path: root/src/interp/database.boot

-- Copyright (c) 1991-2002, The Numerical Algorithms Group Ltd.
-- All rights reserved.
-- Copyright (C) 2007-2012, 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,
-- PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
-- PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
-- LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
-- NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
-- SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.


import nlib
import g_-cndata
import c_-util
import clam
import cattable
import compat
import daase
namespace BOOT

$getUnexposedOperations := true
$globalExposureGroupAlist := []


--% 

pathToDatabase name ==
  if dbdir := systemDatabaseDirectory() then
    path := strconc(dbdir,name)
    if $verbose then
      formatToStdout('"   Using local database ~a..",path)
  else
    path := strconc(systemRootDirectory(),'"algebra/",name)
  path


--%

getConstructorAbbreviationFromDB: %Constructor -> %Symbol
getConstructorAbbreviationFromDB ctor ==
  GETDATABASE(ctor,"ABBREVIATION")

getConstructorCategory: %Constructor -> %Form
getConstructorCategory ctor ==
  getConstructorKindFromDB ctor = 'category =>
    GETDATABASE(ctor,"CONSTRUCTORCATEGORY")
  getConstructorModemap(ctor).mmTarget

getConstructorKindFromDB: %Constructor -> %Maybe %ConstructorKind
getConstructorKindFromDB ctor ==
  GETDATABASE(ctor,"CONSTRUCTORKIND")

getConstructorAncestorsFromDB: %Constructor -> %List %Constructor
getConstructorAncestorsFromDB ctor ==
  GETDATABASE(ctor,"ANCESTORS")

++ return the modemap of the constructor or the instantiation
++ of the constructor `form'. 
getConstructorModemap: %Constructor -> %Mode
getConstructorModemap ctor ==
  GETDATABASE(ctor, 'CONSTRUCTORMODEMAP)
    or dbConstructorModemap loadDBIfNecessary constructorDB ctor

getConstructorFormFromDB: %Constructor -> %Form
getConstructorFormFromDB ctor ==
  GETDATABASE(ctor,"CONSTRUCTORFORM")

++ Return the generic instantiation form of a constructor,
++ where the arguments are the parameters used in its
++ original definition.  Builtin constructors are also handled.
genericInstanceForm form ==
  [op,:args] := form
  builtinConstructor? op => builtinInstanceForm form
  getConstructorFormFromDB op

getConstructorSourceFileFromDB: %Constructor -> %Maybe %String
getConstructorSourceFileFromDB ctor ==
  GETDATABASE(ctor,"SOURCEFILE")

getConstructorModuleFromDB: %Constructor -> %Maybe %String
getConstructorModuleFromDB ctor ==
  GETDATABASE(ctor,"OBJECT")

getConstructorDocumentationFromDB: %Constructor -> %List %Form
getConstructorDocumentationFromDB ctor ==
  GETDATABASE(ctor,"DOCUMENTATION")

getConstructorOperationsFromDB: %Constructor -> %List %List %Form
getConstructorOperationsFromDB ctor ==
  GETDATABASE(ctor,"OPERATIONALIST")

getConstructorFullNameFromDB: %Symbol -> %Constructor
getConstructorFullNameFromDB ctor ==
  GETDATABASE(ctor,"CONSTRUCTOR")

getConstructorArgsFromDB: %Constructor -> %List %Symbol
getConstructorArgsFromDB ctor ==
  GETDATABASE(ctor,"CONSTRUCTORARGS")

++ returns a list of Boolean values indicating whether the 
++ parameter type at the corresponding position is a category.
getDualSignature: %Constructor -> %Form
getDualSignature ctor ==
  db := constructorDB ctor or return nil
  dbDualSignature db or GETDATABASE(ctor,'COSIG)

getConstructorPredicates: %Constructor -> %List %Thing
getConstructorPredicates ctor ==
  db := constructorDB ctor
  dbBeingDefined? db => dbPredicates db
  dbPredicates loadDBIfNecessary db

getConstructorParentsFromDB: %Constructor -> %List %Constructor
getConstructorParentsFromDB ctor ==
  GETDATABASE(ctor,"PARENTS")

