[Haskell-cafe] Having trouble with zip12..
I have some code that looks like this and I'm having trouble with it: zip12 ((tails . nub) flightPaths) wayPoints etopsPackets (hd geoCaches) groundSpeeds headings (map windShift headings) (regulations !! 2) (foldr (\|/) (tail pathDistances)) [ghy x | x - [1..], full x] (nub . nub) arrivalSchedule The domain is air traffic control and I need to generate 12-tuples for aircraft that are within a particular radius of the tower. When I evaluate that expression with 'take 4' it works fine. When I evaluate it with 'take 6' it works as well. But, when I evaluate it with 'take 5' I get the following runtime error from H# in Visual Studio (it runs fine on the command line). This is particularly odd because I'm not using Sql. The type initializer for 'System.Data.SqlClient.SqlConnection' threw an exception. Exception (TypeInitializationException): Source=System.Data; Target=null; Tag=null; TypeName=System.Data.SqlClient.SqlConnection; Message = The type initializer for 'System.Data.SqlClient.SqlConnection' threw an exception. InnerException (TypeInitializationException): Source=System.Data; Target=null; Tag=null; Message = The type initializer for 'System.Data.SqlClient.SqlConnectionFactory' threw an exception. StackTrace = at System.Data.SqlClient.SqlConnection..cctor() InnerException (TypeInitializationException): Source=System.Data; Target=null; Tag=null; Message = The type initializer for 'System.Data.SqlClient.SqlPerformanceCounters' threw an exception. StackTrace = at System.Data.SqlClient.SqlConnectionFactory..ctor() at System.Data.SqlClient.SqlConnectionFactory..cctor() InnerException (ConfigurationErrorsException): Source=System.Configuration; Target=null; Tag=null; Line=21; Message = The value of the property 'traceOutputOptions' cannot be parsed. The error is: The enumeration value must be one of the following: None, LogicalOperationStack, DateTime, Timestamp, ProcessId, ThreadId, Callstack. (C:\Documents and Settings\Paey\Desktop\Projects\RPMC\bin\Debug\RPMC.vshost.exe.config line 21) StackTrace = at System.Configuration.BaseConfigurationRecord.EvaluateOne(String[] keys, SectionInput input, Boolean isTrusted, FactoryRecord factoryRecord, SectionRecord sectionRecord, Object parentResult) at System.Configuration.BaseConfigurationRecord.Evaluate(FactoryRecord factoryRecord, SectionRecord sectionRecord, Object parentResult, Boolean getLkg, Boolean getRuntimeObject, Object result, Object resultRuntimeObject) at System.Configuration.BaseConfigurationRecord.GetSectionRecursive(String configKey, Boolean getLkg, Boolean checkPermission, Boolean getRuntimeObject, Boolean requestIsHere, Object result, Object resultRuntimeObject) at System.Configuration.BaseConfigurationRecord.GetSectionRecursive(String configKey, Boolean getLkg, Boolean checkPermission, Boolean getRuntimeObject, Boolean requestIsHere, Object result, Object resultRuntimeObject) at System.Configuration.BaseConfigurationRecord.GetSectionRecursive(String configKey, Boolean getLkg, Boolean ch... (truncated) ...olean checkPermission) at System.Configuration.BaseConfigurationRecord.GetSection(String configKey) at System.Configuration.ClientConfigurationSystem.System.Configuration.Internal.IInternalConfigSystem.GetSection(String sectionName) at System.Configuration.ConfigurationManager.GetSection(String sectionName) at System.Configuration.PrivilegedConfigurationManager.GetSection(String sectionName) at System.Diagnostics.DiagnosticsConfiguration.GetConfigSection() at System.Diagnostics.DiagnosticsConfiguration.Initialize() at System.Diagnostics.Switch.InitializeConfigSettings() at System.Diagnostics.Switch.InitializeWithStatus() at System.Diagnostics.Switch.get_SwitchSetting() at System.Diagnostics.TraceSwitch.get_Level() at System.Data.ProviderBase.DbConnectionPoolCounters..ctor(String categoryName, String categoryHelp) at System.Data.SqlClient.SqlPerformanceCounters..ctor() at System.Data.SqlClient.SqlPerformanceCounters..cctor() BareMessage = The value of the property 'traceOutputOptions' cannot be parsed. The error is: The enumeration value must be one of the following: None, LogicalOperationStack, DateTime, Timestamp, ProcessId, ThreadId, Callstack. Filename = C:\Documents and Settings\Pley\Desktop\Projects\RPMC\bin\Debug\RPMC.vshost.exe.config Errors (ConfigurationException[]): Length=1; Rank=1; Count=1; #0 (ConfigurationErrorsException): Source=null; Target=null; Tag=null; StackTrace=null; BareMessage=(-BareMessage); Filename=(-Filename); Line=21; Message = The value of the property 'traceOutputOptions' cannot be parsed. The error is: The enumeration value must be one of the following: None, LogicalOperationStack, DateTime, Timestamp, ProcessId, ThreadId, Callstack. (C:\Documents and Settings\Pley\Desktop\Projects\RPMC\bin\Debug\RPMC.vshost.exe.config line 21) Errors (ConfigurationException[]): Length=1; Rank=1; Count=1; #0 (ConfigurationErrorsException):
Re: [Haskell-cafe] Having trouble with zip12..
