DOC: mention sweeprolog-swipl-path in the manual

Start the top-level TCP server just-in-time

* sweeprolog.el (sweeprolog-init): do not start TCP server
unconditionally
(sweeprolog-top-level): start it here instead, on demand.
* sweep.pl (sweep_top_level_server/2): wait for TCP server thread to
start before returning control to Emacs.
* README.org (The Prolog Top-Level): add implementation note.

Add sweeprolog-analyze-some-terms to after-change-functions

Document and test sweeprolog-electric-layout-mode

*
sweeprolog.el (sweeprolog-electric-layout-post-self-insert-function):
add docstring.
(sweeprolog-electric-layout-mode): expand docstring, indent after
closing brackets.
* sweeprolog-tests.el: add tests.
* README.org (Aligning with multiple spaces): rename to...
(Maintaining Code Layout): new section, including...
(Inserting the Right Number of Spaces)
(Electric Layout mode): new sections.

ADDED: minor mode for automatic whitespace insertion

* sweep.pl (sweep_context_callable/2): only consider the context to be
callable if a neck is present up the tree, i.e. not in the head.
* sweeprolog.el (sweeprolog-context-callable-p): new function,
extracted from (sweeprolog-predicate-completion-at-point)
(sweeprolog-electric-layout-post-self-insert-function): new function.
(sweeprolog-electric-layout-mode): new minor mode.

Simplify completion at point, bump patch version

ENHANCED: revise predicate completion at point

Completion at point now detects whether predicate completion is
appropriate, by parsing Prolog code back from point to determine the
context of point.  If predicate completion is not appropriate,
fallback to atom completion.

ADDED: user option specifying where to define new predicates

* sweeprolog.el (sweeprolog-default-new-predicate-location)
(sweeprolog-new-predicate-location-above-current): new functions.
(sweeprolog-new-predicate-location-function): new user option.
(sweeprolog-maybe-define-predicate): use it.

FIXED: possible error in sweeprolog-describe-predicate

Highlight test case head terms in a dedicated face

DOC: document sweeprolog-xref-project-source-files in the manual

ADDED: new command sweeprolog-xref-project-source-files

FIXED: find user predicate definitions more reliably

Catch error in kill-buffer-hook when top-level thread is dead

Bump version to 0.8.4

TEST: add test for updating syntax error faces

Recognize backslash as part of an operator in tokenization

FIXED: clear syntax error face after fix more aggressively

FIXED: properly update query highlighting in the toplevel

FIXED: simplify & make variable highlighting more reliable

FIXED: only consider backslash as an escape inside strings

FIXED: restrict variable underlining to current clause

FIXED: variable name completion on Emacs 27

* sweeprolog.el (sweeprolog-variable-completion-at-point): don't rely
on char-uppercase-p
* sweeprolog-tests.el (complete-variable): new test.

ADDED: sweeprolog-forward/backward/mark-predicate

REFACTOR: Simplify and deduplicate code all around

* sweeprolog.el (sweeprolog-colourise-*): rename to sweeprolog-analyze-*

FIXED: correctly recognize "public" head terms

TEST: add two test cases

FIXED: sweeprolog-identifier-at-point could return unbound module

Fixed defcustom type for sweeprolog-top-level-display-action

FIXED: write_sweep_module_location/0 for Windows.

Use term_string/2 to parse M:F/N terms encoded in strings

Organize and split sweeprolog.el into sections

Adhere to the convention of using "Emacs's" instead of "Emacs'"

DOC: added section "Code Completion" to the manual

ADDED: completion-at-point for variable names

* sweeprolog.el (sweeprolog-local-variables-collection,
sweeprolog-variable-completion-at-point): new
functions. (sweeprolog-mode): add to
completion-at-point-functions. (sweeprolog-mode-syntax-table): update
according to char_type(Char, prolog_symbol).

Update NEWS.org and bump package version

ADDED: context-based command for inserting new clauses or terms

* sweeprolog.el (sweeprolog--forward-hole, sweeprolog--backward-hole):
new functions.
(sweeprolog-forward-hole): new command.
(sweeprolog-end-of-predicate-definition,sweeprolog-insert-clause,
sweeprolog-maybe-insert-next-clause,
sweeprolog-maybe-define-predicate): new functions.
(sweeprolog-insert-term-functions): new hook.
(sweeprolog-insert-term-dwim): new command.
(sweeprolog-mode-map): bind new commands.
* sweeprolog-tests.el (dwim-define-predicate): new test case.
* README.org (Context-Based Term Insertion): new section.

ENHANCED: render refs to Prolog library in help buffers

* sweeprolog.el (sweeprolog-render-html-a): recognize and render
references to Prolog library files.

