--- /dev/null
+/************************************************************************
+ ************************************************************************
+ FAUST compiler
+ Copyright (C) 2003-2004 GRAME, Centre National de Creation Musicale
+ ---------------------------------------------------------------------
+ This program is free software; you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation; either version 2 of the License, or
+ (at your option) any later version.
+
+ This program is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with this program; if not, write to the Free Software
+ Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ ************************************************************************
+ ************************************************************************/
+
+
+
+#include <assert.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <limits.h>
+#include "tlib.hh"
+
+// Declaration of implementation
+static Tree calcDeBruijn2Sym (Tree t);
+static Tree substitute(Tree t, int n, Tree id);
+static Tree calcsubstitute(Tree t, int level, Tree id);
+static Tree liftn(Tree t, int threshold);
+static Tree calcliftn(Tree t, int threshold);
+
+// recursive trees
+
+Sym DEBRUIJN = symbol ("DEBRUIJN");
+Sym DEBRUIJNREF = symbol ("DEBRUIJNREF");
+Sym SUBSTITUTE = symbol ("SUBSTITUTE");
+
+Sym SYMREC = symbol ("SYMREC");
+Sym SYMRECREF = symbol ("SYMRECREF");
+Sym SYMLIFTN = symbol ("LIFTN");
+
+//Tree NOVAR = tree("NOVAR");
+
+//-----------------------------------------------------------------------------------------
+// rec, isRec : declare recursive trees
+//-----------------------------------------------------------------------------------------
+
+// de Bruijn declaration of a recursive tree
+Tree rec(Tree body)
+{
+ return tree(DEBRUIJN, body);
+}
+
+bool isRec(Tree t, Tree& body)
+{
+ return isTree(t, DEBRUIJN, body);
+}
+
+Tree ref(int level)
+{
+ assert(level > 0);
+ return tree(DEBRUIJNREF, tree(level)); // reference to enclosing recursive tree starting from 1
+}
+
+bool isRef(Tree t, int& level)
+{
+ Tree u;
+
+ if (isTree(t, DEBRUIJNREF, u)) {
+ return isInt(u->node(), &level);
+ } else {
+ return false;
+ }
+}
+
+
+//-----------------------------------------------------------------------------------------
+// Recursive tree in symbolic notation (using a recursive definition property)
+//-----------------------------------------------------------------------------------------
+Tree RECDEF = tree(symbol("RECDEF"));
+
+// declaration of a recursive tree using a symbolic variable
+Tree rec(Tree var, Tree body)
+{
+ Tree t = tree(SYMREC, var);
+ t->setProperty(RECDEF, body);
+ return t;
+}
+
+bool isRec(Tree t, Tree& var, Tree& body)
+{
+ if (isTree(t, SYMREC, var)) {
+ body = t->getProperty(RECDEF);
+ return true;
+ } else {
+ return false;
+ }
+}
+
+
+Tree ref(Tree id)
+{
+ return tree(SYMREC, id); // reference to a symbolic id
+}
+
+bool isRef(Tree t, Tree& v)
+{
+ return isTree(t, SYMREC, v);
+}
+
+//-----------------------------------------------------------------------------------------
+// L'aperture d'un arbre est la plus profonde reference de Bruijn qu'il contienne.
+// Les references symboliques compte pour zero ce qui veut dire qu'un arbre d'aperture
+// 0 ne compte aucun reference de bruijn libres.
+
+int CTree::calcTreeAperture( const Node& n, const tvec& br )
+{
+ int x;
+ if (n == DEBRUIJNREF) {
+
+ if (isInt(br[0]->node(), &x)) {
+ return x;
+ } else {
+ return 0;
+ }
+
+ } else if (n == DEBRUIJN) {
+
+ return br[0]->fAperture - 1;
+
+ } else {
+ // return max aperture of branches
+ int rc = 0;
+ tvec::const_iterator b = br.begin();
+ tvec::const_iterator z = br.end();
+ while (b != z) {
+ if ((*b)->aperture() > rc) rc = (*b)->aperture();
+ ++b;
+ }
+ return rc;
+ }
+}
+
+Tree lift(Tree t) { return liftn(t, 1); }
+
+void printSignal(Tree sig, FILE* out, int prec=0);
+
+// lift (t) : increase free references by 1
+
+#if 0
+static Tree _liftn(Tree t, int threshold);
+
+static Tree liftn(Tree t, int threshold)
+{
+ fprintf(stderr, "call of liftn("); printSignal(t, stderr); fprintf(stderr, ", %d)\n", threshold);
+ Tree r = _liftn(t, threshold);
+ fprintf(stderr, "return of liftn("); printSignal(t, stderr); fprintf(stderr, ", %d) -> ", threshold);
+ printSignal(r, stderr); fprintf(stderr, "\n");
