Function maybeUpdateTextMarker

src/codemirror.ts:35–68

(
  textMarker: TextMarker,
  ch: string,
  cursor: CodeMirror.Position,
  characterBeforeCursor: string
)

// Helps simulate a typing as completed effect. Will only work on the same line.
function maybeUpdateTextMarker(
  textMarker: TextMarker,
  ch: string,
  cursor: CodeMirror.Position,
  characterBeforeCursor: string
): boolean {
  if (cursor.line != textMarker.pos.line || cursor.ch != textMarker.pos.ch) {
    return false;
  }
  if (ch === 'Backspace') {
    if (characterBeforeCursor === '') {
      return false;
    }
    textMarker.spanElement.innerText = characterBeforeCursor + textMarker.spanElement.innerText;
    return true;
  }
  if (ch.length > 1 || ch === '\n') {
    return false;
  }
  const innerText = textMarker.spanElement.innerText;
  if (innerText.length === 1) {
    // TODO(prem): Why is this necessary?
    // This was necessary for the following case:
    // In GitHub, type "def fib(n)" and accept the completion.
    // Then go to a new line in the function and type "fib(5)".
    // On the ")", it should freeze.
    return false;
  }
  if (!innerText.startsWith(ch)) {
    return false;
  }
  textMarker.spanElement.innerText = textMarker.spanElement.innerText.substring(1);
  return true;
}

export class CodeMirrorManager {
  private client: LanguageServerClient;