~theo/fsharp-mode

781e75c82806faf3106bd23eec579ab8bf779f0d — Theodor Thornhill 3 years ago
Initial commit
5 files changed, 1029 insertions(+), 0 deletions(-)

A .gitignore
A LICENSE.md
A README.org
A fsharp-mode-font.el
A fsharp-mode.el
A  => .gitignore +13 -0
@@ 1,13 @@
*.elc
bin
tmp

# Useful for doing releases
emacs-fsharp-mode-bin/

# Dependency archive
fsautocomplete-*.zip

# Development
obj/
.ionide/

A  => LICENSE.md +208 -0
@@ 1,208 @@
Copyright 2011-2015


    Robin Neatherway
    Jurgen Hurtzel
    Jason Imison
    Chris Barrett

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

    http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.

------------------------------------------------------------

Apache License, Version 2.0
===========================

Apache License   
Version 2.0, January 2004    
http://www.apache.org/licenses/    

### TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION


**1. Definitions.**

 - "License" shall mean the terms and conditions for use, reproduction,
and distribution as defined by Sections 1 through 9 of this document.

 - "Licensor" shall mean the copyright owner or entity authorized by
the copyright owner that is granting the License.

 - "Legal Entity" shall mean the union of the acting entity and all
other entities that control, are controlled by, or are under common
control with that entity. For the purposes of this definition,
"control" means (i) the power, direct or indirect, to cause the
direction or management of such entity, whether by contract or
otherwise, or (ii) ownership of fifty percent (50%) or more of the
outstanding shares, or (iii) beneficial ownership of such entity.

 - "You" (or "Your") shall mean an individual or Legal Entity
exercising permissions granted by this License.

 - "Source" form shall mean the preferred form for making modifications,
including but not limited to software source code, documentation
source, and configuration files.

 - "Object" form shall mean any form resulting from mechanical
transformation or translation of a Source form, including but
not limited to compiled object code, generated documentation,
and conversions to other media types.

 - "Work" shall mean the work of authorship, whether in Source or
Object form, made available under the License, as indicated by a
copyright notice that is included in or attached to the work
(an example is provided in the Appendix below).

 - "Derivative Works" shall mean any work, whether in Source or Object
form, that is based on (or derived from) the Work and for which the
editorial revisions, annotations, elaborations, or other modifications
represent, as a whole, an original work of authorship. For the purposes
of this License, Derivative Works shall not include works that remain
separable from, or merely link (or bind by name) to the interfaces of,
the Work and Derivative Works thereof.

 - "Contribution" shall mean any work of authorship, including
the original version of the Work and any modifications or additions
to that Work or Derivative Works thereof, that is intentionally
submitted to Licensor for inclusion in the Work by the copyright owner
or by an individual or Legal Entity authorized to submit on behalf of
the copyright owner. For the purposes of this definition, "submitted"
means any form of electronic, verbal, or written communication sent
to the Licensor or its representatives, including but not limited to
communication on electronic mailing lists, source code control systems,
and issue tracking systems that are managed by, or on behalf of, the
Licensor for the purpose of discussing and improving the Work, but
excluding communication that is conspicuously marked or otherwise
designated in writing by the copyright owner as "Not a Contribution."

 - "Contributor" shall mean Licensor and any individual or Legal Entity
on behalf of whom a Contribution has been received by Licensor and
subsequently incorporated within the Work.

**2. Grant of Copyright License.**
Subject to the terms and conditions of
this License, each Contributor hereby grants to You a perpetual,
worldwide, non-exclusive, no-charge, royalty-free, irrevocable
copyright license to reproduce, prepare Derivative Works of,
publicly display, publicly perform, sublicense, and distribute the
Work and such Derivative Works in Source or Object form.

**3. Grant of Patent License.**
Subject to the terms and conditions of
this License, each Contributor hereby grants to You a perpetual,
worldwide, non-exclusive, no-charge, royalty-free, irrevocable
(except as stated in this section) patent license to make, have made,
use, offer to sell, sell, import, and otherwise transfer the Work,
where such license applies only to those patent claims licensable
by such Contributor that are necessarily infringed by their
Contribution(s) alone or by combination of their Contribution(s)
with the Work to which such Contribution(s) was submitted. If You
institute patent litigation against any entity (including a
cross-claim or counterclaim in a lawsuit) alleging that the Work
or a Contribution incorporated within the Work constitutes direct
or contributory patent infringement, then any patent licenses
granted to You under this License for that Work shall terminate
as of the date such litigation is filed.

**4. Redistribution.**
You may reproduce and distribute copies of the
Work or Derivative Works thereof in any medium, with or without
modifications, and in Source or Object form, provided that You
meet the following conditions:

 - You must give any other recipients of the Work or
    Derivative Works a copy of this License; and
 
 - You must cause any modified files to carry prominent notices
    stating that You changed the files; and

 - You must retain, in the Source form of any Derivative Works
    that You distribute, all copyright, patent, trademark, and
    attribution notices from the Source form of the Work,
    excluding those notices that do not pertain to any part of
    the Derivative Works; and

 - If the Work includes a "NOTICE" text file as part of its
    distribution, then any Derivative Works that You distribute must
    include a readable copy of the attribution notices contained
    within such NOTICE file, excluding those notices that do not
    pertain to any part of the Derivative Works, in at least one
    of the following places: within a NOTICE text file distributed
    as part of the Derivative Works; within the Source form or
    documentation, if provided along with the Derivative Works; or,
    within a display generated by the Derivative Works, if and
    wherever such third-party notices normally appear. The contents
    of the NOTICE file are for informational purposes only and
    do not modify the License. You may add Your own attribution
    notices within Derivative Works that You distribute, alongside
    or as an addendum to the NOTICE text from the Work, provided
    that such additional attribution notices cannot be construed
    as modifying the License.

