)))

            ;; In unit sections we indent right to the left.
!          ((delphi-is token-kind delphi-unit-sections) (throw 'done 0))

            ;; A previous terminator means we can stop.
            ((delphi-is token-kind delphi-previous-terminators)
--- 1357,1365 ----
                                            delphi-indent-level)))

            ;; In unit sections we indent right to the left.
!          ((and (delphi-is token-kind delphi-unit-sections)
!                (not (delphi-is token-kind delphi-interface-types)))
!           (throw 'done 0))

            ;; A previous terminator means we can stop.
            ((delphi-is token-kind delphi-previous-terminators)
***************
*** 1457,1463 ****
                      ;; Indent to the matching start ( or [.
                      (delphi-indent-of (delphi-group-start token)))

!                   ((delphi-is token-kind delphi-unit-statements) 0)

                     ((delphi-is token-kind delphi-comments)
                      ;; In a comment.
--- 1465,1475 ----
                      ;; Indent to the matching start ( or [.
                      (delphi-indent-of (delphi-group-start token)))

!                   ((and (delphi-is token-kind delphi-unit-statements)
!                         (not
!                          (delphi-is token-kind delphi-interface-types)))
!                         1)
!                    0)

                     ((delphi-is token-kind delphi-comments)
                      ;; In a comment.

bug#260: delphi-mode does not properly format interface definitions

[Simon South]

A bug snuck through in my original patch.  I've pasted a fixed version 
below.

What the patch does is make delphi-mode indent by default after the 
"interface" keyword.  This works fine for interface definitions and 
actually works fairly well overall, since the keywords that typically 
follow "interface" used in the other sense (like "uses" and "type") 
cancel the indentation and give the intended formatting.  However, it 
fails when "interface" is used as a unit separator and followed by 
"function" or "procedure", for instance.


*** delphi.el.orig	Thu May 15 17:57:29 2008
--- delphi.el	Fri May 16 12:19:25 2008
***************
*** 262,271 ****
   (defconst delphi-decl-sections '(type const var label resourcestring)
     "Denotes the start of a declaration section.")

   (defconst delphi-class-types '(class object)
     "Class types.")

! (defconst delphi-composite-types `(,@delphi-class-types record)
     "Types that contain declarations within them.")

   (defconst delphi-unit-sections
--- 262,275 ----
   (defconst delphi-decl-sections '(type const var label resourcestring)
     "Denotes the start of a declaration section.")

+ (defconst delphi-interface-types '(dispinterface interface)
+   "Interface types.")
+
   (defconst delphi-class-types '(class object)
     "Class types.")

! (defconst delphi-composite-types
!   `(,@delphi-class-types ,@delphi-interface-types record)
     "Types that contain declarations within them.")

   (defconst delphi-unit-sections
***************
*** 859,866 ****
         (delphi-stmt-line-indent-of token delphi-indent-level))))

   (defun delphi-composite-type-start (token last-token)
!   ;; Returns true (actually the last-token) if the pair equals (= 
class) or (=
!   ;; record), and nil otherwise.
     (if (and (eq 'equals (delphi-token-kind token))
              (delphi-is (delphi-token-kind last-token) 
delphi-composite-types))
         last-token))
--- 863,870 ----
         (delphi-stmt-line-indent-of token delphi-indent-level))))

   (defun delphi-composite-type-start (token last-token)
!   ;; Returns true (actually the last-token) if the pair equals (= 
class), (=
!   ;; interface), or (= record), and nil otherwise.
     (if (and (eq 'equals (delphi-token-kind token))
              (delphi-is (delphi-token-kind last-token) 
delphi-composite-types))
         last-token))
***************
*** 1252,1258 ****
             (throw 'done (delphi-line-indent-of token 0)))

            ;; Unit statements mean we indent right to the left.
!          ((delphi-is token-kind delphi-unit-statements) (throw 'done 0))
            )
           (unless (delphi-is token-kind delphi-whitespace)
              (setq last-token token))
--- 1256,1264 ----
             (throw 'done (delphi-line-indent-of token 0)))

            ;; Unit statements mean we indent right to the left.
!          ((and (delphi-is token-kind delphi-unit-statements)
!                (not (delphi-composite-type-start token last-token)))
!           (throw 'done 0))
            )
           (unless (delphi-is token-kind delphi-whitespace)
              (setq last-token token))
***************
*** 1351,1357 ****
                                            delphi-indent-level)))

            ;; In unit sections we indent right to the left.
!          ((delphi-is token-kind delphi-unit-sections) (throw 'done 0))

            ;; A previous terminator means we can stop.
            ((delphi-is token-kind delphi-previous-terminators)
--- 1357,1365 ----
                                            delphi-indent-level)))