getSuperDomainFromDB: %Constructor -> %Form
getSuperDomainFromDB ctor ==
  GETDATABASE(ctor,"SUPERDOMAIN")
  
getConstructorAttributes: %Constructor -> %Form
getConstructorAttributes ctor ==
  dbAttributes loadDBIfNecessary constructorDB ctor

niladicConstructor?: %Constructor -> %Boolean
niladicConstructor? ctor ==
  form := getConstructorFormFromDB ctor => form.args = nil
  false

constructorHasCategoryFromDB: %Pair(%Thing,%Thing) -> %List %Code
constructorHasCategoryFromDB p ==
  GETDATABASE(p,"HASCATEGORY")

getConstructorDefaultFromDB: %Constructor -> %Maybe %Symbol
getConstructorDefaultFromDB ctor ==
  GETDATABASE(ctor,"DEFAULTDOMAIN")

getOperationFromDB: %Symbol -> %List %Sig
getOperationFromDB op ==
  GETDATABASE(op,"OPERATION")

getOperationModemapsFromDB: %Symbol -> %List %Modemap
getOperationModemapsFromDB op ==
  GETDATABASE(op,"MODEMAPS")


getConstructorArity: %Constructor -> %Short
getConstructorArity ctor ==
  sig := getConstructorSignature ctor => #rest sig
  -1

getConstructorKind: %Constructor -> %Maybe %ConstructorKind
getConstructorKind ctor ==
  kind := getConstructorKindFromDB ctor =>
    kind is "domain" and isDefaultPackageName ctor => "package"
    kind
  builtinFunctorName? ctor => "domain"
  builtinCategoryName? ctor => "category"
  nil

categoryConstructor? ctor ==
  getConstructorKindFromDB ctor is "category"
    or builtinCategoryName? ctor

--% Functions for manipulating MODEMAP DATABASE

++ We are about to finish the elaboration of the category `form' with
++ given `body' and `signature'.  Return the list of all modemaps
++ of operators exported by generic instantiation of the category constructor.
++ Note: The structure of the modemaps is that understood by the
++ interpreter, but that of the of the compiler.
modemapsFromCategory(db,form,body,signature) ==
  sl := [["$",:"*1"],:pairList(form.args,rest $PatternVariableList)]
  form := applySubst(sl,form)
  body := applySubst(sl,body)
  signature := applySubst(sl,signature)
  opAlist := applySubst(sl,categoryExports $domainShell) or return nil
  nonCategorySigAlist :=
    mkAlistOfExplicitCategoryOps substitute("*1","$",body)
  catPredList := [['ofCategory,"*1",form],
    :[['ofCategory,a,m] for a in form.args for m in signature.source
       for cat? in dbDualSignature(db).source | cat? ]]
  op := dbConstructor db
  cond :=
    dbImplicitData db is [isubst,icond] =>
      [['%exist,ASSOCRIGHT isubst,applySubst(sl,applySubst(isubst,icond))]]
    nil
  mms := nil
  for (entry:= [[op,sig,:.],pred,sel]) in opAlist |
    listMember?(sig,LASSOC(op,nonCategorySigAlist)) repeat
      pred' := mkpf([pred,:catPredList,:cond],'AND)
      modemap := [["*1",:sig],[pred',sel]]
      mms := [[op,:interactiveModemapForm modemap],:mms]
  mms

