Dear All,
Continuing with array update, now I want to wrap the array into a record.
Basically to convert it into a 2D matrix. I want to put it into an abstract
type, like
---- UMatrix.dcl ------
definition module UMatrix
import StdArray, StdClass
// UMatrix : Unboxed matrix, elemType must be one of the available unboxed types
::UMatrix elemType | Array {#} elemType
// ... more stuff ...
---------------------------
with the following implementation module:
---- UMatrix.icl ------
implementation module UMatrix
import StdArray, StdInt, StdBool, StdMisc, StdList, StdEnum
::UMatrix elemType = { rows :: !Int
, cols :: !Int
, vals :: ({#} elemType)
}
// ... more stuff ...
---------------------------
The problem I am facing is update in place of the array vals, I want to have
the following function (from implementation)
...........................
// adds one matrix onto another (in place add)
fAdd :: *(UMatrix elemType) (UMatrix elemType) -> *(UMatrix elemType) | Array
{#} elemType & Arith elemType
fAdd m1 m2
| sameSize m1 m2
# (arr, m1) = m1!vals // <--- PROBLEM HERE
= {m1 & vals = updateInPlace arr f (size m2.vals)}
= abort "Invalid matrix add"
where
f v p = v + m2.vals.[p]
// ...
// .. where updateInPlace is the array update in-place which I put together
with your help before. ...
// ...
// updates array first parameter with a function taking its value at p and p
itself
updateInPlace :: *(a e) (e Int -> e) Int -> *(a e) | Array a e
updateInPlace arr1 f maxPos = updateLoop_ arr1 f 0 maxPos
where
updateLoop_ :: *(a e) (e Int -> e) Int Int -> *(a e) | Array a e
updateLoop_ arr1 f pos maxPos
| pos == maxPos = arr1
# (v, arr1) = arr1![pos]
= {(updateLoop_ arr1 f (pos+1) maxPos) & [pos] = f v pos}
............................
The problem is that updateInPlace expects a unique array, but the signature I
am getting in PROBLEM HERE is
m1!vals :: ({#a}, u:(UMatrix v:a))
i.e., the array inside the record is not unique (at least, this is how I
understand it).
I have tried to define UMatrix with . and attribute variables in the hope that
it will change the signature of the record "!" operator, but with no luck. And
read the manual and the clean book but nothing said in b&w about the "!"
operator, at least for me as I couldn't link the whole concept of uniqueness
propagation for records.
How can I extract the array from the unique parameter in fAdd and expect it to
be unique?
Thanks in advance
Carlos
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