Re: [racket-users] db: nested transactions

Yes, that should be fine. One note about your sample code: the isolation mode of inner transactions must be #f (the default); you can't change isolation levels once you've started an outer transaction. Also keep in mind that nested transactions are not supported for ODBC connections. Ryan

[racket-users] Racket v6.2

Racket version 6.2 is now available from http://racket-lang.org/ With this release we are taking a major step forward to get our user community even more involved than in the past. Over the past six months, we have re-organized the Racket code base into a small core code repo and many other

Re: [racket-users] db: nested transactions

On 06/24/2015 07:46 AM, George Neuner wrote: Hi Ryan, On 6/23/2015 12:20 PM, Ryan Culpepper wrote: Yes, that should be fine. One note about your sample code: the isolation mode of inner transactions must be #f (the default); you can't change isolation levels once you've started an outer

Re: [racket-users] Macro-introducing macros with inter-macro communication channel

On 06/19/2015 03:07 PM, Thomas Dickerson wrote: Hi All, I'm trying to figure out how best to implement the following pattern of macro behavior: Let's say we are writing Loop macro that implements a looped computation over a specified body. I would like to then be able to (a) introduce

Re: [racket-users] stops in Macros that Work Together

On 07/06/2015 10:04 PM, Anthony Carrico wrote: I've been working through Macros that Work Together (on my way to working through Sets-of-Scopes). I've come across something that is slightly unclear to me in the section on local-expand: E ::= a mapping from name to transform I don't believe

Re: [racket-users] problems with sql-timestamp and date*

On 08/22/2015 06:18 PM, George Neuner wrote: On 8/22/2015 5:50 PM, Jon Zeppieri wrote: On Sat, Aug 22, 2015 at 4:36 PM, George Neunergneun...@comcast.net wrote: The latter code using date works properly (modulo the time zone field) and gives consistent results, but the former using date*

[racket-users] Racket v6.2.1

Racket version 6.2.1 is now available from http://racket-lang.org/ Version 6.2.1 patches the recent v6.2 release in three small ways: * For the How to Design Programs teaching languages, DrRacket offers an option to use the old style for printing the constants `true`, `false`, and

Re: [racket-users] inconsistency/bug in math/array

I think I've run into this problem before. The type of array-slice-ref is (Array A) (Listof Slice-Spec) -> (Array A) where Slice-Spec = (U (Sequenceof Integer) Integer ) The problem is that integers are also sequences, so the contract generated for Slice-Spec just discards the Integer

Re: [racket-users] interface to unix sockets

I think someone was working on listener code for unix sockets a year or so ago, but I don't remember who or how far they got. Pull requests are welcome. Ryan On 8/31/15 2:36 PM, qwe-te...@yandex.ru wrote: Racket provides unix-socket-connect and lacks listener. Is it going to be added in

Re: [racket-users] Lost in ellipsis depths

Here's one more solution, using "template metafunctions" (inspired by Redex's metafunctions). And yes, most of the point of template metafunctions is to have something that cooperates with ellipses like you want. > (require syntax/parse syntax/parse/experimental/template

Re: [racket-users] Iterating Through Database

On 09/29/2015 12:28 PM, Tim Roberts wrote: I'm coming to Racket after many decades of programming in other languages. One of the things that still gives me trouble is being able to know exactly what type of "thing" I have at any given point. Let me give you an example, which is actually quire

[racket-users] Racket v6.3

Racket version 6.3 is now available from http://racket-lang.org/ - Racket's macro expander uses a new representation of binding called "set of scopes". The new binding model provides a simpler explanation of how macros preserve binding, especially across module boundaries and in

[racket-users] Racket v6.4

Racket version 6.4 is now available from http://racket-lang.org/ - We fixed a security vulnerability in the web server. The existing web server is vulnerable to a navigation attack if it is also enabled to serve files statically; that is, any file readable by the web server is

Re: [racket-users] Top Level Variables or List of Shared Libraries

The openssl library uses scheme_register_process_global to make sure it initializes the openssl foreign library only once. See the end of openssl/mzssl.rkt. Ryan On 01/28/2016 02:33 PM, Leif Andersen wrote: Since a lot of people were at POPL last week, I think it's worth pinging this list

Re: [racket-users] Store value with unsupported type in Postgres?

