Huge refactoring of language server

.github/workflows/build.yml

@@ -37,7 +37,7 @@ jobs:
       - name: Install Go
         uses: actions/setup-go@v2
         with:
-          go-version: '1.13'
+          go-version: '1.16.9'
 
       - name: Build and Test
         run: |

.gitignore

@@ -1,2 +1,3 @@
+.old
 build.sh
-arduino-language-server*
+arduino-language-server*

README.md

@@ -62,20 +62,28 @@ go test -v ./...
 ```
 ## Usage
 
-To run the Arduino Language Server you need:
+The language server it's not intended for direct usage by humans via the command line terminal.
+The purpose of this program is to provide C++/.ino language-related functionality to the IDEs so, in general, it's the IDE that talks to the language server via stdin/stdout using the slightly modified JSONRPC protocol defined in the LSP specification.
+
+The prerequisites to run the Arduino Language Server are:
 
 - [Arduino CLI](https://github.com/arduino/arduino-cli)
+- [clangd](we suggest the builds here https://github.com/clangd/clangd/releases)
 
-After building, call:
+To start the language server the IDE must provide the path to Arduino CLI and clangd with the following flags in addition to the target board FQBN:
 
 ```
-./arduino-language-server -cli-config <path-to-cli-config>
-```
-For example:
-```
-./arduino-language-server -cli-config $HOME/.arduino15/arduino-cli.yaml
+./arduino-language-server \
+ -clangd /usr/local/bin/clangd \
+ -cli /usr/local/bin/arduino-cli \
+ -cli-config $HOME/.arduino15/arduino-cli.yaml \
+ -fqbn arduino:mbed:nanorp2040connect
 ```
-Note: If you do not have an Arduino CLI config file, you can create one by running:
+
+The -fqbn flag represents the board you're actually working on (different boards may implement different features/API, if you change board you need to restart the language server with another fqbn).
+The support for the board must be installed with the `arduino-cli core install ...` command before starting the language server.
+
+If you do not have an Arduino CLI config file, you can create one by running:
 ```
 arduino-cli config init
 ```

go.mod

@@ -1,12 +1,14 @@
 module github.com/arduino/arduino-language-server
 
-go 1.12
+go 1.16
 
 require (
-	github.com/arduino/arduino-cli v0.0.0-20201215104024-6a177ebf56f2
-	github.com/arduino/go-paths-helper v1.5.0
-	github.com/fatih/color v1.7.0
+	github.com/arduino/arduino-cli v0.0.0-20211111113528-bf4a7844a79b
+	github.com/arduino/go-paths-helper v1.6.1
+	github.com/fatih/color v1.13.0
 	github.com/pkg/errors v0.9.1
-	github.com/sourcegraph/jsonrpc2 v0.0.0-20200429184054-15c2290dcb37
-	github.com/stretchr/testify v1.6.1
+	github.com/stretchr/testify v1.7.0
+	go.bug.st/json v1.15.6
+	go.bug.st/lsp v0.0.0-20211202163946-3ad3994172a0
+	google.golang.org/grpc v1.42.0
 )