You may add Your own copyright statement to Your modifications and
may provide additional or different license terms and conditions
for use, reproduction, or distribution of Your modifications, or
for any such Derivative Works as a whole, provided Your use,
reproduction, and distribution of the Work otherwise complies with
the conditions stated in this License.

**5. Submission of Contributions.**
Unless You explicitly state otherwise,
any Contribution intentionally submitted for inclusion in the Work
by You to the Licensor shall be under the terms and conditions of
this License, without any additional terms or conditions.
Notwithstanding the above, nothing herein shall supersede or modify
the terms of any separate license agreement you may have executed
with Licensor regarding such Contributions.

**6. Trademarks.**
This License does not grant permission to use the trade
names, trademarks, service marks, or product names of the Licensor,
except as required for reasonable and customary use in describing the
origin of the Work and reproducing the content of the NOTICE file.

**7. Disclaimer of Warranty.**
Unless required by applicable law or
agreed to in writing, Licensor provides the Work (and each
Contributor provides its Contributions) on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
implied, including, without limitation, any warranties or conditions
of TITLE, NON-INFRINGEMENT, MERCHANTABILITY, or FITNESS FOR A
PARTICULAR PURPOSE. You are solely responsible for determining the
appropriateness of using or redistributing the Work and assume any
risks associated with Your exercise of permissions under this License.

**8. Limitation of Liability.**
In no event and under no legal theory,
whether in tort (including negligence), contract, or otherwise,
unless required by applicable law (such as deliberate and grossly
negligent acts) or agreed to in writing, shall any Contributor be
liable to You for damages, including any direct, indirect, special,
incidental, or consequential damages of any character arising as a
result of this License or out of the use or inability to use the
Work (including but not limited to damages for loss of goodwill,
work stoppage, computer failure or malfunction, or any and all
other commercial damages or losses), even if such Contributor
has been advised of the possibility of such damages.

**9. Accepting Warranty or Additional Liability.**
While redistributing
the Work or Derivative Works thereof, You may choose to offer,
and charge a fee for, acceptance of support, warranty, indemnity,
or other liability obligations and/or rights consistent with this
License. However, in accepting such obligations, You may act only
on Your own behalf and on Your sole responsibility, not on behalf
of any other Contributor, and only if You agree to indemnify,
defend, and hold each Contributor harmless for any liability
incurred by, or claims asserted against, such Contributor by reason
of your accepting any such warranty or additional liability.

A  => README.org +200 -0
@@ 1,200 @@
[[http://melpa.org/#/fsharp-mode][file:http://melpa.org/packages/fsharp-mode-badge.svg]]
[[https://stable.melpa.org/#/fsharp-mode][file:https://stable.melpa.org/packages/fsharp-mode-badge.svg]]
[[https://github.com/fsharp/emacs-fsharp-mode/actions][file:https://github.com/fsharp/emacs-fsharp-mode/workflows/CI/badge.svg]]
* fsharp-mode

Provides support for the F# language in Emacs. Includes the following features:

- Syntax highlighting and indentation
- Support for F# Interactive
- Via [[https://github.com/joaotavora/eglot/issues][Eglot]] LSP-client integration:
  - Displays type signatures and tooltips
  - Flymake
  - Completion
  - Jump to definition [[https://www.gnu.org/software/emacs/manual/html_node/emacs/Xref.html][Find Identifier References]] (Xref)

** LSP mode
Previous versions of =fsharp-mode= (mis)used a second repository [[https://github.com/rneatherway/emacs-fsharp-mode-bin][emacs-fsharp-mode-bin]] to distribute =fsautocomplete.exe= and =fsharp-mode= together.

The current version of =fsharp-mode= installs =fsautocomplete.exe= automatically via [[https://github.com/joaotavora/eglot][eglot-fsharp]] (part of this repo) or
[[https://github.com/emacs-lsp/lsp-mode][lsp-mode]] (untested).

=fsharp-mode= is tested with Emacs 26.1+ and NET Core 2.1 (LTS)

** Installation

*** Package

=fsharp-mode= is available on [[https://melpa.org][MELPA]] and can
be installed using the built-in package manager.

