Add compiler support for implicit parameters.

	* interp/compiler.boot (bindPredicateExistentials): Rename from
	constructorCondition.  Now return a substitution on success,
	otherwise failure.
	(solveEquation): New.
	(solveSubsumption): Likewise.
	(deduceImplicitParameters): Likewise.
	(evaluateConstructorModemap): Use it. Tidy.

4 files changed, 109 insertions, 21 deletions

diff --git a/configure b/configure
index 24db3418..2f5f7d0e 100755
--- a/configure
+++ b/configure
@@ -1,6 +1,6 @@
 #! /bin/sh
 # Guess values for system-dependent variables and create Makefiles.
-# Generated by GNU Autoconf 2.65 for OpenAxiom 1.5.0-2011-09-03.
+# Generated by GNU Autoconf 2.65 for OpenAxiom 1.5.0-2011-11-02.
 #
 # Report bugs to <open-axiom-bugs@lists.sf.net>.
 #
@@ -701,8 +701,8 @@ MAKEFLAGS=
 # Identity of this package.
 PACKAGE_NAME='OpenAxiom'
 PACKAGE_TARNAME='openaxiom'
-PACKAGE_VERSION='1.5.0-2011-09-03'
-PACKAGE_STRING='OpenAxiom 1.5.0-2011-09-03'
+PACKAGE_VERSION='1.5.0-2011-11-02'
+PACKAGE_STRING='OpenAxiom 1.5.0-2011-11-02'
 PACKAGE_BUGREPORT='open-axiom-bugs@lists.sf.net'
 PACKAGE_URL=''
 
@@ -1493,7 +1493,7 @@ if test "$ac_init_help" = "long"; then
   # Omit some internal or obsolete options to make the list less imposing.
   # This message is too long to be a string in the A/UX 3.1 sh.
   cat <<_ACEOF
-\`configure' configures OpenAxiom 1.5.0-2011-09-03 to adapt to many kinds of systems.
+\`configure' configures OpenAxiom 1.5.0-2011-11-02 to adapt to many kinds of systems.
 
 Usage: $0 [OPTION]... [VAR=VALUE]...
 
@@ -1568,7 +1568,7 @@ fi
 
 if test -n "$ac_init_help"; then
   case $ac_init_help in
-     short | recursive ) echo "Configuration of OpenAxiom 1.5.0-2011-09-03:";;
+     short | recursive ) echo "Configuration of OpenAxiom 1.5.0-2011-11-02:";;
    esac
   cat <<\_ACEOF
 
@@ -1679,7 +1679,7 @@ fi
 test -n "$ac_init_help" && exit $ac_status
 if $ac_init_version; then
   cat <<\_ACEOF
-OpenAxiom configure 1.5.0-2011-09-03
+OpenAxiom configure 1.5.0-2011-11-02
 generated by GNU Autoconf 2.65
 
 Copyright (C) 2009 Free Software Foundation, Inc.
@@ -2669,7 +2669,7 @@ cat >config.log <<_ACEOF
 This file contains any messages produced by compilers while
 running configure, to aid debugging if configure makes a mistake.
 
-It was created by OpenAxiom $as_me 1.5.0-2011-09-03, which was
+It was created by OpenAxiom $as_me 1.5.0-2011-11-02, which was
 generated by GNU Autoconf 2.65.  Invocation command line was
 
   $ $0 $@
@@ -5570,7 +5570,7 @@ fi
 
 # Define the identity of the package.
  PACKAGE='openaxiom'
- VERSION='1.5.0-2011-09-03'
+ VERSION='1.5.0-2011-11-02'
 
 
 cat >>confdefs.h <<_ACEOF
@@ -21575,7 +21575,7 @@ cat >>$CONFIG_STATUS <<\_ACEOF || ac_write_fail=1
 # report actual input values of CONFIG_FILES etc. instead of their
 # values after options handling.
 ac_log="
-This file was extended by OpenAxiom $as_me 1.5.0-2011-09-03, which was
+This file was extended by OpenAxiom $as_me 1.5.0-2011-11-02, which was
 generated by GNU Autoconf 2.65.  Invocation command line was
 
   CONFIG_FILES    = $CONFIG_FILES
@@ -21641,7 +21641,7 @@ _ACEOF
 cat >>$CONFIG_STATUS <<_ACEOF || ac_write_fail=1
 ac_cs_config="`$as_echo "$ac_configure_args" | sed 's/^ //; s/[\\""\`\$]/\\\\&/g'`"
 ac_cs_version="\\
-OpenAxiom config.status 1.5.0-2011-09-03
+OpenAxiom config.status 1.5.0-2011-11-02
 configured by $0, generated by GNU Autoconf 2.65,
   with options \\"\$ac_cs_config\\"
 
diff --git a/configure.ac b/configure.ac
index 1a6bbc30..3b8c86c9 100644
--- a/configure.ac
+++ b/configure.ac
@@ -33,7 +33,7 @@ dnl  Makefiles for building OpenAxiom interpreter, compiler, libraries, and
 dnl  auxiliary tools where appropriate.
 dnl
 
-AC_INIT([OpenAxiom], [1.5.0-2011-09-03], 
+AC_INIT([OpenAxiom], [1.5.0-2011-11-02], 
         [open-axiom-bugs@lists.sf.net])
 
 dnl Most of the macros used in this configure.ac are defined in files
diff --git a/src/ChangeLog b/src/ChangeLog
index d404b7fe..04edac55 100644
--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -1,5 +1,17 @@
+2011-11-02  Gabriel Dos Reis  <gdr@cs.tamu.edu>
+
+	Add compiler support for implicit parameters.
+	* interp/compiler.boot (bindPredicateExistentials): Rename from
+	constructorCondition.  Now return a substitution on success,
+	otherwise failure.
+	(solveEquation): New.
+	(solveSubsumption): Likewise.
+	(deduceImplicitParameters): Likewise.
+	(evaluateConstructorModemap): Use it. Tidy.
+
 2011-10-31  Gabriel Dos Reis  <gdr@cs.tamu.edu>
 
+	Add interpreter support for implicit parameters.
 	* interp/i-funsel.boot (evalMmCond0): Tidy. Call evalMmGuard to
 	validate modemap evaluation.
 	(evalMmGuard): New.
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