113 lines
2.0 KiB
Go
113 lines
2.0 KiB
Go
package cmdlang
|
|
|
|
import (
|
|
"bufio"
|
|
"context"
|
|
"errors"
|
|
"fmt"
|
|
"io"
|
|
"os"
|
|
"strings"
|
|
)
|
|
|
|
func echoBuiltin(ctx context.Context, args invocationArgs) (object, error) {
|
|
if len(args.args) == 0 {
|
|
return asStream(""), nil
|
|
}
|
|
|
|
var line strings.Builder
|
|
for _, arg := range args.args {
|
|
if s, ok := arg.(fmt.Stringer); ok {
|
|
line.WriteString(s.String())
|
|
}
|
|
}
|
|
|
|
return asStream(line.String()), nil
|
|
}
|
|
|
|
func toUpperBuiltin(ctx context.Context, args invocationArgs) (object, error) {
|
|
// Handle args
|
|
return mapFilterStream{
|
|
in: args.inStream,
|
|
mapFn: func(x object) (object, bool) {
|
|
s, ok := x.(string)
|
|
if !ok {
|
|
return nil, false
|
|
}
|
|
return strings.ToUpper(s), true
|
|
},
|
|
}, nil
|
|
}
|
|
|
|
func catBuiltin(ctx context.Context, args invocationArgs) (object, error) {
|
|
if err := args.expectArgn(1); err != nil {
|
|
return nil, err
|
|
}
|
|
|
|
filename, err := args.stringArg(0)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
|
|
return &fileLinesStream{filename: filename}, nil
|
|
}
|
|
|
|
type fileLinesStream struct {
|
|
filename string
|
|
f *os.File
|
|
scnr *bufio.Scanner
|
|
}
|
|
|
|
func (f *fileLinesStream) next() (object, error) {
|
|
var err error
|
|
|
|
// We open the file on the first pull. That way, an unconsumed stream won't result in a FD leak
|
|
if f.f == nil {
|
|
f.f, err = os.Open(f.filename)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
f.scnr = bufio.NewScanner(f.f)
|
|
}
|
|
|
|
if f.scnr.Scan() {
|
|
return f.scnr.Text(), nil
|
|
}
|
|
if f.scnr.Err() == nil {
|
|
return nil, io.EOF
|
|
}
|
|
return nil, f.scnr.Err()
|
|
}
|
|
|
|
func (f *fileLinesStream) close() error {
|
|
if f.f != nil {
|
|
return f.f.Close()
|
|
}
|
|
return nil
|
|
}
|
|
|
|
func errorTestBuiltin(ctx context.Context, args invocationArgs) (object, error) {
|
|
return &timeBombStream{args.inStream, 2}, nil
|
|
}
|
|
|
|
type timeBombStream struct {
|
|
in stream
|
|
x int
|
|
}
|
|
|
|
func (ms *timeBombStream) next() (object, error) {
|
|
if ms.x > 0 {
|
|
ms.x--
|
|
return ms.in.next()
|
|
}
|
|
return nil, errors.New("BOOM")
|
|
}
|
|
|
|
func (ms *timeBombStream) close() error {
|
|
closable, ok := ms.in.(closableStream)
|
|
if ok {
|
|
return closable.close()
|
|
}
|
|
return nil
|
|
}
|