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//+build ignore
package custom_formatter_example
import "core:fmt"
import "core:io"
SomeType :: struct {
value: int,
}
My_Custom_Base_Type :: distinct u32
main :: proc() {
// Ensure the fmt._user_formatters map is initialized
fmt.set_user_formatters(new(map[typeid]fmt.User_Formatter))
// Register custom formatters for my favorite types
err := fmt.register_user_formatter(type_info_of(SomeType).id, SomeType_Formatter)
assert(err == .None)
err = fmt.register_user_formatter(type_info_of(My_Custom_Base_Type).id, My_Custom_Base_Formatter)
assert(err == .None)
// Use the custom formatters.
fmt.printfln("SomeType{{42}}: '%v'", SomeType{42})
fmt.printfln("My_Custom_Base_Type(0xdeadbeef): '%v'", My_Custom_Base_Type(0xdeadbeef))
}
SomeType_Formatter :: proc(fi: ^fmt.Info, arg: any, verb: rune) -> bool {
m := cast(^SomeType)arg.data
switch verb {
case 'v', 'd': // We handle `%v` and `%d`
fmt.fmt_int(fi, u64(m.value), true, 8 * size_of(SomeType), verb)
case:
return false
}
return true
}
My_Custom_Base_Formatter :: proc(fi: ^fmt.Info, arg: any, verb: rune) -> bool {
m := cast(^My_Custom_Base_Type)arg.data
switch verb {
case 'v', 'b':
value := u64(m^)
for value > 0 {
if value & 1 == 1 {
io.write_string(fi.writer, "Hellope!", &fi.n)
} else {
io.write_string(fi.writer, "Hellope?", &fi.n)
}
value >>= 1
}
case:
return false
}
return true
}
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