            ;; In unit sections we indent right to the left.
!          ((and (delphi-is token-kind delphi-unit-sections)
!                (not (delphi-is token-kind delphi-interface-types)))
!           (throw 'done 0))

            ;; A previous terminator means we can stop.
            ((delphi-is token-kind delphi-previous-terminators)
***************
*** 1457,1463 ****
                      ;; Indent to the matching start ( or [.
                      (delphi-indent-of (delphi-group-start token)))

!                   ((delphi-is token-kind delphi-unit-statements) 0)

                     ((delphi-is token-kind delphi-comments)
                      ;; In a comment.
--- 1465,1474 ----
                      ;; Indent to the matching start ( or [.
                      (delphi-indent-of (delphi-group-start token)))

!                   ((and (delphi-is token-kind delphi-unit-statements)
!                         (not
!                          (delphi-is token-kind delphi-interface-types)))
!                    0)

                     ((delphi-is token-kind delphi-comments)
                      ;; In a comment.

bug#259: delphi-mode does not properly format interface definitions

[Simon South]

A bug snuck through in my original patch.  I've pasted a fixed version
below.

What the patch does is make delphi-mode indent by default after the
"interface" keyword.  This works fine for interface definitions and
actually works fairly well overall, since the keywords that typically
follow "interface" used in the other sense (like "uses" and "type")
cancel the indentation and give the intended formatting.  However, it
fails when "interface" is used as a unit separator and followed by
"function" or "procedure", for instance.


*** delphi.el.orig	Thu May 15 17:57:29 2008
--- delphi.el	Fri May 16 12:19:25 2008
***************
*** 262,271 ****
   (defconst delphi-decl-sections '(type const var label resourcestring)
     "Denotes the start of a declaration section.")

   (defconst delphi-class-types '(class object)
     "Class types.")

! (defconst delphi-composite-types `(,@delphi-class-types record)
     "Types that contain declarations within them.")

   (defconst delphi-unit-sections
--- 262,275 ----
   (defconst delphi-decl-sections '(type const var label resourcestring)
     "Denotes the start of a declaration section.")

+ (defconst delphi-interface-types '(dispinterface interface)
+   "Interface types.")
+
   (defconst delphi-class-types '(class object)
     "Class types.")

! (defconst delphi-composite-types
!   `(,@delphi-class-types ,@delphi-interface-types record)
     "Types that contain declarations within them.")

   (defconst delphi-unit-sections
***************
*** 859,866 ****
         (delphi-stmt-line-indent-of token delphi-indent-level))))

   (defun delphi-composite-type-start (token last-token)
!   ;; Returns true (actually the last-token) if the pair equals (=
class) or (=
!   ;; record), and nil otherwise.
     (if (and (eq 'equals (delphi-token-kind token))
              (delphi-is (delphi-token-kind last-token)
delphi-composite-types))
         last-token))
--- 863,870 ----
         (delphi-stmt-line-indent-of token delphi-indent-level))))

   (defun delphi-composite-type-start (token last-token)
!   ;; Returns true (actually the last-token) if the pair equals (=
class), (=
!   ;; interface), or (= record), and nil otherwise.
     (if (and (eq 'equals (delphi-token-kind token))
              (delphi-is (delphi-token-kind last-token)
delphi-composite-types))
         last-token))
***************
*** 1252,1258 ****
             (throw 'done (delphi-line-indent-of token 0)))

            ;; Unit statements mean we indent right to the left.
!          ((delphi-is token-kind delphi-unit-statements) (throw 'done 0))
            )
           (unless (delphi-is token-kind delphi-whitespace)
              (setq last-token token))
--- 1256,1264 ----
             (throw 'done (delphi-line-indent-of token 0)))

            ;; Unit statements mean we indent right to the left.
!          ((and (delphi-is token-kind delphi-unit-statements)
!                (not (delphi-composite-type-start token last-token)))
!           (throw 'done 0))
            )
           (unless (delphi-is token-kind delphi-whitespace)
              (setq last-token token))
***************
*** 1351,1357 ****
                                            delphi-indent-level)))

            ;; In unit sections we indent right to the left.
!          ((delphi-is token-kind delphi-unit-sections) (throw 'done 0))

            ;; A previous terminator means we can stop.
            ((delphi-is token-kind delphi-previous-terminators)
--- 1357,1365 ----
                                            delphi-indent-level)))

            ;; In unit sections we indent right to the left.
!          ((and (delphi-is token-kind delphi-unit-sections)
!                (not (delphi-is token-kind delphi-interface-types)))
!           (throw 'done 0))