mfeathers:
I have some code that looks like this and I'm having trouble with it:
zip12 ((tails . nub) flightPaths) wayPoints etopsPackets (hd geoCaches)
groundSpeeds headings (map windShift headings) (regulations !! 2)
(foldr (\|/) (tail pathDistances)) [ghy x | x - [1..], full x]
(nub . nub) arrivalSchedule
The domain is air traffic control and I need to generate 12-tuples for
aircraft that are within a particular radius of the tower.
12 tuples are really really unusual. It sounds like perhaps you should
be using a custom data type here.
data Aircraft = Aircraft
{ wayPoints= currentWayPoints
, groundSpeeds = ...
, headings = ...
, etc ...
}
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Re: [Haskell-cafe] Having trouble with zip12..
You're zipping 12 lists here, so how about testing each list individually? This will narrow down the problem considerably. Michael Feathers wrote: I have some code that looks like this and I'm having trouble with it: zip12 ((tails . nub) flightPaths) wayPoints etopsPackets (hd geoCaches) groundSpeeds headings (map windShift headings) (regulations !! 2) (foldr (\|/) (tail pathDistances)) [ghy x | x - [1..], full x] (nub . nub) arrivalSchedule The domain is air traffic control and I need to generate 12-tuples for aircraft that are within a particular radius of the tower. When I evaluate that expression with 'take 4' it works fine. When I evaluate it with 'take 6' it works as well. But, when I evaluate it with 'take 5' I get the following runtime error from H# in Visual Studio (it runs fine on the command line). This is particularly odd because I'm not using Sql. The type initializer for 'System.Data.SqlClient.SqlConnection' threw an exception. Exception (TypeInitializationException): Source=System.Data; Target=null; Tag=null; TypeName=System.Data.SqlClient.SqlConnection; Message = The type initializer for 'System.Data.SqlClient.SqlConnection' threw an exception. InnerException (TypeInitializationException): Source=System.Data; Target=null; Tag=null; Message = The type initializer for 'System.Data.SqlClient.SqlConnectionFactory' threw an exception. StackTrace = at System.Data.SqlClient.SqlConnection..cctor() InnerException (TypeInitializationException): Source=System.Data; Target=null; Tag=null; Message = The type initializer for 'System.Data.SqlClient.SqlPerformanceCounters' threw an exception. StackTrace = at System.Data.SqlClient.SqlConnectionFactory..ctor() at System.Data.SqlClient.SqlConnectionFactory..cctor() InnerException (ConfigurationErrorsException): Source=System.Configuration; Target=null; Tag=null; Line=21; Message = The value of the property 'traceOutputOptions' cannot be parsed. The error is: The enumeration value must be one of the following: None, LogicalOperationStack, DateTime, Timestamp, ProcessId, ThreadId, Callstack. (C:\Documents and Settings\Paey\Desktop\Projects\RPMC\bin\Debug\RPMC.vshost.exe.config line 21) StackTrace = at System.Configuration.BaseConfigurationRecord.EvaluateOne(String[] keys, SectionInput input, Boolean isTrusted, FactoryRecord factoryRecord, SectionRecord sectionRecord, Object parentResult) at System.Configuration.BaseConfigurationRecord.Evaluate(FactoryRecord factoryRecord, SectionRecord sectionRecord, Object parentResult, Boolean getLkg, Boolean getRuntimeObject, Object result, Object resultRuntimeObject) at System.Configuration.BaseConfigurationRecord.GetSectionRecursive(String configKey, Boolean getLkg, Boolean checkPermission, Boolean getRuntimeObject, Boolean requestIsHere, Object result, Object resultRuntimeObject) at System.Configuration.BaseConfigurationRecord.GetSectionRecursive(String configKey, Boolean getLkg, Boolean checkPermission, Boolean getRuntimeObject, Boolean requestIsHere, Object result, Object resultRuntimeObject) at System.Configuration.BaseConfigurationRecord.GetSectionRecursive(String configKey, Boolean getLkg, Boolean ch... (truncated) ...olean checkPermission) at System.Configuration.BaseConfigurationRecord.GetSection(String configKey) at System.Configuration.ClientConfigurationSystem.System.Configuration.Internal.IInternalConfigSystem.GetSection(String sectionName) at System.Configuration.ConfigurationManager.GetSection(String sectionName) at System.Configuration.PrivilegedConfigurationManager.GetSection(String sectionName) at