Re: Priority Map with efficient search on values?

2017-04-07 Thread Andy Fingerhut 
My first quick take is that you would be served well by creating your own
data structure that wraps a priority queue for efficient access by minimum
value, and a sorted map for efficient access by key, including subseq's of
keys.

That combination won't give you subseq's on values, but you could toss in a
sorted set with [ ] pairs (the key present in there to serve as
a tie-breaker for key,value pairs with equal value, otherwise the sorted
map would only keep one pair per value).  Come to think of it, that should
give you efficient access to the minimum value entry all by itself, so the
priority queue would be unnecessary then.

These suggestions are off the cuff, and intended to maximize reuse of
existing code with least amount of new code required.  It wouldn't
necessarily minimize the memory required.

Andy

On Fri, Apr 7, 2017 at 8:49 PM, Brian Beckman  wrote:

> I have found a few data types in Clojure that support search and priority
> queues. In particular, I found
>
> Priority Maphttps://github.com/clojure/data.priority-map
> PSQhttps://goo.gl/Dw4gkV
> data.avlhttps://goo.gl/e07q7H
>
> I would be grateful for a few clarifying words on whether any of these can
> meet my requirements out-of-the-box before I begin a deep-dive. Forgive me
> for being a bit lazy (actually, just in a hurry), but I thought I'd check
> whether someone knows an answer for me off-the-cuff.
>
> I need collections of [k v] pairs supporting efficient peek, pop, get, and
> subseq-style search on either the key space or on the value space. I need
> all operations on just one of the two spaces.
>
> Priority map supports efficient peek and pop of the value space on its API
> surface, but I don't see a get subseq (or rsubseq) or other way to quickly
> search the value space on the API surface. The comments in the source
> suggest that there is an auxiliary inverse sorted map from values to keys.
> The supported "get" operation seems to operate on the key space, but I
> could use one on the value space (see line 313 of https://goo.gl/qhfXKL).
> Perhaps that inverse map easy to get at, in which case I'll be done.
>
> PSQ supports peek and pop on values, and efficient search on keys,
> according to its documentation. Do I read that correctly?
>
> I have not read the documentation for data.avl deeply enough to know
> whether it will do my job out-of-the box. But I am sure I could build what
> I need on top of AVL trees, RB trees, 2-3 trees, splay trees, etc. I'm just
> looking to save myself work (and use tested software).
>
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Priority Map with efficient search on values?

2017-04-07 Thread Brian Beckman 
I have found a few data types in Clojure that support search and priority 
queues. In particular, I found 

Priority Maphttps://github.com/clojure/data.priority-map
PSQhttps://goo.gl/Dw4gkV
data.avlhttps://goo.gl/e07q7H

I would be grateful for a few clarifying words on whether any of these can 
meet my requirements out-of-the-box before I begin a deep-dive. Forgive me 
for being a bit lazy (actually, just in a hurry), but I thought I'd check 
whether someone knows an answer for me off-the-cuff.

I need collections of [k v] pairs supporting efficient peek, pop, get, and 
subseq-style search on either the key space or on the value space. I need 
all operations on just one of the two spaces.

Priority map supports efficient peek and pop of the value space on its API 
surface, but I don't see a get subseq (or rsubseq) or other way to quickly 
search the value space on the API surface. The comments in the source 
suggest that there is an auxiliary inverse sorted map from values to keys. 
The supported "get" operation seems to operate on the key space, but I 
could use one on the value space (see line 313 of https://goo.gl/qhfXKL). 
Perhaps that inverse map easy to get at, in which case I'll be done.

PSQ supports peek and pop on values, and efficient search on keys, 
according to its documentation. Do I read that correctly?

I have not read the documentation for data.avl deeply enough to know 
whether it will do my job out-of-the box. But I am sure I could build what 
I need on top of AVL trees, RB trees, 2-3 trees, splay trees, etc. I'm just 
looking to save myself work (and use tested software).

