Extend StreamFormatting to seperate linewrap and indenting

As indenting and line wrapping hints are implemented teogether, we
always track indent and linewrapping hints, but only make use of them
when indenting, or linewrapping, are enabled.

lib/custom_streams.gi

@@ -339,11 +339,8 @@ InstallMethod( PrintFormattingStatus, "output text custom",
 ##
 InstallMethod( SetPrintFormattingStatus, "output text custom",
         [IsOutputTextCustomRep and IsOutputTextStream,
-         IsBool],
+         IsObject],
         function( str, stat)
-    if stat = fail then
-        Error("Print formatting status must be true or false");
-    else
+    CheckValidPrintFormattingStatus(stat);
         str!.formatting := stat;
-    fi;
 end);

lib/streams.gd

@@ -959,24 +959,31 @@ DeclareGlobalFunction( "InputOutputLocalProcess" );
 ##  and harmless if it to passed as input to ⪆,
 ##  but may be unhelpful if the output is to be passed as input to another
 ##  program.
-##  It is possible to turn off this behaviour for a stream using the
-##  <Ref Oper="SetPrintFormattingStatus"/> operation, and to test whether it
-##  is on or off using <Ref Oper="PrintFormattingStatus"/>.
+##  It is possible to control this behaviour for a stream using the
+##  <Ref Oper="SetPrintFormattingStatus"/> operation, and to query it
+##  using <Ref Oper="PrintFormattingStatus"/>.
+##  <P/>
+##  The formatting status is stored in a record with two members,
+##  <A>linewrap</A> and <A>indent</A>, which control if GAP wraps lines,
+##  or indents, respectively. These two both take a boolean.
+##  <P/>
+##  For backwards compatability, all functions which control print formatting
+##  will also take a boolean, which sets <A>linewrap</A> and <A>indent</A> to
+##  the given boolean value.
 ##  <P/>
 ##  <Ref Oper="SetPrintFormattingStatus"/> sets whether output sent to the
 ##  output stream <A>stream</A> via <Ref Func="PrintTo"/>,
 ##  <Ref Func="AppendTo"/>, etc.
 ##  will be formatted with line breaks and
-##  indentation.  If  the  second  argument <A>newstatus</A> is <K>true</K>
-##  then output will be so formatted, and if <K>false</K> then it will not.
-##  If the stream is not a text stream, only <K>false</K> is allowed.
+##  indentation. The second argument <A>newstatus</A> is a record or boolean,
+##  as described above.
+##  If the stream is not a text stream, both <A>linewrap</A> and <A>indent</A>
+##  can only be set to <K>false</K>.
 ##  <P/>
-##  <Ref Oper="PrintFormattingStatus"/> returns <K>true</K> if output sent to
-##  the output text stream <A>stream</A>  via <Ref Func="PrintTo"/>,
-##  <Ref Func="AppendTo"/>, etc.
-##  will be formatted with line breaks and
-##  indentation, and <K>false</K> otherwise.
-##  For non-text streams, it returns <K>false</K>.
+##  <Ref Oper="PrintFormattingStatus"/> returns a record containing the
+##  current value of <A>linewrap</A> and <A>indent</A> for the output text
+##  stream <A>stream</A>. For non-text streams, these values area always
+##  both <K>false</K>.
 ##  If as argument <A>stream</A> the string <C>"*stdout*"</C> is given, these
 ##  functions refer to the formatting status of the standard output (so usually
 ##  the user's terminal screen).<P/>
@@ -997,7 +1004,7 @@ DeclareGlobalFunction( "InputOutputLocalProcess" );
 ##  gap> Print(s,"\n");
 ##  [ 2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37, 41, 43, 47, 53, 59, 61,
 ##    67, 71, 73, 79, 83, 89, 97, 101, 103, 107, 109, 113 ]
-##  gap> SetPrintFormattingStatus(str, false);
+##  gap> SetPrintFormattingStatus(str, rec(indent:=false,linewrap:=false));
 ##  gap> PrintTo(str,Primes{[1..30]});
 ##  gap> s;
 ##  "[ 2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37, 41, 43, 47, 53, 59, 61,\
@@ -1015,7 +1022,7 @@ DeclareGlobalFunction( "InputOutputLocalProcess" );
 ##  </ManSection>
 ##  <#/GAPDoc>
 ##
-DeclareOperation( "SetPrintFormattingStatus", [IsOutputStream, IsBool] );
+DeclareOperation( "SetPrintFormattingStatus", [IsOutputStream, IsObject] );
 DeclareOperation( "PrintFormattingStatus", [IsOutputStream] );
 
 
@@ -1259,3 +1266,6 @@ DeclareGlobalFunction( "InputFromUser" );
 ##  <#/GAPDoc>
 ##
 DeclareGlobalFunction( "OpenExternal" );
+
+DeclareGlobalFunction( "_CheckValidPrintFormattingStatus");
+DeclareGlobalFunction( "_DefaultPrintFormattingStatus");

lib/streams.gi

@@ -860,7 +860,8 @@ function( str, append )
             Unbind(str[i]);
         od;
     fi;
-    return Objectify( OutputTextStringType, [ str, true ] );
+    return Objectify( OutputTextStringType,
+        [ str, _DefaultPrintFormattingStatus() ] );
 end );
 