Handle operators that contain '.' more reliably

FIXED: handling of operators as predicate completion candidates

FIXED: don't include irrelevant candidates in apropos results

* sweep.pl (sweep_predicate_apropos/2): filter candidates by minimum
match quality.

ENHANCED: add predicate properties list in help buffers

* sweep.pl (sweep_predicate_properties/2): new predicate.
* sweeprolog.el (sweeprolog--render-predicate-properties): new
function.
(sweeprolog--describe-predicate): use it.

ENHANCED: load and initialize sweep-module just-in-time

Instead of loading sweep-module and initializing Prolog as part of
loading sweeprolog.el (subject to the user option
sweeprolog-init-on-load), this commit introduces just-in-time loading
and initialization of Prolog.  Suggested by Stefan Monnier.

* sweeprolog.el: (sweeprolog--open-query): new function, wraps
sweeprolog-open-query and initializes Prolog on the first call. Used
in place of sweeprolog-open-query throughout.
(sweeprolog-init-on-load): make variable obsolete.

ENHANCED: teach sweep to jump to C code for built-in predicates

* sweeprolog.el:
- sweeprolog-swipl-sources: new user option.
- sweeprolog-native-predicate-location: new function.
- sweeprolog-predicate-location: use it.
- README.org: Built-in Native Predicates: new section.

sweeprolog-describe-predicate compatibility with Emacs 27

ENHANCED: prompt for sweeprolog-describe-predicate

Following feedback from Jan Wielemaker

FIXED: additional compatibility issue with buttons

FIXED: sweeprolog-describe-predicate compatibility with Emacs 28

ADDED: new command for showing help for Prolog predicates

* sweep.pl: sweep_predicate_html_documentation/2: new predicate
* sweeprolog.el:
- sweeprolog-read-predicate-history: new variable.
- sweeprolog-read-predicate: use it, and default to the predicate at
point.
- sweeprolog--colour-term-to-faces: quote symbol
- sweeprolog-describe-predicate: new command.
- sweeprolog-help-prefix-map: bind it.
* README.org: Prolog Help: mention it.

Use list notation for format/2

Extracted locating libswipl and sweep-module to sweep_link.pl

ADDED: new command for showing help for Prolog modules

* sweep.pl: sweep_module_html_documentation/2: new predicate.
* sweeprolog.el:
- sweeprolog-read-module-history: new variable.
- sweeprolog-read-module-name: use it.
- sweeprolog--describe-module: new function.
- sweeprolog-describe-module: new command.
- sweeprolog-help-prefix-map: new keymap.
- sweeprolog-prefix-map: bind it keymap to `h'.
* README.org: Prolog Help: new section.

ENHANCED: update xref data for buffer after exporting predicate

FIXED: possible loop finding start of clause at start of buffer

ADDED: new command for exporting Prolog predicates

* sweep.pl: sweep_local_predicate_export_comment/2: new predicate.
* sweeprolog.el:
- sweeprolog-read-exportable-predicate-prompt: new user option.
- sweeprolog--exportable-predicates: new buffer local variable.
- sweeprolog--colour-term-to-faces: accumulate exportable predicates.
- sweeprolog-colourise-buffer: reset sweeprolog--exportable-predicates.
- sweeprolog-export-predicate: new command.
- sweeprolog-mode-map: bind it.
- sweeprolog-menu: bind it.
- README.org: document it.

DOC: mention new sweep Prolog flag in README.org and NEWS.org

FIXED: sweep_identifier_at_point/2: possible infinite failure loop

FIXED: disregard stderr when invoking write_sweep_module_location

ENHANCED: create Prolog flag sweep=true when running under sweep

Remove unused dependencies library(help) and library(prolog_server)

Load libswipl ahead of sweep-module if it's an ELF

DOC: index some keystrokes in the manual

PORT: Try to find emacs-module.h in the $MINGW_ROOT to build it along with
the Windows versions.

DOC: Update section "Things to do"

ENHANCED: use next-error-select-buffer when switching to a buffer

* sweeprolog.el: sweeprolog-mode: add hook to
window-selection-change-functions.

FIXED: sweeprolog-end-of-top-term would get confused by "=.."

* sweeprolog.el: sweeprolog-end-of-top-term: don't stop after "=..".
* sweeprolog-tests.el: add unit test.

