From 7bfbd1929d6e122ee609d7df006e57b351755c74 Mon Sep 17 00:00:00 2001
From: TatriX <tatrics@gmail.com>
Date: Wed, 26 Feb 2020 15:18:07 +0100
Subject: [PATCH] scel: Add support for completion-at-point-functions and
 company-mode

---
 CHANGELOG.md          | 14 ++++++++++++++
 el/sclang-language.el | 18 ++++++++++++++++++
 el/sclang-mode.el     | 18 +++++++++++++++---
 3 files changed, 47 insertions(+), 3 deletions(-)
 create mode 100644 CHANGELOG.md

diff --git a/CHANGELOG.md b/CHANGELOG.md
new file mode 100644
index 0000000..f08e7a5
--- /dev/null
+++ b/CHANGELOG.md
@@ -0,0 +1,14 @@
+# Changelog
+All notable changes to this project will be documented in this file.
+
+The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
+and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
+
+## [Unreleased]
+
+### Added
+ - Support for `completion-at-point-functions` and `company` via `company-capf`
+
+### Changed
+ - `M-<tab>` or `C-M-i` is no longer bound to `sclang-complete-symbol`
+   to make builtin completion work as expected.
diff --git a/el/sclang-language.el b/el/sclang-language.el
index 40f2bbb..4239355 100644
--- a/el/sclang-language.el
+++ b/el/sclang-language.el
@@ -453,6 +453,24 @@ are considered."
 		(insert " \n"))))
 	   (sclang-message "Making completion list...%s" "done")))))
 
+(defun sclang-completion-at-point ()
+  "Function used for `completion-at-point-functions' in `sclang-mode'."
+  (let* ((end (point))
+	 (beg (save-excursion
+		(backward-sexp 1)
+		(skip-syntax-forward "'")
+		(point)))
+	 (pattern (buffer-substring-no-properties beg end))
+	 (case-fold-search nil)
+	 (predicate (if (sclang-class-name-p pattern)
+                        #'sclang-class-name-p
+                      #'sclang-method-name-p)))
+    (list beg
+          end
+          (all-completions pattern sclang-symbol-table predicate)
+          :exclusive 'no
+          :company-docsig #'identity)))
+
 ;; =====================================================================
 ;; introspection
 ;; =====================================================================
diff --git a/el/sclang-mode.el b/el/sclang-mode.el
index 2c15218..83ce830 100644
--- a/el/sclang-mode.el
+++ b/el/sclang-mode.el
@@ -15,8 +15,15 @@
 ;; Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301
 ;; USA
 
+;;; Code:
+
 (require 'cl-lib)
 
+;; Make byte-compiler happy by declaring external functions and
+;; variables.
+(declare-function company-mode "ext:company")
+(defvar company-backends)
+
 (eval-when-compile
   (require 'font-lock)
   (require 'sclang-util))
@@ -125,7 +132,6 @@
   (define-key map "\C-c\C-f"		'sclang-eval-document)
   ;; language information
   (define-key map "\C-c\C-n"		'sclang-complete-symbol)
-  (define-key map "\M-\t"			'sclang-complete-symbol)
   (define-key map "\C-c:"			'sclang-find-definitions)
   (define-key map "\C-c;"			'sclang-find-references)
   (define-key map "\C-c}"			'sclang-pop-definition-mark)
@@ -667,8 +673,7 @@ Returns the column to indent to."
 
 (defun sclang-mode ()
   "Major mode for editing SuperCollider language code.
-\\{sclang-mode-map}
-"
+\\{sclang-mode-map}"
   (interactive)
   (kill-all-local-variables)
   (set-syntax-table sclang-mode-syntax-table)
@@ -679,6 +684,13 @@ Returns the column to indent to."
   (sclang-set-font-lock-keywords)
   (sclang-init-document)
   (sclang-make-document)
+
+  ;; Setup completion
+  (add-hook 'completion-at-point-functions
+            #'sclang-completion-at-point nil 'local)
+  (when (fboundp 'company-mode)
+    (add-to-list 'company-backends 'company-capf))
+
   (run-hooks 'sclang-mode-hook))
 
 ;; =====================================================================