Created
August 8, 2024 13:09
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Option struct with default values
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| package main | |
| import ( | |
| "fmt" | |
| "time" | |
| ) | |
| type Config struct { | |
| Timeout time.Duration | |
| Name string | |
| } | |
| // this uses a pointer to allow it to be changed before use | |
| func (c *Config) init() { | |
| if c.Timeout == 0 { | |
| c.Timeout = 10 * time.Second | |
| } | |
| if c.Name == "" { | |
| c.Name = "default name" | |
| } | |
| } | |
| func (c Config) String() string { | |
| return fmt.Sprintf("using %q with %s timeout", c.Name, c.Timeout) | |
| } | |
| // this allows c to be just a stack value and not a pointer | |
| // the Config c will be gone right after using it | |
| func use(c Config) { | |
| c.init() | |
| fmt.Println(c) | |
| } | |
| func main() { | |
| cfg := Config{} | |
| use(cfg) | |
| // simple struct creation, not taking a pointer to it | |
| cfg2 := Config{Name: "some other name"} | |
| use(cfg2) | |
| cfg3 := Config{Name: "yet another name", Timeout: 3 * time.Second} | |
| use(cfg3) | |
| } |
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