++ We are about to finish the elaboration of the generic instantiation
++ of the function `form.op' with `signature'. Return a list of modemaps
++ for operations from `opAlist' explicitly exported by the functor.
++ Note: the structure of modemaps same as for modemapsFromCategory.
modemapsFromFunctor(db,form,opAlist) ==
  f2p := pairList(form.args,rest $PatternVariableList) -- "*1" is for "$"
  form := [.,:argl] := applySubst(f2p,form)
  opAlist := applySubst(f2p,opAlist)
  signature := applySubst(f2p,dbConstructorModemap(db).mmSignature)
  for u in form for v in signature repeat
    if symbolMember?(u,$PatternVariableList) then
      -- we are going to be EVALing categories containing these
      -- pattern variables
      $e := put(u,'mode,v,$e)
  nonCategorySigAlist :=
    mkAlistOfExplicitCategoryOps signature.target or return nil
  catCond :=
    dbImplicitData db is [isubst,icond] =>
      [['%exist,ASSOCRIGHT isubst,applySubst(f2p,applySubst(isubst,icond))]]
    nil
  mms := nil
  for (entry := [[op,sig,:.],pred,sel]) in opAlist |
    or/[listMember?(sig,catSig) for catSig in
      allLASSOCs(op,nonCategorySigAlist)] repeat
        skip :=
          argl ~= nil and CONTAINED("$",sig.source) => 'SKIP
          nil
        patternList := listOfPatternIds sig
        --get relevant predicates
        predList :=
          [[(cat? => 'ofCategory; 'ofType),a,m]
            for a in argl for m in signature.source
              for cat? in dbDualSignature(db).source
                | symbolMember?(a,$PatternVariableList)]
        l := listOfPatternIds predList
        if "OR"/[not symbolMember?(u,l) for u in argl] then
          sayMSG ['"cannot handle modemap for",:bright op,
                          '"by pattern match" ]
          skip := 'SKIP
        modemap := [[form,:substitute(form,"$",sig)],
                     [mkpf([pred,:predList,:catCond],'AND),
                       substitute(form,"$",sel),:skip]]
        mms := [[op,:interactiveModemapForm modemap],:mms]
  mms

rebuildCDT(filemode) ==
  clearConstructorAndLisplibCaches()
  $databaseQueue:local :=nil
  $e: local := $EmptyEnvironment    -- We may need to evaluate Categories
  buildDatabase(filemode,false)
  $IOindex:= 1
  $InteractiveFrame:= $EmptyEnvironment
  0

buildDatabase(filemode,expensive) ==
  $InteractiveMode: local:= true
  $constructorList := nil       --looked at by buildLibdb
  $ConstructorCache:= hashTable 'EQ
  SAY '"Making constructor autoload"
  makeConstructorsAutoLoad()
  SAY '"Building category table"
  genCategoryTable()
  SAY '"Building libdb.text"
  buildLibdb()
  SAY '"splitting libdb.text"
  dbSplitLibdb()
  SAY '"creating browse constructor index"
  dbAugmentConstructorDataTable()
  SAY '"Building browse.lisp"
  buildBrowsedb()
  SAY '"Building constructor users database"
  mkUsersHashTable()
  SAY '"Saving constructor users database"
  saveUsersHashTable()
  SAY '"Building constructor dependents database"
  mkDependentsHashTable()
  SAY '"Saving constructor dependents database"
  saveDependentsHashTable()
  SAY '"Building glossary files"
  buildGloss()

saveUsersHashTable() ==
  _$ERASE('USERS,'DATABASE,'a)
  stream:= writeLib1('USERS,'DATABASE,'a)
  for k in MSORT HKEYS $usersTb repeat
    rwrite(k, tableValue($usersTb, k), stream)
  RSHUT stream

saveDependentsHashTable() ==
  _$ERASE('DEPENDENTS,'DATABASE,'a)
  stream:= writeLib1('DEPENDENTS,'DATABASE,'a)
  for k in MSORT HKEYS $depTb repeat
    rwrite(k, tableValue($depTb, k), stream)
  RSHUT stream

getUsersOfConstructor(con) ==
  stream := readLib1('USERS, 'DATABASE, 'a)
  val := rread(con, stream, nil)
  RSHUT stream
  val

getDependentsOfConstructor(con) ==
  stream := readLib1('DEPENDENTS, 'DATABASE, 'a)
  val := rread(con, stream, nil)
  RSHUT stream
  val

orderPredicateItems(pred1,sig,skip) ==
  pred:= signatureTran pred1
  pred is ["AND",:l] => orderPredTran(l,sig,skip)
  pred

orderPredTran(oldList,sig,skip) ==
  lastPreds := nil
  --(1) make two kinds of predicates appear last:
  -----  (op *target ..) when *target does not appear later in sig
  -----  (isDomain *1 ..)
  for pred in oldList repeat
    ((pred is [op,pvar,.] and op in '(isDomain ofCategory)
       and pvar = sig.target and not symbolMember?(pvar,sig.source)) or
        (not skip and pred is ['isDomain,"*1",.])) =>
          oldList := remove(oldList,pred)
          lastPreds := [pred,:lastPreds]

