[nongnu] elpa/sweeprolog 030037d1d6 4/5: ADDED: New command for expanding macros

[ELPA Syncer]

branch: elpa/sweeprolog
commit 030037d1d66be8e4ffb564af553c74d8249b6c18
Author: Eshel Yaron <me@eshelyaron.com>
Commit: Eshel Yaron <me@eshelyaron.com>

    ADDED: New command for expanding macros
    
    * sweep.pl (sweep_expand_macro/2): New predicate.
    * sweeprolog.el (sweeprolog-expand-macro-at-pos): New function.
    (sweeprolog-expand-macro-at-point): New command.
    (sweeprolog-context-menu-functions): Add...
    (sweeprolog-context-menu-for-macro): New function.
    * README.org (Macro Expansion): New section.
---
 README.org    | 31 +++++++++++++++++++++++++++++++
 sweep.pl      | 13 ++++++++++++-
 sweeprolog.el | 44 +++++++++++++++++++++++++++++++++++++++++++-
 3 files changed, 86 insertions(+), 2 deletions(-)

diff --git a/README.org b/README.org
index 31b8fe1750..286463297a 100644
--- a/README.org
+++ b/README.org
@@ -2004,6 +2004,37 @@ After invoking either ~C-c C--~ or ~C-c C-+~, you can 
continue to
 decrement or increment the same set of numbered variables by repeating
 with ~-~ and ~+~.
 
+** Macro Expansion
+:PROPERTIES:
+:CUSTOM_ID: macro-expansion
+:DESCRIPTION: Commands for expanding SWI-Prolog macros
+:ALT_TITLE: Macro Expansion
+:END:
+
+Recent versions of SWI-Prolog include a pre-processing mechanism called
+/Prolog macros/, implemented in ~library(macros)~.  It provides a convenient
+way for computing terms at compile time and using them in code.
+
+Macros are defined using special rules with ~#define(Macro, Replacement)~
+head terms.  Then, when SWI-Prolog reads a term of the form ~#(Macro)~
+during compilation, it invokes the macro replacement rule and uses the
+expanded term instead.
+
+Sweep can replace macro invocations with their expansions.  To expand a
+macro in your source code, use the following command:
+
+#+FINDEX: sweeprolog-expand-macro-at-point
+- Command: sweeprolog-expand-macro-at-point :: Replace the Prolog macro
+  invocation starting at point with its expansion.
+
+You can call this command with point on the ~#~ macro indicator to expand
+the macro inline.  To undo the expansion, use ~C-/~ (~undo~).
+
+With Context Menu mode enabled, you can also expand macros by right-clicking
+on the ~#~ and selecting =Expand Macro= from the context menu.  See also
+[[#context-menu][Context Menu]].
+
+
 * Prolog Help
 :PROPERTIES:
 :CUSTOM_ID: prolog-help
diff --git a/sweep.pl b/sweep.pl
index c8a154c943..5dfc17d0e5 100644
--- a/sweep.pl
+++ b/sweep.pl
@@ -86,7 +86,8 @@
             sweep_current_breakpoints/2,
             sweep_current_breakpoints_in_region/2,
             sweep_breakpoint_range/2,
-            sweep_breakpoint_file/2
+            sweep_breakpoint_file/2,
+            sweep_expand_macro/2
           ]).
 
 :- use_module(library(pldoc)).
@@ -104,6 +105,7 @@
 :- use_module(library(prolog_pack)).
 :- use_module(library(prolog_deps)).
 :- use_module(library(dcg/high_order)).
+:- use_module(library(macros)).
 
 :- if(exists_source(library(help))).
 :- use_module(library(help)).
@@ -1296,3 +1298,12 @@ sweep_breakpoint_range(Id, [Beg|End]) :-
 sweep_breakpoint_file(Id, File) :-
     breakpoint_property(Id, file(File0)),
     atom_string(File0, File).
+
+sweep_expand_macro(String0, String) :-
+    sweep_current_module(M),
+    term_string(Term0, String0, [variable_names(Vs),
+                                 subterm_positions(Pos0),
+                                 module(M)]),
+    functor(Term0, '#', 1),
+    macros:expand_macros(M, Term0, Term, Pos0, _, _, _),
+    term_string(Term, String, [variable_names(Vs), module(M)]).
diff --git a/sweeprolog.el b/sweeprolog.el
index a2d8042117..132c995924 100644
--- a/sweeprolog.el
+++ b/sweeprolog.el
@@ -5500,6 +5500,11 @@ GOAL."
   (interactive)
   (sweeprolog-describe-predicate sweeprolog-context-menu-predicate-at-click))
 
+(defun sweeprolog-context-menu-expand-macro ()
+  "Expand Prolog macro at mouse click."
+  (interactive)
+  (sweeprolog-expand-macro-at-pos sweeprolog-context-menu-point-at-click))
+
 (defun sweeprolog-context-menu-rename-variable ()
   "Rename Prolog variable at mouse click."
   (interactive)
@@ -5668,12 +5673,24 @@ POINT is the buffer position of the mouse click."
        (define-key-after menu [sweeprolog-breakpoint]
          `(menu-item "Breakpoint" ,submenu))))))
 
+(defun sweeprolog-context-menu-for-macro (menu tok beg _end _point)
+  "Extend MENU with macro-related commands if TOK at BEG is one."
+  (pcase tok
+    (`("macro" . ,expansion)
+     (setq sweeprolog-context-menu-point-at-click beg)
+     (define-key menu [sweeprolog-expand-macro]
+                 `(menu-item "Expand Macro"
+                             sweeprolog-context-menu-expand-macro
+                             :help ,(format "Expand macro to %s" expansion)
+                             :keys "\\[sweeprolog-expand-macro-at-point]")))))
+
 (defvar sweeprolog-context-menu-functions
   '(sweeprolog-context-menu-for-clause
     sweeprolog-context-menu-for-file
     sweeprolog-context-menu-for-module
     sweeprolog-context-menu-for-predicate
-    sweeprolog-context-menu-for-variable)
+    sweeprolog-context-menu-for-variable
+    sweeprolog-context-menu-for-macro)
   "Functions that create context menu entries for Prolog tokens.
 Each function receives as its arguments the menu, the Prolog
 token's description, its start position, its end position, and
@@ -6390,6 +6407,31 @@ If OTHER-WINDOW is non-nil, find it in another window."
       (tabulated-list-print))
     (pop-to-buffer buf)))
 
+(defun sweeprolog-expand-macro-at-pos (pos)
+  "Expand Prolog macro starting at POS.
+
+Return nil if POS is not the beginning of a macro invocation."
+  (let* ((end (save-excursion
+                (goto-char pos)
+                (sweeprolog--forward-sexp)
+                (point)))
+         (expansion
+          (sweeprolog--query-once "sweep" "sweep_expand_macro"
+                                  (buffer-substring-no-properties
+                                   pos end))))
+    (when expansion
+      (combine-after-change-calls
+        (delete-region pos end)
+        (save-excursion
+          (goto-char pos)
+          (insert expansion)))
+      t)))
+
+(defun sweeprolog-expand-macro-at-point (point)
+  "Expand Prolog macro starting at POINT."
+  (interactive "d" sweeprolog-mode)
+  (unless (sweeprolog-expand-macro-at-pos point)
+    (user-error "No macro invocation at point")))
 
 ;;;; Footer