-- Copyright (c) 1991-2002, The Numerical Algorithms Group Ltd.
-- All rights reserved.
-- Copyright (C) 2007-2008, Gabriel Dos Reis.
-- All rights reserved.
--
-- Redistribution and use in source and binary forms, with or without
-- modification, are permitted provided that the following conditions are
-- met:
--
--     - Redistributions of source code must retain the above copyright
--       notice, this list of conditions and the following disclaimer.
--
--     - Redistributions in binary form must reproduce the above copyright
--       notice, this list of conditions and the following disclaimer in
--       the documentation and/or other materials provided with the
--       distribution.
--
--     - Neither the name of The Numerical Algorithms Group Ltd. nor the
--       names of its contributors may be used to endorse or promote products
--       derived from this software without specific prior written permission.
--
-- THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
-- IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
-- TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
-- PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER
-- OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
-- EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
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-- LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
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-- SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.


import g_-util
namespace BOOT

module c_-util where
  clearReplacement: %Symbol -> %Thing
  replaceSimpleFunctions: %Form -> %Form

--% 
++ if true continue compiling after errors
$scanIfTrue := false


+++ If non nil, holds compiled value of 'Rep' of the current domain.
$Representation := nil


$formalArgList := []

--% Optimization control

++ true if we have to proclaim function signatures in the generated Lisp.
$optProclaim := false

++ true if we have to inline simple functions before codegen.
$optReplaceSimpleFunctions := false


--%

++ If using old `Rep' definition semantics, return `$' when m is `Rep'.
++ Otherwise, return `m'.
dollarIfRepHack m ==
  m = "Rep" and $useRepresentationHack => "$"
  m

++ The inverse of the above.
RepIfRepHack m ==
  m = "$" and $useRepresentationHack => "Rep"
  m

++ If using old `Rep' definition semantics, return `$' is m is `Rep'.
-- ??? Eventually this and the above should be merged and/or removed.
substituteDollarIfRepHack m ==
  $useRepresentationHack => substitute("$","Rep",m)
  m


++ Returns true if the form `t' is an instance of the Tuple constructor.
isTupleInstance: %Form -> %Boolean
isTupleInstance t ==
  t is ["Tuple",.]

++ Returns true if the signature `sig' describes a function that can
++ accept a homogeneous variable length argument list.
isHomoegenousVarargSignature: %Signature -> %Boolean
isHomoegenousVarargSignature sig ==
  #sig = 1 and isTupleInstance first sig

++ Returns true if the arguments list `args' match in shape the
++ parameter type list `sig'.  This means that either the number
++ of arguments is exactly the number of parameters, or that the
++ signature describes a homogeneous vararg operation.
enoughArguments: (%List,%Signature) -> %Boolean
enoughArguments(args,sig) ==
  #args = #sig or isHomoegenousVarargSignature sig

++ Returns true if the operation described by the signature `sig'
++ wants its arguments as a Tuple object.
wantArgumentsAsTuple: (%List,%Signature) -> %Boolean
wantArgumentsAsTuple(args,sig) ==
  isHomoegenousVarargSignature sig and #args ^= #sig

--% Debugging Functions
 
--CONTINUE() == continue()
continue() == FIN comp($x,$m,$f)
 
LEVEL(:l) == APPLY('level,l)
level(:l) ==
  null l => same()
  l is [n] and INTEGERP n => displayComp ($level:= n)
  SAY '"Correct format: (level n) where n is the level you want to go to"
 
UP() == up()
up() == displayComp ($level:= $level-1)
 
SAME() == same()
same() == displayComp $level
 
DOWN() == down()
down() == displayComp ($level:= $level+1)
 
displaySemanticErrors() ==
  n:= #($semanticErrorStack:= REMDUP $semanticErrorStack)
  n=0 => nil
  l:= NREVERSE $semanticErrorStack
  $semanticErrorStack:= nil
  sayBrightly bright '"  Semantic Errors:"
  displaySemanticError(l,$OutputStream)
  sayBrightly '" "
  displayWarnings()
 
displaySemanticError(l,stream) ==
  for x in l for i in 1.. repeat
    sayBrightly(['"      [",i,'"] ",:first x],stream)
 
displayWarnings() ==
  n:= #($warningStack:= REMDUP $warningStack)
  n=0 => nil
  sayBrightly bright '"  Warnings:"
  l := NREVERSE $warningStack
  displayWarning(l,$OutputStream)
  $warningStack:= nil
  sayBrightly '" "
 