If you're not already using MELPA, add the following to your init.el:

#+BEGIN_SRC elisp
  ;;; Initialize MELPA
  (require 'package)
  (add-to-list 'package-archives '("melpa" . "http://melpa.org/packages/"))
  (unless package-archive-contents (package-refresh-contents))
  (package-initialize)

  ;;; Install fsharp-mode
  (unless (package-installed-p 'fsharp-mode)
    (package-install 'fsharp-mode))

  (require 'fsharp-mode)
#+END_SRC

If you are a user of [[https://github.com/jwiegley/use-package][use-package]] you can instead do

#+BEGIN_SRC elisp
(use-package fsharp-mode
  :defer t
  :ensure t)
#+END_SRC

*** From source

I recommend to use [[https://cask.github.io/why-cask.html][Cask]]. Add this to your =Cask= file:

#+BEGIN_SRC elisp
(depends-on "fsharp-mode" :git "https://github.com/fsharp/emacs-fsharp-mode.git")
#+END_SRC

** Eglot integration

=eglot-fsharp= is part of this package and provides integration to [[https://github.com/joaotavora/eglot][Eglot]] Emacs LSP client:

   - Automatic =fsautocomplete= download
   - Workaround for non-LSP standard-compliant

Add to your config:
#+BEGIN_SRC elisp
(require 'eglot-fsharp)
#+END_SRC

and execute =M-x eglot=


** Projects

=fsharp-mode= has support for Emacs build-in project management via =project.el=

** Configuration

*** Compiler and REPL paths

The F# compiler and interpreter should be set to good defaults for
your OS as long as the relevant executables can be found on your PATH
or in other standard locations. If you have a non-standard setup you
may need to configure these paths manually.

On Windows:

#+BEGIN_SRC elisp
(setq inferior-fsharp-program "c:\\Path\\To\\Fsi.exe")
#+END_SRC

On Unix-like systems, you must use the *--readline-* flag to ensure F#
Interactive will work correctly with Emacs. Typically =fsi= and =fsc= are
invoked through the shell scripts =fsharpi= and =fsharpc=:

#+BEGIN_SRC elisp
(setq inferior-fsharp-program "path/to/fsharpi --readline-")
#+END_SRC

***  Key Bindings

If you are new to Emacs, you might want to use the menu (call
=menu-bar-mode= if you don't see it). However, it's usually faster to learn
a few useful bindings:

| Key binding      | Description                               |
|------------------+-------------------------------------------|
| =C-c C-r=        | Evaluate region                           |
| =C-c C-f=        | Load current buffer into toplevel         |
| =C-c C-e=        | Evaluate current toplevel phrase          |
| =C-M-x=          | Evaluate current toplevel phrase          |
| =C-M-h=          | Mark current toplevel phrase              |
| =C-c C-s=        | Show interactive buffer                   |
| =C-c C-c=        | Compile with fsc                          |
| =C-c x=          | Run the executable                        |
| =C-c C-a=        | Open alternate file (.fsi or .fs)         |
| =C-c l=          | Shift region to left                      |
| =C-c r=          | Shift region to right                     |
| =C-c <up>=       | Move cursor to the beginning of the block |
| =C-c C-d=, =M-.= | Jump to definition of symbol at point     |
| =C-c C-b=, =M-,= | Return to where point was before jump.    |


To interrupt the interactive mode, use =C-c C-c=. This is useful if your
code does an infinite loop or a very long computation.

If you want to shift the region by 2 spaces, use: =M-2 C-c r=

In the interactive buffer, use ==M-RET= to send the code without
explicitly adding the =;;= thing.


** Editor

In order to change tab size it is possible to put this in emacs profile:

#+BEGIN_SRC elisp
(setq-default fsharp-indent-offset 2)
#+END_SRC

Because the F# language is sensitive to indentation, you might wan't to highlight indentation:

#+BEGIN_SRC elisp
(add-hook 'fsharp-mode-hook 'highlight-indentation-mode)
#+END_SRC

** Troubleshooting

=fsharp-mode= is still under development, so you may encounter some
issues. Please report them so we can improve things! Open an issue on [[https://github.com/fsharp/emacs-fsharp-mode/][Github]].

*** No autocompletion in FSX files

The root cause is documented in this Ionide issue:  [[https://github.com/ionide/ionide-vscode-fsharp/issues/1244][4.2.0 - No auto complete or typechecking in FSX files]]

As a workaround can add a reference to the facade netstandard assembly (path is platform/SDK-dependent).

On Arch Linux using [[https://aur.archlinux.org/packages/dotnet-sdk-lts-bin][dotnet sdk lts]] add this to your =fsx= file:
#+BEGIN_SRC fsharp
#r "/opt/dotnet/sdk/2.1.801/ref/netstandard.dll"
#+END_SRC

*** Project file issues

If your project file does not seem to be being parsed correctly, so
that you have missing references or other incorrect intellisense
results, it is possible to obtain a detailed log of LSP events in this buffers:


- =*EGLOT (PROJECT/fsharp-mode) stderr*=
- =*EGLOT (PROJECT/fsharp-mode) output*=
- =*EGLOT (PROJECT/fsharp-mode) events*=

** Contributing

This project is maintained by the
[[http://fsharp.org/][F# Software Foundation]], with the repository hosted
on [[https://github.com/fsharp/emacs-fsharp-mode][GitHub]].

Pull requests are welcome. Please run the test-suite with =make
test= before submitting a pull request.

*** Maintainers

The maintainers of this repository appointed by the F# Core Engineering Group are:

 - [[https://github.com/juergenhoetzel][Jürgen Hötzel]], [[http://github.com/forki][Steffen Forkmann]], [[http://github.com/kjnilsson][Karl Nilsson]] and [[http://github.com/guillermooo][Guillermo López-Anglada]]
 - The primary maintainer for this repository is [[https://github.com/juergenhoetzel][Jürgen Hötzel]]

Previous maintainers:
 - [[https://github.com/rneatherway][Robin Neatherway]]





A  => fsharp-mode-font.el +371 -0
@@ 1,371 @@
;;; fsharp-mode-font.el --- Syntax highlighting for F#

;; Copyright (C) 1997 INRIA

;; Author: 1993-1997 Xavier Leroy, Jacques Garrigue and Ian T Zimmerman
;;         2010-2011 Laurent Le Brun <laurent@le-brun.eu>
;; Maintainer: Robin Neatherway <robin.neatherway@gmail.com>
;; Keywords: languages

;; This file is not part of GNU Emacs.

