DSL EXPRESSION:
$z = ENV["HOME"][1]


AST:
"block" [tt:block] [nt:StatementBlock]
    "=" [tt:equals] [nt:Assignment]
        "$z" [tt:field_name] [nt:DirectFieldValue]
        "[]" [tt:[]] [nt:ArrayOrMapIndexAccess]
            "ENV" [tt:kw_env] [nt:EnvironmentVariable]
                ""HOME"" [tt:string_literal] [nt:string_literal]
            "1" [tt:int_literal] [nt:int_literal]