            ;; A previous terminator means we can stop.
            ((delphi-is token-kind delphi-previous-terminators)
***************
*** 1457,1463 ****
                      ;; Indent to the matching start ( or [.
                      (delphi-indent-of (delphi-group-start token)))

!                   ((delphi-is token-kind delphi-unit-statements) 0)

                     ((delphi-is token-kind delphi-comments)
                      ;; In a comment.
--- 1465,1474 ----
                      ;; Indent to the matching start ( or [.
                      (delphi-indent-of (delphi-group-start token)))

!                   ((and (delphi-is token-kind delphi-unit-statements)
!                         (not
!                          (delphi-is token-kind delphi-interface-types)))
!                    0)

                     ((delphi-is token-kind delphi-comments)
                      ;; In a comment.

bug#260: marked as done (delphi-mode does not properly format interface definitions)

[Emacs bug Tracking System]

[-- Attachment #1: Type: text/plain, Size: 839 bytes --]


Your message dated Sun, 18 May 2008 00:11:07 -0400
with message-id <jwvprrkl0am.fsf-monnier+emacsbugreports@gnu.org>
and subject line Close
has caused the Emacs bug report #260,
regarding delphi-mode does not properly format interface definitions
to be marked as done.

This means that you claim that the problem has been dealt with.
If this is not the case it is now your responsibility to reopen the
bug report if necessary, and/or fix the problem forthwith.

(NB: If you are a system administrator and have no idea what this
message is talking about, this may indicate a serious mail system
misconfiguration somewhere. Please contact don@donarmstrong.com
immediately.)


-- 
260: http://emacsbugs.donarmstrong.com/cgi-bin/bugreport.cgi?bug=260
Emacs Bug Tracking System
Contact don@donarmstrong.com with problems

[-- Attachment #2: Type: message/rfc822, Size: 6779 bytes --]

From: Simon South <ssouth@slowcomputing.org>
To: bug-gnu-emacs@gnu.org
Subject: Re: delphi-mode does not properly format interface definitions
Date: Fri, 16 May 2008 12:33:23 -0400
Message-ID: <482DB753.7080905@slowcomputing.org>

A bug snuck through in my original patch.  I've pasted a fixed version 
below.

What the patch does is make delphi-mode indent by default after the 
"interface" keyword.  This works fine for interface definitions and 
actually works fairly well overall, since the keywords that typically 
follow "interface" used in the other sense (like "uses" and "type") 
cancel the indentation and give the intended formatting.  However, it 
fails when "interface" is used as a unit separator and followed by 
"function" or "procedure", for instance.


*** delphi.el.orig	Thu May 15 17:57:29 2008
--- delphi.el	Fri May 16 12:19:25 2008
***************
*** 262,271 ****
   (defconst delphi-decl-sections '(type const var label resourcestring)
     "Denotes the start of a declaration section.")

   (defconst delphi-class-types '(class object)
     "Class types.")

! (defconst delphi-composite-types `(,@delphi-class-types record)
     "Types that contain declarations within them.")

   (defconst delphi-unit-sections
--- 262,275 ----
   (defconst delphi-decl-sections '(type const var label resourcestring)
     "Denotes the start of a declaration section.")

+ (defconst delphi-interface-types '(dispinterface interface)
+   "Interface types.")
+
   (defconst delphi-class-types '(class object)
     "Class types.")

! (defconst delphi-composite-types
!   `(,@delphi-class-types ,@delphi-interface-types record)
     "Types that contain declarations within them.")

   (defconst delphi-unit-sections
***************
*** 859,866 ****
         (delphi-stmt-line-indent-of token delphi-indent-level))))

   (defun delphi-composite-type-start (token last-token)
!   ;; Returns true (actually the last-token) if the pair equals (= 
class) or (=
!   ;; record), and nil otherwise.
     (if (and (eq 'equals (delphi-token-kind token))
              (delphi-is (delphi-token-kind last-token) 
delphi-composite-types))
         last-token))
--- 863,870 ----
         (delphi-stmt-line-indent-of token delphi-indent-level))))

   (defun delphi-composite-type-start (token last-token)
!   ;; Returns true (actually the last-token) if the pair equals (= 
class), (=
!   ;; interface), or (= record), and nil otherwise.
     (if (and (eq 'equals (delphi-token-kind token))
              (delphi-is (delphi-token-kind last-token) 
delphi-composite-types))
         last-token))
***************
*** 1252,1258 ****
             (throw 'done (delphi-line-indent-of token 0)))

            ;; Unit statements mean we indent right to the left.
!          ((delphi-is token-kind delphi-unit-statements) (throw 'done 0))
            )
           (unless (delphi-is token-kind delphi-whitespace)
              (setq last-token token))
--- 1256,1264 ----
             (throw 'done (delphi-line-indent-of token 0)))