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Re: was Re: ANN: Orchestra, complete instrumentation for clojure.spec

2017-04-07 Thread Colin Fleming 
>
> I have longed for a statically compiled language with type inference with
> the simplicity and consistency of Clojure's syntax that also supports
> generative testing and works on the JVM but alas, I have not found one.
> Frege and PureScript both look interesting but I am unsure of Frege's
> longevity and PureScript's performance on the JVM's Javascript
> environment.


Note that both of those options both suffer from very difficult interop -
PureScript will probably not have any at all since it will be expecting to
interop with JS, and Frege has some but it's clunky due to the type system
mismatch.

Personally I long for a Kotlin/Clojure hybrid, to the point that I have
seriously considered trying to build one.

On 8 April 2017 at 14:57, Didier  wrote:

>  | I think you missed my point, which is only "Spec is great as we have
> the power of Clojure" - sure, just don't forget you have the power of
> ANOther language in that language as well.
>
> Hum, I've probably missed your point sorry, I'm still not following.
>
>  | no, this will, or at least should, be caught. 10/0 is not an int, and
> typed "/' would reject 0 as an ill-typed denominator.
>
> In most static type systems this will not be caught, because they don't
> have a fraction type. So this is actually a function that takes two number
> types, and 0 is a number too, so it will type check, but throw an exception
> at runtime.
>
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Re: was Re: ANN: Orchestra, complete instrumentation for clojure.spec

2017-04-07 Thread Didier 
 | I think you missed my point, which is only "Spec is great as we have the 
power of Clojure" - sure, just don't forget you have the power of ANOther 
language in that language as well.

Hum, I've probably missed your point sorry, I'm still not following.

 | no, this will, or at least should, be caught. 10/0 is not an int, and typed 
"/' would reject 0 as an ill-typed denominator.

In most static type systems this will not be caught, because they don't have a 
fraction type. So this is actually a function that takes two number types, and 
0 is a number too, so it will type check, but throw an exception at runtime. 

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Re: Atom in macros ==> Can't embed object in code

2017-04-07 Thread James Reeves 
Why don't you put the "let" that defines the atom counter inside the quoted
form?

- James

On 7 April 2017 at 22:21, Max Muranov  wrote:

> I need to create logger for machine learning debugging. First, I wanted to
> perform this string:
>
> (create-logger 10 "Epoch #" :epoch ", Error: " :error)
>
> This code will cause this output while training:
>
> Epoch #10, Error: 2.0
> Epoch #20, Error: 1.0
> Epoch #30, Error: 0.0
> Epoch #40, Error: 0.0
> ...
>
> I wrote this code:
>
> ;; Training logging
>
> (defmulti resolve-logger-keyword (fn [kwd] kwd))
>
> (defmethod resolve-logger-keyword :epoch [_]
>   (fn [trainer] (.getIteration trainer)))
>
> (defmethod resolve-logger-keyword :error [_]
>   (fn [trainer] (.getError trainer)))
>
> (defmacro create-log-func [args]
>   `(fn [trainer#]
>  (for [arg# ~args]
>(if (keyword? arg#)
>  ((resolve-logger-keyword arg#) trainer#)
>  arg#
>
> (defn create-logger [each-n-messages & args]
>   (let [counter (atom 0)
> logger-message (create-log-func args)]
> (fn [trainer]
>   (swap! counter inc)
>   (when (<= each-n-messages @counter)
> (swap! counter (fn [_] 0))
> (println (apply str (logger-message trainer)))
>
>
> This code works fine. But now I want this line be possible:
>
> (create-logger 10 "Epoch #" :epoch ", Error: " (* :error -1))
>
>
> In other words, I want to perform operations over this logger parameters.
> It's inside of the logger, so at first I need to make macro create-logger
> instead of function.
> I try to write this:
>
> (defmacro create-logger [each-n-messages & args]
>   (let [counter# (atom 0)
> logger-message (create-log-func args)]
> `(fn [trainer#]
>   (swap! ~counter# inc)
>  ;   These lines are not important yet
>  ; (when (<= ~each-n-messages @~counter)
>  ;   (swap! ~counter (fn [_] 0))
>  ;   (println (apply str (~logger-message trainer#)))
>
> And after trying to execute the first line:
>
> (create-logger 10 "Epoch #" :epoch ", Error: " :error)
>
> I get the error:
>
> clojure.lang.Compiler$CompilerException: java.lang.RuntimeException: Can't
> embed object in code, maybe print-dup not defined:
> clojure.lang.Atom@501e8e4f, compiling:(D:\Programming\
> Clojure\Projects\trade-ai-server\src\trade_ai_server\ai_trader.clj:97:1)
>
>
>
>
>
>
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Re: Stackoverflow error on including link to the same object

