Merge pull request #442 from joelverhagen/readonlyspan

Add ReadOnlySpan implementation

CSharp.lua/CoreSystem.Lua/All.lua

@@ -33,6 +33,7 @@ return function(dir, conf)
   load("DateTime")
   load("Collections.EqualityComparer")
   load("Array")
+  load("ReadOnlySpan")
   load("Type")
   load("Collections.List")
   load("Collections.Dictionary")

CSharp.lua/CoreSystem.Lua/CoreSystem/ReadOnlySpan.lua

@@ -0,0 +1,95 @@
+--[[
+Copyright 2017 YANG Huan ([email protected]).
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+  http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+--]]
+
+local System = System
+
+local throw = System.throw
+local ArgumentOutOfRangeException = System.ArgumentOutOfRangeException
+local IndexOutOfRangeException = System.IndexOutOfRangeException
+
+local ReadOnlySpan = {
+  __ctor__ = function (this, input, ...)
+    if type(input) == "table" then
+      local argsLen = select("#", ...)
+      local maxLength = input:getLength()
+      local start, length
+      if argsLen == 2 then
+        start, length = ...
+        if start >= maxLength then
+          throw(ArgumentOutOfRangeException("start"))
+        end
+        if start + length > maxLength then
+          throw(ArgumentOutOfRangeException("length"))
+        end 
+      else
+        start, length = 0, maxLength
+      end
+      this._array = input
+      this._min = start
+      this._max = start + length - 1
+    else
+      this._array = System.Array.new(this.__genericT__, 1)
+      this._array:set(0, input)
+      this._min = 0
+      this._max = 0
+    end
+  end,
+  get = function (this, index)
+    local i = this._min + index
+    if i > this._max then
+      throw(IndexOutOfRangeException("index"))
+    end
+    return this._array:get(i)
+  end,
+  getIsEmpty = function (this)
+    return this:getLength() <= 0
+  end,
+  getLength = function (this)
+    return this._max - this._min + 1
+  end,
+  Slice = function (this, start, ...)
+    local newMin = this._min + start
+    if newMin > this._max then
+      throw(ArgumentOutOfRangeException("start"))
+    end
+
+    local newMax
+    local argsLen = select("#", ...)
+    if argsLen == 1 then
+      length = ...
+      newMax = newMin + length - 1
+      if newMax > this._max then
+        throw(ArgumentOutOfRangeException("length"))
+      end
+    else
+      newMax = this._max
+    end
+    local ctor = System.ReadOnlySpan(this.__genericT__)
+    return ctor(this._array, newMin, newMax - newMin + 1)
+  end,
+  ctorArray = function (array)
+    local ctor = System.ReadOnlySpan(array.__genericT__)
+    return ctor(array)    
+  end
+}
+
+local ReadOnlySpanFn = System.defStc("System.ReadOnlySpan", function (T)
+  return {
+    __genericT__ = T
+  }
+end, ReadOnlySpan, 1)
+
+System.ReadOnlySpan = ReadOnlySpanFn

CSharp.lua/System.xml

@@ -345,6 +345,10 @@ limitations under the License.
         <method name="Create" ArgCount="7" Template="System.ValueTuple({0}, {1}, {2}, {3}, {4}, {5}, {6})" />
         <method name="Create" ArgCount="8" Template="System.ValueTuple({0}, {1}, {2}, {3}, {4}, {5}, {6}, {7})" />
       </class>
+      <class name="ReadOnlySpan`1" Name="System.ReadOnlySpan">
+        <method name=".ctor" Template="{0}" />
+        <method name="op_Implicit" ArgCount="1" Name="ctorArray" />
+      </class>
       <class name="Nullable`1" Name="System.Nullable">
         <method name=".ctor" Template="{0}" />
         <property name="HasValue">