microsoft-visualbasic-runtime/Scripting/Runtime/BinaryOperator.vb

#Region "Microsoft.VisualBasic::b78c275b4a9348fc00ecfb15990c859c, Microsoft.VisualBasic.Core\Scripting\Runtime\BinaryOperator.vb"

    ' Author:
    ' 
    '       asuka (amethyst.asuka@gcmodeller.org)
    '       xie (genetics@smrucc.org)
    '       xieguigang (xie.guigang@live.com)
    ' 
    ' Copyright (c) 2018 GPL3 Licensed
    ' 
    ' 
    ' GNU GENERAL PUBLIC LICENSE (GPL3)
    ' 
    ' 
    ' This program is free software: you can redistribute it and/or modify
    ' it under the terms of the GNU General Public License as published by
    ' the Free Software Foundation, either version 3 of the License, or
    ' (at your option) any later version.
    ' 
    ' This program is distributed in the hope that it will be useful,
    ' but WITHOUT ANY WARRANTY; without even the implied warranty of
    ' MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    ' GNU General Public License for more details.
    ' 
    ' You should have received a copy of the GNU General Public License
    ' along with this program. If not, see <http://www.gnu.org/licenses/>.



    ' /********************************************************************************/

    ' Summaries:

    '     Class BinaryOperator
    ' 
    '         Properties: Name
    ' 
    '         Constructor: (+2 Overloads) Sub New
    '         Function: __invokeInternal, CreateOperator, InvokeSelfLeft, InvokeSelfRight, Match
    '                   MatchLeft, MatchRight, ToString
    ' 
    ' 
    ' /********************************************************************************/

#End Region

Imports System.Reflection
Imports System.Runtime.CompilerServices
Imports Microsoft.VisualBasic.ComponentModel.Collection.Generic
Imports Microsoft.VisualBasic.ComponentModel.DataSourceModel.Repository

Namespace Scripting.Runtime

    ''' <summary>
    ''' Binary operator invoker
    ''' </summary>
    Public Class BinaryOperator : Implements INamedValue

        ReadOnly methods As MethodInfo()

        ''' <summary>
        ''' The name of this binary operator
        ''' </summary>
        Public Property Name As String Implements IKeyedEntity(Of String).Key

        ''' <summary>
        ''' 
        ''' </summary>
        ''' <param name="[overloads]">重名的运算符函数方法</param>
        ''' 
        <MethodImpl(MethodImplOptions.AggressiveInlining)>
        Sub New([overloads] As MethodInfo())
            Call Me.New([overloads](Scan0).Name, [overloads])
        End Sub

        ''' <summary>
        ''' 可以通过继承<see cref="MethodInfo"/>类型来自定义函数，再使用这个操作符对象应用于脚本运行时环境之中
        ''' </summary>
        ''' <param name="name$"></param>
        ''' <param name="methods"></param>
        Sub New(name$, methods As MethodInfo())
            Me.Name = name
            Me.methods = methods
        End Sub

        Public Overrides Function ToString() As String
            If methods.Length = 1 Then
                Return Name
            Else
                Return $"{Name} (+{methods.Length} Overloads)"
            End If
        End Function

        ''' <summary>
        ''' ``args op me``.(参数在左边)
        ''' </summary>
        ''' <param name="type"></param>
        ''' <returns></returns>
        ''' 
        <MethodImpl(MethodImplOptions.AggressiveInlining)>
        Public Function MatchLeft(type As Type) As MethodInfo
            Return Match(type, 0)
        End Function

        ''' <summary>
        ''' ``me op args``.(参数在右边)
        ''' </summary>
        ''' <param name="type"></param>
        ''' <returns></returns>
        ''' 
        <MethodImpl(MethodImplOptions.AggressiveInlining)>
        Public Function MatchRight(type As Type) As MethodInfo
            Return Match(type, 1)
        End Function

        Public Function Match(type As Type, pos%) As MethodInfo
            Dim depthMin% = Integer.MaxValue
            Dim target As MethodInfo = Nothing

            For Each m As MethodInfo In methods
                ' 参数在右边，即第二个参数
                Dim parm As ParameterInfo = m.GetParameters(pos) ' base type
                Dim depth%

                If type.IsInheritsFrom(parm.ParameterType, False, depth) Then
                    If depth < depthMin Then
                        depthMin = depth
                        target = m
                    End If
                End If
            Next

            If target Is Nothing Then
                If Runtime.Numerics.IndexOf(Type.GetTypeCode(type)) > -1 Then
                    For Each m As MethodInfo In methods
                        Dim parm As ParameterInfo = m.GetParameters(pos) ' base type
                        If Runtime.Numerics.IndexOf(Type.GetTypeCode(parm.ParameterType)) > -1 Then
                            Return m
                        End If
                    Next
                End If
            End If

            Return target
        End Function

        ''' <summary>
        ''' 参数在右边
        ''' </summary>
        ''' <param name="self"></param>
        ''' <param name="obj"></param>
        ''' <param name="result"></param>
        ''' <returns></returns>
        ''' 
        <MethodImpl(MethodImplOptions.AggressiveInlining)>
        Public Function InvokeSelfLeft(self As Object, obj As Object, ByRef result As Object) As Boolean
            Return __invokeInternal(self, obj, 0, result)
        End Function

        Private Function __invokeInternal(self As Object, obj As Object, pos%, ByRef result As Object) As Boolean
            Dim type As Type = obj.GetType
            Dim target As MethodInfo = Match(type, If(pos = 1, 0, 1))

            If Not target Is Nothing Then
                If pos = 0 Then
                    result = target.Invoke(Nothing, {self, obj})
                Else
                    result = target.Invoke(Nothing, {obj, self})
                End If
            Else
                Return False
            End If

            Return True
        End Function

        ''' <summary>
        ''' 参数在左边
        ''' </summary>
        ''' <param name="obj"></param>
        ''' <param name="self"></param>
        ''' <param name="result"></param>
        ''' <returns></returns>
        ''' 
        <MethodImpl(MethodImplOptions.AggressiveInlining)>
        Public Function InvokeSelfRight(obj As Object, self As Object, ByRef result As Object) As Boolean
            Return __invokeInternal(self, obj, 1, result)
        End Function

        Public Shared Function CreateOperator(methods As MethodInfo()) As BinaryOperator
            If methods.IsNullOrEmpty Then
                Return Nothing
            Else
                Return New BinaryOperator([overloads]:=methods)
            End If
        End Function
    End Class
End Namespace