* interp/parse.boot (parseHas): Constants are not attributes.

	* interp/compiler.boot (compHasFormat): Handle signature for
	constants too.
	* interp/info.boot (actOnInfo): Likewise.
	* algebra/data.spad.pamphlet (sample$Byte): Make a constant.
	(SystemInteger): Export constant 'sample'.
	(SystemNonNegativeInteger): Likewise.
	* algebra/aggcat2.spad.pamphlet (FiniteLinearAggregateFunctions2):
	Use 'sample' or 'random' elements when allocating new aggregates.

3 files changed, 14 insertions, 12 deletions

diff --git a/src/interp/compiler.boot b/src/interp/compiler.boot
index aa09ea1f..b5faa805 100644
--- a/src/interp/compiler.boot
+++ b/src/interp/compiler.boot
@@ -1101,6 +1101,7 @@ compElt(form,m,E) ==
     E:= addDomain(aDomain,E)
     mmList:= getModemapListFromDomain(anOp,0,aDomain,E)
     modemap:=
+      -- FIXME: do this only for constants.
       n:=#mmList
       1=n => mmList.(0)
       0=n =>
@@ -1112,7 +1113,6 @@ compElt(form,m,E) ==
       mmList.(0)
     [sig,[pred,val]]:= modemap
     #sig^=2 and ^val is ["elt",:.] => nil --what does the second clause do ????
---+
     val := genDeltaEntry [opOf anOp,:modemap]
     convert([["call",val],first rest sig,E], m) --implies fn calls used to access constants
   compForm(form,m,E)
@@ -1121,9 +1121,7 @@ compElt(form,m,E) ==
 
 compHas: (%Form,%Mode,%Env) -> %Maybe %Triple
 compHas(pred is ["has",a,b],m,$e) ==
-  --b is (":",:.) => (.,.,E):= comp(b,$EmptyMode,E)
   $e:= chaseInferences(pred,$e)
-  --pred':= ("has",a',b') := formatHas(pred)
   predCode:= compHasFormat pred
   coerce([predCode,$Boolean,$e],m)
 
@@ -1136,7 +1134,7 @@ compHasFormat (pred is ["has",olda,b]) ==
   [a,:.] := comp(a,$EmptyMode,$e) or return nil
   a := SUBLISLIS(formals,argl,a)
   b is ["ATTRIBUTE",c] => ["HasAttribute",a,["QUOTE",c]]
-  b is ["SIGNATURE",op,sig] =>
+  b is ["SIGNATURE",op,sig,:.] =>
      ["HasSignature",a,
        mkList [MKQ op,mkList [mkTypeForm type for type in sig]]]
   isCategoryForm(b,$e) => ["HasCategory",a,mkTypeForm b]
diff --git a/src/interp/info.boot b/src/interp/info.boot
index 36daa11c..878b78b0 100644
--- a/src/interp/info.boot
+++ b/src/interp/info.boot
@@ -97,7 +97,7 @@ formatInfo u ==
     b="%noBranch" => ["COND",:liftCond [["not",formatPred a],formatInfo c]]
     ["COND",:liftCond [formatPred a,formatInfo b],:
       liftCond [["not",formatPred a],formatInfo c]]
-  systemError '"formatInfo"
+  systemError ['"formatInfo",u]
  
 liftCond (clause is [ante,conseq]) ==
   conseq is ["COND",:l] =>
@@ -118,7 +118,7 @@ formatPred u ==
     ["has",a,["ATTRIBUTE",b]]
   atom u => u
   u is ["and",:v] => ["and",:[formatPred w for w in v]]
-  systemError '"formatPred"
+  systemError ['"formatPred",u]
  
 chaseInferences(pred,$e) ==
   foo hasToInfo pred where
@@ -220,18 +220,21 @@ actOnInfo(u,$e) ==
     cat:= ["CATEGORY",key,["ATTRIBUTE",att]]
     $e:= put(name,"value",[vval,mkJoin(cat,vmode),venv],$e)
       --there is nowhere %else that this sort of thing exists
-  u is ["SIGNATURE",name,operator,modemap] =>
+  u is ["SIGNATURE",name,operator,modemap,:q] =>
+    kind := 
+      q is ["constant"] => "CONST" 
+      "ELT"
     implem:=
       (implem:=ASSOC([name,:modemap],get(operator,'modemap,$e))) =>
           CADADR implem
-      name = "$" => ['ELT,name,-1]
-      ['ELT,name,substitute('$,name,modemap)]
+      name = "$" => [kind,name,-1]
+      [kind,name,substitute('$,name,modemap)]
     $e:= addModemap(operator,name,modemap,true,implem,$e)
     [vval,vmode,venv]:= GetValue name
     compilerMessage('"augmenting %1: %2p", 
-      [name,["SIGNATURE",operator,modemap]])
+       [name,["SIGNATURE",operator,modemap,:q]])
     key:= if CONTAINED("$",vmode) then "domain" else name
-    cat:= ["CATEGORY",key,["SIGNATURE",operator,modemap]]
+    cat:= ["CATEGORY",key,["SIGNATURE",operator,modemap,:q]]
     $e:= put(name,"value",[vval,mkJoin(cat,vmode),venv],$e)
   u is ["has",name,cat] =>
     [vval,vmode,venv]:= GetValue name
@@ -255,7 +258,7 @@ actOnInfo(u,$e) ==
       $e:= put(name,"value",[vval,mkJoin(cat,vmode),venv],$e)
     SAY("extension of ",vval," to ",cat," ignored")
     $e
-  systemError '"knownInfo"
+  systemError ['"actOnInfo",u]
  
 mkJoin(cat,mode) ==
   mode is ['Join,:cats] => ['Join,cat,:cats]
diff --git a/src/interp/parse.boot b/src/interp/parse.boot
index cff6ef7c..92c040bd 100644
--- a/src/interp/parse.boot
+++ b/src/interp/parse.boot
@@ -211,6 +211,7 @@ parseHas t ==
       kk = "domain" or kk = "category" => [makeNonAtomic y]
       y is ["ATTRIBUTE",:.] => [y]
       y is ["SIGNATURE",:.] => [y]
+      y is [":",op,type] => [["SIGNATURE",op,[type],"constant"]]
       [["ATTRIBUTE",y]]
  
 parseDEF: %ParseForm -> %Form