displayWarning(l,stream) ==
  for x in l for i in 1.. repeat
    sayBrightly(['"      [",i,'"] ",:x],stream)
 
displayComp level ==
  $bright:= " << "
  $dim:= " >> "
  if $insideCapsuleFunctionIfTrue=true then
    sayBrightly ['"error in function",:bright $op,'%l]
  --mathprint removeZeroOne mkErrorExpr level
  pp removeZeroOne mkErrorExpr level
  sayBrightly ['"****** level",:bright level,'" ******"]
  [$x,$m,$f,$exitModeStack]:= ELEM($s,level)
  SAY("$x:= ",$x)
  SAY("$m:= ",$m)
  SAY "$f:="
  F_,PRINT_-ONE $f
  nil
 
mkErrorExpr level ==
  bracket ASSOCLEFT DROP(level-#$s,$s) where
    bracket l ==
      #l<2 => l
      l is [a,b] =>
        highlight(b,a) where
          highlight(b,a) ==
            atom b =>
              substitute(var,b,a) where
                var:= INTERN STRCONC(STRINGIMAGE $bright,STRINGIMAGE b,STRINGIMAGE $dim)
            highlight1(b,a) where
              highlight1(b,a) ==
                atom a => a
                a is [ =b,:c] => [$bright,b,$dim,:c]
                [highlight1(b,first a),:highlight1(b,rest a)]
      substitute(bracket rest l,first rest l,first l)
 
compAndTrace [x,m,e] ==
  SAY("tracing comp, compFormWithModemap of: ",x)
  TRACE_,1(["comp","compFormWithModemap"],nil)
  T:= comp(x,m,e)
  UNTRACE_,1 "comp"
  UNTRACE_,1 "compFormWithModemap"
  T
 
errorRef s == 
  stackWarning('"%1b has no value", [s])
 
unErrorRef s == 
  unStackWarning('"'%1b has no value",[s])
 
--% ENVIRONMENT FUNCTIONS
 
consProplistOf(var,proplist,prop,val) ==
  semchkProplist(var,proplist,prop,val)
  $InteractiveMode and (u:= assoc(prop,proplist)) =>
    RPLACD(u,val)
    proplist
  [[prop,:val],:proplist]
 
warnLiteral x ==
  stackWarning('"%1b is BOTH a variable a literal",[x])
 
intersectionEnvironment(e,e') ==
  ce:= makeCommonEnvironment(e,e')
  ic:= intersectionContour(deltaContour(e,ce),deltaContour(e',ce))
  e'':= (ic => addContour(ic,ce); ce)
  --$ie:= e''   this line is for debugging purposes only
 
deltaContour([[c,:cl],:el],[[c',:cl'],:el']) ==
  ^el=el' => systemError '"deltaContour" --a cop out for now
  eliminateDuplicatePropertyLists contourDifference(c,c') where
    contourDifference(c,c') == [first x for x in tails c while (x^=c')]
    eliminateDuplicatePropertyLists contour ==
      contour is [[x,:.],:contour'] =>
        LASSOC(x,contour') =>
                               --save some CONSing if possible
          [first contour,:DELLASOS(x,eliminateDuplicatePropertyLists contour')]
        [first contour,:eliminateDuplicatePropertyLists contour']
      nil
 