2017-04-07 Thread udkl 
No problem. 

I'm actually very new to Clojure  but someone posted that on the 
clojure slack channel today. Serendipity.

On Friday, April 7, 2017 at 2:31:43 PM UTC-7, Max Muranov wrote:
>
> Yes, that's exactly what I needed, thank you!
>

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Re: was Re: ANN: Orchestra, complete instrumentation for clojure.spec

2017-04-07 Thread Gregg Reynolds 
On Apr 6, 2017 3:47 PM, "Raoul Duke"  wrote:

I am writing to ignorantly sincerely ask how spec + Orchestra compares to
other statically typed out of the box JVM languages. What are the succint
wins over not Scala shudder but eg Kotlin Ceylon, heck Frege, et. al.?


i could be wrong, but i do not view spec as a type system.  more like the
dual of a type system. clojure does not do types, strictly speaking.  there
are lots of reasons to like it, but "it types" is not one of them.  spec
does not change this.

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Re: was Re: ANN: Orchestra, complete instrumentation for clojure.spec

2017-04-07 Thread Gregg Reynolds 
On Apr 7, 2017 12:07 AM, "Didier"  wrote:



Types are not very precise though, like it will catch 10/"123", but not
10/0, because the type isn't more precise then int.


no, this will, or at least should, be caught. 10/0 is not an int, and typed
"/' would reject 0 as an ill-typed denominator.

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Re: was Re: ANN: Orchestra, complete instrumentation for clojure.spec

2017-04-07 Thread Colin Yates 
Not sure where you are getting the assertion of equivalence from, it
certainly isn't what I meant. I think you missed my point, which is only
"Spec is great as we have the power of Clojure" - sure, just don't forget
you have the power of ANOther language in that language as well.

I think comparing Clojure Spec against _only_ a static typing machine to be
disingenuous, that's all.

Love, peace and goodwill to all :-).

On Friday, 7 April 2017, Didier  wrote:

> @Colin Yates
>
> If spec is a DSL to describe invariants and the static typing of other
> languages are too, then it's not true that all static typing DSLs can
> express what the spec DSL can.
>
> If you say, could I build spec in other languages, or can I put asserts in
> the code using the full languages, ya off course you can, but not without
> considerable effort. Similarly, you can add static typing to Clojure, but
> that also comes with considerable effort.
>
> That's why people skip over this. Can I embed a haskell inside Clojure? I
> could. I could embed a Clojure inside Haskell too. But those are not a
> given feature provided to me for free as standard.
>
> So the discussion should center around what features I get for free. With
> spec, you get a very powerful description DSL, more powerful than most
> static typing ones. You get generative testing, parsing, validation,
> asserts and documentation. With static typing systems, you get a often less
> powerful description DSL, compile time type assertions, and documentation.
>
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Re: Stackoverflow error on including link to the same object

2017-04-07 Thread Max Muranov 
Yes, that's exactly what I needed, thank you!

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Re: was Re: ANN: Orchestra, complete instrumentation for clojure.spec

2017-04-07 Thread Didier 
@Colin Yates

If spec is a DSL to describe invariants and the static typing of other 
languages are too, then it's not true that all static typing DSLs can express 
what the spec DSL can.