On 01/17/2016 06:35 PM, Alexis King wrote: The DB docs for SQL type conversions[1] note that not all Postgres types are supported by Racket, and it recommends using a cast to work around this. It even uses the inet type as an example right at the start of the page. However, I want to store an

Re: [racket-users] Debug help with Unix Write

Unix socket ports are block-buffered, so after writing to them you need to flush the output. Something like (write-json data port) (flush-output port) Your code on github has calls to flush-output without the port argument. That doesn't flush the unix socket port; it flushes the current

Re: [racket-users] Re: how to transform syntax post-expansion?

On 02/14/2016 11:07 PM, Nota Poin wrote: I suppose I could do something like this: (define-syntax (transform-post-expansion stx) (syntax-case (expand stx) () (...))) The macro should use `local-expand` rather than `expand`. See the docs for `local-expand`, since it takes more

Re: [racket-users] Re: using ryanc's oauth2 package with Google?

On 02/14/2016 12:02 PM, Fred Martin wrote: So... even though I chose "Other" as the client type, my API credentials were created with a secret. I had to copy the secret into my client constructor request. From my reading of the oauth 2 API docs, I thought "installed app" clients weren't

Re: [racket-users] Re: Debug help with Unix Write

On 02/12/2016 07:33 PM, Ty Coghlan wrote: Both of you were correct, I had to flush my output and newline terminate it. The final result looks like: (define (broadcast source destination type message port) (let ([h (hash 'source source 'dest destination 'type type 'message

Re: [racket-users] Which html-parsing package?

On 02/17/2016 10:39 AM, Brian Adkins wrote: On Wednesday, February 17, 2016 at 10:35:44 AM UTC-5, Brian Adkins wrote: On Wednesday, February 17, 2016 at 10:20:21 AM UTC-5, Neil Van Dyke wrote: Brian Adkins wrote on 02/17/2016 10:04 AM: http://www.neilvandyke.org/racket-html-parsing/ takes me

Re: [racket-users] Setup/teardown for unit testing

I think it would be more (Racket-)idiomatic to make account a parameter (as in make-parameter) and have something that can update the parameter around a test case. Here is my preferred extension, by example: (define account (make-parameter #f)) (define (call/open-bank proc) (parameterize

Re: [racket-users] Calling a procedure from mysql

On 03/24/2016 06:17 PM, Ty Coghlan wrote: I have the following simple code: (require db) (define mdb (mysql-connect #:user user #:password password)) (query-exec mdb "use starwarsfinal") (query mdb "CALL track_character(?)" "Chewbacca") (disconnect mdb). Where track_character is a procedure

Re: [racket-users] drracket / postgresql error when opening connection for syntax

The problem was a use of (system-type 'machine) in racket/unix-socket. I've pushed a fix. Ryan On 04/06/2016 08:06 AM, WarGrey Gyoudmon Ju wrote: I met this problem before. (system-type 'machine) uses the output of `uname`. On Wed, Apr 6, 2016 at 5:47 PM, Tim Brown

[racket-users] Racket v6.5

Søgaard, John Clements, Leandro Facchinetti, Lehi Toskin, Leif Andersen, Łukasz Dąbek, Marc Kaufmann, Matthew Flatt, Matthias Felleisen, Michael McConville, Mike Sperber, Paul Stansifer, Philippe Meunier, Robby Findler, Rodrigo Setti, Ryan Culpepper, Sam Caldwell, Sam Tobin-Hochstadt, Sorawee

Re: [racket-users] Re: for/list in-query

You might find this function helpful (from the implementation of in-query): (define (in-list/vector->values vs) (make-do-sequence (lambda () (values (lambda (p) (vector->values (car p))) cdr vs pair? #f #f Ryan On 05/04/2016 09:46 AM, Denis

Re: [racket-users] Typo in syntax-class documentation?

On 05/11/2016 03:16 AM, Tim Brown wrote: I found this in the documentation for syntax-class (Link to this section with @secref["stxparse-attrs" #:doc '(lib "syntax/scribblings/syntax.scrbl")]): Consider the following code: (define-syntax-class quark (pattern (a b ...)))

Re: [racket-users] Is my model of (values) accurate?