intersectionContour(c,c') ==
  $var: local
  computeIntersection(c,c') where
    computeIntersection(c,c') ==
      varlist:= REMDUP ASSOCLEFT c
      varlist':= REMDUP ASSOCLEFT c'
      interVars:= intersection(varlist,varlist')
      unionVars:= union(varlist,varlist')
      diffVars:= setDifference(unionVars,interVars)
      modeAssoc:= buildModeAssoc(diffVars,c,c')
      [:modeAssoc,:
        [[x,:proplist]
          for [x,:y] in c | member(x,interVars) and
            (proplist:= interProplist(y,LASSOC($var:= x,c')))]]
    interProplist(p,p') ==
                            --p is new proplist; p' is old one
      [:modeCompare(p,p'),:[pair' for pair in p | (pair':= compare(pair,p'))]]
    buildModeAssoc(varlist,c,c') ==
      [[x,:mp] for x in varlist | (mp:= modeCompare(LASSOC(x,c),LASSOC(x,c')))]
    compare(pair is [prop,:val],p') ==
      --1. if the property-value pair are identical, accept it immediately
      pair=(pair':= assoc(prop,p')) => pair
      --2. if property="value" and modes are unifiable, give intersection
      --       property="value" but value=genSomeVariable)()
      (val':= KDR pair') and prop="value" and
        (m:= unifiable(val.mode,val'.mode)) => ["value",genSomeVariable(),m,nil]
            --this tells us that an undeclared variable received
            --two different values but with identical modes
      --3. property="mode" is covered by modeCompare
      prop="mode" => nil
    modeCompare(p,p') ==
      pair:= assoc("mode",p) =>
        pair':= assoc("mode",p') =>
          m'':= unifiable(rest pair,rest pair') => LIST ["mode",:m'']
          stackSemanticError(['%b,$var,'%d,"has two modes: "],nil)
       --stackWarning ("mode for",'%b,$var,'%d,"introduced conditionally")
        LIST ["conditionalmode",:rest pair]
        --LIST pair
       --stackWarning ("mode for",'%b,$var,'%d,"introduced conditionally")
      pair':= assoc("mode",p') => LIST ["conditionalmode",:rest pair']
        --LIST pair'
    unifiable(m1,m2) ==
      m1=m2 => m1
        --we may need to add code to coerce up to tagged unions
        --but this can not be done here, but should be done by compIf
      m:=
        m1 is ["Union",:.] =>
          m2 is ["Union",:.] => ["Union",:S_+(rest m1,rest m2)]
          ["Union",:S_+(rest m1,[m2])]
        m2 is ["Union",:.] => ["Union",:S_+(rest m2,[m1])]
        ["Union",m1,m2]
      for u in getDomainsInScope $e repeat
        if u is ["Union",:u'] and (and/[member(v,u') for v in rest m]) then
          return m
        --this loop will return NIL if not satisfied
 
addContour(c,E is [cur,:tail]) ==
  [NCONC(fn(c,E),cur),:tail] where
    fn(c,e) ==
        for [x,:proplist] in c repeat
           fn1(x,proplist,getProplist(x,e)) where
              fn1(x,p,ee) ==
                for pv in p repeat fn3(x,pv,ee) where
                 fn3(x,pv,e) ==
                   [p,:v]:=pv
                   if member(x,$getPutTrace) then
                     pp([x,"has",pv])
                   if p="conditionalmode" then
                     RPLACA(pv,"mode")
                     --check for conflicts with earlier mode
                     if vv:=LASSOC("mode",e) then
                        if v ^=vv then
                          stackWarning('"The conditional modes %1p and %2p conflict",
                            [v,vv])
        LIST c
 
makeCommonEnvironment(e,e') ==
  interE makeSameLength(e,e') where  --$ie:=
    interE [e,e'] ==
      rest e=rest e' => [interLocalE makeSameLength(first e,first e'),:rest e]
      interE [rest e,rest e']
    interLocalE [le,le'] ==
      rest le=rest le' =>
        [interC makeSameLength(first le,first le'),:rest le]
      interLocalE [rest le,rest le']
    interC [c,c'] ==
      c=c' => c
      interC [rest c,rest c']
    makeSameLength(x,y) ==
      fn(x,y,#x,#y) where
        fn(x,y,nx,ny) ==
          nx>ny => fn(rest x,y,nx-1,ny)
          nx<ny => fn(x,rest y,nx,ny-1)
          [x,y]
 
printEnv E ==
  for x in E for i in 1.. repeat
    for y in x for j in 1.. repeat
      SAY('"******CONTOUR ",j,'", LEVEL ",i,'":******")
      for z in y repeat
        TERPRI()
        SAY("Properties Of: ",first z)
        for u in rest z repeat
          PRIN0 first u
          printString ": "
          PRETTYPRINT tran(rest u,first u) where
            tran(val,prop) ==
              prop="value" => DROP(-1,val)
              val
 
prEnv E ==
  for x in E for i in 1.. repeat
    for y in x for j in 1.. repeat
      SAY('"******CONTOUR ",j,'", LEVEL ",i,'":******")
      for z in y | not LASSOC("modemap",rest z) repeat
        TERPRI()
        SAY("Properties Of: ",first z)
        for u in rest z repeat
          PRIN0 first u
          printString ": "
          PRETTYPRINT tran(rest u,first u) where
            tran(val,prop) ==
              prop="value" => DROP(-1,val)
              val
 
