Added exception handling. Fixed some problems with casting. Added STR…

… global function for converting a Lua string to see.base.String.

README.md

@@ -1,4 +1,4 @@
 see
 ===
 
-An API, library, and runtime environment all in on for ComputerCraft.
+An object oriented environment for ComputerCraft.

see/apis/see

@@ -10,6 +10,7 @@ StandardGlobals = { }
 
 --[[
 	Creates a new anonymous class.
+	@param SeeVM:vm The VM to run this function for.
 	@param function:def The function used to define this class.
 	@param table:super The super class for this class. If nil, this class extends see.lang.Object.
 ]]
@@ -19,6 +20,7 @@ end
 
 --[[
 	Gets the type of a given value.
+	@param SeeVM:vm The VM to run this function for.
 	@param value:any The value to get the type of.
 	@return string|table The type identifier if value if primitive, or the class of value if value is an object.
 ]]
@@ -31,6 +33,7 @@ end
 
 --[[
 	Casts a value to a particular class.
+	@param SeeVM:vm The VM to run this function for.
 	@param any:value The value to cast.
 	@param string|table:castType The type to cast to.
 ]]
@@ -45,26 +48,59 @@ function StandardGlobals.cast(vm, value, castType)
 			if type(value) ~= "table" or not value.__type then
 				return tostring(value)
 			elseif value.__type then
-				return value.__type.__cast(value)
+				return value:toString():lstr()
 			end
 		else
 			-- TODO
 		end
 	else
+		return castType.__cast(value)
 		-- Casting to Object.
 		-- TODO
 	end
 end
 
 --[[
 	Casts an object to a different class by setting its metatable.
+	@param SeeVM:vm The VM to run this function for.
 	@param see.base.Object value
 ]]
-function StandardGlobals.reinterpret_cast(value, castType)
+function StandardGlobals.reinterpret_cast(vm, value, castType)
 	if type(value) ~= "table" or not value.__type then error("Cannot use reinterpret_cast to cast a primitive type.") end
 	setmetatable(value, castType.__meta)
 end
 
+--[[
+	Throws an exception.
+	@param SeeVM:vm The VM to run this function for.
+	@param see.base.Exception The exception to throw.
+]]
+function StandardGlobals.throw(vm, exception)
+	vm.lastException = exception
+	error()
+end
+
+--[[
+	Tries to execute code until an error occurs. Calls catch code if an error occurs.
+	@param SeeVM:vm The VM to run this function for.
+	@param function:tryFunc Function to run and catch errors from.
+	@param function:catchFunc(see.base.Exception) Function to run on error.
+]]
+function StandardGlobals.try(vm, tryFunc, catchFunc)
+	local suc, err = pcall(tryFunc)
+	if suc then return end
+	if err then vm.lastException = vm:loadClassFromAny("see.rt.RuntimeException").new(err) end
+	catchFunc(vm.lastException)
+end
+
+--[[
+	Converts a Lua string to a see.base.String.
+	@param string:str
+]]
+function StandardGlobals.STR(vm, str)
+	return vm.base.String.new(str)
+end
+
 SeeVM = { }
 SeeVM.__index = SeeVM
 
@@ -73,6 +109,8 @@ SeeVM.__index = SeeVM
 ]]
 function SeeVM.new(natives)
 	local self = { }
+	setmetatable(self, SeeVM)
+
 	self.standardGlobals = { }
 	for k, v in pairs(StandardGlobals) do
 		self.standardGlobals[k] = function(...) return StandardGlobals[k](self, ...) end
@@ -82,8 +120,8 @@ function SeeVM.new(natives)
 	self.classes = { }
 	self.natives = natives
 	self.classPaths = { }
-	setmetatable(self, SeeVM)
 	self.base.Object = self:loadClassFromAny("see.base.Object")
+	self.base.Exception = self:loadClassFromAny("see.base.Exception")
 	self.base.System = self:loadClassFromAny("see.base.System")
 	self.base.Array  = self:loadClassFromAny("see.base.Array")
 	self.base.String = self:loadClassFromAny("see.base.String")
@@ -101,7 +139,6 @@ function getByPackage(t, package, del)
 	if not del then del = "%." end
 	local f = package:find(del)
 	if f then
-		print(package .. " contains " .. del)
 		return getByPackage(t[package:sub(1, f - 1)], package:sub(f + 1), del)
 	else
 		return t[package]
@@ -265,6 +302,7 @@ function SeeVM:loadClass(def, annotations, name)
 	class.__name = name
 
 	function class.new(...)
+		if not class.init then error("Could not instantiate class " .. name .. ". No init method.") end
 		local self = { }
 		self.__type = class
 		setmetatable(self, class.__meta)
@@ -274,7 +312,7 @@ function SeeVM:loadClass(def, annotations, name)
 
 	-- Extend Object by default.
 	if abool then
-		setmetatable(class, self.base.Object.__meta)
+		setmetatable(class, self.base.Object)
 	end
 
 	-- Import base classes.

