Added: new import resolver system which allows for custom user import resolving.

ast/nodes.statements.cs

@@ -28,12 +28,12 @@
 
 		public override void Compile(sunContext context)
 		{
-			var file = context.Imports.ResolveImport(this);
-			if (file == null)
+			var result = context.Import(ImportFile.Value);
+			switch (result)
 			{
-				return; // the file has already been imported
+				case sunImportResult.Missing:
+				case sunImportResult.FailedToLoad: throw new sunMissingImportException(this);
 			}
-			context.Compile(file);
 		}
 	}
 

compiler.cs

@@ -8,30 +8,34 @@ namespace arookas
 {
 	public class sunCompiler
 	{
-		Stack<string> files;
-		string defaultRootDir, rootDir;
-		public string RootDir
+		public sunCompilerResults Compile(string name, Stream output)
 		{
-			get { return rootDir ?? defaultRootDir; }
-			set { rootDir = value; }
+			return Compile(name, output, sunImportResolver.Default);
 		}
-
-		public sunCompiler()
-		{
-			defaultRootDir = AppDomain.CurrentDomain.BaseDirectory;
-		}
-
-		public sunCompilerResults Compile(string file, Stream output)
+		public sunCompilerResults Compile(string name, Stream output, sunImportResolver resolver)
 		{
+			if (name == null)
+			{
+				throw new ArgumentNullException("name");
+			}
+			if (output == null)
+			{
+				throw new ArgumentNullException("output");
+			}
+			if (resolver == null)
+			{
+				throw new ArgumentNullException("resolver");
+			}
 			var results = new sunCompilerResults();
 			var timer = Stopwatch.StartNew();
 			try
 			{
-				files = new Stack<string>(5);
-				sunContext context = new sunContext(output, RootDir);
-				context.EnterFile += EnterFile;
-				context.ExitFile += ExitFile;
-				context.Compile(file);
+				sunContext context = new sunContext(output, resolver);
+				var result = context.Import(name);
+				if (result != sunImportResult.Loaded)
+				{
+					throw new sunImportException(name, result);
+				}
 				context.Text.Terminate(); // NOTETOSELF: don't do this in sunScript because imported files will add this as well
 				foreach (var function in context.SymbolTable.Functions)
 				{
@@ -51,17 +55,10 @@ namespace arookas
 			{
 				results.Error = ex;
 			}
-			catch (ParserLogException ex)
-			{
-				results.Error = new sunParserException(files.Peek(), ex[0]);
-			}
 			timer.Stop();
 			results.CompileTime = timer.Elapsed;
 			return results;
 		}
-
-		void EnterFile(object sender, sunFileArgs e) { files.Push(e.File); }
-		void ExitFile(object sender, sunFileArgs e) { files.Pop(); }
 	}
 
 	public class sunCompilerResults

context.cs

@@ -16,21 +16,31 @@ namespace arookas
 		public sunSymbolTable SymbolTable { get; private set; }
 		public sunScopeStack Scopes { get; private set; }
 		public sunLoopStack Loops { get; private set; }
-		public sunImportTable Imports { get; private set; }
-
-		public event EventHandler<sunFileArgs> EnterFile;
-		public event EventHandler<sunFileArgs> ExitFile;
+		public sunImportResolver ImportResolver { get; private set; }
 
 		// open/close
-		public sunContext(Stream stream, string rootDir)
+		public sunContext(Stream output)
+			: this(output, sunImportResolver.Default)
 		{
+
+		}
+		public sunContext(Stream output, sunImportResolver importResolver)
+		{
+			if (output == null)
+			{
+				throw new ArgumentNullException("output");
+			}
+			if (importResolver == null)
+			{
+				throw new ArgumentNullException("importResolver");
+			}
 			DataTable = new sunDataTable();
 			SymbolTable = new sunSymbolTable();
 			Scopes = new sunScopeStack();
 			Loops = new sunLoopStack();
-			Imports = new sunImportTable(rootDir);
+			ImportResolver = importResolver;
 
-			writer = new aBinaryWriter(stream, Endianness.Big, Encoding.GetEncoding(932));
+			writer = new aBinaryWriter(output, Endianness.Big, Encoding.GetEncoding(932));
 			Text = new sunWriter(writer);
 			writer.PushAnchor();
 