If you say, could I build spec in other languages, or can I put asserts in the 
code using the full languages, ya off course you can, but not without 
considerable effort. Similarly, you can add static typing to Clojure, but that 
also comes with considerable effort.

That's why people skip over this. Can I embed a haskell inside Clojure? I 
could. I could embed a Clojure inside Haskell too. But those are not a given 
feature provided to me for free as standard. 

So the discussion should center around what features I get for free. With spec, 
you get a very powerful description DSL, more powerful than most static typing 
ones. You get generative testing, parsing, validation, asserts and 
documentation. With static typing systems, you get a often less powerful 
description DSL, compile time type assertions, and documentation. 

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Atom in macros ==> Can't embed object in code

2017-04-07 Thread Max Muranov 
I need to create logger for machine learning debugging. First, I wanted to 
perform this string:

(create-logger 10 "Epoch #" :epoch ", Error: " :error)

This code will cause this output while training:

Epoch #10, Error: 2.0
Epoch #20, Error: 1.0
Epoch #30, Error: 0.0
Epoch #40, Error: 0.0
...

I wrote this code:

;; Training logging

(defmulti resolve-logger-keyword (fn [kwd] kwd))

(defmethod resolve-logger-keyword :epoch [_]
  (fn [trainer] (.getIteration trainer)))

(defmethod resolve-logger-keyword :error [_]
  (fn [trainer] (.getError trainer)))

(defmacro create-log-func [args]
  `(fn [trainer#]
 (for [arg# ~args]
   (if (keyword? arg#)
 ((resolve-logger-keyword arg#) trainer#)
 arg#

(defn create-logger [each-n-messages & args]
  (let [counter (atom 0)
logger-message (create-log-func args)]
(fn [trainer]
  (swap! counter inc)
  (when (<= each-n-messages @counter)
(swap! counter (fn [_] 0))
(println (apply str (logger-message trainer)))


This code works fine. But now I want this line be possible:

(create-logger 10 "Epoch #" :epoch ", Error: " (* :error -1))


In other words, I want to perform operations over this logger parameters. 
It's inside of the logger, so at first I need to make macro create-logger 
instead of function.
I try to write this:

(defmacro create-logger [each-n-messages & args]
  (let [counter# (atom 0)
logger-message (create-log-func args)]
`(fn [trainer#]
  (swap! ~counter# inc)
 ;   These lines are not important yet  
 ; (when (<= ~each-n-messages @~counter)
 ;   (swap! ~counter (fn [_] 0))
 ;   (println (apply str (~logger-message trainer#)))

And after trying to execute the first line:

(create-logger 10 "Epoch #" :epoch ", Error: " :error)

I get the error:

clojure.lang.Compiler$CompilerException: java.lang.RuntimeException: Can't 
embed object in code, maybe print-dup not defined: 
clojure.lang.Atom@501e8e4f, 
compiling:(D:\Programming\Clojure\Projects\trade-ai-server\src\trade_ai_server\ai_trader.clj:97:1)






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Re: Stackoverflow error on including link to the same object

2017-04-07 Thread udkl 
Can you try  #' ?

 #' means the var itself, not the value inside the var

On Friday, March 31, 2017 at 2:04:29 PM UTC-7, Max Muranov wrote:
>
> But if I perform such thing this in clojure:
>
> (send-off (:movement-agent game) (fn [_] game))
>
>
>
> As I found out, I get something like this:
>
> Game {:heroes-container obj[Ref],
>   :movement-agent obj[Agent{:val
>Game {:heroes-container obj[Ref],
>  :movement-agent obj[Agent{:val
> Game {:heroes-container obj[Ref],
>   :movement-agent obj[Agent{:val
>   Game  }}
>
>
>
>
> And I get this error: java.lang.StackOverflowError: null
>
> Why is this happening? Why this is not links but the actual hash-maps? Is 
> there a way to make this work
>
>
>
>

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Re: was Re: ANN: Orchestra, complete instrumentation for clojure.spec

2017-04-07 Thread Colin Yates 
So I see Clojure Spec as an "internal DSL if you squint" for
describing invariants that are enforced at runtime. Static typing is
also an "internal DSL if you squint" for describing
data-shape-invariants at compile time. With Clojure Spec you have the
entirety of Clojure to describe those invariants, with a static typing
lib you are limited to whatever constructs language provides. So
Clojure Spec is much more open and extensible in that regard.