            ;; Unit statements mean we indent right to the left.
!          ((and (delphi-is token-kind delphi-unit-statements)
!                (not (delphi-composite-type-start token last-token)))
!           (throw 'done 0))
            )
           (unless (delphi-is token-kind delphi-whitespace)
              (setq last-token token))
***************
*** 1351,1357 ****
                                            delphi-indent-level)))

            ;; In unit sections we indent right to the left.
!          ((delphi-is token-kind delphi-unit-sections) (throw 'done 0))

            ;; A previous terminator means we can stop.
            ((delphi-is token-kind delphi-previous-terminators)
--- 1357,1365 ----
                                            delphi-indent-level)))

            ;; In unit sections we indent right to the left.
!          ((and (delphi-is token-kind delphi-unit-sections)
!                (not (delphi-is token-kind delphi-interface-types)))
!           (throw 'done 0))

            ;; A previous terminator means we can stop.
            ((delphi-is token-kind delphi-previous-terminators)
***************
*** 1457,1463 ****
                      ;; Indent to the matching start ( or [.
                      (delphi-indent-of (delphi-group-start token)))

!                   ((delphi-is token-kind delphi-unit-statements) 0)

                     ((delphi-is token-kind delphi-comments)
                      ;; In a comment.
--- 1465,1474 ----
                      ;; Indent to the matching start ( or [.
                      (delphi-indent-of (delphi-group-start token)))

!                   ((and (delphi-is token-kind delphi-unit-statements)
!                         (not
!                          (delphi-is token-kind delphi-interface-types)))
!                    0)

                     ((delphi-is token-kind delphi-comments)
                      ;; In a comment.




[-- Attachment #3: Type: message/rfc822, Size: 1030 bytes --]

From: Stefan Monnier <monnier@iro.umontreal.ca>
To: 260-done@emacsbugs.donarmstrong.com
Subject: Close
Date: Sun, 18 May 2008 00:11:07 -0400
Message-ID: <jwvprrkl0am.fsf-monnier+emacsbugreports@gnu.org>

Duplicate of 259

bug#259: delphi-mode does not properly format interface definitions

[Stefan Monnier]

tag 259 +patch

> A bug snuck through in my original patch.  I've pasted a fixed version
> below.

> What the patch does is make delphi-mode indent by default after the
> "interface" keyword.  This works fine for interface definitions and
> actually works fairly well overall, since the keywords that typically
> follow "interface" used in the other sense (like "uses" and "type")
> cancel the indentation and give the intended formatting.  However, it
> fails when "interface" is used as a unit separator and followed by
> "function" or "procedure", for instance.

Can someone confirm whether this patch does the right thing?


        Stefan


> *** delphi.el.orig	Thu May 15 17:57:29 2008
> --- delphi.el	Fri May 16 12:19:25 2008
> ***************
> *** 262,271 ****
>   (defconst delphi-decl-sections '(type const var label resourcestring)
>     "Denotes the start of a declaration section.")

>   (defconst delphi-class-types '(class object)
>     "Class types.")

> ! (defconst delphi-composite-types `(,@delphi-class-types record)
>     "Types that contain declarations within them.")

>   (defconst delphi-unit-sections
> --- 262,275 ----
>   (defconst delphi-decl-sections '(type const var label resourcestring)
>     "Denotes the start of a declaration section.")

> + (defconst delphi-interface-types '(dispinterface interface)
> +   "Interface types.")
> +
>   (defconst delphi-class-types '(class object)
>     "Class types.")

> ! (defconst delphi-composite-types
> !   `(,@delphi-class-types ,@delphi-interface-types record)
>     "Types that contain declarations within them.")

>   (defconst delphi-unit-sections
> ***************
> *** 859,866 ****
>         (delphi-stmt-line-indent-of token delphi-indent-level))))

>   (defun delphi-composite-type-start (token last-token)
> !   ;; Returns true (actually the last-token) if the pair equals (=
> class) or (=
> !   ;; record), and nil otherwise.
>     (if (and (eq 'equals (delphi-token-kind token))
>              (delphi-is (delphi-token-kind last-token)
> delphi-composite-types))
>         last-token))
> --- 863,870 ----
>         (delphi-stmt-line-indent-of token delphi-indent-level))))

>   (defun delphi-composite-type-start (token last-token)
> !   ;; Returns true (actually the last-token) if the pair equals (=
> class), (=
> !   ;; interface), or (= record), and nil otherwise.
>     (if (and (eq 'equals (delphi-token-kind token))
>              (delphi-is (delphi-token-kind last-token)
> delphi-composite-types))
>         last-token))
> ***************
> *** 1252,1258 ****
>             (throw 'done (delphi-line-indent-of token 0)))

