public Expression gen(Context ctx) throws SemanticException {
Expression res = null;
Expression srcExpr = null;
String opname = fOp.getText();
if (fSrcExpr != null) {
srcExpr = fSrcExpr.gen(ctx);
res = gen1(ctx, srcExpr);
} else {
// if no source expression is given, it is either a
// variable or a reference to expression determined by
// context. In the latter case we use the context as
// source expression and proceed as if it has been given
// explicitly.
if (!fHasParentheses) {
// variable?
// (7) check for variable
Type type = ctx.varTable().lookup(opname);
if (type != null) res = new ExpVariable(opname, type);
}
// do we have a context expression that is implicitly
// assumed to be the source expression?
if (res == null) {
ExprContext ec = ctx.exprContext();
if (!ec.isEmpty()) {
// construct source expression
ExprContext.Entry e = ec.peek();
srcExpr = new ExpVariable(e.fName, e.fType);
if (e.fType.isCollection()) fFollowsArrow = true;
res = gen1(ctx, srcExpr);
} else
throw new SemanticException(
fOp,
"Undefined " + (fHasParentheses ? "operation" : "variable") + " `" + opname + "'.");
}
}
if (fIsPre) {
if (!ctx.insidePostCondition())
throw new SemanticException(fOp, "Modifier @pre is only allowed in postconditions.");
res.setIsPre();
}
if (opname.equals("oclIsNew")) {
if (!ctx.insidePostCondition())
throw new SemanticException(fOp, "Operation oclIsNew is only allowed in postconditions.");
}
return res;
}
public Expression gen(Context ctx) throws SemanticException {
String opname = fOp.getText();
Expression res = null;
Expression range, expr;
// check for empty range: do we have a context expression that
// is implicitly assumed to be the source expression?
if (fRange != null) range = fRange.gen(ctx);
else {
ExprContext ec = ctx.exprContext();
if (!ec.isEmpty()) {
// construct source expression
ExprContext.Entry e = ec.peek();
range = new ExpVariable(e.fName, e.fType);
} else throw new SemanticException(fOp, "Need a collection to apply `" + opname + "'.");
}
if (!range.type().isCollection())
throw new SemanticException(
fOp,
"Source of `"
+ opname
+ "' expression must be a collection, "
+ "found source expression of type `"
+ range.type()
+ "'.");
VarDeclList declList = new VarDeclList(true);
if (fDeclList.isEmpty()) {
// when there are no explicit var decls, we declare an
// internal variable with the element type
ExprContext ec = ctx.exprContext();
CollectionType ct = (CollectionType) range.type();
String var = ec.push(ct.elemType());
expr = fExpr.gen(ctx);
ec.pop();
// use the generated element variable
VarDecl decl = new VarDecl(var, ct.elemType());
declList.add(decl);
} else {
declList = fDeclList.gen(ctx, range);
// enter declared variable into scope before evaluating
// the argument expression
Symtable vars = ctx.varTable();
vars.enterScope();
fDeclList.addVariablesToSymtable(vars, declList.varDecl(0).type());
expr = fExpr.gen(ctx);
vars.exitScope();
}
try {
Integer id = (Integer) GParser.queryIdentMap.get(opname);
if (id == null)
throw new SemanticException(
fOp, "Internal error: unknown query operation `" + opname + "'.");
int idval = id.intValue();
switch (idval) {
case GParser.Q_SELECT_ID:
case GParser.Q_COLLECT_ID:
case GParser.Q_REJECT_ID:
case GParser.Q_ISUNIQUE_ID:
case GParser.Q_SORTEDBY_ID:
case GParser.Q_ANY_ID:
case GParser.Q_ONE_ID:
VarDecl decl;
if (declList.isEmpty()) decl = null;
else if (declList.size() == 1) decl = declList.varDecl(0);
else
throw new SemanticException(
fOp, "Only one element variable in " + opname + " expression allowed.");
switch (idval) {
case GParser.Q_SELECT_ID:
res = new ExpSelect(decl, range, expr);
break;
case GParser.Q_COLLECT_ID:
res = new ExpCollect(decl, range, expr);
break;
case GParser.Q_REJECT_ID:
res = new ExpReject(decl, range, expr);
break;
case GParser.Q_ISUNIQUE_ID:
res = new ExpIsUnique(decl, range, expr);
break;
case GParser.Q_SORTEDBY_ID:
res = new ExpSortedBy(decl, range, expr);
break;
case GParser.Q_ANY_ID:
res = new ExpAny(decl, range, expr);
break;
case GParser.Q_ONE_ID:
res = new ExpOne(decl, range, expr);
break;
}
break;
case GParser.Q_EXISTS_ID:
res = new ExpExists(declList, range, expr);
break;
case GParser.Q_FORALL_ID:
res = new ExpForAll(declList, range, expr);
break;
default:
// internal error
throw new SemanticException(
fOp, "Internal error: unknown query operation `" + opname + "'.");
}
} catch (ExpInvalidException ex) {
throw new SemanticException(fOp, ex);
}
return res;
}
