Poly/ML September 2011

polyml@lists.polyml.org

5 participants
7 discussions

Inspecting structures
by ramana.kumar＠gmail.com 27 Jan '16

27 Jan '16

Is there a way to look at the contents (i.e. signature) of a structure without opening it? (I suppose you could just open it then call a lot of PolyML.Compiler.forgetXXX, but that's quite tedious) Also, is it possible to retrieve the long path of an identifier in scope? Something that will, for example, take the rev in scope and say that it came from List. Finally, what about searching for an identifier that would come into scope if you opened some structures?

3 5

[Fwd: Re: [polyml] Building Poly/ML on MacOS X 10.6]
by rda＠lemma-one.com 29 Dec '14

29 Dec '14

I wrote: > I am completely baffled. I thought I hada solved all my problems on > MacOS X > 10.6 and was just tidying up, when I had to recompile a 32 bit > version of > Poly/ML to test a tidied up make file. This failed because > PolyML.Compiler.printTypesWithStructureName no longer exists. The same > problem happened when i rebuild a 64 bit version. What has happened? but it was a false alarm: my make file was wrong for other reasons and the absence of PolyML.Compiler.printTypesWithStructureName was not relevant. No doubt there are good reasons why this variable has been withdrawn. Regards, Rob.

3 6

local specifications in signatures
by ramana.kumar＠gmail.com 01 Oct '11

01 Oct '11

The syntax reference here http://www.csci.csusb.edu/dick/samples/ml.syntax.html#Specification suggests that I should be able to write signature foo = sig local open CharVectorSlice in val baz : vector -> slice end end (making use of "other_spec" in the syntax reference above) But PolyML complains when it hits the "local" Poly/ML 5.4.1 Release > use"foo.sig"; Error- in 'foo.sig', line 2. end expected but local was found Am I wrong in thinking that that is a valid signature specification? Is there an official reference for the syntax of the language PolyML compiles? Do I have to keep repeating LongStructureName.type_i_want in my specifications? Or maybe it is typical to just export types liberally (because I could do type v = CharVectorSlice.vector at the top of that signature, etc.)

2 1

Dud exception traces
by aleks0＠gmail.com 26 Sep '11

26 Sep '11

Howdy, I'm trying to track down a bug, but PolyML.exception_trace doesn't seem to be working right. See the following example. % test_exp.ML exception test_exp; fun f () = raise test_exp; fun g () = (2 + (f ())); fun h () = 2 * (g ()); bash> poly --use test_exp.ML Poly/ML 5.4.2 Testing exception test_exp val f = fn: unit -> 'a val g = fn: unit -> int val h = fn: unit -> int > h (); Exception- test_exp raised > PolyML.exception_trace h; Exception trace for exception - test_exp raised in test_stuff.ML line 2 End of trace Exception- test_exp raised > I'm using the latest Poly/ML SVN version. a

2 3

Memory consumption profiling in PolyML
by Thomas.Sewell＠nicta.com.au 24 Sep '11

24 Sep '11

Hello to the PolyML users mailing list. I'm an Isabelle/HOL user from the L4.verified project at NICTA, and we're having some issues with Isabelle using far too much memory. I have a feature request that would be useful in diagnosing the problem. The current implementation of PolyML provides an object profiling mechanism PolyML.objProfile which analyses memory consumed by a given object, decomposed by size. As a trivial issue, there doesn't seem to be a good way to profile all the heap, since threading may make some objects inaccessible from the current root function. The big issue is that the profile doesn't tell me anything useful at all. ML> PolyML.objProfile (Thy_Info.get_theory "Nat"); Immutable object sizes and counts 1 229872 2 2557083 3 756596 4 1283875 5 811230 6 24521 7 102914 8 9200 9 9452 10 20660 ... The development is too big for me to have a chance of identifying which objects of size 2, 4 and 5 are consuming all the memory. By comparison, an object profile could be really valuable if it were decomposed by type (or possible type and/or closure). This would hopefully make it straightforward to hunt down the worst-offending modules. On a related note, Don Stewart gave a talk about his experience in Haskell working at Galois recently, and pointed out that profiling by types in their runtime effectively eliminated their problems with the famous Haskell space-leak issue. It seems to me this would be roughly compatible with the existing objProfile algorithm. I had a look at the code and got as far as realising I had no hope of understanding how PolyML encodes types internally. Does this seem like a reasonable feature request? Yours, Thomas.

2 2

Memory consumption profiling in PolyML
by Thomas.Sewell＠nicta.com.au 23 Sep '11

23 Sep '11

I may have overstated Don's point. I didn't mean that it was no longer a problem with the language - I was saying that this was an effective way to eliminate the problem within a given program. Space leaks are certainly a huge problem with the language. For novice/casual users the runtime is effectively a black box and space leaks are a showstopper. Don was pointing out that if your process involves using these tools routinely (such as at Galois) then the problem diminishes greatly. Yours, Thomas. On 23/09/11 16:10, Paul A. Steckler wrote: > On Fri, Sep 23, 2011 at 2:58 PM, Thomas Sewell > <Thomas.Sewell(a)nicta.com.au> wrote: >> On a related note, Don Stewart gave a talk about his experience in Haskell >> working at Galois recently, and pointed out that profiling by types in their >> runtime effectively eliminated their problems with the famous Haskell >> space-leak issue. > Do you mean, they now have a good idea where to stuff seq's in their code? > > Still a bother to have to routinely run the memory profiler on your code. > > -- Paul

1 0

Pretty printing of functor arguments
by phil.clayton＠lineone.net 03 Sep '11

03 Sep '11

Just a minor observation: when I enter e.g. functor F () = struct end; Poly/ML prints back functor F (sig end) : sig end Generally, when Functor_Arguments is a Specification, it prints back with an enclosing sig ... end. Even if the whole response is not a valid piece of syntax, it would seem nice to have a valid Functor_Arguments printed back. (I made exactly the same mistake initially!) Phil

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Poly/ML September 2011