108 lines
1.9 KiB
Go
108 lines
1.9 KiB
Go
package cmdlang
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import (
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"context"
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"errors"
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"fmt"
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"io"
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"os"
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"strings"
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)
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type Inst struct {
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out io.Writer
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rootEC *evalCtx
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}
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type InstOption func(*Inst)
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func WithOut(out io.Writer) InstOption {
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return func(i *Inst) {
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i.out = out
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}
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}
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func New(opts ...InstOption) *Inst {
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rootEC := evalCtx{}
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rootEC.addCmd("echo", invokableFunc(echoBuiltin))
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rootEC.addCmd("set", invokableFunc(setBuiltin))
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rootEC.addCmd("toUpper", invokableStreamFunc(toUpperBuiltin))
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rootEC.addCmd("cat", invokableFunc(catBuiltin))
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rootEC.addMacro("if", macroFunc(ifBuiltin))
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//rootEC.addCmd("testTimebomb", invokableStreamFunc(errorTestBuiltin))
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rootEC.setVar("hello", strObject("world"))
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inst := &Inst{
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out: os.Stdout,
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rootEC: &rootEC,
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}
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for _, opt := range opts {
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opt(inst)
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}
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return inst
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}
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func (inst *Inst) Out() io.Writer {
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if inst.out == nil {
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return os.Stdout
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}
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return inst.out
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}
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func (inst *Inst) Eval(ctx context.Context, expr string) (any, error) {
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res, err := inst.eval(ctx, expr)
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if err != nil {
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return nil, err
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}
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goRes, ok := toGoValue(res)
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if !ok {
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return nil, errors.New("result not convertable to go")
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}
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return goRes, nil
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}
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func (inst *Inst) eval(ctx context.Context, expr string) (object, error) {
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ast, err := parse(strings.NewReader(expr))
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if err != nil {
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return nil, err
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}
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eval := evaluator{inst: inst}
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return eval.evalScript(ctx, inst.rootEC, ast)
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}
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func (inst *Inst) EvalAndDisplay(ctx context.Context, expr string) error {
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res, err := inst.eval(ctx, expr)
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if err != nil {
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return err
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}
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return inst.display(ctx, res)
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}
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func (inst *Inst) display(ctx context.Context, res object) (err error) {
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switch v := res.(type) {
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case nil:
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if _, err = fmt.Fprintln(inst.out, "(nil)"); err != nil {
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return err
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}
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case stream:
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return forEach(v, func(o object, _ int) error { return inst.display(ctx, o) })
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default:
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if _, err = fmt.Fprintln(inst.out, v.String()); err != nil {
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return err
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}
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}
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return nil
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}
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