>            ;; Unit statements mean we indent right to the left.
> !          ((delphi-is token-kind delphi-unit-statements) (throw 'done 0))
>            )
>           (unless (delphi-is token-kind delphi-whitespace)
>              (setq last-token token))
> --- 1256,1264 ----
>             (throw 'done (delphi-line-indent-of token 0)))

>            ;; Unit statements mean we indent right to the left.
> !          ((and (delphi-is token-kind delphi-unit-statements)
> !                (not (delphi-composite-type-start token last-token)))
> !           (throw 'done 0))
>            )
>           (unless (delphi-is token-kind delphi-whitespace)
>              (setq last-token token))
> ***************
> *** 1351,1357 ****
>                                            delphi-indent-level)))

>            ;; In unit sections we indent right to the left.
> !          ((delphi-is token-kind delphi-unit-sections) (throw 'done 0))

>            ;; A previous terminator means we can stop.
>            ((delphi-is token-kind delphi-previous-terminators)
> --- 1357,1365 ----
>                                            delphi-indent-level)))

>            ;; In unit sections we indent right to the left.
> !          ((and (delphi-is token-kind delphi-unit-sections)
> !                (not (delphi-is token-kind delphi-interface-types)))
> !           (throw 'done 0))

>            ;; A previous terminator means we can stop.
>            ((delphi-is token-kind delphi-previous-terminators)
> ***************
> *** 1457,1463 ****
>                      ;; Indent to the matching start ( or [.
>                      (delphi-indent-of (delphi-group-start token)))

> !                   ((delphi-is token-kind delphi-unit-statements) 0)

>                     ((delphi-is token-kind delphi-comments)
>                      ;; In a comment.
> --- 1465,1474 ----
>                      ;; Indent to the matching start ( or [.
>                      (delphi-indent-of (delphi-group-start token)))

> !                   ((and (delphi-is token-kind delphi-unit-statements)
> !                         (not
> !                          (delphi-is token-kind delphi-interface-types)))
> !                    0)

>                     ((delphi-is token-kind delphi-comments)
>                      ;; In a comment.

bug#259: delphi-mode does not properly format interface definitions

[Simon South]

Stefan Monnier wrote:
> Can someone confirm whether this patch does the right thing?

It doesn't.  I've pasted a short program listing below to test with. 
The patch I submitted will make delphi-mode indent the definition of 
TestInterface correctly, except that *everything* between the first 
instance of "interface" and "implementation" is indented one tab space 
too far to the right.

The solution will be to have delphi-mode identify "interface", on its 
own, as a unit section, and "= interface" as the start of an interface 
definition.  My patch makes the function "delphi-composite-type-start" 
identify "= interface" as a composite type, so that's part of it done. 
However, this seems to get overridden in delphi-enclosing-indent-of: As 
I understand it, as the function parses the line it first identifies "= 
interface" as a composite type and sets the indentation properly, but 
then later parses "interface" again on its own and cancels the 
indentation.  (My patch makes the function ignore "interface" the second 
time so the indentation never gets cancelled, but then that triggers the 
problem illustrated by the code sample below.)

The fix may be as simple as making delphi-enclosing-indent-of interpret 
"interface" as a unit section only if an equals sign wasn't previously 
parsed, especially as there already seems to be some logic to do this 
(see how the "equals-encountered" variable is used).  But my LISPmanship 
is poor and I couldn't get this to work myself.

I'll take another stab at it this weekend, but if someone monitoring 
this list has experience with programming modes and is looking for an 
easy enhancement to make, this could be it...

---

{ Sample unit for testing emacs bug #259, "delphi-mode does not
   properly format interface definitions.  This shows the correct
   indentation. }
unit TestIndentation;

interface

function TestFunction: String;

type
   TestInterface = interface
     function TestInterfaceFunction: String;
   end;

implementation

function TestFunction: String;
begin
   Result := 'Test Function Output';
end;

end.

-- 
Simon South
ssouth@slowcomputing.org

bug#259: delphi-mode does not properly format interface definitions

[martin rudalics]

[-- Attachment #1: Type: text/plain, Size: 401 bytes --]

> I'll take another stab at it this weekend, but if someone monitoring 
> this list has experience with programming modes and is looking for an 
> easy enhancement to make, this could be it...

Merely for fun: I once spent some time writing my own pascal mode but
never finished it.  I attach a copy (you simply have to load it and
do M-x pas-mode in the buffer you're visiting).  Tell me if it DTRT.

[-- Attachment #2: pas-mode.el.gz --]
[-- Type: application/x-gzip, Size: 19737 bytes --]

bug#259: delphi-mode does not properly format interface definitions

[Simon South]

Here's a patch that I believe is correct.  This adds proper support for 
the "dispinterface" keyword and for the "interface" keyword when used to 
define interfaces.