prModemaps E ==
  listOfOperatorsSeenSoFar:= nil
  for x in E for i in 1.. repeat
    for y in x for j in 1.. repeat
      for z in y | null member(first z,listOfOperatorsSeenSoFar) and
        (modemap:= LASSOC("modemap",rest z)) repeat
          listOfOperatorsSeenSoFar:= [first z,:listOfOperatorsSeenSoFar]
          TERPRI()
          PRIN0 first z
          printString ": "
          PRETTYPRINT modemap
 
prTriple T ==
   SAY '"Code:"
   pp T.0
   SAY '"Mode:"
   pp T.1
 
TrimCF() ==
  new:= nil
  old:= CAAR $CategoryFrame
  for u in old repeat
    if not ASSQ(first u,new) then
      uold:= rest u
      unew:= nil
      for v in uold repeat if not ASSQ(first v,unew) then unew:= [v,:unew]
      new:= [[first u,:NREVERSE unew],:new]
  $CategoryFrame:= [[NREVERSE new]]
  nil

--%
 
++ Returns non-nil if `t' is a known type in the environement `e'.
isKnownType: (%Mode,%Env) -> %Form
isKnownType(t,e) ==
  atom t =>
    t in '($ constant) => t
    t' := assoc(t,getDomainsInScope e) => t'
    get(first getmode(t,e),"isCategory",$CategoryFrame) => t
    STRINGP t => t
  t is ["Mapping",:sig] => 
    and/[isKnownType(t',e) for t' in sig] => t
    nil
  ctor := first t
  ctor in $BuiltinConstructorNames => t -- ??? check Record and Union fields
  -- ??? Ideally `e' should be a local extension of $CategoryFrame
  -- ??? so that we don't have to access it here as a global state.
  get(ctor,"isFunctor",$CategoryFrame) 
    or get(ctor,"isCategory",$CategoryFrame) => t
  nil
 
diagnoseUknownType: (%Mode,%Env) -> %Thing
diagnoseUknownType(t,e) ==
  if not isKnownType(t,e) then
    stackWarning('"%1pb is unknown.  Try importing it.",[t])

 
--% PREDICATES
 
 
isConstantId(name,e) ==
  IDENTP name =>
    pl:= getProplist(name,e) =>
      (LASSOC("value",pl) or LASSOC("mode",pl) => false; true)
    true
  false
 
isFalse() == nil
 
isFluid s == atom s and "$"=(PNAME s).(0)
 
isFunction(x,e) ==
  get(x,"modemap",e) or GETL(x,"SPECIAL") or x="case" or getmode(x,e) is [
    "Mapping",:.]
 
isLiteral: (%Symbol,%Env) -> %Boolean
isLiteral(x,e) == 
  get(x,"isLiteral",e)
 

makeLiteral: (%Symbol,%Env) -> %Thing
makeLiteral(x,e) == 
  put(x,"isLiteral","true",e)
 
isSomeDomainVariable s ==
  IDENTP s and #(x:= PNAME s)>2 and x.(0)="#" and x.(1)="#"
 
isSubset(x,y,e) ==
  ($useRepresentationHack and x="$" and y="Rep") or x=y or
    LASSOC(opOf x,get(opOf y,"Subsets",e) or GETL(opOf y,"Subsets")) or
      LASSOC(opOf x,get(opOf y,"SubDomain",e)) or
        opOf(y)='Type or opOf(y)='Object
 
isDomainInScope(domain,e) ==
  domainList:= getDomainsInScope e
  atom domain =>
    MEMQ(domain,domainList) => true
    not IDENTP domain or isSomeDomainVariable domain => true
    false
  (name:= first domain)="Category" => true
  ASSQ(name,domainList) => true
--   null CDR domain or domainMember(domain,domainList) => true
--   false
  isFunctor name => false
  true --is not a functor
 
isSymbol x == IDENTP x or x=nil
 
isSimple x ==
  atom x or $InteractiveMode => true
  x is [op,:argl] and
    isSideEffectFree op and (and/[isSimple y for y in argl])
 
isSideEffectFree op ==
  member(op,$SideEffectFreeFunctionList) or op is ["elt",.,op'] and
    isSideEffectFree op'
 
