path: root/src/interp/functor.boot

-- Copyright (c) 1991-2002, The Numerical Algorithms Group Ltd.
-- All rights reserved.
-- Copyright (C) 2007-2011, Gabriel Dos Reis.
-- All rights reserved.
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import lisplib
import interop
import category
namespace BOOT

--% Functions for building categories
 
CategoryPrint(D,$e) ==
  SAY "--------------------------------------"
  SAY "Name (and arguments) of category:"
  PRETTYPRINT canonicalForm D
  SAY "operations:"
  PRETTYPRINT categoryExports D
  SAY "attributes:"
  PRETTYPRINT categoryAttributes D
  SAY "This is a sub-category of"
  PRETTYPRINT first categoryRef(D,4)
  for u in second categoryRef(D,4) repeat
    SAY("This has an alternate view: slot ",rest u," corresponds to ",first u)
  for u in third categoryRef(D,4) repeat
    SAY("This has a local domain: slot ",rest u," corresponds to ",first u)
  for j in 6..maxIndex D repeat
    u := categoryRef(D,j)
    null u => SAY "another domain"
    first u isnt [.,:.] => SAY("Alternate View corresponding to: ",u)
    PRETTYPRINT u

--%  Domain printing
keyItem a ==
  isDomain a => CDAR domainRef(a,4)
  a
  --The item that domain checks on
 
--Global strategy here is to maintain a list of substitutions
--  ( in $Sublis), of vectors and the names that they have,
--  which may be either local names ('View1') or global names ('Where1')
--  The global names are remembered on $Sublis from one
--  invocation of DomainPrint1 to the next
 
DomainPrint(D,brief) ==
  -- If brief is non-nil, %then only a summary is printed
  $WhereList: local := nil
  $Sublis: local := nil
  $WhereCounter: local := 1
  env:= $e or $EmptyEnvironment --in case we are called from top level
  categoryObject? D => CategoryPrint(D,env)
  $Sublis:= [[keyItem D,:'original]]
  SAY '"-----------------------------------------------------------------------"
  DomainPrint1(D,nil,env)
  while ($WhereList) repeat
    s:= $WhereList
    $WhereList:= nil
    for u in s repeat
      TERPRI()
      SAY ['"Where ",first u,'" is:"]
      DomainPrint1(rest u,brief,env)
  SAY '"-----------------------------------------------------------------------"
 
DomainPrint1(D,brief,$e) ==
  vector? D and not isDomain D => PacPrint D
  if vector? D then
    D := D.4 --if we were passed a vector, go to the domain
  Sublis:=
    [:
      [[rest u,:makeSymbol strconc('"View",toString i)]
        for u in D for i in 1..],:$Sublis]
  for u in D for i in 1.. repeat
    brief and i>1 => nil
    uu := copyVector rest u
    uu.4 := '"This domain"
    if not brief then
      SAY ['"View number ",i,'" corresponding to categories:"]
      PRETTYPRINT first u
    if i=1 and vector? uu.5 then
      vv := copyVector uu.5
      uu.5 := vv
      for j in 0..maxIndex vv repeat
        if vector? vv.j then
          l := ASSQ(keyItem vv.j,Sublis)
          if l
             then name:= rest l
             else
              name := DPname()
              Sublis := [[keyItem vv.j,:name],:Sublis]
              $Sublis := [first Sublis,:$Sublis]
              $WhereList := [[name,:vv.j],:$WhereList]
          vv.j := name
    if i>1 then
      uu.1 := uu.2 := uu.5 := '"As in first view"
    for i in 6..maxIndex uu repeat
      uu.i := DomainPrintSubst(uu.i,Sublis)
      if vector? uu.i then
        name := DPname()
        Sublis := [[keyItem uu.i,:name],:Sublis]
        $Sublis := [first Sublis,:$Sublis]
        $WhereList := [[name,:uu.i],:$WhereList]
        uu.i := name
      if uu.i is [.,:v] and vector? v then
        name := DPname()
        Sublis := [[keyItem v,:name],:Sublis]
        $Sublis := [first Sublis,:$Sublis]
        $WhereList := [[name,:v],:$WhereList]
        uu.i := [first uu.i,:name]
    brief => PRETTYPRINT uu.0
    PRETTYPRINT uu
 
DPname() ==
  name := INTERNL strconc('"Where",toString $WhereCounter)
  $WhereCounter := $WhereCounter+1
  name
 
PacPrint v ==
  vv := copyVector v
  for j in 0..maxIndex vv repeat
    if vector? vv.j then
      l := ASSQ(keyItem vv.j,Sublis)
      if l
         then name := rest l
         else
          name := DPname()
          Sublis := [[keyItem vv.j,:name],:Sublis]
          $Sublis := [first Sublis,:$Sublis]
          $WhereList := [[name,:vv.j],:$WhereList]
      vv.j := name
    if cons? vv.j and vector?(u:=rest vv.j) then
      l := ASSQ(keyItem u,Sublis)
      if l
         then name := rest l
         else
          name := DPname()
          Sublis := [[keyItem u,:name],:Sublis]
          $Sublis := [first Sublis,:$Sublis]
          $WhereList := [[name,:u],:$WhereList]
      vv.j.rest := name
  PRETTYPRINT vv
 