ADDED: Flymake integration in sweeprolog-mode

* sweeprolog.el:
- sweeprolog-enable-flymake: new user option.
- sweeprolog--diagnostics: new buffer-local variable.
- sweeprolog--diagnostics-report-fn,
sweeprolog--diagnostics-changes-beg,
sweeprolog--diagnostics-changes-end: new buffer-local variables.
- sweeprolog-defface: add docstrings for generated functions.
- sweeprolog--colourise: accumulate diagnostics when
sweeprolog-enable-flymake is non-nil.
- sweeprolog-colourise-buffer, sweeprolog-colourise-some-terms: report
diagnostics when sweeprolog-enable-flymake is non-nil.
- sweeprolog-show-diagnostics: new command in sweeprolog-mode buffers.
- sweeprolog-mode-map: bind it.
- sweeprolog-diagnostic-function: new function.
- sweeprolog-mode: use it when sweeprolog-enable-flymake is non-nil.
* README.org: Examining diagnostics: new section.
* NEWS.org: announce flymake integration.

DOC: add descriptions to all manual sections

FIXED: quote file paths passed to shell-command-to-string

* sweeprolog.el: sweeprolog--ensure-module: quote paths and use
packaged sweep.pl
* README.org: fix typo

ADDED: new command and user option for updating whitespace

* sweeprolog.el:
- sweeprolog-align-spaces: new command, updates whitespace around
point according to SWI-Prolog conventions.
- sweeprolog-enable-cycle-spacing: new user option, when non-nil
sweeprolog-align-spaces is added to cycle-spacing-actions.
- sweeprolog-mode: use it.
- README.org: document it.
- NEWS.org: announce it.

FIXED: detecting end of clause with inline comments ending with "."

Use sweep.pl from the ELPA package rather than from SWI-Prolog

DOC: added short documentation for sweep as a SWI-Prolog package

PORT: don't use defvar-keymap, introduced only in Emacs 29

TEST: add unit test for nested Elisp->Prolog->Elisp call chains

ENHANCED: allow for Elisp->Prolog->Elisp->... call chains

DOC: add manual sections "Contributing" and "Things to do"

Announce recent changes in NEWS.org, bump version to 0.5.0

DOC: describe the Top-level Menu and signaling in the manual

* README.org:
- The Top-level Menu buffer: new section.
- Sending signals to running top-levels: new section.

ADDED: key and menu bindings for sweeprolog-list-top-levels

* sweeprolog.el:
- sweeprolog-prefix-map: bind sweeprolog-list-top-levels to T
- sweeprolog-menu: add menu entry for sweeprolog-list-top-levels

ADDED: new command for signaling a top-level from the Top-level Menu

* sweeprolog.el:
- sweeprolog-top-level-menu-signal: new command
- sweeprolog-top-level-menu-mode-map: bind it to s

ADDED: new command for signaling the current top-level

* sweeprolog.el:
- sweeprolog-top-level-signal-current: new command
- sweeprolog-top-level-mode-map: bind it to C-c C-c

FIXED: top-level buffer to thread synchronization

ADDED: new command for signaling Prolog top-level threads

* sweep.pl: sweep_thread_signal/2: new predicate.

* sweeprolog.el:
- sweeprolog-signal-thread: new function, Elisp interface for
sweep_thread_signal/2.
- sweeprolog-top-level-thread-id: new buffer-local variable in
sweeprolog-top-level buffers.
- sweeprolog-top-level-signal: new command.
- sweeprolog-top-level-mode: signal top-level thread with
thread_exit/1 when buffer is killed.

FIXED: reverse args modes in sweeprolog-document-predicate-at-point

ADDED: sweep Top-level Menu for listing Prolog top-levels

* sweep.pl
- sweep_top_level_threads/2: new predicate for querying
currently active Prolog top-level threads

* sweeprolog.el
- sweeprolog-top-level-menu--entries: new function, exposing
sweep_top_level_threads/2 to Elisp.
- sweeprolog-top-level-menu-mode: new major mode derived from
tabulated-list-mode
- sweeprolog-top-level-menu-go-to: new command, switches to the
top-level buffer of the Top-level Menu entry at point
- sweeprolog-top-level-menu-kill: new command, kills the top-level
buffer of the Top-level Menu entry at point
- sweeprolog-top-level-menu-new: new command, creates a new top-level
from the Top-level Menu
- sweeprolog-list-top-levels: new command, opens the Top-level Menu

NEWS.org: announce sweeprolog-document-predicate-at-point

README.org: fix typos

DOC: Add docstrings to some undocumented internal functions

DOC: new manual section "Documenting predicates"

ADDED: new command sweeprolog-document-predicate-at-point

ADDED: new function sweeprolog-definition-at-point

DOC: document new eldoc integration

ADDED: on-the-fly documentation for predicates with eldoc

ADDED: auto-insert integration for filling in Prolog module headers

* sweeprolog-module-header-comment-skeleton: new user option

FIXED: clear highlighting from whitespace after a fullstop

NEWS.org: remove version macro using internal package-desc-version

FIXED: error when indenting after prefix operator

DOC: say sweep-module instead of sweeprolog-module in the manual

DOC: add missing source block in Getting Started section