{
* USnippetValidator.pas
*
* Implements a static class that checks a snippet for validity.
*
* v1.0 of 27 May 2009 - Original version.
*
*
* ***** BEGIN LICENSE BLOCK *****
*
* Version: MPL 1.1
*
* The contents of this file are subject to the Mozilla Public License Version
* 1.1 (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.mozilla.org/MPL/
*
* Software distributed under the License is distributed on an "AS IS" basis,
* WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License for
* the specific language governing rights and limitations under the License.
*
* The Original Code is USnippetValidator.pas
*
* The Initial Developer of the Original Code is Peter Johnson
* (http://www.delphidabbler.com/).
*
* Portions created by the Initial Developer are Copyright (C) 2009 Peter
* Johnson. All Rights Reserved.
*
* ***** END LICENSE BLOCK *****
}
unit USnippetValidator;
interface
uses
// Project
UBaseObjects, USnippets;
type
{
TSnippetValidator:
Static class that checks a snippet for validity.
}
TSnippetValidator = class(TNoConstructObject)
public
class function HasValidDependsList(const Snippet: TRoutine;
out ErrorMsg: string): Boolean;
{Recursively checks dependency list of a snippet for validity.
@param Snippet [in] Snippet for which dependencies are to be checked.
@param ErrorMsg [out] Message that describes error. Undefined if True
returned.
@return True if dependency list is valid or False if not.
}
class function Validate(const Snippet: TRoutine;
out Error: string): Boolean;
{Checks a snippet for validity.
@param Snippet [in] Snippet to be checked.
@param ErrorMsg [out] Message that describes error. Undefined if True
returned.
@return True if snippet valid or False if not.
}
end;
implementation
uses
// Delphi
SysUtils,
// Project
USnippetKindInfo;
{ TSnippetValidator }
class function TSnippetValidator.HasValidDependsList(const Snippet: TRoutine;
out ErrorMsg: string): Boolean;
{Recursively checks dependency list of a snippet for validity.
@param Snippet [in] Snippet for which dependencies are to be checked.
@param ErrorMsg [out] Message that describes error. Undefined if True
returned.
@return True if dependency list is valid or False if not.
}
type
{
TSnippetKinds:
Set of TSnippetKind values.
}
TSnippetKinds = set of TSnippetKind;
function DependsListIsCircular(const Snippet: TRoutine;
const DependsList: TRoutineList): Boolean;
{Checks if dependency list is circular, i.e. a snippet is referenced in own
chain of dependencies. Recursive function.
@param Snippet [in] Snippet to be checked.
@param DependsList [in] A dependency list.
@return True if dependency list is circular, false if not.
}
var
RequiredSnippet: TRoutine; // iterates through DependsList
begin
Result := False;
for RequiredSnippet in DependsList do
begin
if RequiredSnippet.ID = Snippet.ID then
Result := True
else
Result := DependsListIsCircular(Snippet, RequiredSnippet.Depends);
if Result then
Exit;
end;
end;
function DependsListHasKinds(const DependsList: TRoutineList;
const Kinds: TSnippetKinds): Boolean;
{Recursively checks if a dependency list contains snippets of specified
kinds.
@param DependsList [in] A dependency list.
@param Kinds [in] Set of snippet kinds to check for.
@return True if one or more of specified kinds are found, false if not.
}
var
RequiredSnippet: TRoutine; // iterates through depends list
begin
Result := False;
for RequiredSnippet in DependsList do
begin
if RequiredSnippet.Kind in Kinds then
Result := True
else
Result := DependsListHasKinds(RequiredSnippet.Depends, Kinds);
if Result then
Exit;
end;
end;
resourcestring
// Error messages
sInvalidKind = 'Invalid snippet kind in depends list for %0:s "%1:s".';
sCircular = '%0:s "%1:s" cannot depend on itself';
begin
Result := True;
case Snippet.Kind of
skFreeform:
begin
// Freeform snippet can have any snippet in list but must not depend on
// itself
Result := not DependsListIsCircular(Snippet, Snippet.Depends);
if not Result then
ErrorMsg := Format(
sCircular, [
TSnippetKindInfoList.Instance[Snippet.Kind].Description,
Snippet.Name
]
);
end;
skRoutine:
begin
// Routine must not depend on itself and must not depend of freeform code
// ** MUST do test for circularity first
Result := not DependsListIsCircular(Snippet, Snippet.Depends);
if not Result then
ErrorMsg := Format(
sCircular, [
TSnippetKindInfoList.Instance[Snippet.Kind].Description,
Snippet.Name
]
)
else
begin
Result := not DependsListHasKinds(Snippet.Depends, [skFreeform]);
if not Result then
ErrorMsg := Format(
sInvalidKind,
[
TSnippetKindInfoList.Instance[Snippet.Kind].Description,
Snippet.Name
]
);
end;
end;
skConstant, skTypeDef:
begin
// Constants and TypeDefs may only depend on other Constants and TypeDefs
// and cannot depend on themselves
// ** MUST do test for circularity first
Result := not DependsListIsCircular(Snippet, Snippet.Depends);
if not Result then
ErrorMsg := Format(
sCircular, [
TSnippetKindInfoList.Instance[Snippet.Kind].Description,
Snippet.Name
]
)
else
begin
Result := not DependsListHasKinds(
Snippet.Depends, [skFreeform, skRoutine]
);
if not Result then
ErrorMsg := Format(
sInvalidKInd,
[
TSnippetKindInfoList.Instance[Snippet.Kind].Description,
Snippet.Name
]
)
end
end;
end;
end;
class function TSnippetValidator.Validate(const Snippet: TRoutine;
out Error: string): Boolean;
{Checks a snippet for validity.
@param Snippet [in] Snippet to be checked.
@param ErrorMsg [out] Message that describes error. Undefined if True
returned.
@return True if snippet valid or False if not.
}
begin
Result := HasValidDependsList(Snippet, Error);
end;
end.