DomainPrintSubst(item,Sublis) ==
  item is [a,:b] =>
    c1 := DomainPrintSubst(a,Sublis)
    c2 := DomainPrintSubst(b,Sublis)
    sameObject?(c1,a) and sameObject?(c2,b) => item
    [c1,:c2]
  l := ASSQ(item,Sublis)
  l => rest l
  l := ASSQ(keyItem item,Sublis)
  l => rest l
  item
 
--%  Utilities
 
mkDevaluate a ==
  a = nil => nil
  a is ['QUOTE,a'] =>
    a' = nil => nil
    a
  a is '$ => MKQ '$
  a is ['%list,:.] =>
    a.args = nil => nil
    a
  ['devaluate,a]
 
getDomainView(domain,catform) ==
  u := HasCategory(domain,catform) => u
  c := eval catform
  u := HasCategory(domain,c.0) => u
  -- note:  this is necessary because of domain == another domain, e.g.
  -- Ps are defined to be SUPs with specific arguments so that if one
  -- asks if a P is a Module over itself, here one has catform= (Module
  -- (P I)) yet domain is a SUP.  By oding this evaluation, c.0=SUP as
  -- well and test works --- RDJ 10/31/83
  throwKeyedMsg("S2IF0009",[devaluate domain, catform])
 
getPrincipalView domain ==
  pview := domain
  for [.,:view] in domain.4 repeat
    if #view > #pview then
      pview := view
  pview
 
CategoriesFromGDC x ==
  x isnt [.,:.] => nil
  x is ['%list,a,:b] and a is ['QUOTE,a'] =>
    union([[a']],"union"/[CategoriesFromGDC u for u in b])
  x is ['QUOTE,a] and a is [b] => [a]
 
compCategories u ==
  u isnt [.,:.] => u
  cons? u.op =>
    error ['"compCategories: need an atom in operator position", u.op]
  u.op in '(Record Union Mapping) =>
    -- There is no modemap property for these guys so do it by hand.
    [u.op, :[compCategories1(a,$SetCategory) for a in u.args]]
  u is ['SubDomain,D,.] => compCategories D
  v := get(u.op,'modemap,$e)
  v isnt [.,:.] =>
    error ['"compCategories: could not get proper modemap for operator",u.op]
  if rest v then
    sayBrightly ['"compCategories: ", '"%b", '"Warning", '"%d",
                 '"ignoring unexpected stuff at end of modemap"]
    pp rest v
  -- the next line "fixes" a bad modemap which sometimes appears ....
  --
  if rest v and null CAAAR v then
    v := rest v
  v := resolvePatternVars(first(v).mmSource, u.args) -- replaces #n forms
  -- select the modemap part of the first entry, and skip result etc.
  [u.op,:[compCategories1(a,b) for a in u.args for b in v]]
 
compCategories1(u,v) ==
-- v is the mode of u
  u isnt [.,:.] => u
  u is [":",x,t] => [u.op,x,compCategories1(t,v)]
  isCategoryForm(v,$e) => compCategories u
  [c,:.] := comp(macroExpand(u,$e),v,$e) => c
  error 'compCategories1
 
NewbFVectorCopy(u,domName) ==
  v := newShell # u
  for i in 0..5 repeat vectorRef(v,i) := vectorRef(u,i)
  for i in 6..maxIndex v | cons? vectorRef(u,i) repeat
    vectorRef(v,i) := [function Undef,[domName,i],:first vectorRef(u,i)]
  v
 
optFunctorBody x ==
  atomic? x => x
  x is ['DomainSubstitutionMacro,parms,body] =>
    optFunctorBody DomainSubstitutionFunction(parms,body)
  x is ['%list,:l] =>
    null l => nil
    l:= [optFunctorBody u for u in l]
    and/[optFunctorBodyQuotable u for u in l] =>
      ['QUOTE,[optFunctorBodyRequote u for u in l]]
    ['%list,:l]
  x is ['PROGN,:l] => ['PROGN,:optFunctorPROGN l]
  x is ['%when,:l] =>
    l := [v for u in l | v := relevantClause u] where
            relevantClause u ==
              u is [pred,:conseq] =>
                u := [optFunctorBody pred,:optFunctorPROGN conseq]
                u is ['%otherwise] => nil
                u
              nil
    l = nil => nil
    CAAR l='%otherwise =>
      (null CDAR l => nil; null CDDAR l => CADAR l; ["PROGN",:CDAR l])
    null rest l and null CDAR l =>
            --there is no meat to this conditional form
      pred:= CAAR l
      pred isnt [.,:.] => nil
      first pred="HasCategory" => nil
      ['%when,:l]
    ['%when,:l]
  [optFunctorBody u for u in x]
 
