package cmdlang import ( "context" "errors" "fmt" "strconv" ) type object interface { String() string Truthy() bool } type listObject []object func (lo *listObject) Append(o object) { *lo = append(*lo, o) } func (s listObject) String() string { return fmt.Sprintf("%v", []object(s)) } func (s listObject) Truthy() bool { return len(s) > 0 } type hashObject map[string]object func (s hashObject) String() string { return fmt.Sprintf("%v", map[string]object(s)) } func (s hashObject) Truthy() bool { return len(s) > 0 } type strObject string func (s strObject) String() string { return string(s) } func (s strObject) Truthy() bool { return string(s) != "" } func toGoValue(obj object) (interface{}, bool) { switch v := obj.(type) { case nil: return nil, true case strObject: return string(v), true case listObject: xs := make([]interface{}, 0, len(v)) for _, va := range v { x, ok := toGoValue(va) if !ok { continue } xs = append(xs, x) } return xs, true case hashObject: xs := make(map[string]interface{}) for k, va := range v { x, ok := toGoValue(va) if !ok { continue } xs[k] = x } return xs, true case proxyObject: return v.p, true } return nil, false } func fromGoValue(v any) (object, error) { switch t := v.(type) { case nil: return nil, nil case string: return strObject(t), nil default: return proxyObject{t}, nil } } type macroArgs struct { eval evaluator ec *evalCtx currentStream stream ast *astCmd argShift int } func (ma macroArgs) nargs() int { return len(ma.ast.Args[ma.argShift:]) } func (ma *macroArgs) shift(n int) { ma.argShift += n } func (ma macroArgs) identIs(ctx context.Context, n int, expectedIdent string) bool { if n >= len(ma.ast.Args[ma.argShift:]) { return false } lit := ma.ast.Args[ma.argShift+n].Ident if lit == nil { return false } return *lit == expectedIdent } func (ma *macroArgs) shiftIdent(ctx context.Context) (string, bool) { if ma.argShift >= len(ma.ast.Args) { return "", false } lit := ma.ast.Args[ma.argShift].Ident if lit != nil { ma.argShift += 1 return *lit, true } return "", false } func (ma macroArgs) evalArg(ctx context.Context, n int) (object, error) { if n >= len(ma.ast.Args[ma.argShift:]) { return nil, errors.New("not enough arguments") // FIX } return ma.eval.evalArg(ctx, ma.ec, ma.ast.Args[ma.argShift+n]) } func (ma macroArgs) evalBlock(ctx context.Context, n int, args []object, pushScope bool) (object, error) { obj, err := ma.evalArg(ctx, n) if err != nil { return nil, err } block, ok := obj.(blockObject) if !ok { return nil, errors.New("not a block object") } ec := ma.ec if pushScope { ec = ec.fork() } for i, n := range block.block.Names { if i < len(args) { ec.setVar(n, args[i]) } } return ma.eval.evalBlock(ctx, ec, block.block) } type invocationArgs struct { inst *Inst ec *evalCtx currentStream stream args []object kwargs map[string]*listObject } // streamableSource takes a stream. If the stream is set, the inStream and invocation arguments are consumed as is. // If not, then the first argument is consumed and returned as a stream. func (ia invocationArgs) streamableSource(inStream stream) (invocationArgs, stream, error) { if inStream != nil { return ia, inStream, nil } if len(ia.args) < 1 { return ia, nil, errors.New("expected at least 1 argument") } switch v := ia.args[0].(type) { case listObject: return ia.shift(1), &listIterStream{list: v}, nil } return ia, nil, errors.New("expected arg 0 to be streamable") } func (ia invocationArgs) expectArgn(x int) error { if len(ia.args) < x { return errors.New("expected at least " + strconv.Itoa(x) + " args") } return nil } func (ia invocationArgs) stringArg(i int) (string, error) { if len(ia.args) < i { return "", errors.New("expected at least " + strconv.Itoa(i) + " args") } s, ok := ia.args[i].(fmt.Stringer) if !ok { return "", errors.New("expected a string arg") } return s.String(), nil } func (ia invocationArgs) fork(currentStr stream, args []object) invocationArgs { return invocationArgs{ inst: ia.inst, ec: ia.ec, currentStream: currentStr, args: args, kwargs: make(map[string]*listObject), } } func (ia invocationArgs) shift(i int) invocationArgs { return invocationArgs{ inst: ia.inst, ec: ia.ec, currentStream: ia.currentStream, args: ia.args[i:], kwargs: ia.kwargs, } } // invokable is an object that can be executed as a command type invokable interface { invoke(ctx context.Context, args invocationArgs) (object, error) } type macroable interface { invokeMacro(ctx context.Context, args macroArgs) (object, error) } type streamInvokable interface { invokable invokeWithStream(context.Context, stream, invocationArgs) (object, error) } type invokableFunc func(ctx context.Context, args invocationArgs) (object, error) func (i invokableFunc) invoke(ctx context.Context, args invocationArgs) (object, error) { return i(ctx, args) } type invokableStreamFunc func(ctx context.Context, inStream stream, args invocationArgs) (object, error) func (i invokableStreamFunc) invoke(ctx context.Context, args invocationArgs) (object, error) { return i(ctx, nil, args) } func (i invokableStreamFunc) invokeWithStream(ctx context.Context, inStream stream, args invocationArgs) (object, error) { return i(ctx, inStream, args) } type blockObject struct { block *astBlock } func (bo blockObject) String() string { return "block" } func (bo blockObject) Truthy() bool { return len(bo.block.Statements) > 0 } type macroFunc func(ctx context.Context, args macroArgs) (object, error) func (i macroFunc) invokeMacro(ctx context.Context, args macroArgs) (object, error) { return i(ctx, args) } func isTruthy(obj object) bool { if obj == nil { return false } return obj.Truthy() } type proxyObject struct { p interface{} } func (p proxyObject) String() string { return fmt.Sprintf("proxyObject{%T}", p.p) } func (p proxyObject) Truthy() bool { //TODO implement me panic("implement me") }