@@ -67,16 +77,24 @@ namespace arookas
 			return false;
 		}
 
-		// imports
-		public void Compile(string file)
+		// imports/compilation
+		public sunImportResult Import(string name)
 		{
-			Imports.PushDir(file);
-			OnEnterFile(new sunFileArgs(file));
-			var parser = new sunParser();
-			var tree = parser.Parse(file);
-			tree.Compile(this);
-			OnExitFile(new sunFileArgs(file));
-			Imports.PopDir();
+			if (name == null)
+			{
+				throw new ArgumentNullException("name");
+			}
+			sunScriptFile file;
+			var result = ImportResolver.ResolveImport(name, out file);
+			if (result == sunImportResult.Loaded)
+			{
+				ImportResolver.EnterFile(file);
+				var parser = new sunParser();
+				var tree = parser.Parse(file);
+				tree.Compile(this);
+				ImportResolver.ExitFile(file);
+			}
+			return result;
 		}
 
 		// builtins
@@ -218,32 +236,18 @@ namespace arookas
 			writer.WriteS32(SymbolTable.Count);
 			writer.WriteS32(Scopes.Root.VariableCount);
 		}
-
-		// events
-		void OnEnterFile(sunFileArgs e)
-		{
-			var func = EnterFile;
-			if (func != null)
-			{
-				func(this, e);
-			}
-		}
-		void OnExitFile(sunFileArgs e)
-		{
-			var func = ExitFile;
-			if (func != null)
-			{
-				func(this, e);
-			}
-		}
 	}
 
-	class sunFileArgs : EventArgs
+	public class sunFileArgs : EventArgs
 	{
-		public string File { get; private set; }
+		public sunScriptFile File { get; private set; }
 
-		public sunFileArgs(string file)
+		public sunFileArgs(sunScriptFile file)
 		{
+			if (file == null)
+			{
+				throw new ArgumentNullException("file");
+			}
 			File = file;
 		}
 	}

exceptions.cs

@@ -33,6 +33,27 @@ namespace arookas
 		}
 	}
 
+	public class sunImportException : sunCompilerException
+	{
+		public string Name { get; private set; }
+		public sunImportResult Result { get; private set; }
+		public override string Message { get { return String.Format("Name: {0}, Result: {1}", Name, Result); } }
+
+		public sunImportException(string name, sunImportResult result)
+		{
+			if (name == null)
+			{
+				throw new ArgumentNullException("name");
+			}
+			if (!result.IsDefined())
+			{
+				throw new ArgumentOutOfRangeException("name");
+			}
+			Name = name;
+			Result = result;
+		}
+	}
+
 	// wrapper around Grammatica exceptions
 	class sunParserException : sunScriptException
 	{