optFunctorBodyQuotable u ==
  u = nil or integer? u or string? u => true
  u isnt [.,:.] => false
  u is ['QUOTE,:.] => true
  false
 
optFunctorBodyRequote u ==
  u isnt [.,:.] => u
  u is ['QUOTE,v] => v
  systemErrorHere ["optFunctorBodyRequote",u]
 
optFunctorPROGN l ==
  l is [x,:l'] =>
    worthlessCode x => optFunctorPROGN l'
    l':= optFunctorBody l'
    l' is [nil] => [optFunctorBody x]
    [optFunctorBody x,:l']
  l
 
worthlessCode x ==
  x is ['%when,:l] and (and/[x is [.,y] and worthlessCode y for x in l]) => true
  x is ['PROGN,:l] => (null (l':= optFunctorPROGN l) => true; false)
  x is ['%list] => true
  null x => true
  false
 
cons5(p,l) ==
  l and (CAAR l = first p) => [p,: rest l]
  # l < 5 => [p,:l]
  QCDDDDR(l).rest := nil
  [p,:l]
 
setVector0(catNames,definition) ==
          --returns code to set element 0 of the vector
          --to the definition of the category
  definition:= mkTypeForm definition
  for u in catNames repeat
    definition:= ['%store,['%tref,u,0],definition]
  definition
 
setVector12 args ==
            --The purpose of this function is to replace place holders
            --e.g. argument names or gensyms, by real values
  null args => nil
  args1:=args2:=args
  for u in $extraParms repeat
            --A typical element of $extraParms, which is set in
            --DomainSubstitutionFunction, would be (gensym) cons
            --(category parameter), e.g. DirectProduct(length vl,NNI)
            --as in DistributedMultivariatePolynomial
    args1:=[u.op,:args1]
    args2:=[u.args,:args2]
  freeof(categoryExports $domainShell,args1) and
      freeof($domainShell.2,args1) and
          freeof($domainShell.4,args1) => nil  
  [['SetDomainSlots124,'$,['QUOTE,args1],['%list,:args2]]]
 where freeof(a,b) ==
         a isnt [.,:.] => null symbolMember?(a,b)
         freeof(first a,b) => freeof(rest a,b)
         false
 
SetDomainSlots124(vec,names,vals) ==
  l := pairList(names,vals)
  vectorRef(vec,1) := sublisProp(l,vectorRef(vec,1))
  vectorRef(vec,2) := sublisProp(l,vectorRef(vec,2))
  l:= [[a,:devaluate b] for a in names for b in vals]
  vectorRef(vec,4) := applySubst(l,vectorRef(vec,4))
  vectorRef(vec,1) := applySubst(l,vectorRef(vec,1))
 
sublisProp(subst,props) ==
  null props => nil
  [cp,:props']:= props
  (a' := inspect(cp,subst)) where
    inspect(cp is [a,cond,:l],subst) ==
      cond=true => cp
                        --keep original CONS
      cond is ['or,:x] =>
        (or/[inspect(u,subst) for u in x] => [a,true,:l]; nil)
      cond is ["has",nam,b] and (val:= ASSQ(nam,subst)) =>
        ev:=
          b is ['ATTRIBUTE,c] => HasAttribute(rest val,c)
          b is ['SIGNATURE,c] => HasSignature(rest val,c)
          isDomainForm(b,$CategoryFrame) => b=rest val
          HasCategory(rest val,b)
        ev => [a,true,:l]
        nil
      cp
  not a' => sublisProp(subst,props')
  props' := sublisProp(subst,props')
  sameObject?(a',cp) and sameObject?(props',rest props) => props
  [a',:props']
 
setVector3(name,instantiator) ==
      --generates code to set element 3 of 'name' from 'instantiator'
      --element 3 is data structure representing category
      --returns a single LISP statement
  instantiator is ['DomainSubstitutionMacro,.,body] => setVector3(name,body)
  ['%store,['%tref,name,3],mkTypeForm instantiator]
 
mkDomainFormer x ==
  if x is ['DomainSubstitutionMacro,parms,body] then
    x := DomainSubstitutionFunction(parms,body)
    x := applySubst($extraParms,x)
    --The next line ensures that only one copy of this structure will
    --appear in the BPI being generated, thus saving (some) space
  x is ['Join,:.] => ['eval,['QUOTE,x]]
  x
 
mkTypeForm x ==
  x isnt [.,:.] => mkDevaluate x
  x.op in '(CATEGORY mkCategory) => MKQ x
  x is [":",selector,dom] =>
    ['%list,MKQ ":",MKQ selector,mkTypeForm dom]
  x.op is '%call => ['MKQ, optCall x]
        --The previous line added JHD/BMT 20/3/84
        --Necessary for proper compilation of DPOLY SPAD
  x is [op] =>
    op in '(Join %list) => nil
    MKQ x
  ['%list,MKQ x.op,:[mkTypeForm a for a in x.args]]
 