isAlmostSimple x ==
  --returns (<new predicate> . <list of assignments>) or nil
  $assignmentList: local --$assigmentList is only used in this function
  transform:=
    fn x where
      fn x ==
        atom x or null rest x => x
        [op,y,:l]:= x
        op="has" => x
        op="is" => x
        op="%LET" =>
          IDENTP y => (setAssignment LIST x; y)
          (setAssignment [["%LET",g:= genVariable(),:l],["%LET",y,g]]; g)
        op = "case" and IDENTP y => x
        isSideEffectFree op => [op,:mapInto(rest x, function fn)]
        $assignmentList:= "failed"
      setAssignment x ==
        $assignmentList="failed" => nil
        $assignmentList:= [:$assignmentList,:x]
  $assignmentList="failed" => nil
  wrapSEQExit [:$assignmentList,transform]
 
incExitLevel u ==
  adjExitLevel(u,1,1)
  u
 
decExitLevel u ==
  (adjExitLevel(u,1,-1); removeExit0 u) where
    removeExit0 x ==
      atom x => x
      x is ["exit",0,u] => removeExit0 u
      [removeExit0 first x,:removeExit0 rest x]
 
adjExitLevel(x,seqnum,inc) ==
  atom x => x
  x is [op,:l] and MEMQ(op,'(SEQ REPEAT COLLECT)) =>
    for u in l repeat adjExitLevel(u,seqnum+1,inc)
  x is ["exit",n,u] =>
    (adjExitLevel(u,seqnum,inc); seqnum>n => x; rplac(CADR x,n+inc))
  x is [op,:l] => for u in l repeat adjExitLevel(u,seqnum,inc)
 
wrapSEQExit l ==
  null rest l => first l
  [:c,x]:= [incExitLevel u for u in l]
  ["SEQ",:c,["exit",1,x]]
 
 
--% UTILITY FUNCTIONS
 
--appendOver x == "append"/x
 
removeEnv t == [t.expr,t.mode,$EmptyEnvironment]  -- t is a triple
 
-- This function seems no longer used
--ordinsert(x,l) ==
--  null l => [x]
--  x=first l => l
--  _?ORDER(x,first l) => [x,:l]
--  [first l,:ordinsert(x,rest l)]
 
makeNonAtomic x ==
  atom x => [x]
  x
 
flatten(l,key) ==
  null l => nil
  first l is [k,:r] and k=key => [:r,:flatten(rest l,key)]
  [first l,:flatten(rest l,key)]
 
genDomainVar() ==
  $Index:= $Index+1
  INTERNL STRCONC("#D",STRINGIMAGE $Index)
 
genVariable() ==
  INTERNL STRCONC("#G",STRINGIMAGE ($genSDVar:= $genSDVar+1))
 
genSomeVariable() ==
  INTERNL STRCONC("##",STRINGIMAGE ($genSDVar:= $genSDVar+1))
 
listOfIdentifiersIn x ==
  IDENTP x => [x]
  x is [op,:l] => REMDUP ("append"/[listOfIdentifiersIn y for y in l])
  nil
 
mapInto(x,fn) == [FUNCALL(fn,y) for y in x]
 
numOfOccurencesOf(x,y) ==
  fn(x,y,0) where
    fn(x,y,n) ==
      null y => 0
      x=y => n+1
      atom y => n
      fn(x,first y,n)+fn(x,rest y,n)
 
compilerMessage(msg,args) ==
  $PrintCompilerMessageIfTrue => sayPatternMsg(msg,args)
 
printDashedLine() ==
  SAY
   '"--------------------------------------------------------------------------"
 
stackSemanticError(msg,expr) ==
  BUMPERRORCOUNT "semantic"
  if $insideCapsuleFunctionIfTrue then msg:= [$op,": ",:msg]
  if atom msg then msg:= LIST msg
  entry:= [msg,expr]
  if not member(entry,$semanticErrorStack) then $semanticErrorStack:=
    [entry,:$semanticErrorStack]
  $scanIfTrue and $insideCapsuleFunctionIfTrue=true and #$semanticErrorStack-
    $initCapsuleErrorCount>3 => THROW("compCapsuleBody",nil)
  nil
 
stackWarning(msg,args == nil) ==
  msg := buildMessage(msg, args)
  if $insideCapsuleFunctionIfTrue then msg:= [$op,": ",:msg]
  if not member(msg,$warningStack) then $warningStack:= [msg,:$warningStack]
  nil
 
unStackWarning(msg,args) ==
  msg := buildMessage(msg,args)
  if $insideCapsuleFunctionIfTrue then msg:= [$op,": ",:msg]
  $warningStack:= EFFACE(msg,$warningStack)
  nil
 
