elvish/eval/builtin_fn_misc.go
2019-04-18 22:58:06 +01:00

148 lines
2.7 KiB
Go

package eval
// Misc builtin functions.
import (
"fmt"
"io/ioutil"
"math/rand"
"net"
"path/filepath"
"time"
"unicode/utf8"
"github.com/elves/elvish/eval/vals"
"github.com/elves/elvish/parse"
)
// Builtins that have not been put into their own groups go here.
func init() {
addBuiltinFns(map[string]interface{}{
"nop": nop,
"kind-of": kindOf,
"constantly": constantly,
"resolve": resolve,
"-source": source,
// Time
"esleep": sleep,
"-time": _time,
"-ifaddrs": _ifaddrs,
})
// For rand and randint.
rand.Seed(time.Now().UTC().UnixNano())
}
func nop(opts RawOptions, args ...interface{}) {
// Do nothing
}
func kindOf(fm *Frame, args ...interface{}) {
out := fm.ports[1].Chan
for _, a := range args {
out <- vals.Kind(a)
}
}
func constantly(args ...interface{}) Callable {
// XXX Repr of this fn is not right
return NewGoFn(
"created by constantly",
func(fm *Frame) {
out := fm.ports[1].Chan
for _, v := range args {
out <- v
}
},
)
}
func resolve(fm *Frame, head string) string {
// Emulate static resolution of a command head. This needs to be kept in
// sync with (*compiler).form.
_, special := builtinSpecials[head]
if special {
return "special"
}
explode, ns, name := ParseVariableRef(head)
if !explode && fm.ResolveVar(ns, name+FnSuffix) != nil {
return "$" + head + FnSuffix
}
return "(external " + parse.Quote(head) + ")"
}
func source(fm *Frame, fname string) error {
path, err := filepath.Abs(fname)
if err != nil {
return err
}
code, err := readFileUTF8(path)
if err != nil {
return err
}
n, err := parse.AsChunk(fname, code)
if err != nil {
return err
}
scriptGlobal := fm.local.static()
for name := range fm.up.static() {
scriptGlobal.set(name)
}
op, err := compile(fm.Builtin.static(),
scriptGlobal, n, NewScriptSource(fname, path, code))
if err != nil {
return err
}
return fm.Eval(op)
}
func readFileUTF8(fname string) (string, error) {
bytes, err := ioutil.ReadFile(fname)
if err != nil {
return "", err
}
if !utf8.Valid(bytes) {
return "", fmt.Errorf("%s: source is not valid UTF-8", fname)
}
return string(bytes), nil
}
func sleep(fm *Frame, t float64) error {
d := time.Duration(float64(time.Second) * t)
select {
case <-fm.Interrupts():
return ErrInterrupted
case <-time.After(d):
return nil
}
}
func _time(fm *Frame, f Callable) error {
t0 := time.Now()
err := f.Call(fm, NoArgs, NoOpts)
t1 := time.Now()
dt := t1.Sub(t0)
fmt.Fprintln(fm.ports[1].File, dt)
return err
}
func _ifaddrs(fm *Frame) error {
addrs, err := net.InterfaceAddrs()
if err != nil {
return err
}
out := fm.ports[1].Chan
for _, addr := range addrs {
out <- addr.String()
}
return nil
}