On 07/22/2016 07:58 PM, David Storrs wrote: Thanks Jon, I appreciate the clear explanation. I'm using call-with-values in database code in order to turn a list into an acceptable set of bind parameters. Here's an example: (query-exec conn "insert into foo (bar, baz) values ($1, $2)"

Re: [racket-users] equivalence relation for hash keys

See `define-custom-hash-types` in `racket/dict`. Note that you'll need to use `dict-ref` instead of `hash-ref`, etc. Ryan On 08/04/2016 12:34 PM, Jos Koot wrote: Hi As far as I can see a hash has three options only for the equivalence relation comparing keys: eq?, eqv? and equal?. Would it

Re: [racket-users] Typed Racket is Unsound because of module->namespace

It seems that a typed module needs to be as *protected* as TR itself, but not as *powerful* (or privileged) as TR. Otherwise one could define a malicious typed module that uses the power TR grants it to break sandboxing. Is the combination of protected but not powerful possible in the current

Re: [racket-users] Fun with keyword-apply

On 02/08/2017 04:41 PM, Dan Liebgold wrote: Hi all - I have an odd syntax I'm trying to maintain backward compatibility with, but I'd like to take advantage of keyword parameters to accommodate the presence/absence/ordering of those parameters. Here's an example of what I'm trying to do:

Re: [racket-users] Detecting EOT when reading a TCP port

read-line returns eof when the port is closed, which is completely different from sending byte 04 (or any other byte or sequence of bytes) over the port. ;; set up {client,server}-{in,out} ports (write-byte 4 client-out) (flush-output client-out) (read-byte server-in) ;; => 4

Re: [racket-users] syntax-properties, local-expand, and a struct

On 9/28/16 12:04 PM, William J. Bowman wrote: On Fri, Sep 23, 2016 at 02:58:23PM -0400, Ryan Culpepper wrote: It appears that the constructor macro (implemented by self-ctor-transformer in racket/private/define-struct.rkt) transfers the syntax properties from the macro use to its expansion (see

Re: [racket-users] syntax-parse #:with and error messages

On 09/28/2016 02:33 PM, 'William J. Bowman' via Racket Users wrote: I recently ran into a problem that took me hours to diagnose. It turns out that a `#:with` clause in a syntax-parse was not matching, but I would never have guessed that from the error message I got. Here is a simplified

Re: [racket-users] Constructing unicode surrogates

Does one of the `string-normalize-*` functions do what you want? Ryan On 10/08/2016 01:06 PM, Jens Axel Søgaard wrote: Hi All, The following interaction shows how the reader can be used to construct a surrogate character: > (string-ref "\ud800\udc00" 0) #\ Given the two

Re: [racket-users] Using schemas with the 'db' module

In PostgreSQL, clusters contain databases contain schemas. I think the answer is to use "SET SCHEMA" or the more general "SET search_path". See https://www.postgresql.org/docs/current/static/ddl-schemas.html https://www.postgresql.org/docs/current/static/sql-set.html Ryan On 10/06/2016

Re: [racket-users] How to get non-prefab struct values from manually-expanded syntax?

On 10/03/2016 06:38 PM, Jack Firth wrote: So I'm reading a file in as code and expanding it, then looking for values in a certain syntax property that macros in the expanded code attach. This works fine for prefab structs, but I can't seem to get it to work with transparent structs. The issue

Re: [racket-users] syntax-properties, local-expand, and a struct

On 09/23/2016 02:43 PM, 'William J. Bowman' via Racket Users wrote: Under certain conditions, the value of a syntax property is duplicated. I can't figure out why, or if this is a bug, and any advice would be appreciated. I've attached the smallest program that generates this behavior that

Re: [racket-users] Re: racket command line parameter

On 10/25/2016 04:57 PM, Dan Liebgold wrote: On Tuesday, October 25, 2016 at 1:43:28 PM UTC-7, Alexis King wrote: bound... You need to put the -i flag first, so the command should look like: racket -iI -l Hmm... that give the REPL the proper language but no access to the contents of

Re: [racket-users] Identifier equality of identifiers stashed in preserved syntax properties

On 10/25/2016 08:04 PM, Alexis King wrote: That makes sense; thank you for your quick reply. It might be possible to do something like what you describe, but I do have a little more context that makes this sort of tricky. I’m trying to not just store identifiers but also store prefab structs

