From 685e9eafc1fc9a80e30c234280cc264877bd8a23 Mon Sep 17 00:00:00 2001
From: Andreas Schneider <aksdb@gmx.de>
Date: Tue, 6 Oct 2015 12:01:09 +0200
Subject: [PATCH] Added support for FollowUp line matches

---
 UApp.pas    | 13 +++++++++++
 UFilter.pas | 62 +++++++++++++++++++++++++++++++++++++++++------------
 2 files changed, 61 insertions(+), 14 deletions(-)

diff --git a/UApp.pas b/UApp.pas
index 5a96c71..7bf122b 100644
--- a/UApp.pas
+++ b/UApp.pas
@@ -173,6 +173,10 @@ begin
       begin
         FLogFileName := AParams;
       end;
+    'followup':
+      begin
+        FCurrentLineFilter.SetFollowUp(AParams);
+      end;
   end;
 end;
 
@@ -253,10 +257,19 @@ var
   lineFilter: TLineFilter;
   groupRanges: TGroupRanges;
 begin
+  if (FCurrentLineFilter <> nil)
+    and (FCurrentLineFilter.FollowUpMatch(ALine, groupRanges)) then
+  begin
+    WriteContent(ALine, FCurrentLineFilter.Filters, groupRanges);
+    Exit;
+  end else
+    FCurrentLineFilter := nil; //We assume, nothing matched.
+
   for lineFilter in FLineFilters do
   begin
     if lineFilter.Matches(ALine, groupRanges) then
     begin
+      FCurrentLineFilter := lineFilter; //Remember the last matching filter
       WriteContent(ALine, lineFilter.Filters, groupRanges);
       Break;
     end;
diff --git a/UFilter.pas b/UFilter.pas
index 92aca98..e20d162 100644
--- a/UFilter.pas
+++ b/UFilter.pas
@@ -60,9 +60,14 @@ type
     destructor Destroy; override;
   protected
     FExpression: TRegExpr;
+    FFollowUp: TRegExpr; //Used to evaluate lines belonging this the first match.
     FFilters: TFilterList;
+    function DoMatch(AExpression: TRegExpr; ALine: String;
+      var GroupRanges: TGroupRanges): Boolean;
   public
     function Matches(ALine: String; var GroupRanges: TGroupRanges): Boolean;
+    procedure SetFollowUp(AExpression: String);
+    function FollowUpMatch(ALine: String; var GroupRanges: TGroupRanges): Boolean;
     property Filters: TFilterList read FFilters;
   end;
   TLineFilters = specialize TFPGObjectList<TLineFilter>;
@@ -126,32 +131,61 @@ constructor TLineFilter.Create(AExpression: String);
 begin
   FExpression := TRegExpr.Create(AExpression);
   FFilters := TFilterList.Create;
+  FFollowUp := nil;
 end;
 
 destructor TLineFilter.Destroy;
 begin
   FExpression.Free;
   FFilters.Free;
+  FFollowUp.Free;
   inherited Destroy;
 end;
 
+function TLineFilter.DoMatch(AExpression: TRegExpr; ALine: String;
+  var GroupRanges: TGroupRanges): Boolean;
+var
+  i: Integer;
+begin
+  Result := AExpression.Exec(ALine);
+  if Result then
+  begin
+    {$ifdef debugmatches}writeln('  Match: ', AExpression.Match[0]);{$endif}
+    SetLength(GroupRanges, AExpression.SubExprMatchCount + 1);
+    for i := 0 to AExpression.SubExprMatchCount do
+    begin
+      {$ifdef debugmatches}writeln('    [', i, ']: ', AExpression.Match[i]);{$endif}
+      GroupRanges[i].StartIdx := AExpression.MatchPos[i];
+      GroupRanges[i].EndIdx := GroupRanges[i].StartIdx + AExpression.MatchLen[i];
+    end;
+  end;
+end;
+
 function TLineFilter.Matches(ALine: String; var GroupRanges: TGroupRanges
   ): Boolean;
-var
-  i: Integer;
 begin
-  Result := FExpression.Exec(ALine);
-  if Result then
-  begin
-    {$ifdef debugmatches}writeln('  Match: ', FExpression.Match[0]);{$endif}
-    SetLength(GroupRanges, FExpression.SubExprMatchCount + 1);
-    for i := 0 to FExpression.SubExprMatchCount do
-    begin
-      {$ifdef debugmatches}writeln('    [', i, ']: ', FExpression.Match[i]);{$endif}
-      GroupRanges[i].StartIdx := FExpression.MatchPos[i];
-      GroupRanges[i].EndIdx := GroupRanges[i].StartIdx + FExpression.MatchLen[i];
-    end;
-  end;
+  Result := DoMatch(FExpression, ALine, GroupRanges);
+end;
+
+procedure TLineFilter.SetFollowUp(AExpression: String);
+begin
+  if FFollowUp = nil then
+    FFollowUp := TRegExpr.Create(AExpression)
+  else
+    FFollowUp.Expression := AExpression;
+end;
+
+{
+  If a FollowUp-Expression is set, we evaluate that and return the result.
+  If no expression is set, we simply treat that as having not matched.
+}
+function TLineFilter.FollowUpMatch(ALine: String; var GroupRanges: TGroupRanges
+  ): Boolean;
+begin
+  if FFollowUp <> nil then
+    Result := DoMatch(FFollowUp, ALine, GroupRanges)
+  else
+    Result := False;
 end;
 
 { THighlight }