sxsyn, add support for char literals

src/u_sxsyn.pas

@@ -91,6 +91,7 @@ type
     procedure lexFloatingLiteralFractionalPart();
     procedure lexExponent();
     procedure lexStringLiteral();
+    procedure lexCharLiteral();
     procedure lexRawStringLiteral();
     procedure lexLineComment();
     procedure lexStarComment();
@@ -577,6 +578,25 @@ begin
   end;
 end;
 
+procedure TSynSxSyn.lexCharLiteral();
+begin
+  fTokKind  := TTokenKind.tkStrng;
+  fTokStop  += 1;
+  while fTokStop <= fLineBuf.length do
+  begin
+    case fLineBuf[fTokStop] of
+      '\' : fTokStop += 2;
+      #39 :
+      begin
+        fTokStop  += 1;
+        exit;
+      end
+      else fTokStop += 1;
+    end;
+  end;
+  fTokKind  := TTokenKind.tkError;
+end;
+
 procedure TSynSxSyn.lexStringLiteral();
 var
   firstLine: Boolean;
@@ -770,6 +790,8 @@ begin
     end;
     // number
     '1' .. '9' : lexIntLiteral();
+    // char
+    #39 : lexCharLiteral();
     // "string"
     '"': lexStringLiteral();
     // `string`