stackMessage(msg,args == nil) ==
  if args ^= nil then
    msg := buildMessage(msg,args)
  $compErrorMessageStack:= [msg,:$compErrorMessageStack]
  nil
 
stackMessageIfNone msg ==
  --used in situations such as compForm where the earliest message is wanted
  if null $compErrorMessageStack then $compErrorMessageStack:=
    [msg,:$compErrorMessageStack]
  nil
 
stackAndThrow(msg, args == nil) ==
  if args ^= nil then
    msg := buildMessage(msg,args)
  $compErrorMessageStack:= [msg,:$compErrorMessageStack]
  THROW("compOrCroak",nil)
 
printString x == PRINTEXP (STRINGP x => x; PNAME x)
 
printAny x == if atom x then printString x else PRIN0 x
 
printSignature(before,op,[target,:argSigList]) ==
  printString before
  printString op
  printString ": _("
  if argSigList then
    printAny first argSigList
    for m in rest argSigList repeat (printString ","; printAny m)
  printString "_) -> "
  printAny target
  TERPRI()
 
pmatch(s,p) == pmatchWithSl(s,p,"ok")
 
pmatchWithSl(s,p,al) ==
  s=$EmptyMode => nil
  s=p => al
  v:= assoc(p,al) => s=rest v or al
  MEMQ(p,$PatternVariableList) => [[p,:s],:al]
  null atom p and null atom s and (al':= pmatchWithSl(first s,first p,al)) and
    pmatchWithSl(rest s,rest p,al')
 
elapsedTime() ==
  currentTime:= TEMPUS_-FUGIT()
  elapsedSeconds:= (currentTime-$previousTime)*QUOTIENT(1.0,$timerTicksPerSecond)
  $previousTime:= currentTime
  elapsedSeconds
 
addStats([a,b],[c,d]) == [a+c,b+d]
 
printStats [byteCount,elapsedSeconds] ==
  timeString := normalizeStatAndStringify elapsedSeconds
  if byteCount = 0 then SAY('"Time: ",timeString,'" SEC.") else
    SAY('"Size: ",byteCount,'" BYTES     Time: ",timeString,'" SEC.")
  TERPRI()
  nil
 
extendsCategoryForm(domain,form,form') ==
  --is domain of category form also of category form'?
  --domain is only used for SubsetCategory resolution.
  --and ensuring that X being a Ring means that it
  --satisfies (Algebra X)
  form=form' => true
  form=$Category => nil
  form' is ["Join",:l] => and/[extendsCategoryForm(domain,form,x) for x in l]
  form' is ["CATEGORY",.,:l] =>
    and/[extendsCategoryForm(domain,form,x) for x in l]
  form' is ["SubsetCategory",cat,dom] =>
    extendsCategoryForm(domain,form,cat) and isSubset(domain,dom,$e)
  form is ["Join",:l] => or/[extendsCategoryForm(domain,x,form') for x in l]
  form is ["CATEGORY",.,:l] =>
    member(form',l) or
      stackWarning('"not known that %1 is of mode %2p",[form',form]) or true
  isCategoryForm(form,$EmptyEnvironment) =>
          --Constructs the associated vector
    formVec:=(compMakeCategoryObject(form,$e)).expr
            --Must be $e to pick up locally bound domains
    form' is ["SIGNATURE",op,args,:.] =>
        assoc([op,args],formVec.(1)) or
            assoc(SUBSTQ(domain,"$",[op,args]),
                  SUBSTQ(domain,"$",formVec.(1)))
    form' is ["ATTRIBUTE",at] =>
         assoc(at,formVec.2) or
            assoc(SUBSTQ(domain,"$",at),SUBSTQ(domain,"$",formVec.2))
    form' is ["IF",:.] => true --temporary hack so comp won't fail
    -- Are we dealing with an Aldor category?  If so use the "has" function ...
    # formVec = 1 => newHasTest(form,form')
    catvlist:= formVec.4
    member(form',first catvlist) or
     member(form',SUBSTQ(domain,"$",first catvlist)) or
      (or/
        [extendsCategoryForm(domain,SUBSTQ(domain,"$",cat),form')
          for [cat,:.] in CADR catvlist])
  nil
 
getmode(x,e) ==
  prop:=getProplist(x,e)
  u:= LASSQ("value",prop) => u.mode
  LASSQ("mode",prop)
 
getmodeOrMapping(x,e) ==
  u:= getmode(x,e) => u
  (u:= get(x,"modemap",e)) is [[[.,:map],.],:.] => ["Mapping",:map]
  nil
 
outerProduct l ==
                --of a list of lists
  null l => LIST nil
  "append"/[[[x,:y] for y in outerProduct rest l] for x in first l]
 
sublisR(al,u) ==
  atom u => u
  y:= rassoc(t:= [sublisR(al,x) for x in u],al) => y
  true => t
 
substituteOp(op',op,x) ==
  atom x => x
  [(op=(f:= first x) => op'; f),:[substituteOp(op',op,y) for y in rest x]]
 
