lazutils: added ReplaceSubString

git-svn-id: trunk@35499 -

.gitattributes

@@ -6227,6 +6227,7 @@ test/hello.ahk svneol=native#text/plain
 test/lazutils/TestLazLogger.lpr svneol=native#text/pascal
 test/lazutils/testlazloggercase.pas svneol=native#text/pascal
 test/lazutils/testlazutf8.pas svneol=native#text/plain
+test/lazutils/testlazutils.pas svneol=native#text/plain
 test/lazutils/testlazxml.pas svneol=native#text/plain
 test/lazutils/testpaswstring.lpi svneol=native#text/plain
 test/lazutils/testpaswstring.pas svneol=native#text/plain

components/lazutils/lazlogger.pas

@@ -134,6 +134,8 @@ function DbgS(const Shift: TShiftState): string; overload;
 function DbgS(const ASize: TSize): string; overload;
 
 function ConvertLineEndings(const s: string): string;
+function ReplaceSubstring(const s: string; StartPos, Count: SizeInt;
+                          const Insertion: string): string;
 
 type
 
@@ -921,6 +923,45 @@ begin
   end;
 end;
 
+function ReplaceSubstring(const s: string; StartPos, Count: SizeInt;
+  const Insertion: string): string;
+var
+  MaxCount: SizeInt;
+  InsertionLen: SizeInt;
+  SLen: SizeInt;
+  RestLen: SizeInt;
+  Dest: PByte;
+begin
+  SLen:=length(s);
+  if StartPos>SLen then
+    StartPos:=SLen;
+  if StartPos<1 then StartPos:=1;
+  if Count<0 then Count:=0;
+  MaxCount:=SLen-StartPos+1;
+  if Count>MaxCount then
+    Count:=MaxCount;
+  InsertionLen:=length(Insertion);
+  if (Count=0) and (InsertionLen=0) then
+    exit(s); // nothing to do
+  if (Count=InsertionLen)
+  and CompareMem(PByte(s)+StartPos-1,Pointer(Insertion),Count) then
+    // already the same content
+    exit(s);
+  Setlength(Result,SLen-Count+InsertionLen);
+  Dest:=PByte(Result);
+  if StartPos>1 then begin
+    System.Move(PByte(s)^,Dest^,StartPos-1);
+    inc(Dest,StartPos-1);
+  end;
+  if InsertionLen>0 then begin
+    System.Move(PByte(Insertion)^,Dest^,InsertionLen);
+    inc(Dest,InsertionLen);
+  end;
+  RestLen:=SLen-StartPos-Count+1;
+  if RestLen>0 then
+    System.Move((PByte(s)+StartPos-1+Count)^,Dest^,RestLen);
+end;
+
 { TLazLoggerLogGroupList }
 
 procedure TLazLoggerLogGroupList.Clear;

test/lazutils/testlazutils.pas

@@ -0,0 +1,54 @@
+{
+ Test all with:
+     ./runtests --format=plain --suite=TTestLazUtils
+
+ Test specific with:
+     ./runtests --format=plain --suite=TestReplaceSubstring
+}
+unit TestLazUtils;
+
+{$mode objfpc}{$H+}
+
+interface
+
+uses
+  Classes, SysUtils, fpcunit, testglobals, LazLogger;
+
+type
+
+  { TTestLazUtils }
+
+  TTestLazUtils = class(TTestCase)
+  public
+  published
+    procedure TestReplaceSubstring;
+  end;
+
+implementation
+
+{ TTestLazUTF8 }
+
+procedure TTestLazUtils.TestReplaceSubstring;
+begin
+  AssertEquals('empty string','',ReplaceSubstring('',1,1,''));
+  AssertEquals('empty string insert a','a',ReplaceSubstring('',1,1,'a'));
+  AssertEquals('empty string negative startpos','a',ReplaceSubstring('',-1,1,'a'));
+  AssertEquals('empty string count too big','a',ReplaceSubstring('',-1,10,'a'));
+  AssertEquals('empty string beyond length','a',ReplaceSubstring('',10,10,'a'));
+  AssertEquals('whole','a',ReplaceSubstring('a',1,1,'a'));
+  AssertEquals('whole','b',ReplaceSubstring('a',1,1,'b'));
+  AssertEquals('whole','abc',ReplaceSubstring('a',1,1,'abc'));
+  AssertEquals('first char','abcbc',ReplaceSubstring('abc',1,1,'abc'));
+  AssertEquals('last char single','aba',ReplaceSubstring('abc',3,1,'a'));
+  AssertEquals('last char multi','ababc',ReplaceSubstring('abc',3,1,'abc'));
+  AssertEquals('middle char same','abc',ReplaceSubstring('abc',2,1,'b'));
+  AssertEquals('middle char single','adc',ReplaceSubstring('abc',2,1,'d'));
+  AssertEquals('middle char multi','acdec',ReplaceSubstring('abc',2,1,'cde'));
+  AssertEquals('last multi','adef',ReplaceSubstring('abc',2,2,'def'));
+end;
+
+initialization
+  AddToLazUtilsTestSuite(TTestLazUtils);
+
+end.
+

test/runtests.lpi

@@ -86,9 +86,9 @@
         <UnitName Value="TestBasicCodetools"/>
       </Unit8>
       <Unit9>
-        <Filename Value="lazutils\testlazutf8.pas"/>
+        <Filename Value="lazutils\testlazutils.pas"/>
         <IsPartOfProject Value="True"/>
-        <UnitName Value="TestLazUTF8"/>
+        <UnitName Value="TestLazUtils"/>
       </Unit9>
       <Unit10>
         <Filename Value="codetoolstests\testctxmlfixfragments.pas"/>

test/testunits.pas

@@ -30,7 +30,7 @@ uses
   TestLpi, BugTestCase,
   bug8432, testfileutil, testfileproc,
   // lazutils
-  TestLazUTF8,
+  TestLazUtils, TestLazUTF8,
   // codetools
   TestBasicCodetools, TestCTXMLFixFragments, TestCTRangeScan, TestCTH2Pas,
   TestCompleteBlock, TestStdCodetools,