  --(2a) lastDependList=list of all variables that lastPred forms depend upon
  lastDependList := setUnion/[listOfPatternIds x for x in lastPreds]

  --(2b) dependList=list of all variables that isDom/ofCat forms depend upon
  dependList :=
    setUnion/[listOfPatternIds y for x in oldList |
      x is ['isDomain,.,y] or x is ['ofCategory,.,y]]

  --(3a) newList= list of ofCat/isDom entries that don't depend on
  for x in oldList repeat
    if (x is ['ofCategory,v,body]) or (x is ['isDomain,v,body]) then
      indepvl := listOfPatternIds v
      depvl := listOfPatternIds body
    else
      indepvl := listOfPatternIds x
      depvl := nil
    setIntersection(indepvl,dependList) = nil
        and setIntersection(indepvl,lastDependList) =>
      lastPreds := [:lastPreds,x]
      oldList := remove(oldList,x)

  --(3b) newList= list of ofCat/isDom entries that don't depend on
  while oldList ~= nil repeat
    for x in oldList repeat
      if (x is ['ofCategory,v,body]) or (x is ['isDomain,v,body]) then
        indepvl := listOfPatternIds v
        depvl := listOfPatternIds body
      else
        indepvl := listOfPatternIds x
        depvl := nil
      setIntersection(indepvl,dependList) = nil =>
        dependList := setDifference(dependList,depvl)
        newList := [:newList,x]

  --(4) noldList= what is left over
    (noldList:= setDifference(oldList,newList)) = oldList =>
--    sayMSG '"NOTE: Parameters to domain have circular dependencies"
      newList := [:newList,:oldList]
      return nil
    oldList:=noldList

  for pred in newList repeat
    if pred is ['isDomain,x,y] or x is ['ofCategory,x,y] then
      ids := listOfPatternIds y
      if "and"/[symbolMember?(id,fullDependList) for id in ids] then
        fullDependList := insertWOC(x,fullDependList)
      fullDependList := setUnion(fullDependList,ids)

  newList := [:newList,:lastPreds]

--substitute (isDomain ..) forms as completely as possible to avoid false paths
  newList := isDomainSubst newList
  [['AND,:newList],:setIntersection(fullDependList,sig)]

isDomainSubst u == main where
  main() ==
    u is [head,:tail] =>
      nhead :=
        head is ['isDomain,x,y] => ['isDomain,x,fn(y,tail)]
        head
      [nhead,:isDomainSubst rest u]
    u
  fn(x,alist) ==
    x isnt [.,:.] =>
      ident? x and symbolMember?(x,$PatternVariableList) and (s := findSub(x,alist)) => s
      x
    [first x,:[fn(y,alist) for y in rest x]]
  findSub(x,alist) ==
    null alist => nil
    alist is [['isDomain,y,z],:.] and x = y => z
    findSub(x,rest alist)

signatureTran pred ==
  pred isnt [.,:.] => pred
  pred is ["has",D,catForm] and isCategoryForm(catForm,$e) =>
    ['ofCategory,D,catForm]
  [signatureTran p for p in pred]

interactiveModemapForm mm ==
  --  create modemap form for use by the interpreter.  This function
  --  replaces all specific domains mentioned in the modemap with pattern
  --  variables, and predicates
  mm := replaceVars(copyTree mm,$PatternVariableList,$FormalMapVariableList)
  [pattern := [dc,:sig],pred] := mm
  pred := [fn x for x in pred] where fn x ==
    x is [a,b,c] and a isnt 'isFreeFunction and c isnt [.,:.] => [a,b,[c]]
    x
  [mmpat, patternAlist, partial, patvars] := modemapPattern(pattern,sig)
  [pred,domainPredicateList] := substVars(pred,patternAlist,patvars)
  [pred,:dependList] := 
    fixUpPredicate(pred,domainPredicateList,partial,rest mmpat)
  [cond, :.] := pred
  [mmpat, cond]

