diff options
Diffstat (limited to 'src/interp/compiler.boot')
| -rw-r--r-- | src/interp/compiler.boot | 96 |
1 files changed, 86 insertions, 10 deletions
diff --git a/src/interp/compiler.boot b/src/interp/compiler.boot index 074d225e..88ef6691 100644 --- a/src/interp/compiler.boot +++ b/src/interp/compiler.boot @@ -721,10 +721,77 @@ reshapeArgumentList(form,sig) == wantArgumentsAsTuple(args,sig) => [op,["%Comma",:args]] form -++ Return true is the constructor condition `cond' holds in the -++ elaboration environmemt `e'. -constructorCondition(cond,e) == - cond --FIXME: solve it! +++ Attempt to find values for queries variables `vars' so that +++ the category expression `x' equals the category expression `p'. +solveEquation(x,p,sl,vars) == + ident? p and symbolMember?(p,vars) => + z := symbolTarget(p,sl) => + x = z => sl + 'failed + [[p,:x],:sl] + x isnt [.,:.] or p isnt [.,:.] => + x = p => sl + 'failed + symbolEq?(x.op,p.op) => + #x.args ~= #p.args => 'failed + x.args = nil => sl + and/[sl := solveEquation(x',p',sl,vars) + for x' in x.args for p' in p.args + | sl isnt 'failed or leave 'failed] + 'failed + +++ Attempt to find values for queries variables `vars' so that +++ the category expression `x' subsumes the category expression `p'. +solveSubsumption(x,p,sl,vars,typings,e) == + x isnt [.,:.] or p isnt [.,:.] => solveEquation(x,p,sl,vars) + p = $Type => sl + symbolEq?(x.op,p.op) => solveEquation(x,p,sl,vars) + x.op is 'Join => + x.args = nil => 'failed + or/[sl' := solveSubsumption(x',p,sl,vars,typings,e) for x' in x.args + | sl' isnt 'failed] or 'failed + x is ['CATEGORY,.,:xs] => + or/[sl' := solveSubsumption(x',p,sl,vars,typings,e) for x' in xs + | sl' isnt 'failed] or 'failed + x.op in '(SIGNATURE ATTRIBUTE) => 'failed + getConstructorKind x.op isnt 'category => 'failed --FIXME: for now. + x := applySubst(constructSubst x,getConstructorCategory x.op) + solveSubsumption(x,p,sl,vars,typings,e) + +++ Subroutine of bindPredicateExistentials, with similar semantics. +++ `vars' is the list of quantified variables, and `conds' is a +++ of conditions the conjunction of which makes the whole predicate. +deduceImplicitArguments(vars,conds,e) == + eqs := nil -- equation constraints + typings := nil -- typing constraints + sl := nil + for c in conds while sl isnt 'failed repeat + c is ['ofCategory,x,y] => -- subsumption constraint + ident? x and symbolMember?(x,vars) => + typings := [[x,:y],:typings] + eqs := [[x,:y],:eqs] + c is ['ofType,x,y] => -- exact type constraints + T := comp(x,$EmptyMode,e) + T = nil => sl := 'failed + sl := solveEquation(T.mode,y,sl,vars) + for [x,:y] in eqs while sl isnt 'failed repeat + cat := + x isnt [.,:.] => getXmode(x,e) + applySubst(constructSubst x,getConstructorCategory x.op) + sl := solveSubsumption(cat,y,sl,vars,typings,e) + sl is 'failed => sl + -- Every existential must have a value + or/[symbolTarget(v,sl) = nil for v in vars] => 'failed + sl --FIXME: check typing constraints + +++ Attempt to find values for existentially quantified variables in +++ the predicate `cond' so that it holds in the environment `e'. +++ Return a substitution on success; otherwise fail. +bindPredicateExistentials(cond,e) == + cond is true => nil -- identity substitution + cond is ['%exist,vars,['AND,:conds]] => + deduceImplicitArguments(vars,conds,e) + 'failed ++ The argument list `argl' is used to instantiate a constructor ++ with `modemap' in environment `e'. Return the resulting @@ -734,13 +801,22 @@ evaluateConstructorModemap(argl,modemap is [[dc,:sig],:.],e) == keyedSystemError("S2GE0016",['"evaluateConstructorModemap", '"Incompatible maps"]) #argl ~= #sig.source => nil - constructorCondition(applySubst(sl,modemap.mmCondition),e) isnt true => nil + -- Get `source-level' subtitution in an attempt to deduce implicits. sl := pairList(dc.args,argl) - --make new modemap, subst. actual for formal parameters into modemap - Tl := [[.,.,e] := compOrCroak(a,m,e) - for a in argl for m in applySubst(sl,modemap.mmSource)] - sl := [[x,:T.expr] for x in dc.args for T in Tl] - [applySubst(sl,modemap),e] + sl' := bindPredicateExistentials(applySubst(sl,modemap.mmCondition),e) + sl' is 'failed => nil + -- Subtitute values for implicit in formal modemap. Then substitute + -- the `source-level' arguments into the resulting modemap, before + -- compiling them. Note the sort of bootstrapping process. + signature := applySubst(sl',modemap.mmSignature) + args' := [x for a in argl for m in applySubst(sl,signature.source) + | [x,.,e] := compOrCroak(a,m,e)] + -- Now substitutte elaborations of actual arguments into the formal + -- signature to construct the final result. + signature := applySubst(pairList(dc.args,args'),signature) + -- At this point, the modemap condition was evaluated successfully, + -- so we return plain `true' for that part of the modemap. + [[[[dc.op,:args'],:signature],[true,dc.op]],e] --% SPECIAL EVALUATION FUNCTIONS |