{
* This Source Code Form is subject to the terms of the Mozilla Public License,
* v. 2.0. If a copy of the MPL was not distributed with this file, You can
* obtain one at http://mozilla.org/MPL/2.0/
*
* Copyright (C) 2009-2013, Peter Johnson (www.delphidabbler.com).
*
* $Rev$
* $Date$
*
* Defines a record that uniquely indentifies a snippet in the database, along
* with an object that maintains a list of snippet ID records.
}
unit USnippetIDs;
interface
uses
// Delphi
Generics.Collections,
// Project
IntfCommon;
type
/// <summary>Record that uniquely identifies a code snippet. Specifies name
/// and flag indicating whether snippet is user-defined.</summary>
TSnippetID = record
strict private
var
/// <summary>Internal value of snippet ID.</summary>
fID: string;
public
/// <summary>Creates a record with given ID string.</summary>
constructor Create(const AIDStr: string);
/// <summary>Returns hash of snippet ID.</summary>
function Hash: Integer;
/// <summary>Returns string representation of ID.</summary>
function ToString: string;
/// <summary>Compares two snippet IDs.</summary>
/// <param name="Left">string [in] First ID to compare.</param>
/// <param name="Right">string [in] Second ID to compare.</param>
/// <returns>Integer. 0 if names are same, -ve if Left is less than Right
/// or +ve Left is greater than Right.</returns>
class function Compare(const Left, Right: TSnippetID): Integer; static;
/// <summary>Overload of equality operator for two TSnippetIDs.</summary>
class operator Equal(const Left, Right: TSnippetID): Boolean;
/// <summary>Overload of inequality operator for two TSnippetIDs.</summary>
class operator NotEqual(const Left, Right: TSnippetID): Boolean;
end;
type
/// <summary>Interface supported by objects that implement a list of
/// TSnippetID records.</summary>
ISnippetIDList = interface(IInterface)
['{238CFDCC-E84E-4D29-9BC6-10FBCECBC4FA}']
/// <summary>Gets new list enumerator.</summary>
function GetEnumerator: TEnumerator<TSnippetID>;
/// <summary>Clears the list.</summary>
procedure Clear;
/// <summary>Adds given snippet ID to list and returns its index in list.
/// </summary>
function Add(const SnippetID: TSnippetID): Integer;
/// <summary>Checks if list contains given snippet ID.</summary>
function Contains(const SnippetID: TSnippetID): Boolean;
/// <summary>Returns number of snippet ID records in list.</summary>
function Count: Integer;
/// <summary>Gets snippet ID record from list by index.</summary>
function GetItem(Idx: Integer): TSnippetID;
/// <summary>Stores snippet ID record in list at specified index.</summary>
procedure SetItem(Idx: Integer; const Value: TSnippetID);
/// <summary>Provides read/write access to snippet IDs by index.</summary>
property Items[Idx: Integer]: TSnippetID
read GetItem write SetItem; default;
end;
type
/// <summary>Implements a list of snippet identification records.</summary>
TSnippetIDList = class(TInterfacedObject, ISnippetIDList, IAssignable)
strict private
var
/// <summary>Internal list if snippet ID records.</summary>
fList: TList<TSnippetID>;
public
/// <summary>Constructs empty list object.</summary>
constructor Create;
/// <summary>Destroys object.</summary>
destructor Destroy; override;
/// <summary>Gets new list enumerator.</summary>
/// <remarks>Method of ISnippetIDList.</remarks>
function GetEnumerator: TEnumerator<TSnippetID>;
/// <summary>Clears the list.</summary>
/// <remarks>Method of ISnippetIDList.</remarks>
procedure Clear;
/// <summary>Adds given snippet ID to list and returns its index in list.
/// </summary>
/// <remarks>Method of ISnippetIDList.</remarks>
function Add(const SnippetID: TSnippetID): Integer;
/// <summary>Checks if list contains given snippet ID.</summary>
/// <remarks>Method of ISnippetIDList.</remarks>
function Contains(const SnippetID: TSnippetID): Boolean;
/// <summary>Returns number of snippet ID records in list.</summary>
/// <remarks>Method of ISnippetIDList.</remarks>
function Count: Integer;
/// <summary>Gets snippet ID record from list by index.</summary>
/// <remarks>Method of ISnippetIDList.</remarks>
function GetItem(Idx: Integer): TSnippetID;
/// <summary>Stores snippet ID record in list at specified index.</summary>
/// <remarks>Method of ISnippetIDList.</remarks>
procedure SetItem(Idx: Integer; const Value: TSnippetID);
/// <summary>Copies properties of given list to this one.</summary>
/// <param name="Src">IInterface [in] List whose properties are to be
/// copied. Src must support ISnippetIDList.</param>
/// <remarks>Method of IAssignable.</remarks>
procedure Assign(const Src: IInterface);
end;
implementation
uses
// Delphi
SysUtils, Generics.Defaults,
// Project
CS.Utils.Hashes,
UStrUtils;
{ TSnippetID }
class function TSnippetID.Compare(const Left, Right: TSnippetID): Integer;
begin
Result := StrCompareText(Left.fID, Right.fID);
end;
constructor TSnippetID.Create(const AIDStr: string);
begin
fID := AIDStr;
end;
class operator TSnippetID.Equal(const Left, Right: TSnippetID): Boolean;
begin
Result := Compare(Left, Right) = 0;
end;
function TSnippetID.Hash: Integer;
begin
Result := TextHash(fID);
end;
class operator TSnippetID.NotEqual(const Left, Right: TSnippetID): Boolean;
begin
Result := Compare(Left, Right) <> 0;
end;
function TSnippetID.ToString: string;
begin
Result := fID;
end;
{ TSnippetIDList }
function TSnippetIDList.Add(const SnippetID: TSnippetID): Integer;
begin
Result := fList.Add(SnippetID);
end;
procedure TSnippetIDList.Assign(const Src: IInterface);
var
SrcID: TSnippetID; // references each ID in source
begin
Assert(Supports(Src, ISnippetIDList),
ClassName + '.Assign: Src must support ISnippetIDList');
Clear;
for SrcID in (Src as ISnippetIDList) do
Add(SrcID);
end;
procedure TSnippetIDList.Clear;
begin
fList.Clear;
end;
function TSnippetIDList.Contains(const SnippetID: TSnippetID): Boolean;
begin
Result := fList.Contains(SnippetID);
end;
function TSnippetIDList.Count: Integer;
begin
Result := fList.Count;
end;
constructor TSnippetIDList.Create;
begin
inherited;
fList := TList<TSnippetID>.Create(
TDelegatedComparer<TSnippetID>.Create(
function(const Left, Right: TSnippetID): Integer
begin
Result := TSnippetID.Compare(Left, Right);
end
)
);
end;
destructor TSnippetIDList.Destroy;
begin
fList.Free;
inherited;
end;
function TSnippetIDList.GetEnumerator: TEnumerator<TSnippetID>;
begin
Result := fList.GetEnumerator;
end;
function TSnippetIDList.GetItem(Idx: Integer): TSnippetID;
begin
Result := fList[Idx];
end;
procedure TSnippetIDList.SetItem(Idx: Integer; const Value: TSnippetID);
begin
fList[Idx] := Value;
end;
end.
