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Apr
30 |
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answered | Estimate error in floating point calculations |
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Apr
29 |
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awarded | Supporter |
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Apr
29 |
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awarded | Scholar |
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Apr
29 |
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accepted | Scala Streams: Self-Reference, Function Calls and Lazy Evaluation |
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Apr
27 |
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comment |
Scala Streams: Self-Reference, Function Calls and Lazy Evaluation thanks - that link did indeed help. |
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Apr
27 |
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answered | Scala Streams: Self-Reference, Function Calls and Lazy Evaluation |
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Apr
26 |
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awarded | Teacher |
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Apr
26 |
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answered | sum of small double numbers c++ |
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Apr
26 |
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comment |
Scala Streams: Self-Reference, Function Calls and Lazy Evaluation it's not like lazy val x: String = x.toUpperCase because in your snippet every character in that string needs to have a value before one can compute its upper case. Not so with my example. My example is more like lazy val x: String = "A" + x. This is (conceptually) an infinite string of A's. However, lazy evaluation is not supported via Strings in Scala (AFAIK) and so actually executing that snippet gives me a stack overflow. However, re-writing in terms of streams gives me the equivalent lazy val x: Stream[Char] = 'A' #:: x. This works perfectly, e.g. println(x(1)) prints 'A'.
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Apr
25 |
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Scala Streams: Self-Reference, Function Calls and Lazy Evaluation what is wrong with it as far as I am concerned is the need for the calling code to look inside the SimNumericStream object: I should be able to implement the shift operator on the SimNumericStream object itself, hiding the implementation using Scala streams under the hood. Am I wrong, or does the fact that one form works whereas the other doesn't break the idea of referential transparency? |
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Apr
25 |
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Scala Streams: Self-Reference, Function Calls and Lazy Evaluation I guess I am struggling to see why this issue is also not present in the version that works. In that case we also have the "new SimNumericStream" within the definition of the same SimNumericStream (y). Self-replication is not what I'm looking for, just self reference. Perhaps asking the question another way, how would you define a "shift" function that returns a shifted stream and then use that function within the definition of the stream that's being shifted? Is there another way? |
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Apr
25 |
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Scala Streams: Self-Reference, Function Calls and Lazy Evaluation Thanks, but: def main(args: Array[String]): Unit = { lazy val shift = ( sns : SimNumericStream ) => new SimNumericStream( 0 #:: sns.scalstream ) lazy val y : SimNumericStream = shift(y) y.scalstream.take(10).print } Also produces the same (runtime) error whereas (manual) inlining of the function does not. |
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Apr
25 |
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asked | Scala Streams: Self-Reference, Function Calls and Lazy Evaluation |