modemapPattern(mmPattern,sig) ==
  --  Returns a list of the pattern of a modemap, an Alist of the
  --  substitutions made, a boolean flag indicating whether
  --  the result type is partial, and a list of unused pattern variables
  patternAlist := nil
  mmpat := nil
  patvars := $PatternVariableList
  partial := false
  for xTails in tails mmPattern repeat
    x := first xTails
    if x is ['Union,dom,'"failed"] and xTails=sig then
      x := dom
      partial := true
    patvar := rassoc(x,patternAlist)
    not null patvar => mmpat := [patvar,:mmpat]
    patvar := first patvars
    patvars := rest patvars
    mmpat := [patvar,:mmpat]
    patternAlist := [[patvar,:x],:patternAlist]
  [reverse! mmpat,patternAlist,partial,patvars]

substVars(pred,patternAlist,patternVarList) ==
  --make pattern variable substitutions
  domPreds := nil
  for [[patVar,:value],:.] in tails patternAlist repeat
    pred := MSUBST(patVar,value,pred)
    patternAlist := nsubst(patVar,value,patternAlist)
    domPreds := MSUBST(patVar,value,domPreds)
    if not symbolMember?(value,$FormalMapVariableList) then
      domPreds := [["isDomain",patVar,value],:domPreds]
  everything := [pred,patternAlist,domPreds]
  for var in $FormalMapVariableList repeat
    CONTAINED(var,everything) =>
      replacementVar := first patternVarList
      patternVarList := rest patternVarList
      pred := substitute(replacementVar,var,pred)
      domPreds := substitute(replacementVar,var,domPreds)
  [pred, domPreds]

fixUpPredicate(predClause, domainPreds, partial, sig) ==
  --  merge the predicates in predClause and domainPreds into a
  --  single predicate
  [predicate, fn, :skip] := predClause
  predicates :=
    predicate is true => domainPreds or [predicate]
    predicate is ["AND",:.] => [:domainPreds,:predicate.args]
    [predicate,:domainPreds]
  if #predicates > 1 then
    pred := ["AND",:predicates]
    [pred,:dependList]:=orderPredicateItems(pred,sig,skip)
  else
    pred := orderPredicateItems(first predicates,sig,skip)
    dependList:= if pred is ['isDomain,pvar,[.]] then [pvar] else nil
  pred := moveORsOutside pred
  if partial then pred := ["partial", :pred]
  [[pred, fn, :skip],:dependList]

moveORsOutside p ==
  p is ['AND,:q] =>
    q := [moveORsOutside r for r in q]
    x := or/[r for r in q | r is ['OR,:s]] =>
      moveORsOutside(['OR,:[['AND,:SUBST(t,x,q)] for t in rest x]])
    ['AND,:q]
  p

replaceVars(x,oldvars,newvars) ==
  --  replace every identifier in oldvars with the corresponding
  --  identifier in newvars in the expression x
  for old in oldvars for new in newvars repeat
    x := substitute(new,old,x)
  x

++ Return the list of qualifying predicates of the system modemap `mm'.
getConditionListFromMm mm ==
  [., cond] := mm
  if cond is ["partial", :c] then cond := c
  cond is ["AND", :cl] => cl
  cond is ["OR", ["AND", :cl],:.] => cl  --all cl's should give same info
  [cond]