;; This file is free software; you can redistribute it and/or modify
;; it under the terms of the GNU General Public License as published by
;; the Free Software Foundation; either version 3, or (at your option)
;; any later version.

;; This file is distributed in the hope that it will be useful,
;; but WITHOUT ANY WARRANTY; without even the implied warranty of
;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
;; GNU General Public License for more details.

;; You should have received a copy of the GNU General Public License
;; along with GNU Emacs; see the file COPYING.  If not, write to
;; the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
;; Boston, MA 02110-1301, USA.

;;; Commentary:

;;; Code:

;; (require 'fsharp-mode)
;; (require 'dash)

(defgroup fsharp-ui nil
  "F# UI group for the defcustom interface."
  :prefix "fsharp-ui-"
  :group 'fsharp
  :package-version '(fsharp-mode . "1.9.2"))

(defface fsharp-ui-generic-face
  '((t (:inherit default)))
  "Preprocessor face"
  :group 'fsharp-ui)

(defface fsharp-ui-operator-face
  '((t (:foreground "LightSkyBlue")))
  "Preprocessor face"
  :group 'fsharp-ui)

(defface fsharp-ui-warning-face
  '((t (:inherit font-lock-warning-face)))
  "Face for warnings."
  :group 'fsharp-ui)

(defface fsharp-ui-error-face
  '((t (:inherit font-lock-error-face :underline t)))
  "Face for errors"
  :group 'fsharp-ui)

(defmacro def-fsharp-compiled-var (sym init &optional docstring)
  "Defines a SYMBOL as a constant inside an eval-and-compile form
with initial value INITVALUE and optional DOCSTRING."
  `(eval-and-compile
     (defvar ,sym ,init ,docstring)))

(def-fsharp-compiled-var fsharp-shebang-regexp
  "\\(^#!.*?\\)\\([A-Za-z0-9_-]+\\)$"
  "Capture the #! and path of a shebag in one group and the
  executable in another.")

(def-fsharp-compiled-var fsharp-access-control-regexp
  "private\\s-+\\|internal\\s-+\\|public\\s-+"
  "Match `private', `internal', or `public', followed by a space,
  with no capture.")

(def-fsharp-compiled-var fsharp-access-control-regexp-noncapturing
  (format "\\(?:%s\\)" fsharp-access-control-regexp)
  "Same as `fsharp-access-control-regexp', but captures")

(def-fsharp-compiled-var fsharp-inline-rec-regexp
  "inline\\s-+\\|rec\\s-+"
  "Match `inline' or `rec', followed by a space.")

(def-fsharp-compiled-var fsharp-inline-rec-regexp-noncapturing
  (format "\\(?:%s\\)" fsharp-inline-rec-regexp)
  "Match `inline' or `rec', followed by a space, with no capture.")

(def-fsharp-compiled-var fsharp-valid-identifier-regexp
  "[A-Za-z0-9_']+"
  "Match a normal, valid F# identifier -- alphanumeric characters
  plus ' and underbar. Does not capture")

(def-fsharp-compiled-var fsharp-function-def-regexp
  (concat "\\<\\(?:let\\|and\\|with\\)\\s-+"
          fsharp-inline-rec-regexp-noncapturing "?"
          fsharp-access-control-regexp-noncapturing "*"
          (format "\\(%s\\)" fsharp-valid-identifier-regexp)
          "\\(?:\\s-+[A-Za-z_]\\|\\s-*(\\)" ;; matches function arguments or open-paren; unclear why 0-9 not in class
          ))

(def-fsharp-compiled-var fsharp-pattern-function-regexp
  (concat "\\<\\(?:let\\|and\\)\\s-+"
          fsharp-inline-rec-regexp-noncapturing "?"
          fsharp-access-control-regexp-noncapturing "*"
          (format "\\(%s\\)" fsharp-valid-identifier-regexp)
          "\\s-*=\\s-*function")
  "Matches an implicit matcher, eg let foo m = function | \"cat\" -> etc.")

;; Note that this regexp is used for iMenu. To font-lock active patterns, we
;; need to use an anchored match in fsharp-font-lock-keywords.
(def-fsharp-compiled-var fsharp-active-pattern-regexp
  (concat "\\<\\(?:let\\|and\\)\\s-+"
          fsharp-inline-rec-regexp-noncapturing "?"
          fsharp-access-control-regexp-noncapturing "*"
          "(\\(|[A-Za-z0-9_'|]+|\\))\\(?:\\s-+[A-Za-z_]\\|\\s-*(\\)"))

(def-fsharp-compiled-var fsharp-member-access-regexp
  "\\<\\(?:override\\|member\\|abstract\\)\\s-+"
  "Matches members declarations and modifiers on classes.")

(def-fsharp-compiled-var fsharp-member-function-regexp
  (concat fsharp-member-access-regexp
          fsharp-inline-rec-regexp-noncapturing "?"
          fsharp-access-control-regexp-noncapturing "*"
          "\\(?:" fsharp-valid-identifier-regexp "\\.\\)?"
          "\\(" fsharp-valid-identifier-regexp "\\)")
  "Captures the final identifier in a member function declaration.")