However, I see a lot of people stopping the discussion there without
accounting for the fact that you _also_ have the "entirety of
language-X to describe those invariants" for any given language. Pre
and Post conditions have been around since the dawn of time and most
languages (I know about) have asserts. If the language has support for
AOP then even better as the description and application of those
invariants don't need to be embedded in the code in question. This
means that any given language, purely from a "can it enforce this?" is
at least as powerful as Clojure Spec.

And Clojure Spec's ability to feed the generative testing machine is
awesome if you can describe your accepted inputs in that way.

So, in terms of "can I express this invariant" in both static and
statically typed languages? Yep, of course.


Clojure Spec and static type systems are both tools for enforcing
invariants. Can Clojure Spec describe invariants that
StaticTypingLanguage-X can't? No, of course not. Is the machinery
around Clojure Spec useful - absolutely.

I have longed for a statically compiled language with type inference
with the simplicity and consistency of Clojure's syntax that also
supports generative testing and works on the JVM but alas, I have not
found one. Frege and PureScript both look interesting but I am unsure
of Frege's longevity and PureScript's performance on the JVM's
Javascript environment.

On 7 April 2017 at 06:07, Didier  wrote:
> It's different, yet related.
>
> Static type systems and clojure.spec both try to prevent bugs. They're tools 
> to help you write correct programs, the same way that a testing framework is. 
> Neither of them will catch all your bugs unfortunately.
>
> Static type systems catches bugs where you would try to do an operation over 
> a type which does not support it. Types are not very precise though, like it 
> will catch 10/"123", but not 10/0, because the type isn't more precise then 
> int. So int/int will be ok, but int/string will be caught at compile time as 
> a bug.
>
> The advantage of static type systems is that what they do catch, they will 
> catch 100% of the time and they generally run pretty quickly.
>
> Clojure.spec catches bugs where you'll try to do something on a value which 
> isn't acceptable, as well as catch bugs where the relationship between the 
> input and output values is wrong. So it can catch 10/0 and 10/"123". If a 
> parameter was true and functionally that means the output should be false, 
> but a bug causes it to be true instead, well it can also catch that.
>
> The disadvantage of clojure.spec is that you cannot be sure it caught 100% of 
> those bugs. It will catch some, but maybe not all. It will also be much 
> slower to run.
>
> Now, clojure.spec has one more trick up its sleeves. It can be used for 
> static analyses on steroids. If you've ever used Find bugs in java, you know 
> a little what I'm talking about. If you use Spectrum, it will try to catch 
> some of those same bugs at compile time, and it could in theory be made to 
> catch 100% of the bugs static type systems catch. Spectrum is new and not 
> fully featured yet, but so is clojure.spec, so this is a possible future 
> which you can have a taste for today. I recommend checking it out: 
> https://github.com/arohner/spectrum
>
> Alright, that's the part about catching bugs. Now there's more to it. Type 
> declarations are normally helpful documentation too, and so is clojure.spec. 
> Spec, once again, can be way more precise in documenting. Similarly, types 
> can help tooling and error messages, so can spec.
>
> Finally, spec also allows some things types don't even cover, such as parsing 
> and validation of non typed data like json. Spec can parse a complex 
> structure into an AST. It can also validate EDN, or json that was 
> unmarshalled into clojure.
>
> As time goes on, I'm sure someone will find other use cases for it too.
>
> Hope this helps.
>
> P.S.: Clojure also has a static type system called core.typed. It is not as 
> widely used though, and has only one developer working on it. It also doesn't 
> compare to the languages you listed, since it is a gradual type system, more 
> inline with typescript, typed racket and hack.
>
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