setVector5(catNames,locals) ==
  generated:= nil
  for u in locals for uname in catNames repeat
    if w:= assoc(u,generated)
       then w.rest := [uname,:rest w]
       else generated:= [[u,uname],:generated]
  [(w:= mkVectorWithDeferral(first u,second u);
      for v in rest u repeat
         w:= ['%store,['%tref,v,5],w];
        w)
          for u in generated]
 
mkVectorWithDeferral(objects,tag) ==
-- Construct a %vector form, but spots things that aren't safe to instantiate
-- and places them at the end of $ConstantAssignments, so that they get
-- called AFTER the constants of $ have been set up.   JHD 26.July.89
  ['%vector,:
   [if CONTAINED('$,u) then -- It's not safe to instantiate this now
      $ConstantAssignments:=[:$ConstantAssignments,
                             ['%store,['%tref,['%tref,tag,5],count],u]]
      []
    else u
       for u in objects for count in 0..]]
 
DescendCodeAdd(base,flag) ==
  base isnt [.,:.] => DescendCodeVarAdd(base,flag)
  not (modemap:=get(opOf base,'modemap,$CategoryFrame)) =>
      if getmode(opOf base,$e) is ["Mapping",target,:formalArgModes]
         then formalArgs:= take(#formalArgModes,$FormalMapVariableList)
                --argument substitution if parameterized?
 
         else keyedSystemError("S2OR0001",[opOf base])
      DescendCodeAdd1(base,flag,target,formalArgs,formalArgModes)
  for [[[.,:formalArgs],target,:formalArgModes],.] in modemap repeat
    (ans:= DescendCodeAdd1(base,flag,target,formalArgs,formalArgModes))=>
      return ans
  ans
 
DescendCodeAdd1(base,flag,target,formalArgs,formalArgModes) ==
  slist := pairList(formalArgs,rest $addFormLhs)
         --base = comp $addFormLhs-- bound in compAdd
  e:= $e
  newModes := applySubst(slist,formalArgModes)
  or/[not comp(u,m,e) for u in rest $addFormLhs for m in newModes] =>
    return nil
      --I should check that the actual arguments are of the right type
  for u in formalArgs for m in newModes repeat
    [.,.,e]:= compMakeDeclaration(u,m,e)
      --we can not substitute in the formal arguments before we comp
      --for that may change the shape of the object, but we must before
      --we match signatures
  cat:= (compMakeCategoryObject(target,e)).expr
  instantiatedBase:= genvar()
  n:=maxIndex cat
  code:=
    [u
      for i in 6..n | cons? cat.i and cons? (sig:= first cat.i)
         and
          (u:=
            SetFunctionSlots(applySubst(slist,sig),['ELT,instantiatedBase,i],flag,
              'adding))~=nil]
     --The code from here to the end is designed to replace repeated LOAD/STORE
     --combinations (SETELT ...(ELT ..)) by MVCs where this is practicable
  copyvec := newShell (1+n)
  (for u in code repeat
      if update(u,copyvec,[]) then code := remove(code,u))
    where update(code,copyvec,sofar) ==
      code isnt [.,:.] => nil
      code.op in '(%tref ELT) =>
          copyvec.(third code):=union(copyvec.(third code), sofar)
          true
      code is ['%store,['%tref,name,number],u'] =>
        update(u',copyvec,[[name,:number],:sofar])
  for i in 6..n repeat
    for u in copyvec.i repeat
      [name,:count]:=u
      j:=i+1
      while j<= MIN(n,i+63) and LASSOC(name,copyvec.j) = count+j-i repeat j:=j+1
             --Maximum length of an MVC is 64 words
      j:=j-1
      j > i+2 =>
        for k in i..j repeat
          copyvec.k := remove(copyvec.k,[name,:count+k-i])
        code:=[["REPLACE", name, instantiatedBase,
                 KEYWORD::START1, count,
                  KEYWORD::START2, i,
                   KEYWORD::END2, j+1],:code]
    copyvec.i =>
      v:=['%tref,instantiatedBase,i]
      for u in copyvec.i repeat
        [name,:count]:=u
        v:=['%store,['%tref,name,count],v]
      code:=[v,:code]
  [["%LET",instantiatedBase,base],:code]
 