--substituteForFormalArguments(argl,expr) ==
--  SUBLIS([[v,:a] for a in argl for v in $FormalMapVariableList],expr)
 
 -- following is only intended for substituting in domains slots 1 and 4
 -- signatures and categories
sublisV(p,e) ==
  (atom p => e; suba(p,e)) where
    suba(p,e) ==
      STRINGP e => e
      -- no need to descend vectors unless they are categories
      --REFVECP e => LIST2REFVEC [suba(p,e.i) for i in 0..MAXINDEX e]
      isCategory e => LIST2REFVEC [suba(p,e.i) for i in 0..MAXINDEX e]
      atom e => (y:= ASSQ(e,p) => rest y; e)
      u:= suba(p,QCAR e)
      v:= suba(p,QCDR e)
      EQ(QCAR e,u) and EQ(QCDR e,v) => e
      [u,:v]

--% DEBUGGING PRINT ROUTINES used in breaks
 
_?MODEMAPS x == _?modemaps x
_?modemaps x ==
  env:=
    $insideCapsuleFunctionIfTrue=true => $CapsuleModemapFrame
    $f
  x="all" => displayModemaps env
  -- displayOpModemaps(x,old2NewModemaps get(x,"modemap",env))
  displayOpModemaps(x,get(x,"modemap",env))


old2NewModemaps x ==
--  [[dcSig,pred] for [dcSig,[pred,:.],:.] in x]
  x is [dcSig,[pred,:.],:.]  =>  [dcSig,pred]
  x

traceUp() ==
  atom $x => sayBrightly "$x is an atom"
  for y in rest $x repeat
    u:= comp(y,$EmptyMode,$f) =>
      sayBrightly [y,'" ==> mode",'%b,u.mode,'%d]
    sayBrightly [y,'" does not compile"]
 
_?M x == _?m x
_?m x ==
  u:= comp(x,$EmptyMode,$f) => u.mode
  nil
 
traceDown() ==
  mmList:= getFormModemaps($x,$f) =>
    for mm in mmList repeat if u:= qModemap mm then return u
  sayBrightly "no modemaps for $x"
 
qModemap mm ==
  sayBrightly ['%b,"modemap",'%d,:formatModemap mm]
  [[dc,target,:sl],[pred,:.]]:= mm
  and/[qArg(a,m) for a in rest $x for m in sl] => target
  sayBrightly ['%b,"fails",'%d,'%l]
 
qArg(a,m) ==
  yesOrNo:=
    u:= comp(a,m,$f) => "yes"
    "no"
  sayBrightly [a," --> ",m,'%b,yesOrNo,'%d]
  yesOrNo="yes"
 
_?COMP x == _?comp x
_?comp x ==
  msg:=
    u:= comp(x,$EmptyMode,$f) =>
      [MAKESTRING "compiles to mode",'%b,u.mode,'%d]
    nil
  sayBrightly msg
 
_?domains() == pp getDomainsInScope $f
_?DOMAINS() == ?domains()
 
_?mode x == displayProplist(x,[["mode",:getmode(x,$f)]])
_?MODE x == _?mode x
 
_?properties x == displayProplist(x,getProplist(x,$f))
_?PROPERTIES x == _?properties x
 
_?value x == displayProplist(x,[["value",:get(x,"value",$f)]])
_?VALUE x == _?value x
 
displayProplist(x,alist) ==
  sayBrightly ["properties of",'%b,x,'%d,":"]
  fn alist where
    fn alist ==
      alist is [[prop,:val],:l] =>
        if prop="value" then val:= [val.expr,val.mode,'"..."]
        sayBrightly ["   ",'%b,prop,'%d,": ",val]
        fn deleteAssoc(prop,l)
 
displayModemaps E ==
  listOfOperatorsSeenSoFar:= nil
  for x in E for i in 1.. repeat
    for y in x for j in 1.. repeat
      for z in y | null member(first z,listOfOperatorsSeenSoFar) and
        (modemaps:= LASSOC("modemap",rest z)) repeat
          listOfOperatorsSeenSoFar:= [first z,:listOfOperatorsSeenSoFar]
          displayOpModemaps(first z,modemaps)
 
