sweep_variable_start_code/2,
sweep_head_functors_collection/2,
sweep_functors_collection/2,
- sweep_compound_functors_collection/2
+ sweep_compound_functors_collection/2,
+ sweep_term_variable_names/2,
+ sweep_goal_may_cut/2
]).
:- use_module(library(pldoc)).
term_string(Term, String, [variable_names(Vs), module(M)]).
sweep_variable_start_code(C, _) :- code_type(C, prolog_var_start).
+
+sweep_term_variable_names(String, Names) :-
+ term_string(_, String, [variable_names(VarNames)]),
+ maplist([Atom=_,Name]>>atom_string(Atom, Name), VarNames, Names).
+
+sweep_goal_may_cut(String, _) :-
+ term_string(Goal, String),
+ sweep_goal_may_cut_(Goal),
+ !.
+
+sweep_goal_may_cut_((_->A;B)) =>
+ ( sweep_goal_may_cut_(A)
+ ; sweep_goal_may_cut_(B)
+ ).
+sweep_goal_may_cut_(A;B) =>
+ ( sweep_goal_may_cut_(A)
+ ; sweep_goal_may_cut_(B)
+ ).
+sweep_goal_may_cut_((A,B)) =>
+ ( sweep_goal_may_cut_(A)
+ ; sweep_goal_may_cut_(B)
+ ).
+sweep_goal_may_cut_(!) =>
+ true.
+sweep_goal_may_cut_(_) =>
+ false.
adding new clauses to an existing predicate, Sweep Prolog mode
provides the ``do what I mean'' command
@code{sweeprolog-insert-term-dwim}, bound by default to @kbd{C-M-m}
-(or equivalently, @kbd{M-RET}). This command inserts a new term at or
-after point according to the context in which you invoke it.
+(or equivalently, @kbd{M-@key{RET}}). This command inserts a new term in
+the current buffer according to the context in which you invoke it.
@table @kbd
@kindex M-RET
@item M-@key{RET}
@itemx C-M-m
Insert an appropriate Prolog term in the current buffer, based on the
-context at point (@code{sweeprolog-insert-term-dwim}).
+current context (@code{sweeprolog-insert-term-dwim}).
@end table
@defvar sweeprolog-insert-term-functions
By default, @code{sweeprolog-insert-term-dwim} tries the following
insertion functions, in order:
+@defun sweeprolog-maybe-extract-region-to-predicate
+If the region is active, extract the selected goal into a separate
+predicate. @xref{Extract Goal}.
+@end defun
+
@defun sweeprolog-maybe-insert-next-clause
If the last token before point is a fullstop ending a predicate
clause, insert a new clause below it.
The cursor is left between the parentheses of the @code{test()} head
term, and the @code{TestBody} variable is marked as a hole
(@pxref{Holes}). To insert another unit test, place point after a
-complete test case and type @kbd{C-M-m} (or @kbd{M-RET}) to invoke
+complete test case and type @kbd{C-M-m} (or @kbd{M-@key{RET}}) to invoke
@code{sweeprolog-insert-term-dwim} (@pxref{Insert Term DWIM, ,
Context-Based Term Insertion}).
right-clicking on the @code{#} and selecting @samp{Expand Macro} from
the context menu. @xref{Context Menu}.
+@node Extract Goal
+@section Extracting Goals to Separate Predicates
+
+Sweep can help you extract a part of the body of a Prolog clause into
+a separate predicate, so you can reuse it in other places.
+
+@findex sweeprolog-extract-region-to-predicate
+@deffn Command sweeprolog-extract-region-to-predicate
+Extract the goal between point and mark into a new predicate.
+@end deffn
+
+This command extracts the selected goal into a separate predicate. It
+prompts you for the name of the new predicate and inserts a definition
+for that predicate in the current buffer, while replacing the current
+region with a call to this new predicate. The body of the new
+predicate is the goal in the current region, and this command
+determines the arguments of the new predicate based on the variables
+that the goal to extract shares with the containing clause.
+
+If the selected goal contains a cut whose scope would change as a
+result of being extracted from the current clause,
+@code{sweeprolog-extract-region-to-predicate} warns you about it and
+asks you to confirm before continuing.
+
+By default, @code{sweeprolog-extract-region-to-predicate} is not bound
+directly to any key in Sweep Prolog mode; instead, you can it by
+typing @kbd{M-@key{RET}} (@code{sweeprolog-insert-term-dwim}) when the
+region is active. @xref{Insert Term DWIM}).
+
+With Context Menu mode enabled, you can also invoke this command by
+right-clicking on an active region.
