vchimishuk / config Goto Github PK

NAME
    Package config implements parser for simple but powerful language used for
    configuration files.

AUTHORS
    Viacheslav Chimishuk <[email protected]>

COPYING
    This programm is released under the GNU General Public License version 3 or
    later, which is distributed in the COPYING file. You should have received
    a copy of the GNU General Public License along with this program.  If not,
    see <http://www.gnu.org/licenses/>.

DESCRIPTION
    Configuration file description language syntax is pretty simple and contains
    of sequence of properties and blocks.

    Property is a traditional key=value pair. Property definition exaples:
    string-property-name = "property-value"
    int-property-name = 100

    Block is a group of properties. Block definition exaples:
    block-name {
        prop-name = "value"
    }
    another-block-name {
        prop-name = "value"
        next-prop-name = "value"
    }

    Both, property and block can be optional, required or repeated. Client
    passes supported configuration file structure (number of properties,
    blocks, its type, etc) -- specification, to the parser. Parser checks
    input file according to the provided specification, so client can be sure
    that required properties are present, have expected type -- no futher
    validation needed on client-side.

    #-style comments are suppored too. Optional semicolon can be used at the
    end of property definition.

    Supported property types.
     * bool -- true or false boolean constant.
       bool-prop = true
       bool-prop = false
     * duration -- duration type. Same format as Go's time.ParseDuration() uses.
       See more: https://pkg.go.dev/time#ParseDuration
       duration-prop = 30s
       duration-prop = 1h
       duration-prop = 1h30m
     * int -- integer type
       int-prop = 100500
     * string -- double-quoted string type
       string-prop = "value"
       string-prop = "foo\"bar"

EXAMPLES
	spec := &Spec{
		Properties: []*PropertySpec{
			&PropertySpec{
				Type:    TypeString,
				Name:    "name",
				Repeat:  false,
				Require: true,
			},
			&PropertySpec{
				Type:    TypeInt,
				Name:    "size",
				Repeat:  false,
				Require: true,
			},
			&PropertySpec{
				Type:    TypeDuration,
				Name:    "duration",
				Repeat:  false,
				Require: false,
			},
		},
	}
	input := `
        name = "example"
        size = 1024
        duration = 1h
        `

	cfg, err := Parse(spec, input)
	if err != nil {
		fmt.Fprintf(os.Stderr, "configuration parsing failed: %s", err)
	}

	fmt.Printf("name = %s", cfg.StringOr("name", "default-name"))
	fmt.Printf("size = %d", cfg.Int("size"))
	fmt.Printf("duration = %d", cfg.Duration("duration"))