formspec.json

{
    "scopeName": "source.formspec",
    "injectionSelector": "string",
    "patterns": [
        {
            "match": "([a-z0-9_\\-]+?)(\\[[^'\"\\[\\]]*\\]?)",
            "captures": {
                "1": {
                    "name": "entity.name.function.lua"
                },
                "2": {
                    "patterns": [
                        {
                            "match": "[,;\\[\\]\\{\\}\\(\\)]",
                            "name": "punctuation.separator.lua"
                        },
                        {
                            "match": "((0x|#)[0-9A-F]+)|(\\d\\.\\d)|\\d",
                            "name": "constant.numeric.lua"
                        },
                        {
                            "match": "true|false",
                            "name": "constant.language.lua"
                        }
                    ]
                }
            }
        }
    ]
}