(def-fsharp-compiled-var fsharp-overload-operator-regexp
  (concat fsharp-member-access-regexp
          fsharp-inline-rec-regexp-noncapturing "?"
          fsharp-access-control-regexp-noncapturing "*"
          "\\(([!%&*+-./<=>?@^|~]+)\\)")
  "Match operators when overloaded by a type/class.")

(def-fsharp-compiled-var fsharp-constructor-regexp
  (concat "^\\s-*"
          fsharp-access-control-regexp-noncapturing "*"
          "\\<\\(new\\) *(.*)[^=]*=")
  "Matches the `new' keyword in a constructor")

(def-fsharp-compiled-var fsharp-type-def-regexp
  (concat "^\\s-*\\<\\(?:type\\|inherit\\)\\s-+"
          fsharp-access-control-regexp-noncapturing "*" ;; match access control 0 or more times
          "\\([A-Za-z0-9_'.]+\\)"))

(def-fsharp-compiled-var fsharp-var-or-arg-regexp
  "\\_<\\([A-Za-z_][A-Za-z0-9_']*\\)\\_>")

(def-fsharp-compiled-var fsharp-explicit-field-regexp
  (concat "^\\s-*\\(?:val\\|abstract\\)\\s-*\\(?:mutable\\s-+\\)?"
          fsharp-access-control-regexp-noncapturing "*" ;; match access control 0 or more times
          "\\([A-Za-z_][A-Za-z0-9_']*\\)\\s-*:\\s-*\\([A-Za-z_][A-Za-z0-9_'<> \t]*\\)"))

(def-fsharp-compiled-var fsharp-attributes-regexp
  "\\(\\[<[A-Za-z0-9_]+[( ]?\\)\\(\".*\"\\)?\\()?>\\]\\)"
  "Match attributes like [<EntryPoint>]; separately groups contained strings in attributes like [<Attribute(\"property\")>]")

;; F# makes extensive use of operators, many of which have some kind of
;; structural significance.
;;
;; In particular:
;; (| ... |)                 -- banana clips for Active Patterns (handled separately)
;; <@ ... @> and <@@ ... @@> -- quoted expressions
;; <| and |>                 -- left and right pipe (also <||, <|||, ||>, |||>)
;; << and >>                 -- function composition
;; |                         -- match / type expressions

(def-fsharp-compiled-var fsharp-operator-quote-regexp
  "\\(<@\\{1,2\\}\\)\\(?:.*\\)\\(@\\{1,2\\}>\\)"
  "Font lock <@/<@@ and @>/@@> operators.")

(def-fsharp-compiled-var fsharp-operator-pipe-regexp
  "<|\\{1,3\\}\\||\\{1,3\\}>"
  "Match the full range of pipe operators -- |>, ||>, |||>, etc.")

(def-fsharp-compiled-var fsharp-operator-case-regexp
  "\\s-+\\(|\\)[A-Za-z0-9_' ]"
  "Match literal | in contexts like match and type declarations.")

(defun fsharp-var-pre-form ()
  (save-excursion
    (re-search-forward "\\(:\\s-*\\w[^)]*\\)?=" nil t)
    (match-beginning 0)))

(defun fsharp-fun-pre-form ()
  (save-excursion
    (search-forward "->")))

;; Preprocessor directives (3.3)
(def-fsharp-compiled-var fsharp-ui-preproessor-directives
  '("#if" "#else" "#endif" "#light"))

;; Compiler directives (12.4)
(def-fsharp-compiled-var fsharp-ui-compiler-directives
  '("#nowarn" "#load" "#r" "#reference" "#I"
    "#Include" "#q" "#quit" "#time" "#help"))

;; Lexical matters (18.4)
(def-fsharp-compiled-var fsharp-ui-lexical-matters
  '("#indent"))

;; Line Directives (3.9)
(def-fsharp-compiled-var fsharp-ui-line-directives
  '("#line"))

;; Identifier replacements (3.11)
(def-fsharp-compiled-var fsharp-ui-identifier-replacements
  '("__SOURCE_DIRECTORY__" "__SOURCE_FILE__" "__LINE__"))

;; F# keywords (3.4)
(def-fsharp-compiled-var fsharp-ui-fsharp-threefour-keywords
  '("abstract" "and" "as" "assert" "base" "begin"
    "class" "default" "delegate" "do" "do!" "done"
    "downcast" "downto" "elif" "else" "end"
    "exception" "extern" "false" "finally" "for" "fun"
    "function" "global" "if" "in" "inherit" "inline"
    "interface" "internal" "lazy" "let" "let!"
    "match" "member" "module" "mutable" "namespace"
    "new" "not" "null" "of" "open" "or" "override"
    "private" "public" "rec" "return" "return!"
    "select" "static" "struct" "then" "to" "true"
    "try" "type" "upcast" "use" "use!"  "val" "void"
    "when" "while" "with" "yield" "yield!"))

