有没有办法 "define" LeMP 中的宏接受 Type 文字输入

Question

我正在使用 Extended CSharp 中的 LeMP v2.8.1，并使用以下快捷方式定义和初始化 class 中的字段：

compileTimeAndRuntime 
{
    public partial class DI : IResolver
    {
        replace (T => ConcurrentDictionary<Type, Expression<Func<IResolver, object>>>) { public T Registrations = new T(); }
        replace (T => ConcurrentDictionary<Type, Func<IResolver, object>>) { public T DelegateCache = new T(); }
    }
}

除了 public 和 internal 修饰符外，替换模式非常相似。但是让我们暂时跳过它们。

我的问题是有没有办法将这个 replace 模式分解为一个 define 宏，这样我就不需要重复这个模式了。

我尝试了类似 define New($T, $F) { $T $F = new $T(); } 的方法，但是当它与这样的类型参数一起使用时它会吐出错误 New(ConcurrentDictionary<Type, Expression<Func<IResolver, object>>>, Registrations)。

Answer 1

对我有用：

compileTimeAndRuntime 
{
    define New($T, $F) { $T $F = new $T(); }
    
    public partial class DI : IResolver
    {
        public New(ConcurrentDictionary<Type, Expression<Func<IResolver, object>>>, Registrations);
        internal New(ConcurrentDictionary<Type, Func<IResolver, object>>, DelegateCache);
    }
}

// Generated from Untitled.ecs by LeMP 2.8.2.0.
public partial class DI : IResolver
{
    public ConcurrentDictionary<Type, Expression<Func<IResolver, object>>> Registrations = new ConcurrentDictionary<Type, Expression<Func<IResolver, object>>>();
    internal ConcurrentDictionary<Type, Func<IResolver, object>> DelegateCache = new ConcurrentDictionary<Type, Func<IResolver, object>>();
}

这是一个更有趣的版本：

// Matches variable declarations and replaces __var with the type name.
// Useful to avoid repeating the type twice when declaring fields in classes.
[Passive] // avoids warning on variable declarations that don't match
define #var(__var, $name = new $T($(..args)) { $(..initializers) }) {
    $T $name = new $T($args) { $initializers };
}

public partial class DI : IResolver
{
    public __var Registrations = new ConcurrentDictionary<Type, Expression<Func<IResolver, object>>>();
    internal __var DelegateCache = new ConcurrentDictionary<Type, Func<IResolver, object>>();
    private __var _array = new int[4] { 0, 10, 20, 30 };
}

// Generated from Untitled.ecs by LeMP 2.8.2.0.
public partial class DI : IResolver
{
    public ConcurrentDictionary<Type, Expression<Func<IResolver, object>>> Registrations = new ConcurrentDictionary<Type, Expression<Func<IResolver, object>>>();
    internal ConcurrentDictionary<Type, Func<IResolver, object>> DelegateCache = new ConcurrentDictionary<Type, Func<IResolver, object>>();
    private int[] _array = new int[4] { 
        0, 10, 20, 30
    };
}

这是基于我的知识 T x = y 有一个形式为 #var(T, x = y) 的 Loyc 树，但是 replace 宏允许你在不知道这些的情况下做同样的事情：

replace (
    { __var $name = new $Type($(..args)) { $(..initializers) }; } =>
    { $Type $name = new $Type($(..args)) { $(..initializers) }; });

抱歉花了这么长时间才回答。

有没有办法 "define" LeMP 中的宏接受 Type 文字输入

Is there way to "define" a macro in LeMP accepting the Type literal input

c#

code-generation

lemp

ec#