ifStmtBranch method

IfStmt ifStmtBranch(Token token)

Implementation

IfStmt ifStmtBranch(Token token) {
  final lexeme = token.lexeme;
  bool isElseBranch = true;
  MathExpr? condition;

  if (token.type != TokenType.kElse) {
    isElseBranch = false;
    condition = math();
    consume(TokenType.kThen, 'Expected "then" keyword before body.');
  }

  const ifTailList = [TokenType.kEnd, TokenType.kElseIf, TokenType.kElse];
  final body = bodyStmt(terminals: ifTailList);

  // Sanity check. We expect to consume one of the items
  // in the terminal list.
  IfStmt? next;
  final p = peek();
  if (!ifTailList.contains(p.type)) {
    throw '${p.pos} Expected end of "$lexeme" block to match with "elseif", "else", or "end".';
  } else {
    final nextToken = advance();
    if (nextToken.type != TokenType.kEnd) {
      // Add elseif and else chains to this node.
      next = ifStmtBranch(nextToken);
    }
  }

  if (isElseBranch) {
    return IfStmt.terminalElse(token, body: body);
  }

  return IfStmt(token, expr: condition!, body: body, nextIfStmt: next);
}