;; "Reserved because they are reserved in OCaml"
(def-fsharp-compiled-var fsharp-ui-ocaml-reserved-words
  '("asr" "land" "lor" "lsl" "lsr" "lxor" "mod" "sig"))

;; F# reserved words for future use
(def-fsharp-compiled-var fsharp-ui-reserved-words
  '("atomic" "break" "checked" "component" "const"
    "constraint" "constructor" "continue" "eager"
    "event" "external" "fixed" "functor" "include"
    "method" "mixin" "object" "parallel" "process"
    "protected" "pure" "sealed" "tailcall" "trait"
    "virtual" "volatile"))

;; RMD 2016-09-30 -- This was pulled out separately with the following comment
;; when I got here. Not clear to me why it's on it's own, or even precisely what
;; the comment means. But: `async' is a valid F# keyword and needs to go someplace,
;; so I've left it here. For now.
;;
;; Workflows not yet handled by fsautocomplete but async
;; always present
(def-fsharp-compiled-var fsharp-ui-async-words
  '("async")
  "Just the word async, in a list.")

(def-fsharp-compiled-var fsharp-ui-word-list-regexp
  (regexp-opt
   `(,@fsharp-ui-async-words
     ,@fsharp-ui-compiler-directives
     ,@fsharp-ui-fsharp-threefour-keywords
     ,@fsharp-ui-identifier-replacements
     ,@fsharp-ui-lexical-matters
     ,@fsharp-ui-ocaml-reserved-words
     ,@fsharp-ui-preproessor-directives
     ,@fsharp-ui-reserved-words
     ,@fsharp-ui-line-directives)
   'symbols))

(defconst fsharp-font-lock-keywords
  (eval-when-compile
    `((,fsharp-ui-word-list-regexp 0 font-lock-keyword-face)
      ;; shebang
      (,fsharp-shebang-regexp
       (1 font-lock-comment-face)
       (2 font-lock-keyword-face))
      ;; attributes
      (,fsharp-attributes-regexp
       (1 font-lock-preprocessor-face)
       (2 font-lock-string-face nil t)
       (3 font-lock-preprocessor-face))
      ;; ;; type defines
      (,fsharp-type-def-regexp 1 font-lock-type-face)
      (,fsharp-function-def-regexp 1 font-lock-function-name-face)
      (,fsharp-pattern-function-regexp 1 font-lock-function-name-face)
      ;; Active Pattern
      ("(|" (0 'fsharp-ui-operator-face)
       ("\\([A-Za-z'_]+\\)\\(|)?\\)"
        nil nil
        (1 font-lock-function-name-face)
        (2 'fsharp-ui-operator-face)))
      (,fsharp-operator-pipe-regexp . 'fsharp-ui-operator-face)
      (,fsharp-member-function-regexp 1 font-lock-function-name-face)
      (,fsharp-overload-operator-regexp 1 font-lock-function-name-face)
      (,fsharp-constructor-regexp 1 font-lock-function-name-face)
      (,fsharp-operator-case-regexp 1 'fsharp-ui-operator-face)
      (,fsharp-operator-quote-regexp  (1 'fsharp-ui-operator-face)
                                      (2 'fsharp-ui-operator-face))
      ("[^:]:\\s-*\\(\\<[A-Za-z0-9_' ]*[^ ;\n,)}=<-]\\)\\(<[^>]*>\\)?"
       (1 font-lock-type-face)
       ;; 'prevent generic type arguments from being rendered in variable face
       (2 'fsharp-ui-generic-face nil t))
      (,(format "^\\s-*\\<\\(let\\|use\\|override\\|member\\|and\\|\\(?:%snew\\)\\)\\_>"
                (concat fsharp-access-control-regexp "*"))
       (0 font-lock-keyword-face) ; let binding and function arguments
       (,fsharp-var-or-arg-regexp
        (fsharp-var-pre-form) nil
        (1 font-lock-variable-name-face nil t)))
      ("\\<fun\\>"
       (0 font-lock-keyword-face) ; lambda function arguments
       (,fsharp-var-or-arg-regexp
        (fsharp-fun-pre-form) nil
        (1 font-lock-variable-name-face nil t)))
      (,fsharp-type-def-regexp
       (0 'font-lock-keyword-face) ; implicit constructor arguments
       (,fsharp-var-or-arg-regexp
        (fsharp-var-pre-form) nil
        (1 font-lock-variable-name-face nil t)))
      (,fsharp-explicit-field-regexp
       (1 font-lock-variable-name-face)
       (2 font-lock-type-face))

      ;; open namespace
      ("\\<open\s\\([A-Za-z0-9_.]+\\)" 1 font-lock-type-face)

      ;; module/namespace
      ("\\_<\\(?:module\\|namespace\\)\s\\([A-Za-z0-9_.]+\\)" 1 font-lock-type-face)
      )))

(defun fsharp-ui-setup-font-lock ()
  "Set up font locking for F# Mode."
  (setq font-lock-defaults
        '(fsharp-font-lock-keywords)))

(add-hook 'fsharp-mode-hook #'fsharp-ui-setup-font-lock)

(defun fsharp--syntax-propertize-function (start end)
  (goto-char start)
  (fsharp--syntax-string end)
  (funcall (syntax-propertize-rules
            ("\\(@\\)\"" (1 (prog1 "|" (fsharp--syntax-string end)))) ; verbatim string
            ("\\(\"\\)\"\"" (1 (prog1 "|" (fsharp--syntax-string end)))) ; triple-quoted string
            ("\\('\\)\\(?:[^\n\t\r\b\a\f\v\\\\]\\|\\\\[\"'ntrbafv\\\\]\\|\\\\u[0-9A-Fa-f]\\{4\\}\\|\\\\[0-9]\\{3\\}\\)\\('\\)"
             (1 "|") (2 "|")) ; character literal
            ("\\((\\)/" (1 "()"))
            ("\\(\(\\)\\*[!%&*+-\\./<=>@^|~?]*[\n\t\r\b\a\f\v ]*\)" (1 "()")) ; symbolic operator starting (* is not a comment
            ("\\(/\\)\\*" (1 ".")))
           start end))