Re: [racket-users] Re: racket command line parameter

On 10/25/2016 06:16 PM, Dan Liebgold wrote: On Tuesday, October 25, 2016 at 2:09:59 PM UTC-7, Ryan Culpepper wrote: racket -e '(enter! "your-module.rkt")' -i BTW, any luck putting a line like this in csh shell script, alias, or windows batch file? For scripting, if your in

Re: [racket-users] find-seconds daylight saving

On 11/08/2016 11:24 PM, George Neuner wrote: [...] - I need to turn the UTC datetimes on all the results back into local times with the right time zone Does the following do what you want? (require srfi/19) ;; date-at-tz : Date Integer -> Date ;; Returns date of equivalent instant in

Re: [racket-users] postgresql sql-timestamp problem - test.rkt (0/1)

On 11/06/2016 09:42 PM, George Neuner wrote: [...] The following in Racket gets it wrong. e.g., [...] => #(struct:sql-timestamp 2016 5 1 5 0 0 0 0) -> "2016-05-01 05:00:00Z" "2016-05-01 00:00:00-05" -> #(struct:sql-timestamp 2016 5 1 0 0 0 0 -18000) #(struct:sql-timestamp 2016 6 12 5 0 0 0 0)

Re: [racket-users] degenerate performance in syntax-parse

On 10/21/2016 05:50 PM, Dan Liebgold wrote: Hi all - In the process of putting together a somewhat complex application using syntax-parse, I discovered that when I specified a repeated pattern in a syntax-class (which was incorrect) AND I had a certain usage of the syntax transformer with an

Re: [racket-users] unit testing syntax errors

See `convert-compile-time-error` and `convert-syntax-error` from the `syntax/macro-testing` library. I should fix the docs to say that the type of the exception can change, so they work best for testing the contents of the exception message. For examples, there are tests for invalid uses of

Re: [racket-users] degenerate performance in syntax-parse

On 10/24/2016 02:15 PM, Dan Liebgold wrote: On Sunday, October 23, 2016 at 1:14:56 PM UTC-7, Ryan Culpepper wrote: [...] 1. A term like `(a <- blend)` will match the first pattern and treat `blend` as a `remap:id`. If you don't want that to happen, there are two ways to prevent it.

Re: [racket-users] syntax-class composed of literals

On 11/16/2016 06:11 PM, Dan Liebgold wrote: Hi, A couple questions about literals in syntax-parse: 1. I'd like to make a syntax-class that is just a set of literals (with a clear error for something not matching any literal). Is there a better way than this: http://pasterack.org/pastes/86722

Re: [racket-users] syntax-class composed of literals

On 11/16/2016 07:42 PM, Dan Liebgold wrote: Literal sets can include datum-literals: (define-literal-set lits #:datum-literals (a b c) (d e)) Ah, oops I missed that keyword parameter. For question 1, that's probably the best way. If you want to suppress the printing of all of the

Re: [racket-users] syntax-class composed of literals

On 11/16/2016 07:51 PM, Vincent St-Amour wrote: FWIW, Eric Dobson wrote a very nice `define-literal-syntax-class` macro that is used extensively inside TR. https://github.com/racket/typed-racket/blob/master/typed-racket-lib/typed-racket/utils/literal-syntax-class.rkt Its companion

Re: [racket-users] syntax-class composed of literals

On 11/16/2016 08:24 PM, Dan Liebgold wrote: FWIW, Eric Dobson wrote a very nice `define-literal-syntax-class` macro that is used extensively inside TR. https://github.com/racket/typed-racket/blob/master/typed-racket-lib/typed-racket/utils/literal-syntax-class.rkt Hmm... I can't quite

[racket-users] server downtime

We will be performing maintenance on one of the PLT servers Monday afternoon. Some services will be unavailable during that time, including PLaneT, mailing list archives, and the old bug database. The main web pages, the package server, and the user and dev mailing lists should be unaffected.

