Files
conf/config.go
2025-03-22 19:53:26 +03:00

110 lines
3.3 KiB
Go

// module conf
//
// import "code.uint32.ru/tiny/conf"
//
// Module conf implements a very simple config parser with two types of
// values: key value pairs and single word options. Each of these must be
// put on separate line in a file like this:
//
// key1 = value
// key2 = value1, value2, value3
// key3=v1,v2,v3
// option1
// option2
//
// Values can also be read from any io.Reader or io.ReadCloser. Note that
// values in key value pairs mey either be separated with spaces or not.
// Typical use case would look like this:
//
// config, err := conf.ParseFile("filename")
// if err != nil {
// // Means we failed to read from file
// // config variable is now nil and unusable
// }
// value, err := config.Find("mykey")
// if err != nil {
// // Means that key has not been found
// }
// // value now holds conf.Setting.
// n, err := value.Float64() // tries to parse float from Setting.Value field.
// //if err is nil then n holds float64.
//
// There is also a quicker Get() method which returns no errors
// ("i'm feeling lucky" way to lookup values). If it does not find
// requested key, the returned Setting has empty string in Value field.
//
// value2 := config.Get("otherkey")
// mybool, err := value2.Bool() // tries to interpret Setting.Value field as bool
// // mybool now holds boolean if "otherkey" was found and error returned
// // by Bool() method is nil.
//
// Even shorter syntax would be:
//
// listnumbers, err := config.Get("numbers").IntSlice()
// // Note that we'd still like to check for errors even if
// // we're sure the key exists to make sure all values are converted.
// // listnumbers holds slice of ints. If err is nil all of found values
// // have been converted successfully.
//
// To check whether single-word options were found use:
//
// if config.HasOption("wordoption") {
// // do something
// }
//
// See description of module's other methods which are
// quite self-explanatory.
package conf
// Config holds parsed keys and values. Settings and Options can be
// accessed with Config.Settings and Config.Options maps directly.
type Config struct {
// Settings store key value pairs ("key = value" in config file)
// all key value pairs found when parsing input are accumulated in this map.
Settings map[string]string
// Options map stores single word options ("option" in config file)
Options map[string]struct{}
}
// Find looks up a Setting and returns it. If returned error is not nil
// the requested key was not found and returned Setting has empty string in Value
// field.
func (c *Config) Find(key string) (s Setting, err error) {
v, ok := c.Settings[key]
if !ok {
err = ErrNotFound
}
s.Value = v
return
}
// Get returns a Setting. If key was not found the returned Setting Value
// will be empty string.
func (c *Config) Get(key string) (s Setting) {
s.Value = c.Settings[key]
return
}
// GetDefault looks up a Setting with requested key.
// If lookup fails it returns Setting with Value field set to def.
func (c *Config) GetDefault(key, def string) (s Setting) {
v, ok := c.Settings[key]
switch ok {
case true:
s.Value = v
default:
s.Value = def
}
return
}
// HasOption returns true if line:
//
// "key"
//
// was found in the parsed file
func (c *Config) HasOption(option string) (exists bool) {
_, exists = c.Options[option]
return
}