--% General object traversal functions
 
GCOPY ob == COPY ob  -- for now
 
--%
++ format the set of candidate operations.
displayAmbiguousSignatures(op,sigs) ==
  [:showCandidate(op, sig) for sig in sigs] where
     showCandidate(op,sig) ==
       ["%l", "        ", op, '": ", 
         :bright formatUnabbreviated ["Mapping",:sig]]

++ Display diagnostic message about ambiguous operation `op', with
++ possible resolutions given by the list `sigs'.
ambiguousSignatureError(op, sigs) ==
  stackSemanticError(['"signature of lhs not unique.  Candidates are:",
    :displayAmbiguousSignatures($op,sigs)],nil)

--% 

-- A function is simple if it looks like a super combinator, and it
-- does not use its environment argument.  They can be safely replaced
-- by more efficient (hopefully) functions.

getFunctionReplacement: %Symbol -> %Form
getFunctionReplacement name ==
  GET(compileTimeBindingOf name, "SPADreplace")

++ remove any replacement info possibly associated with `name'.
clearReplacement name ==
  REMPROP(name,"SPADreplace")

eqSubstAndCopy: (%List, %List, %Form) -> %Form
eqSubstAndCopy(args,parms,body) ==
  SUBLIS(pairList(parms,args),body,KEYWORD::TEST,function EQ)

eqSubst: (%List, %List, %Form) -> %Form
eqSubst(args,parms,body) ==
  NSUBLIS(pairList(parms,args),body,KEYWORD::TEST,function EQ)


++ returns true if `form' does not really induce computations.
isAtomicForm: %Form -> %Boolean
isAtomicForm form ==
  atom form or first form = "QUOTE"

++ Walk `form' and replace simple functions as appropriate.
replaceSimpleFunctions form ==
  isAtomicForm form => form
  -- 1. process argument first.
  for args in tails rest form repeat
    arg' := replaceSimpleFunctions(arg := first args)
    not EQ(arg',arg) =>
      rplac(first args, arg')
  -- 2. see if we know something about this function.
  [fun,:args] := form
  atom fun =>
    null (fun' := getFunctionReplacement fun) => form
    -- 2.1. the renaming case.
    atom fun' =>
      rplac(first form,fun')
      NBUTLAST form
    -- 2.2. the substitution case.
    fun' is ["XLAM",parms,body] =>
      -- conservatively approximate eager semantics
      and/[isAtomicForm first as for as in tails args] =>
        -- alpha rename before substitution.
	newparms := [GENSYM() for p in parms]
	body := eqSubstAndCopy(newparms,parms,body)
	eqSubst(args,newparms,body)
      -- get cute later.
      form
    form
  fun' := replaceSimpleFunctions fun
  not EQ(fun',fun) => rplac(first form,fun')
  form

++ record optimizations permitted at level `level'.
setCompilerOptimizations level ==
  level = nil => nil
  INTEGERP level =>
    if level = 0 then
      -- explicit request for no optimization.
      $optProclaim := false
      $optReplaceSimpleFunctions := false
    if level > 0 then 
      $optProclaim := true
      $optReplaceSimpleFunctions := true
  coreError '"unknown optimization level request"


--%

++ Proclaim the type of the capsule function `op' with signature `sig'.
++ Note that all capsule functions take an additional argument 
++ standing for the domain of computation object.
proclaimCapsuleFunction(op,sig) ==
  LAM_,EVALANDFILEACTQ
    ["DECLAIM",["FTYPE",
       ["FUNCTION",[:[vmType first d for d in tails rest sig],"%Shell"], 
          vmType first sig],op]] where
      vmType d ==
        getVMType normalize(d,true)
      normalize(d,top?) ==
        d = "$" => 
          not top? => "*"
          -- If the representation is explicitly stated, use it.  That way
          -- we optimize abstractions just as well as builtins.
          r := get("Rep","value",$e) => normalize(r.expr,top?)
          -- Cope with old-style constructor definition
          atom $functorForm => [$functorForm] 
          normalize($functorForm,top?)
        atom d => 
          top? => "%Thing"
          getmode(d,$e) => "*"
          d
        [first d, :[normalize(first args,false) for args in tails rest d]]