DescendCode(code,flag,viewAssoc,EnvToPass) ==
  -- flag = true if we are walking down code always executed;
  -- otherwise set to conditions in which
  code=nil => nil
  code='%noBranch => nil
  isMacro(code,$e) => nil --RDJ: added 3/16/83
  code is ['add,base,:codelist] =>
    codelist:=
      [v for u in codelist | (v:= DescendCode(u,flag,viewAssoc,EnvToPass))~=nil]
                  -- must do this first, to get this overriding Add code
    ['PROGN,:DescendCodeAdd(base,flag),:codelist]
  code is ['PROGN,:codelist] =>
    ['PROGN,:
            --Two REVERSEs leave original order, but ensure last guy wins
      reverse! [v for u in reverse codelist |
                    (v:= DescendCode(u,flag,viewAssoc,EnvToPass))~=nil]]
  code is ['%when,:condlist] =>
    c:= [[u2:= ProcessCond first u,:q] for u in condlist] where q() ==
          null u2 => nil
          f:=
            TruthP u2 => flag;
            TruthP flag =>
               flag := ['NOT,u2]
               u2
            flag := ['AND,flag,['NOT,u2]];
            ['AND,flag,u2]
          [DescendCode(v, f,
            if first u is ['HasCategory,dom,cat]
              then [[dom,:cat],:viewAssoc]
              else viewAssoc,EnvToPass) for v in rest u]
    TruthP CAAR c => ['PROGN,:CDAR c]
    while (c and (last c is [c1] or last c is [c1,[]]) and
            (c1 = '%true or c1 is ['HasAttribute,:.])) repeat
                   --strip out some worthless junk at the end
        c:=reverse! rest reverse! c
    null c => '(LIST)
    ['%when,:c]
  code is ["%LET",name,body,:.] =>
                    --only keep the names that are useful
    u:=member(name,$locals) =>
        CONTAINED('$,body) and isDomainForm(body,$e) =>
          --instantiate domains which depend on $ after constants are set
          code:=['%store,['%tref,['%tref,'$,5],#$locals-#u],code]
          $epilogue:=
            TruthP flag => [code,:$epilogue]
            [['%when,[ProcessCond  flag,code]],:$epilogue]
          nil
        code
    code -- doItIf deletes entries from $locals so can't optimize this
  code is ['CodeDefine,sig,implem] =>
             --Generated by doIt in COMPILER BOOT
    dom:= EnvToPass
    dom:=
      u:= LASSOC(dom,viewAssoc) => ['getDomainView,dom,u]
      dom
    body:= ['CONS,implem,dom]
    u := SetFunctionSlots(sig,body,flag,'original)
    -- ??? We do not resolve default definitions, yet.
    if not $insideCategoryPackageIfTrue then
      updateCapsuleDirectory([second(u).args,third u],flag)
    ConstantCreator u =>
      if flag ~= true then u:= ['%when,[ProcessCond flag,u]]
      $ConstantAssignments:= [u,:$ConstantAssignments]
      nil
    u
  code is ['_:,:.] => (code.first := '%list; code.rest := nil)
      --Yes, I know that's a hack, but how else do you kill a line?
  code is ['%list,:.] => nil
  code is ['devaluate,:.] => nil
  code is ['MDEF,:.] => nil
  code is ['%call,:.] => code
  code is ['%store,:.] => code -- can be generated by doItIf
  stackWarning('"unknown Functor code: %1 ",[code])
  code
 
ConstantCreator u ==
  null u => false
  u is ['%store,['%tref,.,.],u'] => ConstantCreator u'
  u is ['CONS,:.] => false
  true
 
ProcessCond cond ==
  ncond := applySubst($pairlis,cond)
  integer? POSN1(ncond,$NRTslot1PredicateList) => predicateBitRef ncond
  cond

TryGDC cond ==
            --sees if a condition can be optimised by the use of
            --information in $getDomainCode
  cond isnt [.,:.] => cond
  cond is ['HasCategory,:l] =>
    solved := nil
    for u in $getDomainCode while solved = nil repeat
      if u is ["%LET",name, =cond] then
        solved := name
    solved ~= nil => solved
    cond
  cond
 
SetFunctionSlots(sig,body,flag,mode) == --mode is either "original" or "adding"
  null body => return nil
  u := first $catvecList
  for catImplem in LookUpSigSlots(sig,categoryExports u) repeat
    catImplem is [q,.,index] and (q='ELT or q='CONST) =>
      if q is 'CONST and body is ['CONS,a,b] then
         body := ['CONS,'IDENTITY,['FUNCALL,a,b]]
      body:= ['%store,['%tref,'$,index],body]
      not vector? $SetFunctions => nil --packages don't set it
      if TruthP flag then             -- unconditionally defined function
        vectorRef(u,index) := true
      TruthP vectorRef($SetFunctions,index) =>   -- the function was already assigned
        return body := nil
      vectorRef($SetFunctions,index) :=
        TruthP flag => true
        not vectorRef($SetFunctions,index) => flag
        ['_or,vectorRef($SetFunctions,index),flag]
    catImplem is ['Subsumed,:truename] =>
      mode='original =>
        truename is [fn,:.] and fn in '(Zero One) => nil --hack by RDJ 8/90
        body := SetFunctionSlots(truename,body,nil,mode)
    keyedSystemError("S2OR0002",[catImplem])
  body is ['%store,:.] => body
  nil
 
