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;
}
/** Handles shorthand notation for collect and expands to an explicit collect expression. */
private Expression collectShorthandWithArgs(String opname, Expression srcExpr)
throws SemanticException {
Expression res = null;
// c.op() 201 (5) with implicit (3,1)
CollectionType cType = (CollectionType) srcExpr.type();
Type elemType = cType.elemType();
if (elemType.isObjectType()) {
MClass srcClass = ((ObjectType) elemType).cls();
MOperation op = srcClass.operation(opname, true);
if (op != null) {
// check for isQuery operation with OCL body
if (!op.hasExpression())
throw new SemanticException(
fOp,
"Operation `"
+ srcClass.name()
+ "::"
+ op.signature()
+ "' cannot be used in OCL expression "
+ "(only side effect-free operations with a return type and an OCL expression as body may be used).");
// transform c.op(...) into c->collect($e | $e.op(...))
ExpVariable eVar = new ExpVariable("$e", elemType);
fArgExprs[0] = eVar;
try {
// constructor performs additional checks
res = new ExpObjOp(op, fArgExprs);
} catch (ExpInvalidException ex) {
throw new SemanticException(
fOp,
"In operation call `" + srcClass.name() + "::" + opname + "': " + ex.getMessage());
}
res = genImplicitCollect(srcExpr, res, elemType);
}
}
if (res == null) {
// try (1) predefined OCL operation
res = collectShorthandStdOp(opname, srcExpr, cType, elemType);
}
return res;
}
/** Handles shorthand notation for collect and expands to an explicit collect expression. */
private Expression collectShorthandWithOutArgs(String opname, Expression srcExpr)
throws SemanticException {
Expression res = null;
// c.op 200 (5) with implicit (2,4,1)
CollectionType cType = (CollectionType) srcExpr.type();
Type elemType = cType.elemType();
if (elemType.isObjectType()) {
MClass srcClass = ((ObjectType) elemType).cls();
MAttribute attr = srcClass.attribute(opname, true);
if (attr != null) {
// (2) attribute operation on object type (no arguments)
// transform c.a into c->collect($e | $e.a)
ExpVariable eVar = new ExpVariable("$e", elemType);
ExpAttrOp eAttr = new ExpAttrOp(attr, eVar);
res = genImplicitCollect(srcExpr, eAttr, elemType);
} else {
MAssociationEnd dstEnd = srcClass.navigableEnd(opname);
if (dstEnd != null) {
// (4) navigation operation on object type must be
// a role name
// transform c.r into c->collect($e | $e.r)
ExpVariable eVar = new ExpVariable("$e", elemType);
Expression eNav = genNavigation(fOp, srcClass, eVar, dstEnd);
res = genImplicitCollect(srcExpr, eNav, elemType);
}
}
}
if (res == null) {
// ! objectType || ! (attr || navigation)
// try (1) predefined OCL operation
res = collectShorthandStdOp(opname, srcExpr, cType, elemType);
}
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;
}
private Expression gen1(Context ctx, Expression srcExpr) throws SemanticException {
Expression res = null;
String opname = fOp.getText();
Type srcType = srcExpr.type();
// generate argument expressions
fArgExprs = new Expression[fArgs.size() + 1];
fArgExprs[0] = srcExpr;
Iterator it = fArgs.iterator();
int i = 1;
while (it.hasNext()) {
ASTExpression astExpr = (ASTExpression) it.next();
fArgExprs[i++] = astExpr.gen(ctx);
}
// flags for various cases
final int SRC_SIMPLE_TYPE = 0x100;
final int SRC_OBJECT_TYPE = 0x200;
final int SRC_COLLECTION_TYPE = 0x400;
final int DOT = 0x010;
final int ARROW = 0x020;
final int NO_PARENTHESES = 0x000;