I've tested this on the sample unit I posted earlier and on some other 
files and it works fine.  I'll put together a more complete test case 
and post it here as well if it's useful.

The changes are:

- Added a "delphi-interface-types" constant to identify the "interface" 
and "dispinterface" keywords.

- Updated the definition of "delphi-composite-types" to include 
interface types.

- Updated the description of "delphi-composite-type-start" to include 
interface types (and to mention "object", which was previously missing).

- Modified the "delphi-enclosing-indent-of" function to recognize the 
dual meaning of "interface".  When that keyword is encountered, the 
function searches backwards to find the previous non-whitespace token. 
If that token is an equals sign, "interface" is interpreted as the start 
of an interface definition; otherwise it's assumed to be the start of a 
unit section.

- Updated the copyright and authorship notices.  (Let's see if the email 
addresses make it through...)

---

*** delphi.el.orig	Thu May 15 17:57:29 2008
--- delphi.el	Fri May 23 04:01:37 2008
***************
*** 1,9 ****
   ;;; delphi.el --- major mode for editing Delphi source (Object 
Pascal) in Emacs

! ;; Copyright (C) 1998, 1999, 2001, 2002, 2003, 2004, 2005, 2006, 2007
   ;; Free Software Foundation, Inc.

! ;; Author: Ray Blaak <blaak@infomatch.com>
   ;; Maintainer: FSF  (Blaak's email addr bounces, Aug 2005)
   ;; Keywords: languages

--- 1,10 ----
   ;;; delphi.el --- major mode for editing Delphi source (Object 
Pascal) in Emacs

! ;; Copyright (C) 1998, 1999, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 
2008
   ;; Free Software Foundation, Inc.

! ;; Authors: Ray Blaak <blaak@infomatch.com>,
! ;;          Simon South <ssouth@member.fsf.org>
   ;; Maintainer: FSF  (Blaak's email addr bounces, Aug 2005)
   ;; Keywords: languages

***************
*** 262,271 ****
   (defconst delphi-decl-sections '(type const var label resourcestring)
     "Denotes the start of a declaration section.")

   (defconst delphi-class-types '(class object)
     "Class types.")

! (defconst delphi-composite-types `(,@delphi-class-types record)
     "Types that contain declarations within them.")

   (defconst delphi-unit-sections
--- 263,276 ----
   (defconst delphi-decl-sections '(type const var label resourcestring)
     "Denotes the start of a declaration section.")

+ (defconst delphi-interface-types '(dispinterface interface)
+   "Interface types.")
+
   (defconst delphi-class-types '(class object)
     "Class types.")

! (defconst delphi-composite-types
!   `(,@delphi-class-types ,@delphi-interface-types record)
     "Types that contain declarations within them.")

   (defconst delphi-unit-sections
***************
*** 859,866 ****
         (delphi-stmt-line-indent-of token delphi-indent-level))))

   (defun delphi-composite-type-start (token last-token)
!   ;; Returns true (actually the last-token) if the pair equals (= 
class) or (=
!   ;; record), and nil otherwise.
     (if (and (eq 'equals (delphi-token-kind token))
              (delphi-is (delphi-token-kind last-token) 
delphi-composite-types))
         last-token))
--- 864,872 ----
         (delphi-stmt-line-indent-of token delphi-indent-level))))

   (defun delphi-composite-type-start (token last-token)
!   ;; Returns true (actually the last-token) if the pair equals (= 
class), (=
!   ;; dispinterface), (= interface), (= object), or (= record), and nil
!   ;; otherwise.
     (if (and (eq 'equals (delphi-token-kind token))
              (delphi-is (delphi-token-kind last-token) 
delphi-composite-types))
         last-token))
***************
*** 1351,1357 ****
                                            delphi-indent-level)))

            ;; In unit sections we indent right to the left.
!          ((delphi-is token-kind delphi-unit-sections) (throw 'done 0))

            ;; A previous terminator means we can stop.
            ((delphi-is token-kind delphi-previous-terminators)
--- 1357,1385 ----
                                            delphi-indent-level)))

            ;; In unit sections we indent right to the left.
!          ((delphi-is token-kind delphi-unit-sections)
!           (throw 'done
!                  ;; Handle specially the case of "interface", which 
can be used
!                  ;; to start either a unit section or an interface 
definition.
!                  (if (delphi-is token-kind delphi-interface-types)
!                      (progn
!                        ;; Find the previous non-whitespace token.
!                        (while (progn
!                                 (setq last-token token
!                                       token (delphi-previous-token token)
!                                       token-kind (delphi-token-kind 
token))
!                                 (and token
!                                      (delphi-is token-kind
!                                                 delphi-whitespace))))
!                        ;; If this token is an equals sign, "interface" 
is being
!                        ;; used to start an interface definition and we 
should
!                        ;; treat it as a composite type; otherwise, we 
should
!                        ;; consider it the start of a unit section.
!                        (if (and token (eq token-kind 'equals))
!                            (delphi-line-indent-of last-token
!                                                   delphi-indent-level)
!                          0))
!                    0)))

