Konstantin8105/f4go

package intrinsic

import (
    "bytes"
    "fmt"
    "os"
    "reflect"
)

var units map[int]*os.File

func init() {
    units = map[int]*os.File{}
    units[6] = os.Stdout
}

func REWIND(unit int) {
    units[unit].Seek(0, 0)
}

func WRITE(unit int, format []byte, a ...interface{}) {
again:
    for i := 1; i < len(a); i++ {
        b1, ok1 := a[i].([]byte)
        for j := i + 1; j < len(a); j++ {
            b2, ok2 := a[j].([]byte)
            if ok1 && ok2 {
                b1 = append(b1, b2...)
                a = append(a[:i], append([]interface{}{b1}, a[i+1:]...)...)
                goto again
            }
        }
    }

    for i := range a {
        if str, ok := a[i].([]byte); ok {
            a[i] = string(str)
        }
    }

    fmt.Fprintf(units[unit], string(format), a...)
}

func OPEN(unit int, file []byte) {
    f, err := os.Open(string(file))
    if err != nil {
        panic(err)
    }
    units[unit] = f
}

func CLOSE(unit int) {
    delete(units, unit)
}

func READ(unit *int, format []byte, a ...interface{}) {

    format = bytes.TrimSpace(bytes.ToLower(format))

    // Change from %15.4f to %15f
    for i := 1; i < 20; i++ {
        for j := 1; j <= i; j++ {
            format = bytes.Replace(format,
                []byte(fmt.Sprintf("%c%d.%df", '%', i, j)),
                []byte(fmt.Sprintf("%cf", '%')),
                -1)
        }
    }

    ft := string(format)
    _, err := fmt.Fscanf(units[*unit], ft, a...)
    if err != nil {
        var types string
        for i := range a {
            types += fmt.Sprintf("|%s|", reflect.TypeOf(a[i]))
        }
        panic(fmt.Errorf("READ error for format `%s` : %v\nValues = %v",
            ft, err, types))
    }
}