message: Async load intellisense data files
diff: @@ -16,15 +16,34 @@ export class Completer implements vscode.CompletionItemProvider {
  constructor(extension: Extension) {
  this.extension = extension
  - const defaultCommands = JSON.parse(fs.readFileSync(`${this.extension.extensionRoot}/data/commands.json`).toString())
  - const defaultSymbols = JSON.parse(fs.readFileSync(`${this.extension.extensionRoot}/data/unimathsymbols.json`).toString())
  - const defaultEnvs = JSON.parse(fs.readFileSync(`${this.extension.extensionRoot}/data/environments.json`).toString())
  this.citation = new Citation(extension)
  this.command = new Command(extension)
  - this.command.initialize(defaultCommands, defaultSymbols, defaultEnvs)
  this.environment = new Environment(extension)
  - this.environment.initialize(defaultEnvs)
  this.reference = new Reference(extension)
  + fs.readFile(`${this.extension.extensionRoot}/data/environments.json`, (err1, defaultEnvs) => {
  + if (err1) {
  + this.extension.logger.addLogMessage(`Error reading default environments: ${err1.message}`)
  + return
  + }
  + this.extension.logger.addLogMessage(`Default environments loaded`)
  + fs.readFile(`${this.extension.extensionRoot}/data/commands.json`, (err2, defaultCommands) => {
  + if (err2) {
  + this.extension.logger.addLogMessage(`Error reading default commands: ${err2.message}`)
  + return
  + }
  + this.extension.logger.addLogMessage(`Default commands loaded`)
  + fs.readFile(`${this.extension.extensionRoot}/data/unimathsymbols.json`, (err3, defaultSymbols) => {
  + if (err2) {
  + this.extension.logger.addLogMessage(`Error reading default unimathsymbols: ${err3.message}`)
  + return
  + }
  + this.extension.logger.addLogMessage(`Default unimathsymbols loaded`)
  + const env = JSON.parse(defaultEnvs.toString())
  + this.command.initialize(JSON.parse(defaultCommands.toString()), JSON.parse(defaultSymbols.toString()), env)
  + this.environment.initialize(env)
  + })
  + })
  + })
  }
  provideCompletionItems(document: vscode.TextDocument, position: vscode.Position, _token: vscode.CancellationToken) : Promise<vscode.CompletionItem[]> {
  