++ Returns the domain of computation of the modemap `mm'.  This is not
++ to be confused with `getDomainFromMm' below, which can also return
++ a category.
getDCFromSystemModemap mm ==
  or/[dom for cond in getConditionListFromMm mm |
       cond is ["isDomain","*1",dom]]

getDomainFromMm mm ==
  -- Returns the Domain (or package or category) of origin from a pattern
  -- modemap
  val := or/[opOf t for cond in getConditionListFromMm mm |
              cond is ['isDomain,"*1",t] or cond is ['ofCategory,"*1",t]]
  val = nil =>
    keyedSystemError("S2GE0016",
      ['"getDomainFromMm",'"Can't find domain in modemap condition"])
  val

getFirstArgTypeFromMm mm ==
  -- Returns the type of the first argument or nil
  [pats, cond] := mm
  [.,.,:args] := pats
  null args => nil
  arg1 := first args
  if cond is ['partial, :c] then cond := c
  condList :=
    cond is ['AND, :cl] => cl
    cond is ['OR, ['AND, :cl],:.] => cl  --all cl's should give same info
    [cond]
  type := nil
  for condition in condList while not type repeat
      if condition is ['isDomain, a1, dom] and a1=arg1 then type := dom
  type

isFreeFunctionFromMm mm ==
  -- This returns true is the modemap represents a free function, ie,
  -- one not coming from a domain or category.
  [., cond] := mm
  isFreeFunctionFromMmCond cond

isFreeFunctionFromMmCond cond ==
  -- This returns true is the modemap represents a free function, ie,
  -- one not coming from a domain or category.
  if cond is ['partial, :c] then cond := c
  condList :=
    cond is ['AND, :cl] => cl
    cond is ['OR, ['AND, :cl],:.] => cl  --all cl's should give same info
    [cond]
  iff := false
  for condition in condList while not iff repeat
      if condition is ['isFreeFunction, :.] then iff := true
  iff

getAllModemapsFromDatabase(op,nargs) ==
  $getUnexposedOperations: local := true
  try
    startTimingProcess 'diskread
    getSystemModemaps(op,nargs)
  finally stopTimingProcess 'diskread

getModemapsFromDatabase(op,nargs) ==
  $getUnexposedOperations: local := false
  try
    startTimingProcess 'diskread
    getSystemModemaps(op,nargs)
  finally stopTimingProcess 'diskread

getSystemModemaps(op,nargs) ==
  mml := getOperationFromDB op =>
    mms := nil
    for x in mml | not integer? nargs or nargs = #x.mmSource repeat
      $getUnexposedOperations or isFreeFunctionFromMm(x) or
        isExposedConstructor(getDomainFromMm(x)) => mms := [x,:mms]
      'iterate
    mms
  nil

getInCoreModemaps(modemapList,op,nargs) ==
  mml := LASSOC (op,modemapList) =>
    mml := first mml
    [x for x in mml |
      (not integer? nargs or nargs = #x.mmSource) and
        (cfn := abbreviate (domName := getDomainFromMm x)) and
          ($getUnexposedOperations or isExposedConstructor(domName))]
  nil

mkAlistOfExplicitCategoryOps target ==
  if target is ['add,a,:l] then
    target:=a
  target is ['Join,:l] =>
    "union"/[mkAlistOfExplicitCategoryOps cat for cat in l]
  target is ['CATEGORY,.,:l] =>
    l := flattenSignatureList ['PROGN,:l]
    u :=
      [[op,:sig] for x in l | x is ['SIGNATURE,op,sig,:.]]
    opList := removeDuplicates ASSOCLEFT u
    [[x,:fn(x,u)] for x in opList] where
      fn(op,u) ==
        u is [[a,:b],:c] => (a=op => [b,:fn(op,c)]; fn(op,c))
  isCategoryForm(target,$e) => nil
  keyedSystemError("S2GE0016",
    ['"mkAlistOfExplicitCategoryOps",'"bad signature"])

flattenSignatureList(x) ==
  x isnt [.,:.] => nil
  x is ['SIGNATURE,:.] => [x]
  x is ['IF,cond,b1,b2] =>
    [:flattenSignatureList b1,:flattenSignatureList b2]
  x is ['PROGN,:l] =>
     ll:= []
     for x in l repeat
        x is ['SIGNATURE,:.] => ll := [x,:ll]
        ll:= append(flattenSignatureList x,ll)
     ll
  nil

updateDatabase(fname,cname,systemdir?) ==
 -- for now in NRUNTIME do database update only if forced
  not $forceDatabaseUpdate => nil
  -- these modemaps are never needed in the old scheme
  if oldFname := getConstructorAbbreviationFromDB cname then
    clearClams()
    clearAllSlams []
    if dbLoaded? constructorDB cname then
      clearConstructorCaches()
  if $forceDatabaseUpdate or not systemdir? then
    clearClams()
    clearAllSlams []