Re: [racket-users] Re: How to change text alignment in a text-field% and how to make text-field% read-only but still copy-able

On 12/03/2016 02:15 PM, Winston Weinert wrote: I managed to resolve the alignment question with the following lines: (define e (send my-text-field get-editor)) (send e auto-wrap #t) (send e set-paragraph-alignment 0 'center) However, I'm still at a loss how to make the text-field% read-only

[racket-users] Re: prepared queries

On 3/15/17 12:41 AM, George Neuner wrote: Hi Ryan, Hope you enjoyed the snow day. Lost power here for a while, but fortunately no damage. I did :) My neighborhood didn't get much snow by volume, but what it did get was then rained/sleeted nearly into ice. On 3/13/2017 11:09 PM, Ryan

Re: [racket-users] Reporting exceptions as though they came from the caller

On 03/31/2017 04:00 PM, David Storrs wrote: Imagine I have the following trivial module (ignore that things are defined out of sequence for clarity): #lang racket (define (foo arg) (_baz arg) ; do some checking, raise an exception if there's a problem ...do stuff... ) (define (bar

Re: [racket-users] Virtual connections, threads, and DSN extraction, oh my!

On 03/13/2017 12:49 PM, David Storrs wrote: [...] Assuming I've understood all that correctly, my last question would be how to get around the 'can't do prepare with a virtual connection' issue for situations where I've been passed a connection (perhaps from third party code) and it might or

[racket-users] Re: prepared queries

On 03/13/2017 06:30 PM, George Neuner wrote: Hi Ryan, On 3/13/2017 5:43 PM, Ryan Culpepper wrote: Racket's db library always prepares a statement before executing it, even if there are no query parameters. When allowed, instead of closing the prepared statement immediately after executing

Re: [racket-users] Virtual connections, threads, and DSN extraction, oh my!

On 03/13/2017 03:16 PM, David Storrs wrote: [...] On Mon, Mar 13, 2017 at 2:49 PM, George Neuner > wrote: - It's also fine to pass the VC into other threads. It will be shared state between the threads, but the CP will keep their

Re: [racket-users] Virtual connections, threads, and DSN extraction, oh my!

On 03/13/2017 04:56 PM, George Neuner wrote: On 3/13/2017 3:41 PM, David Storrs wrote: On Mon, Mar 13, 2017 at 2:04 PM, Ryan Culpepper <ry...@ccs.neu.edu <mailto:ry...@ccs.neu.edu>> wrote: If you are using `prepare` just for speed, it might help to know that most base conn

Re: [racket-users] chaining operations on bignum not scalable

On 07/29/2017 02:48 PM, rom cgb wrote: Hi, Probably due to all operations not being in-place, chaining operations on bignums is very costful. for example, using bitwise-bit-field[1] on bignums is atrocious. I also tried (define (reverse-bits n) (for/fold ([reversed 0])

Re: [racket-users] Struct declaration conflict if a file is required implicitly

On 07/23/2017 07:26 AM, Alejandro Sanchez wrote: Hello everyone, I am working on this project: https://gitlab.com/HiPhish/MsgPack.rkt/ I am writing test cases and I ran into a problem with my ‘ext’ structure. It is declared in the file ‘msgpack/main.rkt’, which is required in the file

Re: [racket-users] How do db handles interact with threads and parameters

On 7/24/17 9:11 AM, George Neuner wrote: Hi David, On 7/24/2017 8:18 AM, David Storrs wrote: What happens in the following code? (define dbh (postgresql-connect ...)) ;; Use the DBH in a new thread (thread (thunk (while ...some long-running condition... (sleep 1) ; don't flood the DB

Re: [racket-users] Catching syntax errors

Use `convert-syntax-error` from the `syntax/macro-testing` module: http://docs.racket-lang.org/syntax/macro-testing.html#(form._((lib._syntax%2Fmacro-testing..rkt)._convert-syntax-error)) Ryan On 06/30/2017 04:47 PM, Sam Waxman wrote: Hello, I'm trying to test whether or not certain

Re: [racket-users] Setting parameters between files does not work as expected

You might be interested in `dsn-connect` and the `data-source` structure (http://docs.racket-lang.org/db/connect.html#%28part._.Data_.Source_.Names%29). Ryan On 4/25/17 8:18 PM, David Storrs wrote: Great. Thanks, Phillip! On Tue, Apr 25, 2017 at 2:14 PM, Philip McGrath

Re: [racket-users] Anyone using MongoDB 3.2.15 with DrRacket 6.9?