+
@node Prolog Help
@chapter Prolog Help
(defvar sweeprolog--extra-init-args nil)
(defvar sweeprolog-insert-term-functions
- '(sweeprolog-maybe-insert-next-clause
+ '(sweeprolog-maybe-extract-region-to-predicate
+ sweeprolog-maybe-insert-next-clause
sweeprolog-maybe-define-predicate)
"Hook of functions that insert a Prolog term in a certain context.
(defun sweeprolog-local-variables-collection (&rest exclude)
"Return a list of variable names that occur in the current clause.
-EXCLUDE is a list of variables name to be excluded from the
-resulting list even when found in the current clause."
+EXCLUDE is a list of variable names to exclude from the resulting
+list even when found in the current clause."
(let* ((case-fold-search nil)
(beg (save-mark-and-excursion
(unless (sweeprolog-at-beginning-of-top-term-p)
:help ,(format "Expand macro to %s" expansion)
:keys "\\[sweeprolog-expand-macro-at-point]")))))
+(defun sweeprolog-context-menu-for-region (menu &rest _)
+ "Extend MENU with commands that are only relevant when the region is active."
+ (when (use-region-p)
+ (define-key menu [sweeprolog-extract-region-to-predicate]
+ `(menu-item "Extract to New Predicate"
+ sweeprolog-extract-region-to-predicate
+ :help "Extract the selected goal into a separate predicate"
+ :keys "\\[sweeprolog-extract-region-to-predicate]"))))
+
(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-macro)
+ sweeprolog-context-menu-for-macro
+ sweeprolog-context-menu-for-region)
"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
fun ind (number-to-string ari)))))
+;;;; Extract goals to separate predicates
+
+(defun sweeprolog-extract-region-to-predicate (beg end new)
+ "Extract the Prolog goal from BEG to END into a new predicate, NEW.
+
+BEG and END are buffer positions; interactively, these are the
+beginning and end of the current region. NEW is a string used as
+the functor of the new predicate; interactively, this command
+prompts for NEW in the minibuffer.
+
+This command defines the new predicate with arguments based on
+the variables that the goal to extract shares with the containing
+clause.
+
+The user option `sweeprolog-new-predicate-location-function' says
+where in the buffer to insert the newly created predicate."
+ (interactive "r\nsNew predicate functor: " sweeprolog-mode)
+ ;; TODO - check that NEW isn't already used
+ (let* ((name (sweeprolog-format-string-as-atom new))
+ (body (buffer-substring-no-properties beg end))
+ (vars (condition-case error
+ (sweeprolog--query-once "sweep" "sweep_term_variable_names"
+ body)
+ (prolog-exception
+ (user-error "Region does not contain a valid Prolog term")))))
+ (if (and (sweeprolog--query-once "sweep" "sweep_goal_may_cut" body)
+ (not (y-or-n-p (concat
+ "The selected goal contains a cut whose "
+ "scope would change as a result of this "
+ "operation. Continue?"))))
+ (message "Canceled.")
+ (combine-after-change-calls
+ (goto-char beg)
+ (delete-region beg end)
+ (insert name)
+ (let* ((clause-beg (save-excursion
+ (sweeprolog-beginning-of-top-term)
+ (point)))
+ (clause-end (save-excursion
+ (sweeprolog-end-of-top-term)
+ (point)))
+ (clause-vars
+ (condition-case error
+ (sweeprolog--query-once "sweep" "sweep_term_variable_names"
+ (buffer-substring-no-properties
+ clause-beg clause-end))
+ (prolog-exception (sweeprolog-local-variables-collection))))
+ (neck (or (nth 4 (sweeprolog-definition-at-point)) ":-"))
+ (args (seq-intersection vars clause-vars #'string=)))
+ (when args
+ (insert "(" (mapconcat #'identity args ", ") ")"))
+ (funcall sweeprolog-new-predicate-location-function
+ name (length args) neck)
+ (let ((def-beg (1+ (point))))
+ (insert (concat "\n"
+ name
+ (when args
+ (concat "(" (mapconcat #'identity args ", ") ")"))
+ " "
+ neck
+ "\n"
+ body
+ ".\n"))
+ (indent-region-line-by-line def-beg (point))
+ (goto-char def-beg)))))))
+
+(defun sweeprolog-maybe-extract-region-to-predicate (&rest _)
+ (when (use-region-p)
+ (sweeprolog-extract-region-to-predicate
+ (use-region-beginning)
+ (use-region-end)
+ (read-string "Extract region to new predicate: "))
+ t))
+
;;;; Bug Reports
(defvar reporter-prompt-for-summary-p)
projects / sweep.git / commitdiff