REMOVER(lst,item) ==
  --destructively removes item from lst
  lst isnt [.,:.] =>
    lst=item => nil
    lst
  first lst=item => rest lst
  RPLNODE(lst,REMOVER(first lst,item),REMOVER(rest lst,item))

allLASSOCs(op,alist) ==
  [value for [key,:value] in alist | key = op]

loadDependents fn ==
  isExistingFile [fn,$spadLibFT,"*"] =>
    "dependents" in RKEYIDS(fn,$spadLibFT) =>
      stream:= readLib1(fn,$spadLibFT,"*")
      l:= rread('dependents,stream,nil)
      RSHUT stream
      for x in l repeat
        x='SubDomain => nil
        loadIfNecessary x

--% Miscellaneous Stuff

getOplistForConstructorForm (form := [op,:argl]) ==
  --  The new form is an op-Alist which has entries (<op> . signature-Alist)
  --    where signature-Alist has entries (<signature> . item)
  --      where item has form (<slotNumber> <condition> <kind>)
  --        where <kind> =  ELT | CONST | Subsumed | (XLAM..) ..
  pairlis := pairList($FormalMapVariableList,argl)
  opAlist := getConstructorOperationsFromDB op
  [:getOplistWithUniqueSignatures(op,pairlis,signatureAlist)
      for [op,:signatureAlist] in opAlist]

getOplistWithUniqueSignatures(op,pairlis,signatureAlist) ==
  alist:= nil
  for [sig,:[slotNumber,pred,kind]] in signatureAlist | kind isnt 'Subsumed repeat
    alist:= insertAlist(applySubst(pairlis,[op,sig]),
                applySubst(pairlis,[pred,[kind,nil,slotNumber]]),
                alist)
  alist

--% Exposure Group Code

dropPrefix(fn) ==
  charMember?(stringChar(fn,0),[char "?",char "-",char "+"]) =>
    subString(fn,1)
  fn

--moved to util.lisp
--++loadExposureGroupData() ==
--++  egFile := ['INTERP,'EXPOSED]
--++--  null MAKE_-INPUT_-FILENAME(egFile) =>
--++--    throwKeyedMsg("S2IL0003",[namestring egFile])
--++  stream:= DEFIOSTREAM(['(MODE . INPUT),['FILE,:egFile]],80,0)
--++  $globalExposureGroupAlist := nil
--++  egName  := nil
--++  egFiles := nil
--++  while (x:= readLine stream) ~= %nothing repeat
--++    x := trimTrailingBlank x
--++    # x = 0 => 'iterate                         -- blank line
--++    (x.0 = char "#") or (x.0 = char "*") => 'iterate    -- comment
--++    x.0 = char " " =>
--++       -- possible exposure group member name and library name
--++       null egName =>
--++     throwKeyedMsg("S2IZ0069A",[namestring egFile,x])
--++       x := dropLeadingBlanks x
--++       -- should be two tokens on the line
--++       p := STRPOS('" ",x,1,nil)
--++       null p =>
--++     throwKeyedMsg("S2IZ0069B",[namestring egFile,x])
--++       n := object2Identifier subString(x,0,p)
--++       x := dropLeadingBlanks subString(x,p+1)
--++       # x = 0 =>
--++     throwKeyedMsg("S2IZ0069B",[namestring egFile,x])
--++       egFiles := [[n,:object2Identifier x],:egFiles]
--++    -- have a new group name
--++    if egName then $globalExposureGroupAlist :=
--++      [[egName,:reverse! egFiles],:$globalExposureGroupAlist]
--++    egFiles := nil
--++    STRPOS('" ",x,1,nil) =>
--++      throwKeyedMsg("S2IZ0069C",[namestring egFile,x])
--++    egName := object2Identifier x
--++  if egFiles then $globalExposureGroupAlist :=
--++      [[egName,:reverse! egFiles],:$globalExposureGroupAlist]
--++  SHUT stream
--++  $globalExposureGroupAlist := reverse! $globalExposureGroupAlist
--++  'done

