Hi Tomasz,
I finally got around to fixing the problem that you pointed out with
the two argument concatenate function in the expression language returning
array(general)
My first fix was to update ptolemy/data/expr/ParseTreeTypeInference.java
with a test for the concatenate expression language function.
Edward wrote:
This is a also a feature request...
It might be easy to fix for this particular example by providing
a type constraints function to go with the concatenate function.
I.e., provide a method concatenateType(Array, Array) in UtilityFunctions.
I backed out my first fix and then added concatenateReturnType() to
UtilityFunctions which seems to do the trick.
I added a similar function and test for the single argument
concatenate function. However, if I have
Const {{"a", "b"},{"c"}} -> Expression concatentate(in)
The the output of the Expression is correctly set to {"a", "b", "c"}
However, the type is arrayType(string), not arrayType(string,3).
This is because the input to the Expression is
arrayType(arrayType(string,2)), and I don't have access to
the length of the individual elements.
There is probably a bug here somewhere, but I've spent enough time here.
At the same time, we should fix a similar limitation in the
ArrayAppend actor, which has the following in its constructor:
// FIXME: correct type constraint for length
output.setTypeAtLeast(ArrayType.ARRAY_UNSIZED_BOTTOM);
I can see that the types of the ArrayAppend are unsized, but I'm not
sure how to fix this. (Actually, this margin is too small for my solution :-) )
So, I'm moving on.
_Christopher
Any volunteers to do these? It would be good practice with
a modern type system...
Edward
[kepler-users] Type resolving problem
Christopher Brooks
Fri, 27 Aug 2010 09:32:38 -0700
Hi Tomasz,
I created a test case that fails (attached).
The problem is that if I use the Expression actor with concatenate(),
then the output is arrayType(general) instead of arrayType(string,3).
You wrote:
Hi,
I've read the documentation about expressions, because what I need is to
concatenate two arrays of type: string. When I run it inside Expression
Evaluator I get:
t1 = {"a"}
{"a"}
t2 = {"b"}
{"b"}
t1.getType()
object(arrayType(string,1))
t2.getType()
object(arrayType(string,1))
concatenate(t1, t2)
{"a", "b"}
concatenate(t1, t2).getType()
object(arrayType(string,2))
This is correct and such behaviour is what I'd like to have. However in
Kepler, expression actor always returns type "general" after concatenation no
matter what are its input types. Because of this, I cannot run my workflow as
I get type resolve exception.
I tried configuring output port of expression actor with no effect. I tried
also to use cast() function, with no effect either. Last thing, I cannot use
Concatenate Arrays actor, because the number of arrays is not known during
workflow design - it is determined during runtime, so I must do it in a loop.
Do you have any ideas what may cause the problem?
I think the problem may be with ptolemy.data.expr.UtilityFunctions.
The concatenate expression language function is defined as:
/** Concatenate two arrays.
* The arrays must have the same type.
* Example: concatenate({1,2,3},{4,5,6}) == {1,2,3,4,5,6}.
* @param token1 First array from which tokens are copied to the result.
* @param token2 Second array from which tokens are copied to the result.
* @return An array containing all of the elements of the first argument
* (in order), followed by all of the arguments of the second argument
* (in order).
* @exception IllegalActionException If the arrays do not have
* compatible types.
* @since Ptolemy II 4.1
*/
public static ArrayToken concatenate(ArrayToken token1, ArrayToken token2)
throws IllegalActionException {
Token[] array1 = token1.arrayValue();
Token[] array2 = token2.arrayValue();
int nElements = array1.length + array2.length;
Token[] resultArray = new Token[nElements];
System.arraycopy(array1, 0, resultArray, 0, array1.length);
System.arraycopy(array2, 0, resultArray, array1.length, array2.length);
return new ArrayToken(resultArray);
}
/** Concatenate an array of arrays into a single array.
* Example: concatenate({{1,2,3},{4,5},{6,7}}) == {1,2,3,4,5,6,7}.
* @param token Array of arrays which are to be concatenated.
* @exception IllegalActionException If the argument is not an array of
* arrays.
* @since Ptolemy II 4.1
*/
public static ArrayToken concatenate(ArrayToken token)
throws IllegalActionException {
if (!(token.getElementType() instanceof ArrayType)) {
throw new IllegalActionException(
"The argument to concatenate(ArrayToken) "
+ "must be an array of arrays.");
}
int nElements = 0;
for (int i = 0; i < token.length(); i++) {
nElements += ((ArrayToken) (token.getElement(i))).length();
}
Token[] result = new Token[nElements];
int cursor = 0;
for (int i = 0; i < token.length(); i++) {
Token[] array = ((ArrayToken) (token.getElement(i))).arrayValue();
System.arraycopy(array, 0, result, cursor, array.length);
cursor += array.length;
}
return new ArrayToken(result);
}
I wonder if we need to be more explicit about setting the size of the array?
I'm on vacation until September 7 or 8, so someone else would need to take
a look.
_Christopher
On 8/26/10 11:50 PM, Tomasz ?ok wrote:
Christopher Brooks <cxh at eecs.berkeley.edu>:
Do you have a small test case?
In the attachment you can find two files:
- model.xml is a workflow
- scr1.png is a screenshot from workflow execution
The screenshot shows also the tooltip displayed on output port of
expression actor. There is "arrayType(general)", but according to input
array types and an excerpt from expression evaluator, it should be
"arrayType(string)".
However I found out today that it can work with cast() function:
cast(arrayType(string), concatenate(t1, t2))
Yesterday I wrote, that cast() did not help, but I made a mistake. Sorry
for misleading you with this.
But still - is this behaviour without cast() correct and expected?
Best regards,
Tomek
--
Christopher Brooks, PMP University of California
CHESS Executive Director US Mail: 337 Cory Hall
Programmer/Analyst CHESS/Ptolemy/Trust Berkeley, CA 94720-1774
ph: 510.643.9841 (Office: 545Q Cory)
home: (F-Tu) 707.665.0131 cell: 707.332.0670
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