示例#1
0
func builtinQuoted2List(context *runtime.FunctionCallContext) (*runtime.Value, error) {
	if err := runtime.ValidateArguments(context, runtime.QuotedValue); err != nil {
		return nil, err
	}

	quoted := context.Args[0].Quoted

	if list, isList := quoted.(*parser.ListNode); isList {
		l := runtime.NewListValue()

		for _, listNode := range list.Nodes {
			l.List = append(l.List, runtime.NewQuotedValue(listNode))
		}

		return l, nil
	} else {
		return nil, runtime.NewRuntimeError(context.Pos, "expected a quoted list, not %s", quoted.Name())
	}
}
示例#2
0
func builtinDefmacro(context *runtime.MacroCallContext) (*runtime.Value, error) {
	name := context.Nodes[0].(*parser.IdentifierNode).Token.Data

	if name == "_" {
		return nil, runtime.NewRuntimeError(context.Nodes[0].Pos(), "disallowed macro name")
	}

	if context.Block.Scope.GetSymbol(name) != nil && context.Block.Scope.GetSymbol(name).Const {
		return nil, runtime.NewRuntimeError(context.Nodes[0].Pos(), "%s is a constant and cannot be modified", name)
	}

	argNodes := context.Nodes[1].(*parser.ListNode)
	var args []string
	callback := context.Nodes[2].(*parser.ListNode)

	if len(callback.Nodes) == 0 {
		return nil, runtime.NewRuntimeError(callback.Pos(), "empty macro body")
	}

	for _, argNode := range argNodes.Nodes {
		ident, ok := argNode.(*parser.IdentifierNode)

		if !ok {
			return nil, runtime.NewRuntimeError(argNode.Pos(), "expected an identifier")
		}

		args = append(args, ident.Token.Data)
	}

	macro := runtime.NewMacro(func(handlerContext *runtime.MacroCallContext) (*runtime.Value, error) {
		block := runtime.NewBlock([]parser.Node{callback}, runtime.NewScope(handlerContext.Block.Scope))

		for i, arg := range args {
			block.Scope.SetSymbolLocally(arg, runtime.NewSymbol(runtime.NewQuotedValue(handlerContext.Nodes[i])))
		}

		return block.Eval()
	}, false)

	context.Block.Scope.SetMacro(name, macro)

	return runtime.Nil, nil
}