Hilbish/sink.go

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package main
import (
"bufio"
"fmt"
"io"
"os"
"hilbish/util"
rt "github.com/arnodel/golua/runtime"
)
var sinkMetaKey = rt.StringValue("hshsink")
// #type
// A sink is a structure that has input and/or output to/from
// a desination.
type sink struct{
writer *bufio.Writer
reader *bufio.Reader
file *os.File
ud *rt.UserData
autoFlush bool
}
func setupSinkType(rtm *rt.Runtime) {
sinkMeta := rt.NewTable()
sinkMethods := rt.NewTable()
sinkFuncs := map[string]util.LuaExport{
"flush": {luaSinkFlush, 1, false},
"read": {luaSinkRead, 1, false},
"autoFlush": {luaSinkAutoFlush, 2, false},
"write": {luaSinkWrite, 2, false},
"writeln": {luaSinkWriteln, 2, false},
}
util.SetExports(l, sinkMethods, sinkFuncs)
sinkIndex := func(t *rt.Thread, c *rt.GoCont) (rt.Cont, error) {
s, _ := sinkArg(c, 0)
arg := c.Arg(1)
val := sinkMethods.Get(arg)
if val != rt.NilValue {
return c.PushingNext1(t.Runtime, val), nil
}
keyStr, _ := arg.TryString()
switch keyStr {
case "pipe":
val = rt.BoolValue(false)
if s.file != nil {
fileInfo, _ := s.file.Stat();
val = rt.BoolValue(fileInfo.Mode() & os.ModeCharDevice == 0)
}
}
return c.PushingNext1(t.Runtime, val), nil
}
sinkMeta.Set(rt.StringValue("__index"), rt.FunctionValue(rt.NewGoFunction(sinkIndex, "__index", 2, false)))
l.SetRegistry(sinkMetaKey, rt.TableValue(sinkMeta))
}
// #member
// read() -> string
// --- @returns string
// Reads input from the sink.
func luaSinkRead(t *rt.Thread, c *rt.GoCont) (rt.Cont, error) {
if err := c.Check1Arg(); err != nil {
return nil, err
}
s, err := sinkArg(c, 0)
if err != nil {
return nil, err
}
str, _ := s.reader.ReadString('\n')
return c.PushingNext1(t.Runtime, rt.StringValue(str)), nil
}
// #member
// write(str)
// Writes data to a sink.
func luaSinkWrite(t *rt.Thread, c *rt.GoCont) (rt.Cont, error) {
if err := c.CheckNArgs(2); err != nil {
return nil, err
}
s, err := sinkArg(c, 0)
if err != nil {
return nil, err
}
data, err := c.StringArg(1)
if err != nil {
return nil, err
}
s.writer.Write([]byte(data))
if s.autoFlush {
s.writer.Flush()
}
return c.Next(), nil
}
// #member
// writeln(str)
// Writes data to a sink with a newline at the end.
func luaSinkWriteln(t *rt.Thread, c *rt.GoCont) (rt.Cont, error) {
if err := c.CheckNArgs(2); err != nil {
return nil, err
}
s, err := sinkArg(c, 0)
if err != nil {
return nil, err
}
data, err := c.StringArg(1)
if err != nil {
return nil, err
}
s.writer.Write([]byte(data + "\n"))
if s.autoFlush {
s.writer.Flush()
}
return c.Next(), nil
}
// #member
// flush()
// Flush writes all buffered input to the sink.
func luaSinkFlush(t *rt.Thread, c *rt.GoCont) (rt.Cont, error) {
if err := c.Check1Arg(); err != nil {
return nil, err
}
s, err := sinkArg(c, 0)
if err != nil {
return nil, err
}
s.writer.Flush()
return c.Next(), nil
}
// #member
// autoFlush(auto)
// Sets/toggles the option of automatically flushing output.
// A call with no argument will toggle the value.
// --- @param auto boolean|nil
func luaSinkAutoFlush(t *rt.Thread, c *rt.GoCont) (rt.Cont, error) {
s, err := sinkArg(c, 0)
if err != nil {
return nil, err
}
v := c.Arg(1)
if v.Type() != rt.BoolType && v.Type() != rt.NilType {
return nil, fmt.Errorf("#1 must be a boolean")
}
value := !s.autoFlush
if v.Type() == rt.BoolType {
value = v.AsBool()
}
s.autoFlush = value
return c.Next(), nil
}
func newSinkInput(r io.Reader) *sink {
s := &sink{
reader: bufio.NewReader(r),
}
s.ud = sinkUserData(s)
if f, ok := r.(*os.File); ok {
s.file = f
}
return s
}
func newSinkOutput(w io.Writer) *sink {
s := &sink{
writer: bufio.NewWriter(w),
autoFlush: true,
}
s.ud = sinkUserData(s)
return s
}
func sinkArg(c *rt.GoCont, arg int) (*sink, error) {
s, ok := valueToSink(c.Arg(arg))
if !ok {
return nil, fmt.Errorf("#%d must be a sink", arg + 1)
}
return s, nil
}
func valueToSink(val rt.Value) (*sink, bool) {
u, ok := val.TryUserData()
if !ok {
return nil, false
}
s, ok := u.Value().(*sink)
return s, ok
}
func sinkUserData(s *sink) *rt.UserData {
sinkMeta := l.Registry(sinkMetaKey)
return rt.NewUserData(s, sinkMeta.AsTable())
}