final int PARENTHESES = 0x001;
int opcase;
if (srcType.isObjectType()) opcase = SRC_OBJECT_TYPE;
else if (srcType.isCollection()) opcase = SRC_COLLECTION_TYPE;
else opcase = SRC_SIMPLE_TYPE;
opcase += fFollowsArrow ? ARROW : DOT;
opcase += fHasParentheses ? PARENTHESES : NO_PARENTHESES;
switch (opcase) {
case SRC_SIMPLE_TYPE + DOT + NO_PARENTHESES:
case SRC_SIMPLE_TYPE + DOT + PARENTHESES:
case SRC_COLLECTION_TYPE + ARROW + PARENTHESES:
case SRC_COLLECTION_TYPE + ARROW + NO_PARENTHESES:
// (1) predefined OCL operation
res = genStdOperation(ctx, fOp, opname, fArgExprs);
break;
case SRC_SIMPLE_TYPE + ARROW + NO_PARENTHESES:
case SRC_SIMPLE_TYPE + ARROW + PARENTHESES:
ctx.reportWarning(
fOp,
"application of `"
+ opname
+ "' to a single value should be done with `.' "
+ "instead of `->'.");
// (1) predefined OCL operation
res = genStdOperation(ctx, fOp, opname, fArgExprs);
break;
case SRC_OBJECT_TYPE + DOT + NO_PARENTHESES:
MClass srcClass = ((ObjectType) srcType).cls();
MAttribute attr = srcClass.attribute(opname, true);
if (attr != null) {
// (2) attribute operation on object type (no arguments)
res = new ExpAttrOp(attr, srcExpr);
} else {
// (4) navigation operation on object type
// must be a role name
MAssociationEnd dstEnd = srcClass.navigableEnd(opname);
if (dstEnd != null) res = genNavigation(fOp, srcClass, srcExpr, dstEnd);
else {
// (1) predefined OCL operation
res = genStdOperation(ctx, fOp, opname, fArgExprs);
}
}
break;
case SRC_OBJECT_TYPE + DOT + PARENTHESES:
// (3) "isQuery" operation on object type (possibly with
// arguments) or (1)
MClass srcClass2 = ((ObjectType) srcType).cls();
res = genObjOperation(ctx, srcClass2, srcExpr);
break;
case SRC_OBJECT_TYPE + ARROW + NO_PARENTHESES:
case SRC_OBJECT_TYPE + ARROW + PARENTHESES:
// (6) set operation on single object resulting from
// navigation over associations with multiplicity zero
// or one (p. 7-13 of OMG UML 1.3)
if (srcExpr instanceof ExpNavigation) {
// first map object to set with internal operation
Expression mappedSrcExpr = new ExpObjAsSet(srcExpr);
// replace receiver in arg list
fArgExprs[0] = mappedSrcExpr;
try {
// lookup collection operation
res = ExpStdOp.create(opname, fArgExprs);
} catch (ExpInvalidException ex) {
throw new SemanticException(fOp, ex);
}
} else {
throw new SemanticException(
fOp,
"An arrow operation treating a single object as a "
+ "set may only be applied, if the object results "
+ "from a navigation to an association end with "
+ "multiplicity 0..1.");
}
break;
case SRC_COLLECTION_TYPE + DOT + NO_PARENTHESES:
// c.op 200 (5) with implicit (2,4,1)
if (Options.disableCollectShorthand)
throw new SemanticException(fOp, MSG_DISABLE_COLLECT_SHORTHAND);
res = collectShorthandWithOutArgs(opname, srcExpr);
break;
case SRC_COLLECTION_TYPE + DOT + PARENTHESES:
// c.op() 201 (5) with implicit (3,1)
if (Options.disableCollectShorthand)
throw new SemanticException(fOp, MSG_DISABLE_COLLECT_SHORTHAND);
res = collectShorthandWithArgs(opname, srcExpr);
break;
// throw new SemanticException(fOp,
// "If you want to apply an operation to a collection, please use an `->' instead of a
// `.'. If you are trying to apply the shorthand notation for `collect' - sorry, this is not
// yet supported. Please use the explicit notation.");
default:
throw new RuntimeException("case " + Integer.toHexString(opcase) + " not handled");
}
if (fIsPre) res.setIsPre();
return res;
}