            ;; A previous terminator means we can stop.
            ((delphi-is token-kind delphi-previous-terminators)

bug#259: delphi-mode does not properly format interface definitions

[Stefan Monnier]

> Here's a patch that I believe is correct.  This adds proper support for the
> "dispinterface" keyword and for the "interface" keyword when used to
> define interfaces.

Thank you.  This change is a bit too large to be considered as a "tiny
change" (which don't require copyright papers).  So before we can
install it, we need you to sign the corresponding paperwork.
Would you be willing to sign a copyright assignment for it?  If so,
please fill&email the form below as instructed, so that the FSF can send
you the relevant papers to sign.

Also, delphi-mode is "orphaned" (it doesn't have a maintainer) and since
you seem to be using it and have some knowledge of it, would you be
willing to be the official maintainer of the package?


        Stefan


Please email the following information to assign@gnu.org, and we
will send you the assignment form for your past and future changes.

Please use your full legal name (in ASCII characters) as the subject
line of the message.
----------------------------------------------------------------------
REQUEST: SEND FORM FOR PAST AND FUTURE CHANGES

[What is the name of the program or package you're contributing to?]
Emacs

[Did you copy any files or text written by someone else in these changes?
Even if that material is free software, we need to know about it.]


[Do you have an employer who might have a basis to claim to own
your changes?  Do you attend a school which might make such a claim?]


[For the copyright registration, what country are you a citizen of?]


[What year were you born?]


[Please write your email address here.]


[Please write your postal address here.]





[Which files have you changed so far, and which new files have you written
so far?]
delphi.el

bug#259: marked as done (delphi-mode does not properly format interface definitions)

[Emacs bug Tracking System]

[-- Attachment #1: Type: text/plain, Size: 828 bytes --]


Your message dated Mon, 01 Sep 2008 13:28:04 -0400
with message-id <8763pf6ajf.fsf@cyd.mit.edu>
and subject line Re: Delphi mode
has caused the Emacs bug report #259,
regarding delphi-mode does not properly format interface definitions
to be marked as done.

This means that you claim that the problem has been dealt with.
If this is not the case it is now your responsibility to reopen the
bug report if necessary, and/or fix the problem forthwith.

(NB: If you are a system administrator and have no idea what this
message is talking about, this may indicate a serious mail system
misconfiguration somewhere. Please contact don@donarmstrong.com
immediately.)


-- 
259: http://emacsbugs.donarmstrong.com/cgi-bin/bugreport.cgi?bug=259
Emacs Bug Tracking System
Contact don@donarmstrong.com with problems

[-- Attachment #2: Type: message/rfc822, Size: 7360 bytes --]

From: Simon South <ssouth@slowcomputing.org>
To: bug-gnu-emacs@gnu.org
Subject: delphi-mode does not properly format interface definitions
Date: Fri, 16 May 2008 12:16:00 -0400
Message-ID: <482DB340.3050405@slowcomputing.org>

delphi-mode doesn't properly indent interface definition, things like
this:

type
   IHelloWorld = interface(IInvokable)
     ['{D613A992-AB12-0978-80D1-02B40DF72551}']
     function HelloWorld: String; stdcall;
   end;

This is because it doesn't distinguish between the "interface" keyword
used as a unit separator (i.e., as opposed to "implementation") and
used like a class declaration, as above.

As a result, delphi-mode will incorrectly indent the above code this
way:

type
   IHelloWorld = interface(IInvokable)
['{D613A992-AB12-0978-80D1-02B40DF72551}']
function HelloWorld: String; stdcall;
end;

I've taken a stab at updating delphi.el to distinguish between these
cases and support "dispinterface" properly as well (patch below) but I
don't understand the existing code well enough yet to finish it.  (I
suspect more changes need to be made to the delphi-enclosing-indent-of
function.)  Perhaps someone more familiar with this sort of thing
could help me complete it?

In GNU Emacs 22.1.1 (i386-mingw-nt5.1.2600)
  of 2007-06-02 on RELEASE
Windowing system distributor `Microsoft Corp.', version 5.1.2600
configured using `configure --with-gcc (3.4) --cflags -Ic:/gnuwin32/include'

*** delphi.el.orig	Thu May 15 17:57:29 2008
--- delphi.el	Fri May 16 12:07:37 2008
***************
*** 262,271 ****
   (defconst delphi-decl-sections '(type const var label resourcestring)
     "Denotes the start of a declaration section.")