isExposedConstructor name ==
  -- this function checks the local exposure data in the frame to
  -- see if the given constructor is exposed. The format of
  -- $localExposureData is a vector with
  --   slot 0: list of groups exposed in the frame
  --   slot 1: list of constructors explicitly exposed
  --   slot 2: list of constructors explicitly hidden
  -- check if it is explicitly hidden
  builtinConstructor? name => true
  symbolMember?(name,$localExposureData.2) => false
  -- check if it is explicitly exposed
  symbolMember?(name,$localExposureData.1) => true
  -- check if it is in an exposed group
  found := nil
  for g in $localExposureData.0 while not found repeat
    null (x := GETALIST($globalExposureGroupAlist,g)) => 'iterate
    if GETALIST(x,name) then found := true
  found

displayExposedGroups() ==
  sayKeyedMsg("S2IZ0049A",[$interpreterFrameName])
  if null $localExposureData.0
    then centerAndHighlight '"there are no exposed groups"
    else for g in $localExposureData.0 repeat
      centerAndHighlight g

displayExposedConstructors() ==
  sayKeyedMsg("S2IZ0049B",nil)
  if null $localExposureData.1
    then centerAndHighlight
      '"there are no explicitly exposed constructors"
    else for c in $localExposureData.1 repeat
      centerAndHighlight c

displayHiddenConstructors() ==
  sayKeyedMsg("S2IZ0049C",nil)
  if null $localExposureData.2
    then centerAndHighlight
      '"there are no explicitly hidden constructors"
    else for c in $localExposureData.2 repeat
      centerAndHighlight c

--%
squeezeAll: %List %Code -> %List %Code
squeezeAll x ==
  [SQUEEZE t for t in x]

makeInitialDB [form,kind,abbrev,srcfile] ==
  db := makeDB form.op
  dbConstructorForm(db) := form
  dbConstructorKind(db) := kind
  dbAbbreviation(db) := abbrev
  property(abbrev,'ABBREVIATIONFOR) := form.op
  dbSourceFile(db) := srcfile
  setAutoLoadProperty form.op
  
populateDBFromFile path ==
  try
    dbfile := inputTextFile path
    while (entry := readExpr dbfile) ~= %nothing repeat
      makeInitialDB entry
  finally closeStream dbfile

printInitdbInfo(path,dbfile) == main(path,dbfile) where
  main(path,dbfile) ==
    for x in parseSpadFile path repeat
      x is ['DEF,lhs,:.] => fn(lhs,path,dbfile)
      x is ["where",['DEF,lhs,:.],:.] => fn(lhs,path,dbfile)
  fn(lhs,path,dbfile) ==
    if lhs isnt [.,:.] then lhs := [lhs]
    db := constructorDB lhs.op
    db = nil => nil
    form := [id for x in lhs.args]
              where id() == (x is [":",x',:.] => x'; x)
    form := [lhs.op,:form]
    prettyPrint([form,dbConstructorKind db,dbAbbreviation db,path],dbfile)
    writeNewline dbfile

printAllInitdbInfo(srcdir,dbfile) ==
  paths := DIRECTORY strconc(ensureTrailingSlash srcdir,'"*.spad")
    or coreError strconc('"no .spad file in directory ",srcdir)
  try
    out := outputTextFile dbfile
    for path in paths repeat
      printInitdbInfo(NAMESTRING path,out)
  finally closeStream out

--%

dbLoaded? db ==
  dbLoadPath db ~= nil

loadDBIfNecessary db ==
  ctor := dbConstructor db
  dbLoaded? db => db
  loadDB db

++ Return true if this DB is for a category default package.
macro dbDefaultPackage? db ==
  isDefaultPackageName dbConstructor db