+ return r;
+}
+#endif
+
+
+static Tree liftn(Tree t, int threshold)
+{
+ Tree L = tree( Node(SYMLIFTN), tree(Node(threshold)) );
+ Tree t2 = t->getProperty(L);
+
+ if (!t2) {
+ t2 = calcliftn(t, threshold);
+ t->setProperty(L, t2);
+ }
+ return t2;
+
+}
+
+static Tree calcliftn(Tree t, int threshold)
+{
+ int n;
+ Tree u;
+
+ if (isClosed(t)) {
+
+ return t;
+
+ } else if (isRef(t,n)) {
+
+ if (n < threshold) {
+ // it is a bounded reference
+ return t;
+ } else {
+ // it is a free reference
+ return ref(n+1);
+ }
+
+ } else if (isRec(t,u)) {
+
+ return rec(liftn(u, threshold+1));
+
+ } else {
+ int n = t->arity();
+ //Tree br[4];
+ tvec br(n);
+ for (int i = 0; i < n; i++) {
+ br[i] = liftn(t->branch(i), threshold);
+ }
+ //return CTree::make(t->node(), n, br);
+ return CTree::make(t->node(), br);
+ }
+
+}
+
+//-----------------------------------------------------------
+// Transform a tree from deBruijn to symbolic representation
+//-----------------------------------------------------------
+Tree DEBRUIJN2SYM = tree(symbol("deBruijn2Sym"));
+
+Tree deBruijn2Sym (Tree t)
+{
+ assert(isClosed(t));
+ Tree t2 = t->getProperty(DEBRUIJN2SYM);
+
+ if (!t2) {
+ t2 = calcDeBruijn2Sym(t);
+ t->setProperty(DEBRUIJN2SYM, t2);
+ }
+ return t2;
+}
+
+static Tree calcDeBruijn2Sym (Tree t)
+{
+ Tree body, var;
+ int i;
+
+ if (isRec(t,body)) {
+
+ var = tree(unique("W"));
+ return rec(var, deBruijn2Sym(substitute(body,1,ref(var))));
+
+ } else if (isRef(t,var)) {
+
+ return t;
+
+ } else if (isRef(t,i)) {
+
+ fprintf(stderr, "ERREUR, une reference de Bruijn touvee ! : ");
+ printSignal(t, stderr);
+ fprintf(stderr, ")\n");
+ exit(1);
+ return t;
+
+ } else {
+
+ //Tree br[4];
+ int a = t->arity();
+ tvec br(a);
+
+ for (int i = 0; i < a; i++) {
+ br[i] = deBruijn2Sym(t->branch(i));
+ }
+ //return CTree::make(t->node(), a, br);
+ return CTree::make(t->node(), br);
+ }
+}
+
+static Tree substitute(Tree t, int level, Tree id)
+{
+ Tree S = tree( Node(SUBSTITUTE), tree(Node(level)), id );
+ Tree t2 = t->getProperty(S);
+
+ if (!t2) {
+ t2 = calcsubstitute(t, level, id);
+ t->setProperty(S, t2);
+ }
+ return t2;
+
+}
+
+static Tree calcsubstitute(Tree t, int level, Tree id)
+{
+ int l;
+ Tree body;
+
+ if (t->aperture()<level) {
+// fprintf(stderr, "aperture %d < level %d !!\n", t->aperture(), level);
+ return t;
+ }
+ if (isRef(t,l)) return (l == level) ? id : t;
+ if (isRec(t,body)) return rec(substitute(body, level+1, id));
+
+ int ar = t->arity();
+ //Tree br[4];
+ tvec br(ar);
+ for (int i = 0; i < ar; i++) {
+ br[i] = substitute(t->branch(i), level, id);
+ }
+ //return CTree::make(t->node(), ar, br);
+ return CTree::make(t->node(), br);
+}
+
+
+//--------------------------------------------------------------------------
+// UpdateAperture (t) : recursively mark open and closed terms.
+// closed term : fAperture == 0, open term fAperture == -1
+
+struct Env {
+ Tree fTree; Env* fNext;
+ Env(Tree t, Env* nxt) : fTree(t), fNext(nxt) {}
+};
+
+static void markOpen(Tree t);
+static int recomputeAperture(Tree t, Env* p);
+static int orderof (Tree t, Env* p);
+
+void updateAperture(Tree t)
+{
+ markOpen(t);
+ recomputeAperture(t, NULL);
+}
+
+//----------------------implementation--------------------------------
+
+static void markOpen(Tree t)
+{
+ if (t->aperture() == INT_MAX) return;
+ t->setAperture(INT_MAX);
+ int ar = t->arity();
+ for (int i = 0; i < ar; i++) {
+ markOpen(t->branch(i));
+ }
+}
+
+static int recomputeAperture(Tree t, Env* env)
+{
+ Tree var, body;
+
+ if (t->aperture() == 0) return 0;
+
+ if (isRef(t, var)) {
+
+ return orderof(var, env);
+
+ } else if (isRec(t, var, body)) {
+
+ Env e(var,env);
+ int a = recomputeAperture(body, &e) - 1;
+ if (a<=0) { /*print(t, stderr);*/ t->setAperture(0); }
+ return a;
+
+ } else {
+ // return max aperture of branches
+ int ma = 0;
+ int ar = t->arity();
+ for (int i = 0; i<ar; i++) {
+ int a = recomputeAperture(t->branch(i), env);
+ if (ma < a) ma = a;
+ }
+ if (ma <= 0) { /*print(t, stderr);*/ t->setAperture(0); }
+ return ma;
+ }
+}
+
+
+static int orderof (Tree t, Env* p)
+{
+ if (p == NULL) return 0;
+ if (t == p->fTree) return 1;
+
+ int pos = 1;
+ while (p != NULL) {
+ if (t == p->fTree) return pos;
+ p = p->fNext;
+ pos++;
+ }
+ return 0;
+}
projects / Faustine.git / blobdiff