public static void RenameFirstInstance(string sOld, string sNew, List <CatAstNode> terms)
{
for (int i = 0; i < terms.Count; ++i)
{
if (TermContains(terms[i], sOld))
{
if (terms[i] is AstLambda)
{
AstLambda l = terms[i] as AstLambda;
RenameFirstInstance(sOld, sNew, l.mTerms);
return;
}
else if (terms[i] is AstQuote)
{
AstQuote q = terms[i] as AstQuote;
RenameFirstInstance(sOld, sNew, q.mTerms);
return;
}
else
{
// Should never happen.
throw new Exception("expected either a lamda node or quote node");
}
}
else if (TermEquals(terms[i], sOld))
{
terms[i] = new AstName(sNew);
return;
}
}
throw new Exception(sOld + " was not found in the list of terms");
}
public static void RenameFirstInstance(string sOld, string sNew, List<CatAstNode> terms)
{
for (int i = 0; i < terms.Count; ++i)
{
if (TermContains(terms[i], sOld))
{
if (terms[i] is AstLambda)
{
AstLambda l = terms[i] as AstLambda;
RenameFirstInstance(sOld, sNew, l.mTerms);
return;
}
else if (terms[i] is AstQuote)
{
AstQuote q = terms[i] as AstQuote;
RenameFirstInstance(sOld, sNew, q.mTerms);
return;
}
else
{
// Should never happen.
throw new Exception("expected either a lamda node or quote node");
}
}
else if (TermEquals(terms[i], sOld))
{
terms[i] = new AstName(sNew);
return;
}
}
throw new Exception(sOld + " was not found in the list of terms");
}
public static void RemoveTerm( string var, List<CatAstNode> terms ) {
// Find the first term that either contains, or is equal to the
// free variable
int i = 0;
while (i < terms.Count) {
if (TermContainsOrEquals( terms[ i ], var ))
break;
++i;
}
if (i == terms.Count)
throw new Exception( "error in abstraction elimination algorithm" );
if (i > 0) {
AstQuote q = new AstQuote( terms.GetRange( 0, i ) );
terms.RemoveRange( 0, i );
terms.Insert( 0, q );
terms.Insert( 1, new AstName( "dip" ) );
i = 2;
} else {
i = 0;
}
if (TermEquals( terms[ i ], var )) {
terms[ i ] = new AstName( "id" );
return;
} else if (TermContains( terms[ i ], var )) {
if (terms[ i ] is AstQuote) {
AstQuote subExpr = terms[ i ] as AstQuote;
RemoveTerm( var, subExpr.mTerms );
} else if (TermContains( terms[ i ], var )) {
AstLambda subExpr = terms[ i ] as AstLambda;
RemoveTerm( var, subExpr.mTerms );
} else {
throw new Exception( "internal error: expected either a quotation or lambda term" );
}
terms.Insert( i + 1, new AstName( "papply" ) );
return;
} else {
throw new Exception( "error in abstraction elimination algorithm" );
}
}
public AstDef(PegAstNode node)
: base(node)
{
CheckLabel(AstLabel.Def);
if (node.GetNumChildren() == 0)
{
throw new Exception("invalid function definition node");
}
AstName name = new AstName(node.GetChild(0));
mName = name.ToString();
int n = 1;
// Look to see if a type is defined
if ((node.GetNumChildren() >= 2) && (node.GetChild(1).GetLabel().Equals(AstLabel.FxnType)))
{
mType = new AstFxnType(node.GetChild(1));
++n;
}
while (n < node.GetNumChildren())
{
PegAstNode child = node.GetChild(n);
if (!child.GetLabel().Equals(AstLabel.Param))
{
break;
}
mParams.Add(new AstParam(child));
n++;
}
while (n < node.GetNumChildren())
{
PegAstNode child = node.GetChild(n);
if (!child.GetLabel().Equals(AstLabel.Param))
{
break;
}
mParams.Add(new AstParam(child));
n++;
}
while (n < node.GetNumChildren())
{
PegAstNode child = node.GetChild(n);
if (!child.GetLabel().Equals(AstLabel.MetaDataBlock))
{
break;
}
mpMetaData = new AstMetaDataBlock(child);
n++;
}
while (n < node.GetNumChildren())
{
PegAstNode child = node.GetChild(n);
if (!child.GetLabel().Equals(AstLabel.Def))
{
break;
}
mLocals.Add(new AstDef(child));
n++;
}
while (n < node.GetNumChildren())
{
PegAstNode child = node.GetChild(n);
CatAstNode expr = Create(child);
if (!(expr is AstExpr))
{
throw new Exception("expected expression node");
}
mTerms.Add(expr as AstExpr);
n++;
}
}
public static void RemoveTerm(string var, List<CatAstNode> terms)
{
// Find the first term that either contains, or is equal to the
// free variable
int i = 0;
while (i < terms.Count)
{
if (TermContainsOrEquals(terms[i], var))
break;
++i;
}
if (i == terms.Count)
throw new Exception("error in abstraction elimination algorithm");
if (i > 0)
{
AstQuote q = new AstQuote(terms.GetRange(0, i));
terms.RemoveRange(0, i);
terms.Insert(0, q);
terms.Insert(1, new AstName("dip"));
i = 2;
}
else
{
i = 0;
}
if (TermEquals(terms[i], var))
{
terms[i] = new AstName("id");
return;
}
else if (TermContains(terms[i], var))
{
if (terms[i] is AstQuote)
{
AstQuote subExpr = terms[i] as AstQuote;
RemoveTerm(var, subExpr.mTerms);
}
else if (TermContains(terms[i], var))
{
AstLambda subExpr = terms[i] as AstLambda;
RemoveTerm(var, subExpr.mTerms);
}
else
{
throw new Exception("internal error: expected either a quotation or lambda term");
}
terms.Insert(i + 1, new AstName("papply"));
return;
}
else
{
throw new Exception("error in abstraction elimination algorithm");
}
}
public AstDef(PegAstNode node)
: base(node)
{
CheckLabel(AstLabel.Def);
if (node.GetNumChildren() == 0)
throw new Exception("invalid function definition node");
AstName name = new AstName(node.GetChild(0));
mName = name.ToString();
int n = 1;
// Look to see if a type is defined
if ((node.GetNumChildren() >= 2) && (node.GetChild(1).GetLabel().Equals(AstLabel.FxnType)))
{
mType = new AstFxnType(node.GetChild(1));
++n;
}
while (n < node.GetNumChildren())
{
PegAstNode child = node.GetChild(n);
if (!child.GetLabel().Equals(AstLabel.Param))
break;
mParams.Add(new AstParam(child));
n++;
}
while (n < node.GetNumChildren())
{
PegAstNode child = node.GetChild(n);
if (!child.GetLabel().Equals(AstLabel.Param))
break;
mParams.Add(new AstParam(child));
n++;
}
while (n < node.GetNumChildren())
{
PegAstNode child = node.GetChild(n);
if (!child.GetLabel().Equals(AstLabel.MetaDataBlock))
break;
mpMetaData = new AstMetaDataBlock(child);
n++;
}
while (n < node.GetNumChildren())
{
PegAstNode child = node.GetChild(n);
if (!child.GetLabel().Equals(AstLabel.Def))
break;
mLocals.Add(new AstDef(child));
n++;
}
while (n < node.GetNumChildren())
{
PegAstNode child = node.GetChild(n);
CatAstNode expr = Create(child);
if (!(expr is AstExpr))
throw new Exception("expected expression node");
mTerms.Add(expr as AstExpr);
n++;
}
}