(defun fsharp--syntax-string (end)
  (let* ((pst (syntax-ppss))
         (instr (nth 3 pst))
         (start (nth 8 pst)))
    (when (eq t instr) ; Then we are in a custom string
      (cond
       ((eq ?@ (char-after start)) ; Then we are in a verbatim string
        (while
            (when (re-search-forward "\"\"?" end 'move)
              (if (> (- (match-end 0) (match-beginning 0)) 1)
                  t ;; Skip this "" and keep looking further.
                (put-text-property (- (match-beginning 0) 1) (- (match-end 0) 1)
                                   'syntax-table (string-to-syntax "."))
                (put-text-property (match-beginning 0) (match-end 0)
                                   'syntax-table (string-to-syntax "|"))
                nil)))
        )

       (t ; Then we are in a triple-quoted string
        (when (re-search-forward "\"\"\"" end 'move)
          (put-text-property (- (match-beginning 0) 1) (match-beginning 0)
                             'syntax-table (string-to-syntax "."))
          (put-text-property (match-beginning 0) (match-end 0)
                             'syntax-table (string-to-syntax "|")))
        )))))

(provide 'fsharp-mode-font)

;;; fsharp-mode-font.el ends here

A  => fsharp-mode.el +237 -0
@@ 1,237 @@
;;; fsharp-mode.el --- Support for the F# programming language

;; Copyright (C) 1997 INRIA

;; Author: 1993-1997 Xavier Leroy, Jacques Garrigue and Ian T Zimmerman
;;         2010-2011 Laurent Le Brun <laurent@le-brun.eu>
;;         2012-2014 Robin Neatherway <robin.neatherway@gmail.com>
;;         2017-2019 Jürgen Hötzel
;; Maintainer: Jürgen Hötzel
;; Package-Requires: ((emacs "25")  (s "1.3.1") (dash "1.1.0") (eglot))
;; Keywords: languages
;; Version: 1.9.15

;; This file is not part of GNU Emacs.

;; This file is free software; you can redistribute it and/or modify
;; it under the terms of the GNU General Public License as published by
;; the Free Software Foundation; either version 3, or (at your option)
;; any later version.

;; This file is distributed in the hope that it will be useful,
;; but WITHOUT ANY WARRANTY; without even the implied warranty of
;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
;; GNU General Public License for more details.

;; You should have received a copy of the GNU General Public License
;; along with GNU Emacs; see the file COPYING.  If not, write to
;; the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
;; Boston, MA 02110-1301, USA.

;;; Code:

(require 'compile)

(defgroup fsharp nil
  "Support for the Fsharp programming language, <http://www.fsharp.net/>"
  :group 'languages)

(defcustom fsharp-indent-offset 4
  "Indent Elm code by this number of spaces."
  :type 'integer
  :group 'fsharp
  :safe #'integerp)

;;; ----------------------------------------------------------------------------

(defvar fsharp-mode-map
  (let ((map (make-keymap)))
    (define-key map (kbd "C-c TAB") 'fsharp-indent-line)
    (define-key map (kbd "<tab>") 'fsharp-indent-forward)
    (define-key map (kbd "<backtab>") 'fsharp-indent-backward)
    map)
  "Keymap used in fsharp mode.")

;;;###autoload
(add-to-list 'auto-mode-alist '("\\.fs[iylx]?\\'" . fsharp-mode))

(defvar fsharp-mode-syntax-table
  (let ((syntax-table (make-syntax-table)))
    (modify-syntax-entry ?\\ "\\" syntax-table)
    (modify-syntax-entry ?\( "()1n" syntax-table)
    (modify-syntax-entry ?*  ". 23n" syntax-table)
    (modify-syntax-entry ?\) ")(4n" syntax-table)
    (modify-syntax-entry ?/ ". 12b" syntax-table)
    (modify-syntax-entry ?\n "> b" syntax-table)
    (modify-syntax-entry ?' "_" syntax-table)
    (modify-syntax-entry ?_ "_" syntax-table)
    (modify-syntax-entry ?# "_" syntax-table)
    (modify-syntax-entry ?! "_" syntax-table)

    syntax-table))


(defvar fsharp-mode-hook nil
  "Hook for fsharp-mode")

;;; Indentation

(defun fsharp--find-indentation-of-list ()
  (save-excursion
    (backward-up-list 1)
    (+ (- (current-column) (current-indentation))
       (current-indentation))))

(defmacro fsharp--find-indentation-of-tokens (tokens)
  `(save-excursion
     (re-search-backward (regexp-opt ',tokens) (point-min) t nil)
     (+ (- (current-column) (current-indentation))
        (current-indentation))))

(defmacro fsharp--two-lines-same-token-p (token)
  "Checks if line and previous line start with same token."
  `(and (looking-at ,token)
        (save-excursion
          (forward-line -1)
          (back-to-indentation)
          (looking-at ,token))))

(defmacro fsharp--previous-line-ends-with (tokens)
  `(save-excursion
     (forward-line -1)
     (end-of-line)
     (forward-comment (- (point)))
     (looking-back (regexp-opt ',tokens))))

(defmacro fsharp--previous-line-starts-with (tokens)
  `(save-excursion
     (forward-line -1)
     (back-to-indentation)
     (looking-at-p (regexp-opt ',tokens))))

(defun fsharp-compute-indentation ()
  "Return a column to indent to. 