 
@@ -929,13 +930,9 @@ InstallMethod( PrintFormattingStatus, "output text string",
 ##
 InstallMethod( SetPrintFormattingStatus, "output text string",
         [IsOutputTextStringRep and IsOutputTextStream,
-         IsBool],
+         IsObject],
         function( str, stat)
-    if stat = fail then
-        Error("Print formatting status must be true or false");
-    else
-        str![2] := stat;
-    fi;
+        str![2] := _CheckValidPrintFormattingStatus(stat);
 end);
 
 
@@ -994,7 +991,8 @@ function( str, append )
         atomic OutputTextFileStillOpen do
             AddSet( OutputTextFileStillOpen, fid );
         od;
-        return Objectify( OutputTextFileType, [fid, Immutable(str), true] );
+        return Objectify( OutputTextFileType,
+            [fid, Immutable(str), _DefaultPrintFormattingStatus()]);
     fi;
 end );
 
@@ -1025,7 +1023,8 @@ function( str, append )
         atomic OutputTextFileStillOpen do
             AddSet( OutputTextFileStillOpen, fid );
         od;
-        return Objectify( OutputTextFileType, [fid, Immutable(str), true] );
+        return Objectify( OutputTextFileType,
+            [fid, Immutable(str), _DefaultPrintFormattingStatus() ] );
     fi;
 end );
 
@@ -1130,13 +1129,9 @@ InstallMethod( PrintFormattingStatus, "output text file",
 ##
 InstallMethod( SetPrintFormattingStatus, "output text file",
         [IsOutputTextFileRep and IsOutputTextStream,
-         IsBool],
+         IsObject],
         function( str, stat)
-    if stat = fail then
-        Error("Print formatting status must be true or false");
-    else
-        str![3] := stat;
-    fi;
+        str![3] := _CheckValidPrintFormattingStatus(stat);
 end);
 
 ##  formatting status for stdout or current output
@@ -1151,7 +1146,7 @@ function(str)
   fi;
 end);
 
-InstallOtherMethod( SetPrintFormattingStatus, "for stdout", [IsString, IsBool],
+InstallOtherMethod( SetPrintFormattingStatus, "for stdout", [IsString, IsObject],
 function(str, status)
   if str = "*stdout*" then
     SET_PRINT_FORMATTING_STDOUT(status);
@@ -1255,9 +1250,7 @@ InstallMethod( SetPrintFormattingStatus, "output text none",
         [IsOutputTextNoneRep and IsOutputTextNone,
          IsBool],
         function( str, stat)
-    if stat = fail then
-        Error("Print formatting status must be true or false");
-    fi;
+    _CheckValidPrintFormattingStatus(stat);
 end);
 
 
@@ -1661,7 +1654,7 @@ function ( str )
     if IsOutputTextStream( str )  then
         TryNextMethod();
     fi;
-    return false;
+    return Immutable(rec(indent := false, linewrap := false) );
 end);
 
 
@@ -1676,13 +1669,45 @@ InstallMethod( SetPrintFormattingStatus, "for non-text output stream",
         TryNextMethod();
     fi;
 
-    if stat = true then
-        Error("non-text streams support onlyPrint formatting status false");
-    elif stat = fail then
-        Error("Print formatting status must be true or false");
+    stat := _CheckValidPrintFormattingStatus(stat);
+    if stat.linewrap or stat.indent then
+        Error("non-text streams do not support print formatting");
+    fi;
+end);
+
+
+InstallGlobalFunction( "_CheckValidPrintFormattingStatus",
+function(fs)
+    local r;
+    if IsBool(fs) then
+        if fs = fail then
+            Error("Formatting status cannot be 'fail'");
+        fi;
+    elif IsRecord(fs) then
+        if Set(RecNames(fs)) <> ["indent", "linewrap"] then
+            Error("Formatting status records must contain exactly two components, named 'indent' and 'linewrap'");
+        fi;
+        for r in ["indent","linewrap"] do
+            if not fs.(r) in [false, true] then
+                Error(Concatenation(r, " must be 'true' or 'false' in formatting status record"));
+            fi;
+        od;
+    else
+        Error("Formatting status must be a boolean or a record");
+    fi;
+
+    if fs = true then
+        fs := rec(indent := true, linewrap := true);
+    elif fs = false then
+        fs := rec(indent := false, linewrap := false);
     fi;
+    return Immutable(ShallowCopy(fs));
 end);
 
+InstallGlobalFunction( "_DefaultPrintFormattingStatus",
+function()
+    return Immutable(rec(linewrap := true, indent := true));
+end);
 
 #############################################################################
 ##