import resolver.cs

@@ -0,0 +1,114 @@
+using System;
+using System.Collections.Generic;
+using System.IO;
+using System.Linq;
+
+namespace arookas
+{
+	public abstract class sunImportResolver
+	{
+		static sunImportResolver defaultResolver = new sunDefaultImportResolver();
+		public static sunImportResolver Default { get { return defaultResolver; } }
+
+		public abstract void EnterFile(sunScriptFile file);
+		public abstract void ExitFile(sunScriptFile file);
+		public abstract sunImportResult ResolveImport(string name, out sunScriptFile file);
+
+		// default implementation
+		sealed class sunDefaultImportResolver : sunImportResolver
+		{
+			List<sunScriptFile> imports = new List<sunScriptFile>(10);
+			Stack<sunScriptFile> current = new Stack<sunScriptFile>(5);
+			string rootDirectory;
+
+			public sunDefaultImportResolver()
+			{
+				rootDirectory = AppDomain.CurrentDomain.BaseDirectory;
+			}
+
+			public override void EnterFile(sunScriptFile file) { current.Push(file); }
+			public override void ExitFile(sunScriptFile file) { current.Pop(); }
+			public override sunImportResult ResolveImport(string name, out sunScriptFile file)
+			{
+				file = null;
+				string fullPath;
+				if (Path.IsPathRooted(name))
+				{
+					// if the path is absolute, just use it directly
+					fullPath = name;
+					if (!File.Exists(fullPath))
+					{
+						return sunImportResult.Missing;
+					}
+				}
+				else
+				{
+					// check if the file exists relative to the current one;
+					// if it's not there, check the root directory
+					fullPath = Path.Combine(Path.GetDirectoryName(current.Peek().Name), name);
+					if (!File.Exists(fullPath))
+					{
+						fullPath = Path.Combine(rootDirectory, name);
+						if (!File.Exists(fullPath))
+						{
+							return sunImportResult.Missing;
+						}
+					}
+				}
+				// open the file
+				try
+				{
+					file = new sunScriptFile(name, File.OpenRead(fullPath));
+				}
+				catch
+				{
+					return sunImportResult.FailedToLoad;
+				}
+				// make sure the file has not been imported yet
+				if (imports.Any(i => i.Name == fullPath))
+				{
+					return sunImportResult.Skipped;
+				}
+				imports.Add(file);
+				return sunImportResult.Loaded;
+			}
+		}
+	}
+
+	public enum sunImportResult
+	{
+		Loaded,
+		Skipped,
+		Missing,
+		FailedToLoad,
+	}
+
+	public class sunScriptFile
+	{
+		public string Name { get; private set; }
+		public Stream Stream { get; private set; }
+
+		public sunScriptFile(string name, Stream stream)
+		{
+			if (name == null)
+			{
+				throw new ArgumentNullException("name");
+			}
+			if (stream == null)
+			{
+				throw new ArgumentNullException("stream");
+			}
+			if (!stream.CanRead)
+			{
+				throw new ArgumentException("Stream does not support reading.", "stream");
+			}
+			Name = name;
+			Stream = stream;
+		}
+
+		public TextReader GetReader()
+		{
+			return new StreamReader(Stream);
+		}
+	}
+}

import table.cs

@@ -1,58 +0,0 @@
-using System.Collections.Generic;
-using System.IO;
-
-namespace arookas
-{
-	class sunImportTable
-	{
-		List<string> imports = new List<string>(10);
-		Stack<string> curDir = new Stack<string>(5);
-		string RootDir { get; set; }
-
-		public sunImportTable(string rootDir)
-		{
-			RootDir = rootDir;
-		}
-
-		public void PushDir(string dir) { curDir.Push(Path.GetDirectoryName(dir)); }
-		public void PopDir() { curDir.Pop(); }
-
-		public string ResolveImport(sunImport import)
-		{
-			string fullPath;
-			string file = import.ImportFile.Value;
-			if (Path.IsPathRooted(file))
-			{
-				// if the path is absolute, just use it directly
-				fullPath = file;
-				if (!File.Exists(fullPath))
-				{
-					// could not find file
-					throw new sunMissingImportException(import);
-				}
-			}
-			else
-			{
-				// check if the file exists relative to the current one;
-				// if it's not there, check the root directory
-				fullPath = Path.Combine(curDir.Peek(), file);
-				if (!File.Exists(fullPath))
-				{
-					fullPath = Path.Combine(RootDir, file);
-					if (!File.Exists(fullPath))
-					{
-						// could not find file
-						throw new sunMissingImportException(import);
-					}
-				}
-			}
-			// make sure the file has not been imported yet
-			if (imports.Contains(fullPath))
-			{
-				return null;
-			}
-			imports.Add(fullPath);
-			return fullPath;
-		}
-	}
-}

parser.cs

@@ -1,5 +1,4 @@
 using PerCederberg.Grammatica.Runtime;
-using System.IO;
 using System.Linq;
 
 namespace arookas
@@ -16,13 +15,20 @@ namespace arookas
 			"true", "false",
 		};
 
-		public sunNode Parse(string file)
+		public sunNode Parse(sunScriptFile file)
 		{
-			using (var input = new StreamReader(file))
+			using (var input = file.GetReader())
 			{
-				var parser = new __sunParser(input);
-				var node = parser.Parse();
-				return CreateAst(file, node);
+				try
+				{
+					var parser = new __sunParser(input);
+					var node = parser.Parse();
+					return CreateAst(file.Name, node);
+				}
+				catch (ParserLogException ex)
+				{
+					throw new sunParserException(file.Name, ex[0]);
+				}
 			}
 		}