LookUpSigSlots(sig,siglist) ==
--+ must kill any implementations below of the form (ELT $ NIL)
  if $insideCategoryPackageIfTrue then
           sig := substitute('$,second($functorForm),sig)
  siglist := $lisplibOperationAlist
  removeDuplicates [implem for u in siglist | SigSlotsMatch(sig,first u,implem:=third u)
              and KADDR implem]
 
SigSlotsMatch(sig,pattern,implem) ==
  sig=pattern => true
  #second sig ~= # second pattern => nil
                       --second sig is the actual signature part
  first sig ~= first pattern => nil
  pat' := substitute($definition,'$,second pattern)
  sig' := substitute($definition,'$,second sig)
  sig' = pat' => true
  implem is ['Subsumed,:.] => nil
  sig' = pat'
 
makeMissingFunctionEntry(alist,i) ==
  tran applySubst(alist,$SetFunctions.i) where
    tran x ==
      x is ["HasCategory",a,["QUOTE",b]] => ["has",a,b]
      x is [op,:l] and op in '(AND OR NOT) => [op,:[tran y for y in l]]
      x
 
--%  Under what conditions may views exist?
 
InvestigateConditions catvecListMaker ==
  -- given a principal view and a list of secondary views,
  -- discover under what conditions the secondary view are
  -- always present.
  $Conditions: local:= nil
  $principal: local := nil
  [$principal,:secondaries]:= catvecListMaker
      --We are not interested in the principal view
      --The next block allows for the possibility that $principal may
      --have conditional secondary views
  null secondaries => '(T)
      --return for packages which generally have no secondary views
  if $principal is [op,:.] then
    [principal',:.]:=compMakeCategoryObject($principal,$e)
              --Rather like eval, but quotes parameters first
    for u in second principal'.4 repeat
      if not TruthP(cond:=second u) then
        new:=['CATEGORY,'domain,['IF,cond,['ATTRIBUTE,first u], '%noBranch]]
        $principal is ['Join,:l] =>
          not listMember?(new,l) =>
            $principal:=['Join,:l,new]
        $principal:=['Join,$principal,new]
  principal' :=
    pessimise $principal where
      pessimise a ==
        a isnt [.,:.] => a
        a is ['SIGNATURE,:.] => a
        a is ['IF,cond,:.] =>
          if not listMember?(cond,$Conditions) then
            $Conditions:= [cond,:$Conditions]
          nil
        [pessimise first a,:pessimise rest a]
  null $Conditions => [true,:[true for u in secondaries]]
  PrincipalSecondaries:= getViewsConditions principal'
  MinimalPrimary:= first first PrincipalSecondaries
  MaximalPrimary:= CAAR $domainShell.4
  necessarySecondaries:= [first u for u in PrincipalSecondaries | rest u=true]
  and/[listMember?(u,necessarySecondaries) for u in secondaries] =>
    [true,:[true for u in secondaries]]
  $HackSlot4:=
    MinimalPrimary=MaximalPrimary => nil
    MaximalPrimaries:=[MaximalPrimary,:first CatEval(MaximalPrimary).4]
    MinimalPrimaries:=[MinimalPrimary,:first CatEval(MinimalPrimary).4]
    MaximalPrimaries:=S_-(MaximalPrimaries,MinimalPrimaries)
    [[x] for x in MaximalPrimaries]
  ($Conditions:= Conds($principal,nil)) where
    Conds(code,previous) ==
           --each call takes a list of conditions, and returns a list
           --of refinements of that list
      code isnt [.,:.] => [previous]
      code is ['DomainSubstitutionMacro,.,b] => Conds(b,previous)
      code is ['IF,a,b,c] => union(Conds(b,[a,:previous]),Conds(c,previous))
      code is ['PROGN,:l] => "union"/[Conds(u,previous) for u in l]
      code is ['CATEGORY,:l] => "union"/[Conds(u,previous) for u in l]
      code is ['Join,:l] => "union"/[Conds(u,previous) for u in l]
      [previous]
  $Conditions := remove!([remove!(u,nil) for u in $Conditions],nil)
  partList:=
    [getViewsConditions partPessimise($principal,cond) for cond in $Conditions]
  masterSecondaries:= secondaries
  for u in partList repeat
    for [v,:.] in u repeat
      if not listMember?(v,secondaries) then
        secondaries:= [v,:secondaries]
  list:= [listMember?(u,necessarySecondaries) for u in secondaries]
  for u in $Conditions for newS in partList repeat
    --newS is a list of secondaries and conditions (over and above
    --u) for which they apply
    u:=
      # u=1 => first u
      ['AND,:u]
    for [v,:.] in newS repeat
      for v' in [v,:first CatEval(v).4] repeat
        if (w:=assoc(v',$HackSlot4)) then
          w.rest := if rest w then mkOr(u,rest w) else u
    (list:= update(list,u,secondaries,newS)) where
      update(list,cond,secondaries,newS) ==
        (list2:=
          [flist(sec,newS,old,cond) for sec in secondaries for old in list]) where
            flist(sec,newS,old,cond) ==
              old=true => old
              for [newS2,:morecond] in newS repeat
                old:=
                  not AncestorP(sec,[newS2]) => old
                  cond2:= mkAnd(cond,morecond)
                  null old => cond2
                  mkOr(cond2,old)
              old
        list2
  list:= [[sec,:ICformat u] for u in list for sec in secondaries]
  pv:= getPossibleViews $principal
  -- $HackSlot4 is used in SetVector4 to ensure that conditional
  -- extensions of the principal view are handles correctly
  -- here we build the code necessary to remove spurious extensions
  ($HackSlot4:= [reshape u for u in $HackSlot4]) where
    reshape u ==
      ['%when,[TryGDC ICformat rest u],
             ['%otherwise,['RPLACA,'(CAR TrueDomain),
                             ['delete,['QUOTE,first u],'(CAAR TrueDomain)]]]]
  $supplementaries:=
    [u
      for u in list | not listMember?(first u,masterSecondaries)
        and not (true=rest u) and not listMember?(first u,pv)]
  [true,:[LASSOC(ms,list) for ms in masterSecondaries]]
 