see/lib/see/base/Exception.lua

@@ -0,0 +1,10 @@
+--@import see.base.String
+
+--[[
+	Constructs a new Exception.
+	@param string:message The error message.
+]]
+function Exception:init(message)
+	message = cast(message, String)
+	self.message = message
+end

see/lib/see/base/Object.lua

@@ -2,6 +2,7 @@
 --@native pairs
 --@native setmetatable
 --@native getmetatable
+--@import see.base.String
 
 --[[
 	The super class for all classes loaded in the See Runtime.
@@ -29,5 +30,10 @@ function Object:getClass()
 end
 
 function Object:toString()
-	return tostring(self) .. ":" .. self:getClass().__name
+	return String.new(tostring(self) .. ":" .. self:getClass().__name)
+end
+
+-- TODO: Fix me.
+function Object.__concat(l, r)
+	return cast(l, String):concat(cast(r, String))
 end

see/lib/see/base/String.lua

@@ -1,4 +1,7 @@
 --@native string
+--@native tostring
+--@import see.base.Array
+--@import see.base.System
 
 --[[
 	A mutable, Array-backed string. Faster and more memory efficient than native strings.
@@ -17,14 +20,20 @@ function String.__cast(value)
 end
 
 --[[
-	Constructs a new String which copies the given luaString.
-	@param string:luaString The string to be copied.
+	Constructs a new String which copies the given string.
+	@param string:str The string to be copied.
 ]]
-function String:init(luaString)
+function String:init(str)
 	self.charArray = Array.new()
-	if not luaString then return end
-	for i = 1, #luaString do
-		self.charArray[i] = luaString:sub(i, i):byte()
+	if not str then return end
+	if typeof(str) == "string" then
+		for i = 1, #str do
+			self.charArray[i] = str:sub(i, i):byte()
+		end
+	elseif typeof(str) == String then
+		for i = 1, str:length() do
+			self.charArray[i] = str.charArray[i]
+		end
 	end
 end
 
@@ -48,12 +57,31 @@ function String:length()
 	return self.charArray.length
 end
 
+function String:concat(str)
+	local ret = String.new(self)
+	local len = self:length()
+	for i = 1, str:length() do
+		ret.charArray[i + len] = str.charArray[i]
+	end
+	return ret
+end
+
+function String.__meta.__concat(a, b)
+	return a:concat(b)
+end
+
 --[[
 	Gets a substring of this String.
 	@param number:a Start index.
 	@param number:b End index. Defaults to the length of this String.
 	@return see.base.String A substring of this String.
 ]]
 function String:sub(a, b)
-
+	if not b then b = self:length() end
+
+	-- TODO
+end
+
+function String:toString()
+	return self
 end

see/lib/see/base/System.lua

@@ -1,5 +1,6 @@
 --@native print
 --@native read
+--@native unpack
 
 --[[
 	A utility class for useful system operations.
@@ -20,11 +21,12 @@ end
 function System.print(...)
 	local args = {...}
 	for i = 1, #args do
-		args[i] = cast(str, "string")
+		args[i] = cast(args[i], "string")
 	end
-	print(...)
+	print(unpack(args))
 end
 
+-- TODO: Prevent from trashing global namespace.
 function System.loadNativeAPI(path)
 	os.loadAPI()
 end

see/lib/see/rt/RuntimeException.lua

@@ -0,0 +1,10 @@
+--@extends see.base.Exception
+
+--[[
+	Constructs a new RuntimeException.
+	@param string:message The error message.
+]]
+function RuntimeException:init(message)
+	message = cast(message, String)
+	Exception.init(self, message)
+end

see/lib/see/util/Math.lua

@@ -0,0 +1,11 @@
+function Math.sin(x)
+	-- body
+end
+
+function Math.cos(x)
+	-- body
+end
+
+function Math.tan( ... )
+	-- body
+end

see/programs/see

@@ -13,24 +13,6 @@ local _, err = pcall(function(...)
 
 	os.loadAPI("/see/apis/see")
 
-	local function loadClassesFromPath(path)
-		for _, name in pairs(fs.list(path)) do
-			local subPath = fs.combine(path, name)
-			if fs.isDir(subPath) then
-				loadClassesFromPath(subPath)
-			else
-				if name:sub(-4, -1) == ".lua" then
-					local relativePath = subPath:sub(#classPath + 2)
-					local class, err = vm:loadClassFromFile(subPath, relativePath:gsub("/", "."):sub(1, -5))
-
-					if not class then
-						print("Error loading class '" .. name .. "': " .. tostring(err))
-					end
-				end
-			end
-		end
-	end
-
 	local function runFromPath(classPath, mainClassName, args)
 		local MainClass = vm:loadClassFromAny(mainClassName)
 		if not MainClass then error("Main class not found! ") end

see/test/see/exceptionexample/Test.lua

@@ -0,0 +1,8 @@
+function Test.main(args)
+	try (function()
+		System.print("Running some error-prone code...")
+		notarealfunction()
+	end, function(e)
+		System.print(STR"There was an exception! " .. e.message)
+	end)
+end