Add experimental support for code assistance using a language server (#90)

Added basic support for using the language sever protocol with the [fortran-languague-server](https://github.com/hansec/fortran-language-server)
This is still an experimental feature and contains several bugs. But the idea is to get it out there as fast as possible and fix the bug later on.

Author: krvajal

CHANGELOG.md

@@ -6,114 +6,125 @@ The format is based on [Keep a Changelog](http://keepachangelog.com/)
 and this project adheres to [Semantic Versioning](http://semver.org/).
 
 ## [Unreleased]
-### Added 
-* Syntax highlight for 'forall' construct (#82)
+
+### Added
+
+- Syntax highlight for `forall` construct (#82)
+- Add experimental support for the [Fortran Language Server](https://github.com/hansec/fortran-language-server)
+
+### Changed
+
+- Updated the minimum supported version of VS Code to 1.22.0
 
 ## [1.3.1] - 2018-06-26
 
 ### Fixed
-* Subroutine and function on symbol list were failing with more than one line arguments (#71)
-* Minor syntax highlighting issues (#62, #73)
 
-### Added 
-* Implementation of OpenMP directives highlighting (#17)
-* Syntax highlight on multiple line of dummy arguments
+- Subroutine and function on symbol list were failing with more than one line arguments (#71)
+- Minor syntax highlighting issues (#62, #73)
+
+### Added
+
+- Implementation of OpenMP directives highlighting (#17)
+- Syntax highlight on multiple line of dummy arguments
 
 ## [1.2.0] - 2018-05-25
 
 ### Fixed
-* Linter was broken in previous version (#55)
-* Symbol listing was failing for subroutine without brackets (#61)
+
+- Linter was broken in previous version (#55)
+- Symbol listing was failing for subroutine without brackets (#61)
 
 ### Added
-* Improved indentation rules (#57)
-* Better syntax highlighting of module names (#51)
+
+- Improved indentation rules (#57)
+- Better syntax highlighting of module names (#51)
 
 ## [1.1.0] - 2018-04-16
 
 ### Fixed
 
-* Regression bug in the last release (#44)
+- Regression bug in the last release (#44)
 
 ### Added
 
-* Improvements on preprocessor directives highlighting
+- Improvements on preprocessor directives highlighting
 
 ## [1.0.1] - 2018-03-19
 
 ### Fixed
 
-* Syntax highlighting issues (#32, #34, #36, #37, #38, #39, #41 )
+- Syntax highlighting issues (#32, #34, #36, #37, #38, #39, #41 )
 
 ## [0.6.3] - 2018-01-27
 
 ### Added
 
-* Configuration option to set types of symbols shown
+- Configuration option to set types of symbols shown
 
 ### Fixed
 
-* Implementation of the symbol provider now returns a promise (Fixes #21)
-* Symbol provider now ignores case when searching for subroutines
+- Implementation of the symbol provider now returns a promise (Fixes #21)
+- Symbol provider now ignores case when searching for subroutines
 
 ## [0.6.2] - 2018-01-01
 
 ### Added
 
-* Autoindentation rules for code blocks (thx @graceyangfan for the feature request)
+- Autoindentation rules for code blocks (thx @graceyangfan for the feature request)
 
 ### Fixed
 
-* Fixed some highlighting issues by @pedro-ricardo
+- Fixed some highlighting issues by @pedro-ricardo
 
 ## [0.5.2] - 2017-07-14
 
 ### Fixed
 
-* A bug in the regex to parse output errors from gfortran
-* Now the spawn command uses the directory of the file `gfortran` is analyzing
+- A bug in the regex to parse output errors from gfortran
+- Now the spawn command uses the directory of the file `gfortran` is analyzing
 
 ## [0.5.1] - 2017-07-06
 
 ### Added
 
-* Add `Go -> Go to symbol in file` command support for functions
+- Add `Go -> Go to symbol in file` command support for functions
 
 ## [0.5.0] - 2017-07-06
 
 ### Added
 
-* Add code autocompletion for intrinsic and in document declared functions
+- Add code autocompletion for intrinsic and in document declared functions
 
 ## [0.4.6] - 2017-07-04
 
 ### Added
 
-* Add support for user configuration settings
+- Add support for user configuration settings
 
 ## [0.4.5] - 2017-07-04
 
 ### Fixed
 
-* Fix intrinsic functions docs not loading
+- Fix intrinsic functions docs not loading
 
 ## [0.4.4] - 2017-07-03
 
 ### Added
 
-* Add support for old fortran languague
+- Add support for old fortran languague
   ### Fixed
-* Fix bug #1
+- Fix bug #1
 
 ## [0.4.0] - 2017-05-29
 
 ### Added
 
-* Show docs for intrinsic functions on hover
+- Show docs for intrinsic functions on hover
   ### Changed
-* Updated icon for the extension
-* Fix bug on linter not working
+- Updated icon for the extension
+- Fix bug on linter not working
 