On 08/06/2017 05:49 PM, Cecil McGregor wrote: [...] What are other people using for a NoSQL racket experience? Are you looking for no schema or no ACID? If the latter, the git version of the db library now has experimental support for Apache Cassandra. Ryan -- You received this message

Re: [racket-users] Generate function defintions at compile time

On 08/22/2017 05:29 PM, hiph...@openmailbox.org wrote: Hello, I am writing a Racket library which will make it possible to control the Neovim text editor using Racket. People will be able to use Racket to control Neovim, as well as write plugins for Neovim in Racket.

Re: [racket-users] break-thread + thread-wait can't be handled

On 5/3/17 10:41 PM, Eric Griffis wrote: Hello, I'm having trouble catching "terminate break" exceptions when combining break-thread with thread-wait. MWE 1: (with-handlers ([exn:break:terminate? writeln]) (let ([t (thread (lambda () (thread-wait (current-thread])

Re: [racket-users] syntax-parse attributes in macro-generated macros

On 09/17/2017 01:00 AM, Philip McGrath wrote: [...] I have a macro like `example-macro`, but more complicated and with many, many more potential keyword arguments, so I wanted to write a macro that would let me define `example-macro` with a more declarative syntax, like this:

Re: [racket-users] Re: code reflection

On 10/14/2017 05:01 AM, George Neuner wrote: On 10/14/2017 3:00 AM, Jack Firth wrote: So is there a way ... from normal code ... to get at the locals of functions higher in the call chain?  Or at least the immediate caller? Some reflective capability that I haven't yet

Re: [racket-users] okay for the stepper to blanket disarm all syntax?

On 10/16/2017 12:38 PM, 'John Clements' via users-redirect wrote: I’m in the process of trying to update the stepper to handle check-random, and I’m somewhat baffled by the amount of difficulty I’m running into in and around ‘syntax-disarm’. It occurs to me that it would probably be simpler

Re: [racket-users] Efficient & "nice" communication mechanism between Racket and other languages

On 09/07/2017 12:11 PM, Brian Adkins wrote: I'm considering having a group of programmers create micro-services in various programming languages to be glued together into a single application. I would like a communication mechanism with the following characteristics: * Already supported by

Re: [racket-users] "Test did not clean up resources" message from GUI test runner

On 08/20/2017 09:28 PM, Alex Harsanyi wrote: I just noticed that the GUI test runner displays "test did not clean up resources" messages on my tests, but it is not clear to me what resources are not being cleaned up. I tried to reproduce the problem in the following test case: #lang

Re: [racket-users] confused about raco check-requires error

On 11/21/17 2:57 AM, Alex Harsanyi wrote: I'm trying to use the "raco check-requires" command to determine which requires I should remove from my source files, and the command fails when I include one of my files (the application compiles and runs fine). I managed to reproduce the case as

Re: [racket-users] ssax:make-parser

On 05/15/2018 11:36 PM, John Clements wrote: Interestingly, it looks like this change is a deliberate one, made by Ryan Culpepper back in 2011. Here’s the relevant commit: commit 738bf41d106f4ecd9111bbefabfd78bec8dc2202 Author: Ryan Culpepper <ry...@racket-lang.org> Date: Tue Nov 22 02

Re: [racket-users] Jupyter Racket Kernel - iracket

On 05/01/2018 09:33 PM, Graham Dean wrote: PR submitted :) PR merged. Thanks! Ryan -- You received this message because you are subscribed to the Google Groups "Racket Users" group. To unsubscribe from this group and stop receiving emails from it, send an email to

Re: [racket-users] Cryptography routines in Racket

I have a crypto library in progress that I haven't released yet. The repo is at https://github.com/rmculpepper/crypto, but the repo is missing a lot of local commits and I won't be able to fix it until mid-January. If you want to try out the old version, you'll also need asn1-lib from

Re: [racket-users] Generating automatic testsuites using a macro

On 2/23/18 3:36 PM, 'Paulo Matos' via Racket Users wrote: On 23/02/18 15:13, 'Paulo Matos' via Racket Users wrote: That's true, thanks for pointing it out. I only just noticed you could generate test-suites and test-cases at runtime with make-testcase and make-testsuite. Therefore I will

Re: [racket-users] Confusion about attributes of struct-id

On 08/16/2018 06:04 PM, David Storrs wrote: The struct-id syntax class from syntax/parse/class/struct-id is puzzling me.  Given this preamble: (require (for-syntax syntax/parse/class/struct-id syntax/parse syntax/parse/experimental/template

Re: [racket-users] FFI Trouble (file streams, variadic functions)