ICformat u ==
      u isnt [.,:.] => u
      u is ["has",:.] => compHasFormat u
      u is ['AND,:l] or u is ['and,:l] =>
        l:= removeDuplicates [ICformat v for [v,:l'] in tails l
                                | not listMember?(v,l')]
             -- we could have duplicates after, even if not before
        # l=1 => first l
        l1:= first l
        for u in rest l repeat
          l1:=mkAnd(u,l1)
        l1
      u is ['OR,:l] =>
        (l:= ORreduce l)
        # l=1 => ICformat first l
        l:= ORreduce removeDuplicates [ICformat u for u in l]
                 --causes multiple ANDs to be squashed, etc.
                 -- and duplicates that have been built up by tidying
        (l:= Hasreduce l) where
          Hasreduce l ==
            for u in l | u is ['HasCategory,name,cond] and cond is ['QUOTE,
              cond] repeat
                                  --check that v causes descendants to go
                for v in l | not (v=u) and v is ['HasCategory, =name,['QUOTE,
                  cond2]] repeat
                       if DescendantP(cond,cond2) then l:= remove(l,u)
                       --v subsumes u
            for u in l | u is ['AND,:l'] or u is ['and,:l'] repeat
              for u' in l' | u' is ['HasCategory,name,cond] and cond is ['QUOTE,
                cond] repeat
                                    --check that v causes descendants to go
                  for v in l | v is ['HasCategory, =name,['QUOTE,
                    cond2]] repeat
                        if DescendantP(cond,cond2) then l:= remove(l,u)
                         --v subsumes u
            l
        # l=1 => first l
        ['OR,:l]
      systemErrorHere ["ICformat",u]
  where
    ORreduce l ==
      for u in l | u is ['AND,:.] or u is ['and,:.] repeat
                            --check that B causes (and A B) to go
        for v in l | not (v=u) repeat
          if listMember?(v,u) or (and/[member(w,u) for w in v]) then l:=
            remove(l,u)
                 --v subsumes u
                     --Note that we are ignoring AND as a component.
                     --Convince yourself that this code still works
      l
 
partPessimise(a,trueconds) ==
  a isnt [.,:.] => a
  a is ['SIGNATURE,:.] => a
  a is ['IF,cond,:.] => (listMember?(cond,trueconds) => a; nil)
  [partPessimise(first a,trueconds),:partPessimise(rest a,trueconds)]
 
getPossibleViews u ==
  --returns a list of all the categories that can be views of this one
  [vec,:.]:= compMakeCategoryObject(u,$e) or
    systemErrorHere ["getPossibleViews",u]
  views:= [first u for u in second vec.4]
  null vec.0 => [CAAR vec.4,:views] --*
  [vec.0,:views] --*
      --the two lines marked  ensure that the principal view comes first
      --if you don't want it, rest it off
 
getViewsConditions u ==
 
  --returns a list of all the categories that can be views of this one
  --paired with the condition under which they are such views
  [vec,:.]:= compMakeCategoryObject(u,$e) or
    systemErrorHere ["getViewsConditions",u]
  views:= [[first u,:second u] for u in second vec.4]
  null vec.0 =>
    null first vec.4 => views
    [[CAAR vec.4,:true],:views] --*
  [[vec.0,:true],:views] --*
      --the two lines marked  ensure that the principal view comes first
      --if you don't want it, rest it off
 
