NTERA/NTERA.Engine/Runtime/Base/Keywords.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Reflection;
using NTERA.Engine.Compiler;

namespace NTERA.Engine.Runtime.Base
{
	public static class Keywords
	{
		private class KeywordAttribute : Attribute
		{
			public string Name { get; }

			public bool ImplicitString { get; }
			public bool ImplicitFormatted { get; }

			public KeywordAttribute(string name, bool implicitString = false, bool implicitFormatted = false)
			{
				if (implicitFormatted && !implicitString)
					throw new ArgumentException("Keyword cannot support formatting if it does not use implicit strings");

				Name = name;

				ImplicitString = implicitString;
				ImplicitFormatted = implicitFormatted;
			}
		}

		public static Dictionary<string, Action<EraRuntime, StackFrame, ExecutionNode>> StaticKeywords { get; } = _getKeywords();

		private static Dictionary<string, Action<EraRuntime, StackFrame, ExecutionNode>> _getKeywords()
		{
			var output = new Dictionary<string, Action<EraRuntime, StackFrame, ExecutionNode>>();

			foreach (MethodInfo method in typeof(Keywords).GetMethods(BindingFlags.Public | BindingFlags.Static))
			{
				var keyword = method.GetCustomAttribute<KeywordAttribute>();

				if (keyword != null)
					output[keyword.Name] = (runtime, set, node) => { method.Invoke(null, new object[] { runtime, set, node }); };
			}

			return output;
		}

		[Keyword("DRAWLINE")]
		public static void DrawLine(EraRuntime runtime, StackFrame set, ExecutionNode node)
		{
			runtime.Console.PrintBar();
		}

		[Keyword("DRAWLINEFORM", true, true)]
		public static void DrawLineForm(EraRuntime runtime, StackFrame set, ExecutionNode node)
		{
			var value = runtime.ComputeExpression(set, node.SubNodes.Single());

			runtime.Console.printCustomBar(value.ToString().Trim());
		}

		[Keyword("PRINTFORML", true, true)]
		public static void PrintLine(EraRuntime runtime, StackFrame set, ExecutionNode node)
		{
			var value = runtime.ComputeExpression(set, node.SubNodes.Single());

			runtime.Console.PrintSingleLine(value.ToString().Trim());
		}
	}
}