On 08/27/2018 02:13 PM, Philip McGrath wrote: I am hoping for some help debugging a problem I'm having writing FFI bindings for libxml2. I am trying to use the function `xmlValidateDtd`, which (predictably) validates an XML document against a DTD. To support error reporting, the first

Re: [racket-users] FFI Trouble (file streams, variadic functions)

. -Philip On Mon, Aug 27, 2018 at 8:03 AM Ryan Culpepper <mailto:ry...@ccs.neu.edu>> wrote: On 08/27/2018 02:13 PM, Philip McGrath wrote: > I am hoping for some help debugging a problem I'm having writing FFI > bindings for libxml2. > > I am tryin

Re: [racket-users] Where to put scribblings in 'multi package?

On 08/29/2018 12:37 PM, Erich Rast wrote: I have a preliminary scribbling for the manual of a multi source package, but it doesn't show up in Racket's main documentation when I install the package locally. Here is the directory structure: appy | |--info.rkt |--appy | |--

Re: [racket-users] Using match on hash tables with optional keys

On 8/31/18 4:28 AM, Greg Hendershott wrote: A general trick for optional values with match is something like (or pat (app (λ _ default-value) pat)). But that doesn't work for hash-table which uses [pat path] for each mapping. (At least I couldn't see how.) Here's _a_ way you could write this as

Re: [racket-users] whither `splicing-parameterize`? or am I doing it wrong?

It might make sense to `(set! new-parameterization #f)` at the end so that the parameterization (and the values it holds) can be GC'd sooner when splicing-parameterize is used at top level or module level. Ryan On 1/24/18 6:00 AM, Alexis King wrote: Here is an implementation of a version of

Re: [racket-users] Output Port Shenanigans

On 03/14/2018 06:16 PM, Lehi Toskin wrote: On Wednesday, March 14, 2018 at 10:10:20 AM UTC-7, Matthew Butterick wrote: probably it requires a combination of peek + read, or copying the port. That may be true, but I've been messing around getting *anything* to print from inside that

Re: [racket-users] how to match unbound identifier as literal in `syntax-parse`?

Here's one way: (~and z:id (~fail #:unless (free-identifier=? #'z #'zeta) "expected the identifier `zeta`")) Another way is to make a syntax class (either specifically for `zeta` or parameterized by the identifier) that does the same check. Ryan On 4/3/18 8:33 AM,

Re: [racket-users] Behavior of nested ellipses

On 03/27/2018 11:46 PM, Ryan Culpepper wrote: On 03/27/2018 10:01 PM, Justin Pombrio wrote: I'm surprised by the behavior of using a pattern variable under one set of ellipses in the pattern, and under two sets of ellipses in the template: [...] BTW, it looks like Macro-By-Example[1

Re: [racket-users] Behavior of nested ellipses

On 03/27/2018 10:01 PM, Justin Pombrio wrote: I'm surprised by the behavior of using a pattern variable under one set of ellipses in the pattern, and under two sets of ellipses in the template: | #lang racket (require(for-syntax syntax/parse)) (define-syntax (test stx) (syntax-parse stx [(_

Re: [racket-users] Storing JSON into PostgreSQL 10

On 03/16/2018 11:28 PM, David Storrs wrote: I'm noticing that when I store jsexpr?s into PostgreSQL 10 I end up with them as strings, not as actual JSONB data.  I've read the docs and tried every combination of typecasting / methods of writing that I can think of but nothing ends up working. 

Re: [racket-users] syntax/parse is not hygienic

On 03/04/2018 09:40 PM, Alexis King wrote: [... context ...] Still, with all this context out of the way, my questions are comparatively short: 1. Is this lack of hygiene well-known? I did not find anything in Ryan’s dissertation that explicitly dealt with the question, but I

Re: [racket-users] Creating truly unique instances of structure types?

On 11/6/18 11:31 AM, Alexis King wrote: On Nov 5, 2018, at 20:01, Ryan Culpepper wrote: You could use a chaperone to prohibit `struct-info` Good point! I had forgotten that `struct-info` is a chaperoneable operation. This isn’t ideal, though, since I don’t think `struct-info` is ever

Re: [racket-users] Creating truly unique instances of structure types?