DescendCodeVarAdd(base,flag) ==
   princview := first $catvecList
   [SetFunctionSlots(sig,substitute('ELT,'CONST,implem),flag,'adding) repeat
       for i in 6..maxIndex princview |
         princview.i is [sig:=[op,types],:.] and
           LASSOC([base,:substitute(base,'$,types)],get(op,'modemap,$e)) is
                  [[pred,implem]]]
 
resolvePatternVars(p,args) ==
  p := applySubst(pairList($TriangleVariableList,args),p)
  applySubst(pairList($FormalMapVariableList,args),p)

--% Code Processing Packages

isCategoryPackageName nam ==
  isDefaultPackageName opOf nam

mkOperatorEntry(opSig is [op,sig,:flag],pred,count) ==
  null flag => [opSig,pred,["ELT","$",count]]
  first flag="constant" => [[op,sig],pred,["CONST","$",count]]
  systemError ["unknown variable mode: ",flag]
 
--% Code for encoding function names inside package or domain
 
encodeFunctionName(fun,package is [packageName,:arglist],signature,sep,count)
   ==
    signature':= MSUBST("$",package,signature)
    reducedSig:= mkRepititionAssoc [:rest signature',first signature']
    encodedSig:=
      (strconc/[encodedPair for [n,:x] in reducedSig]) where
        encodedPair() ==
          n=1 => encodeItem x
          strconc(STRINGIMAGE n,encodeItem x)
    encodedName:= INTERNL(getConstructorAbbreviationFromDB packageName,";",
        encodeItem fun,";",encodedSig, sep,STRINGIMAGE count)
    if $LISPLIB then
      $lisplibSignatureAlist:=
        [[encodedName,:signature'],:$lisplibSignatureAlist]
    encodedName

++ Return the linkage name of the local operation named `op'.
encodeLocalFunctionName op ==
  prefix :=
    $prefix => $prefix
    $functorForm => getConstructorAbbreviationFromDB first $functorForm
    stackAndThrow('"There is no context for local function %1b",[op]) 
  makeSymbol strconc(prefix,'";",encodeItem op)
 
splitEncodedFunctionName(encodedName, sep) ==
    -- [encodedPackage, encodedItem, encodedSig, sequenceNo] or nil
    -- sep0 is the separator used in "encodeFunctionName".
    sep0 := '";"
    if not string? encodedName then
        encodedName := STRINGIMAGE encodedName
    null (p1 := STRPOS(sep0, encodedName, 0,    '"*")) => nil
    null (p2 := STRPOS(sep0, encodedName, p1+1, '"*")) => 'inner
--  This is picked up in compile for inner functions in partial compilation
    null (p3 := STRPOS(sep,  encodedName, p2+1, '"*")) => nil
    s1 := subString(encodedName, 0,    p1)
    s2 := subString(encodedName, p1+1, p2-p1-1)
    s3 := subString(encodedName, p2+1, p3-p2-1)
    s4 := subString(encodedName, p3+1)
    [s1, s2, s3, s4]
 
mkRepititionAssoc l ==
  mkRepfun(l,1) where
    mkRepfun(l,n) ==
      null l => nil
      l is [x] => [[n,:x]]
      l is [x, =x,:l'] => mkRepfun(rest l,n+1)
      [[n,:first l],:mkRepfun(rest l,1)]
 
encodeItem x ==
  x is [op,:argl] => getCaps op
  ident? x => symbolName x
  STRINGIMAGE x
 
getCaps x ==
  s:= STRINGIMAGE x
  clist:= [c for i in 0..maxIndex s | upperCase? (c:= s.i)]
  null clist => '"__"
  strconc/[first clist,:[L_-CASE u for u in rest clist]]
 
--% abbreviation code
 
getAbbreviation(name,c) ==
  --returns abbreviation of name with c arguments
  x := getConstructorAbbreviationFromDB name
  X := ASSQ(x,$abbreviationTable) =>
    N:= ASSQ(name,rest X) =>
      C:= ASSQ(c,rest N) => rest C --already there
      newAbbreviation:= mkAbbrev(X,x)
      N.rest := [[c,:newAbbreviation],:rest N]
      newAbbreviation
    newAbbreviation:= mkAbbrev(X,x)
    X.rest := [[name,[c,:newAbbreviation]],:rest X]
    newAbbreviation
  $abbreviationTable:= [[x,[name,[c,:x]]],:$abbreviationTable]
  x
 
mkAbbrev(X,x) == addSuffix(alistSize rest X,x)
 
alistSize c ==
  count(c,1) where
    count(x,level) ==
      level=2 => #x
      null x => 0
      count(CDAR x,level+1)+count(rest x,level)
 
addSuffix(n,u) ==
  s := STRINGIMAGE u
  alphabetic? stringChar(s,maxIndex s) => 
    makeSymbol strconc(s,STRINGIMAGE n)
  INTERNL strconc(s,STRINGIMAGE ";",STRINGIMAGE n)