The numbers we get are the positions we can determine from the
given context. When we cannot find a context to indent to, we
default to the indentation level of previous line."
  (let* ((indent-level-previous-line
          (save-excursion
            (forward-line -1)
            (current-indentation)))
         (positive-offset (+ indent-level-previous-line fsharp-indent-offset)))
    (save-excursion
      (back-to-indentation)
      ;; Now we are positioned at start of indentation.
      ;; Logic below assumes this is true.
      (cond
       ((fsharp--previous-line-ends-with ("=" "<-" "[" "{" "of" "if" "else" ":" "->" "exposing")) positive-offset)
       ((looking-at-p (regexp-opt '("(*" "*)"))) 0)
       ((and (= indent-level-previous-line 0) (looking-at-p "=")) positive-offset)
       ((fsharp--previous-line-starts-with ("type" "let")) positive-offset)
       ((looking-at-p ")") (fsharp--find-indentation-of-list))
       ((looking-at-p "}") (fsharp--find-indentation-of-list))
       ((looking-at-p "]") (fsharp--find-indentation-of-list))
       ((looking-at-p ",") (fsharp--find-indentation-of-list))
       ((looking-at-p "else") (fsharp--find-indentation-of-tokens ("if")))
       ((looking-at-p "then") (fsharp--find-indentation-of-tokens ("if")))
       (t (fsharp-indent-lastly))))))

(defun fsharp-indent-level-2-previous-lines ()
  "Returns indent level of the two previous lines."
  (save-excursion
    ;; Since we save-excursion above, we can go back two lines one by one, and
    ;; return the lines separately.
    (cl-values
     (progn
       (forward-line -1)
       (current-indentation))
     (progn
       (forward-line -1)
       (current-indentation)))))

(defun fsharp-indent-lastly ()
  (interactive)
  (cl-multiple-value-bind (previous-line 2nd-previous-line)
      (fsharp-indent-level-2-previous-lines)
    (cond
     ((and (zerop previous-line) (zerop 2nd-previous-line)) 0)
     ((zerop previous-line) 2nd-previous-line)
     (t
      previous-line))))

(defun fsharp-do-indent (indent)
  (if (<= (current-column) (current-indentation))
      (ignore-errors (indent-line-to indent))
    (save-excursion (ignore-errors (indent-line-to indent)))))

(defun fsharp-indent-line ()
  "Set indent levels for Elm source code.  

Try to indent to the correct level.  If indent level is
ambiguous, multiple invocations will indent tabstops forward."
  (interactive)
  (let ((indent (fsharp-compute-indentation)))
    (fsharp-do-indent indent)))

(defun fsharp-indent-forward (&optional arg)
  "Indent line to the next tabstop."
  (interactive "p")
  (or arg (setq arg 1))
  (fsharp-do-indent
   (indent-next-tab-stop (* arg (current-indentation)))))

(defun fsharp-indent-backward (&optional arg)
  "Indent backwards to the nearest tabstop"
  (interactive "p")
  (or arg (setq arg 1))
  (fsharp-do-indent
   (indent-next-tab-stop
    (save-excursion (back-to-indentation) (current-column)) t)))

;;;###autoload
(define-derived-mode fsharp-mode prog-mode "fsharp"
  :group 'fsharp
  :syntax-table fsharp-mode-syntax-table
  "Major mode for editing fsharp code.

\\{fsharp-mode-map}"

  (require 'fsharp-mode-font)

  ;; ;; Movement
  ;; (setq-local beginning-of-defun-function #'elmo-beginning-of-defun)
  ;; (setq-local end-of-defun-function #'elmo-end-of-defun)
  
  ;; ;; Indentation
  (when (boundp 'electric-indent-inhibit) (setq electric-indent-inhibit t))  
  (setq-local indent-line-function 'fsharp-indent-line)
  (setq-local tab-width fsharp-indent-offset)

  ;; Comments
  (setq-local comment-start-skip "// ")
  (setq-local comment-start "//")
  (setq-local comment-end "")

                                        ; Syntax highlighting
  (setq font-lock-defaults '(fsharp-font-lock-keywords))
  (setq syntax-propertize-function 'fsharp--syntax-propertize-function)

  (run-hooks 'fsharp-mode-hook))


(defconst fsharp-error-regexp-fs
  "^\\([^(\n]+\\)(\\([0-9]+\\),\\([0-9]+\\)):"
  "Regular expression matching the error messages produced by fsc.")

(if (boundp 'compilation-error-regexp-alist)
    (or (memq 'fsharp
              compilation-error-regexp-alist)
        (progn
          (add-to-list 'compilation-error-regexp-alist 'fsharp)
          (add-to-list 'compilation-error-regexp-alist-alist
                       `(fsharp ,fsharp-error-regexp-fs 1 2 3)))))

(provide 'fsharp-mode)

;;; fsharp-mode.el ends here