On 11/5/18 5:26 PM, Alexis King wrote: To my knowledge, there are two main techniques for creating unique values in Racket: `gensym` and structure type generativity. The former seems to be bulletproof — a value created with `gensym` will never be `equal?` to anything except itself – but the

Re: [racket-users] Compilation/Embedding leaves syntax traces

On 9/25/18 1:11 PM, Alexis King wrote: [] Personally, I would appreciate a way to ask Racket to strip all phase ≥1 code and phase ≥1 dependencies from a specified program so that I can distribute the phase 0 code and dependencies exclusively. However, to my knowledge, Racket does not

Re: [racket-users] How do I (de)serialize PKI keys for storage?

On 12/18/18 23:36, David Storrs wrote: I'm trying to persist public/private keys to our database and having some trouble: Welcome to Racket v6.11. > (require crypto crypto/gcrypt) > (crypto-factories gcrypt-factory) > (define key (generate-private-key 'rsa)) > key (object:gcrypt-rsa-key%

Re: [racket-users] Help with evaluation of examples in Scribble

On 3/10/19 4:16 PM, Matt Jadud wrote: Oh! Thank you, Matthew. I see. So, I'm running into the sandbox... as in, the sandbox is doing what it should, and as a result, it is preventing the networked accesses that I've added to my documentation. That's awfully obvious (now that it is put that

Re: [racket-users] exercise 1, racket school 2018

On 6/17/19 4:20 PM, Robert Girault wrote: I was able to do the first half of exercise 1 (see sources at the end of this message) --- write a macro computing some information at run-time. The second half is to write the same macro, but computing some information at compile-time --- I couldn't do

Re: [racket-users] db module + SQLite driver + 'ON CONFLICT' = syntax error

Use "INSERT OR IGNORE" instead. See https://sqlite.org/lang_conflict.html, 3rd paragraph. Ryan On 4/18/19 23:28, David Storrs wrote: On Thu, Apr 18, 2019 at 4:48 PM Jon Zeppieri > wrote: It might well be the SQLlite version. This is a pretty new feature.

Re: [racket-users] db module + SQLite driver + 'ON CONFLICT' = syntax error

On 4/18/19 23:53, David Storrs wrote: On Thu, Apr 18, 2019 at 5:42 PM Ryan Culpepper <mailto:ry...@ccs.neu.edu>> wrote: Use "INSERT OR IGNORE" instead. See https://sqlite.org/lang_conflict.html, 3rd paragraph. Yep.  Unfortunately, this was a simplified case of w

Re: [racket-users] Racket SIGSEGV during FFI call

On 6/26/19 6:34 AM, Christopher Howard wrote: Hi, I have a project going to make Racket bindings to the libhackrf C library installed on my Debian 9 system. I have successfully made and used bindings to around a dozen procedures in the library. However, when I get to the first really important

Re: [racket-users] db module 'query' does not return insert-id

On 4/22/19 20:36, David Storrs wrote: > (require db) > (define db (postgresql-connect  ...args...)) > (simple-result-info (query db "insert into collaborations (name) values ('foojalskdsfls')")) '((insert-id . #f) (affected-rows . 1)) From the docs on the 'simple-result' struct:

Re: [racket-users] how do I clear this FFI-related build error?

On 4/23/19 23:14, Matthew Butterick wrote: Some code relies on the `harfbuzz` library, like so: (define-runtime-lib harfbuzz-lib   [(unix) (ffi-lib "libharfbuzz" '("1" ""))]   [(macosx) (ffi-lib "libharfbuzz.0.dylib")]   [(windows) (ffi-lib "libharfbuzz-0.dll")]) Though this works on my

Re: [racket-users] Getting JSON to work with the DB module

It is not possible, unfortunately. You must do the conversion to and from strings yourself. I've thought about adding a hook for additional conversions based on declared types, but there's no declared type information at all for parameters, and the declared type for results is fragile: a

[racket-users] CFP: 4th Workshop on Meta-Programming Techniques and Reflection (Meta'19), Co-located with SPLASH 2019

Scholliers, Ghent University ### Program Committee Nada Amin, University of Cambridge, UK Edwin Brady, University of St Andrews, UK Andrei Chis, Feenk, Switzerland David Thrane Christiansen, Galois, Portland, Oregon, USA Tom Van Cutsem, Bell Labs, Belgium Ryan Culpepper, Czech Technical University

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