symfony/src/Symfony/Component/DependencyInjection/Tests/Fixtures/yaml/services26.yml

parameters:
    project_dir: '/foo/bar'
    env(FOO): foo
    env(DB): 'sqlite://%%project_dir%%/var/data.db'
    bar: '%env(FOO)%'
    baz: '%env(int:Baz)%'
    json: '%env(json:file:json_file)%'
    db_dsn: '%env(resolve:DB)%'

services:
    test:
        class: '%env(FOO)%'
        arguments:
            - '%env(Bar)%'
            - 'foo%bar%baz'
            - '%baz%'