 ## [Unreleased]
 
-* Initial release
+- Initial release

doc/lang_server_type_autocompletion.gif

@@ -5,7 +5,7 @@
   "version": "1.3.1",
   "publisher": "krvajalm",
   "engines": {
-    "vscode": "^1.19.0"
+    "vscode": "^1.22.0"
   },
   "icon": "images/icon.png",
   "repository": {
@@ -129,14 +129,19 @@
           ],
           "description": "Specify what kind of symbols should be shown by the symbols' provider"
         },
+        "fortran.useLanguageServer": {
+          "type": "boolean",
+          "default": true,
+          "description": "Experimental: Not available in Windows. Use Fortran language server from hansec for Hover, Definition, Find All References, Signature Help, File Outline and Workspace Symbol features"
+       },
         "fortran.preferredCase": {
           "type": "string",
           "default": "lowercase",
           "enum": [
             "lowercase",
             "uppercase"
           ],
-          "description": "Scpecify the word case to use when suggesting autocomplete options (One of 'lowercase' or 'upercase')"
+          "description": "Specify the word case to use when suggesting autocomplete options (One of 'lowercase' or 'upercase')"
         }
       }
     }
@@ -163,7 +168,7 @@
     "remap-istanbul": "^0.8.4",
     "tslint": "^4.0.2",
     "typescript": "^2.0.3",
-    "vscode": "^1.0.3"
+    "vscode": "^1.1.21"
   },
   "husky": {
     "hooks": {
@@ -174,5 +179,8 @@
     "*.ts": [
       "prettier --write"
     ]
+  },
+  "dependencies": {
+    "vscode-languageclient": "^5.1.0"
   }
 }

package.json

@@ -5,14 +5,16 @@ import FortranLintingProvider from './features/linter-provider'
 import FortranHoverProvider from './features/hover-provider'
 import { FortranCompletionProvider } from './features/completion-provider'
 import { FortranDocumentSymbolProvider } from './features/document-symbol-provider'
-import { LANGUAGE_ID } from './lib/helper'
+import { FORTRAN_FREE_FORM_ID } from './lib/helper'
+import { FortranLangServer } from './lang-server'
+import { ConfigurationFeature } from 'vscode-languageclient/lib/configuration'
 
-const FORTRAN_FREE_FORM_ID = { language: LANGUAGE_ID, scheme: 'file' }
 
 export function activate(context: vscode.ExtensionContext) {
   let hoverProvider = new FortranHoverProvider()
   let completionProvider = new FortranCompletionProvider()
   let symbolProvider = new FortranDocumentSymbolProvider()
+
   const extensionConfig = vscode.workspace.getConfiguration('LANGUAGE_ID')
 
   if (extensionConfig.get('linterEnabled', true)) {
@@ -31,4 +33,16 @@ export function activate(context: vscode.ExtensionContext) {
     FORTRAN_FREE_FORM_ID,
     symbolProvider
   )
+  if (extensionConfig.get('useLanguageServer')) {
+    const langServer = new FortranLangServer(context, extensionConfig)
+    langServer.start()
+    langServer.onReady().then(() => {
+      const capabilities = langServer.getCapabilities()
+      if (!capabilities) {
+        return vscode.window.showErrorMessage(
+          'The language server is not able to serve any features at the moment.'
+        )
+      }
+    })
+  }
 }

src/extension.ts

@@ -3,6 +3,7 @@ import * as fs from 'fs'
 import * as vscode from 'vscode'
 import { isPositionInString, intrinsics, FORTRAN_KEYWORDS } from '../lib/helper'
 import { getDeclaredFunctions } from '../lib/functions'
+
 import { EXTENSION_ID } from '../lib/helper'
 
 class CaseCoverter {
@@ -153,5 +154,6 @@ export class FortranCompletionProvider
       )
     }
     return currentWord
+
   }
 }

src/features/completion-provider.ts

@@ -0,0 +1,45 @@
+import {
+  LanguageClient,
+  LanguageClientOptions,
+  Executable,
+} from 'vscode-languageclient'
+import { getBinPath, FORTRAN_FREE_FORM_ID } from './lib/helper'
+
+class FortranLangServer {
+  c: LanguageClient
+  constructor(context, config) {
+    let langServerFlags: string[] = config.get('languageServerFlags', [])
+
+    const serverOptions: Executable = {
+      command: getBinPath('fortran-langserver'),
+      args: [...langServerFlags],
+      options: {},
+    }
+
+    const clientOptions: LanguageClientOptions = {
+      documentSelector: [FORTRAN_FREE_FORM_ID],
+    }
+
+    this.c = new LanguageClient(
+      'fortran-langserver',
+      serverOptions,
+      clientOptions
+    )
+  }
+
+  start() {
+    this.c.start()
+  }
+
+  onReady() {
+    return this.c.onReady()
+  }
+
+  getCapabilities() {
+    const capabilities =
+      this.c.initializeResult && this.c.initializeResult.capabilities
+    return capabilities
+  }
+}
+
+export { FortranLangServer }