{
  "scopeName": "source.reid",
  "patterns": [
    {
      "include": "#expression"
    }
  ],
  "repository": {
    "expression": {
      "patterns": [
        {
          "include": "#letter"
        },
        {
          "include": "#paren-expression"
        }
      ]
    },
    "letter": {
      "match": "a|b|c",
      "name": "keyword.letter"
    },
    "paren-expression": {
      "begin": "\\(",
      "end": "\\)",
      "beginCaptures": {
        "0": {
          "name": "punctuation.paren.open"
        }
      },
      "endCaptures": {
        "0": {
          "name": "punctuation.paren.close"
        }
      },
      "name": "expression.group",
      "patterns": [
        {
          "include": "#expression"
        }
      ]
    }
  }
}