   (defconst delphi-class-types '(class object)
     "Class types.")

! (defconst delphi-composite-types `(,@delphi-class-types record)
     "Types that contain declarations within them.")

   (defconst delphi-unit-sections
--- 262,275 ----
   (defconst delphi-decl-sections '(type const var label resourcestring)
     "Denotes the start of a declaration section.")

+ (defconst delphi-interface-types '(dispinterface interface)
+   "Interface types.")
+
   (defconst delphi-class-types '(class object)
     "Class types.")

! (defconst delphi-composite-types
!   `(,@delphi-class-types ,@delphi-interface-types record)
     "Types that contain declarations within them.")

   (defconst delphi-unit-sections
***************
*** 859,866 ****
         (delphi-stmt-line-indent-of token delphi-indent-level))))

   (defun delphi-composite-type-start (token last-token)
!   ;; Returns true (actually the last-token) if the pair equals (= 
class) or (=
!   ;; record), and nil otherwise.
     (if (and (eq 'equals (delphi-token-kind token))
              (delphi-is (delphi-token-kind last-token) 
delphi-composite-types))
         last-token))
--- 863,870 ----
         (delphi-stmt-line-indent-of token delphi-indent-level))))

   (defun delphi-composite-type-start (token last-token)
!   ;; Returns true (actually the last-token) if the pair equals (= 
class), (=
!   ;; interface), or (= record), and nil otherwise.
     (if (and (eq 'equals (delphi-token-kind token))
              (delphi-is (delphi-token-kind last-token) 
delphi-composite-types))
         last-token))
***************
*** 1252,1258 ****
             (throw 'done (delphi-line-indent-of token 0)))

            ;; Unit statements mean we indent right to the left.
!          ((delphi-is token-kind delphi-unit-statements) (throw 'done 0))
            )
           (unless (delphi-is token-kind delphi-whitespace)
              (setq last-token token))
--- 1256,1264 ----
             (throw 'done (delphi-line-indent-of token 0)))

            ;; Unit statements mean we indent right to the left.
!          ((and (delphi-is token-kind delphi-unit-statements)
!                (not (delphi-composite-type-start token last-token)))
!           (throw 'done 0))
            )
           (unless (delphi-is token-kind delphi-whitespace)
              (setq last-token token))
***************
*** 1351,1357 ****
                                            delphi-indent-level)))

            ;; In unit sections we indent right to the left.
!          ((delphi-is token-kind delphi-unit-sections) (throw 'done 0))

            ;; A previous terminator means we can stop.
            ((delphi-is token-kind delphi-previous-terminators)
--- 1357,1365 ----
                                            delphi-indent-level)))

            ;; In unit sections we indent right to the left.
!          ((and (delphi-is token-kind delphi-unit-sections)
!                (not (delphi-is token-kind delphi-interface-types)))
!           (throw 'done 0))

            ;; A previous terminator means we can stop.
            ((delphi-is token-kind delphi-previous-terminators)
***************
*** 1457,1463 ****
                      ;; Indent to the matching start ( or [.
                      (delphi-indent-of (delphi-group-start token)))

!                   ((delphi-is token-kind delphi-unit-statements) 0)

                     ((delphi-is token-kind delphi-comments)
                      ;; In a comment.
--- 1465,1475 ----
                      ;; Indent to the matching start ( or [.
                      (delphi-indent-of (delphi-group-start token)))

!                   ((and (delphi-is token-kind delphi-unit-statements)
!                         (not
!                          (delphi-is token-kind delphi-interface-types)))
!                         1)
!                    0)

                     ((delphi-is token-kind delphi-comments)
                      ;; In a comment.





[-- Attachment #3: Type: message/rfc822, Size: 1632 bytes --]

From: Chong Yidong <cyd@stupidchicken.com>
To: Simon South <ssouth@slowcomputing.org>
Cc: 259-done@emacsbugs.donarmstrong.com
Subject: Re: Delphi mode
Date: Mon, 01 Sep 2008 13:28:04 -0400
Message-ID: <8763pf6ajf.fsf@cyd.mit.edu>

Simon South <ssouth@slowcomputing.org> writes:

> Chong Yidong wrote:
>> I didn't receive a reply from you previously, so maybe it got lost.
>> Your copyright assignment for Emacs changes has arrived; could you send
>> me the updated patch to delphi mode, so that I can check it into CVS?
>
> Very sorry Chong, this slipped off my radar the first time
> around. Here's the patch, against the source in CVS this morning.

Checked in.  Thanks.