System.Diagnostics.DiagnosticsConfiguration.GetConfigSection() at System.Diagnostics.DiagnosticsConfiguration.Initialize() at System.Diagnostics.Switch.InitializeConfigSettings() at System.Diagnostics.Switch.InitializeWithStatus() at System.Diagnostics.Switch.get_SwitchSetting() at System.Diagnostics.TraceSwitch.get_Level() at System.Data.ProviderBase.DbConnectionPoolCounters..ctor(String categoryName, String categoryHelp) at System.Data.SqlClient.SqlPerformanceCounters..ctor() at System.Data.SqlClient.SqlPerformanceCounters..cctor() BareMessage = The value of the property 'traceOutputOptions' cannot be parsed. The error is: The enumeration value must be one of the following: None, LogicalOperationStack, DateTime, Timestamp, ProcessId, ThreadId, Callstack. Filename = C:\Documents and Settings\Pley\Desktop\Projects\RPMC\bin\Debug\RPMC.vshost.exe.config Errors (ConfigurationException[]): Length=1; Rank=1; Count=1; #0 (ConfigurationErrorsException): Source=null; Target=null; Tag=null; StackTrace=null; BareMessage=(-BareMessage); Filename=(-Filename); Line=21; Message = The value of the property 'traceOutputOptions' cannot be parsed. The error is: The enumeration value must be one of the following: None, LogicalOperationStack, DateTime, Timestamp, ProcessId, ThreadId, Callstack.
Re: [Haskell-cafe] Having trouble with zip12..
-BEGIN PGP SIGNED MESSAGE- Hash: SHA1 Michael Feathers wrote: I have some code that looks like this and I'm having trouble with it: zip12 ((tails . nub) flightPaths) wayPoints etopsPackets (hd geoCaches) groundSpeeds headings (map windShift headings) (regulations !! 2) (foldr (\|/) (tail pathDistances)) [ghy x | x - [1..], full x] (nub . nub) arrivalSchedule Hi Michael, Sorry to distract from your issue, but I note that (nub . nub) can be replaced with just 'nub' since the function nub is idempotent (f . f == f). dibblego @check \x - (nub . nub) x == nub x -- is nub idempotent? lambdabot OK, passed 500 tests. - -- Tony Morris http://tmorris.net/ -BEGIN PGP SIGNATURE- Version: GnuPG v1.4.6 (GNU/Linux) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org iD8DBQFIcS9LmnpgrYe6r60RAiDOAKCJlDaqNd5ssgxrUrrHee75WGzhbgCfftdn 70+4isXh4zaoYly0da2Gdk8= =ryfF -END PGP SIGNATURE- ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Having trouble with zip12..
Sorry guys. I was just bored on a Sunday afternoon so I thought I'd type up a little joke. I thought to myself Gee, how outrageous can I make it? 1) Using and debugging a zip12 function. 2) That fails only on 'take 5' (Brubeck fans take note) 3) Has some absurd arguments like (nub . nub) 4) Is embedded in an air traffic control system 5) Is written in a Microsoft variant of Haskell called H# 6) Silently makes SQL calls when evaluating a pure function 7) Yields an mile long stack trace Sorry all. Boredom made me do it, Michael Paul Visschers wrote: You're zipping 12 lists here, so how about testing each list individually? This will narrow down the problem considerably. Michael Feathers wrote: I have some code that looks like this and I'm having trouble with it: zip12 ((tails . nub) flightPaths) wayPoints etopsPackets (hd geoCaches) groundSpeeds headings (map windShift headings) (regulations !! 2) (foldr (\|/) (tail pathDistances)) [ghy x | x - [1..], full x] (nub . nub) arrivalSchedule The domain is air traffic control and I need to generate 12-tuples for aircraft that are within a particular radius of the tower. When I evaluate that expression with 'take 4' it works fine. When I evaluate it with 'take 6' it works as well. But, when I evaluate it with 'take 5' I get the following runtime error from H# in Visual Studio (it runs fine on the command line). This is particularly odd because I'm not using Sql. The type initializer for 'System.Data.SqlClient.SqlConnection' threw an exception. Exception (TypeInitializationException): Source=System.Data; Target=null; Tag=null; TypeName=System.Data.SqlClient.SqlConnection; Message = The type initializer for 'System.Data.SqlClient.SqlConnection' threw an exception. InnerException (TypeInitializationException): Source=System.Data; Target=null; Tag=null; Message = The type initializer for 'System.Data.SqlClient.SqlConnectionFactory' threw an exception. StackTrace = at System.Data.SqlClient.SqlConnection..cctor() InnerException (TypeInitializationException): Source=System.Data; Target=null; Tag=null; Message = The type initializer for 'System.Data.SqlClient.SqlPerformanceCounters' threw an exception. StackTrace = at System.Data.SqlClient.SqlConnectionFactory..ctor() at System.Data.SqlClient.SqlConnectionFactory..cctor() InnerException (ConfigurationErrorsException): Source=System.Configuration; Target=null; Tag=null; Line=21; Message = The value of the property 'traceOutputOptions' cannot be parsed. The error is: The enumeration value must be one of the following: None, LogicalOperationStack, DateTime, Timestamp, ProcessId, ThreadId, Callstack. (C:\Documents and Settings\Paey\Desktop\Projects\RPMC\bin\Debug\RPMC.vshost.exe.config line 21) StackTrace = at System.Configuration.BaseConfigurationRecord.EvaluateOne(String[] keys, SectionInput input, Boolean isTrusted, FactoryRecord factoryRecord, SectionRecord sectionRecord, Object parentResult) at System.Configuration.BaseConfigurationRecord.Evaluate(FactoryRecord factoryRecord, SectionRecord sectionRecord, Object parentResult, Boolean getLkg, Boolean getRuntimeObject, Object result, Object resultRuntimeObject) at System.Configuration.BaseConfigurationRecord.GetSectionRecursive(String configKey, Boolean getLkg, Boolean checkPermission, Boolean getRuntimeObject, Boolean requestIsHere, Object result, Object resultRuntimeObject) at System.Configuration.BaseConfigurationRecord.GetSectionRecursive(String configKey, Boolean getLkg, Boolean checkPermission, Boolean getRuntimeObject, Boolean requestIsHere, Object result, Object resultRuntimeObject) at System.Configuration.BaseConfigurationRecord.GetSectionRecursive(String configKey, Boolean getLkg, Boolean ch... (truncated) ...olean checkPermission) at System.Configuration.BaseConfigurationRecord.GetSection(String configKey) at System.Configuration.ClientConfigurationSystem.System.Configuration.Internal.IInternalConfigSystem.GetSection(String sectionName) at System.Configuration.ConfigurationManager.GetSection(String sectionName) at System.Configuration.PrivilegedConfigurationManager.GetSection(String sectionName) at System.Diagnostics.DiagnosticsConfiguration.GetConfigSection() at System.Diagnostics.DiagnosticsConfiguration.Initialize() at System.Diagnostics.Switch.InitializeConfigSettings() at System.Diagnostics.Switch.InitializeWithStatus() at System.Diagnostics.Switch.get_SwitchSetting() at System.Diagnostics.TraceSwitch.get_Level() at System.Data.ProviderBase.DbConnectionPoolCounters..ctor(String categoryName, String categoryHelp) at System.Data.SqlClient.SqlPerformanceCounters..ctor() at System.Data.SqlClient.SqlPerformanceCounters..cctor() BareMessage = The value of the property 'traceOutputOptions' cannot be parsed. The error is: The enumeration value must be one of the following: None, LogicalOperationStack, DateTime, Timestamp, ProcessId, ThreadId, Callstack. Filename = C:\Documents and
Re: [Haskell-cafe] Having trouble with zip12..
I win, almost ... 13:13:18 dons dolio: yeah, it was ... almost ... an April 1 style post :) And yes, this was truly shocking on a number of levels. However, we have people doing a lot of weird things with Haskell these days, so its not as absurd that someone would be hacking up a zip12 for an air traffic control system on some MS platform, with SQL in the backend, as it might have been a few years ago :) mfeathers: Sorry guys. I was just bored on a Sunday afternoon so I thought I'd type up a little joke. I thought to myself Gee, how outrageous can I make it? 1) Using and debugging a zip12 function. 2) That fails only on 'take 5' (Brubeck fans take note) 3) Has some absurd arguments like (nub . nub) 4) Is embedded in an air traffic control system 5) Is written in a Microsoft variant of Haskell called H# 6) Silently makes SQL calls when evaluating a pure function 7) Yields an mile long stack trace Sorry all. Boredom made me do it, Michael Paul Visschers wrote: You're zipping 12 lists here, so how about testing each list individually? This will narrow down the problem considerably. Michael Feathers wrote: I have some code that looks like this and I'm having trouble with it: zip12 ((tails . nub) flightPaths) wayPoints etopsPackets (hd geoCaches) groundSpeeds headings (map windShift headings) (regulations !! 2) (foldr (\|/) (tail pathDistances)) [ghy x | x - [1..], full x] (nub . nub) arrivalSchedule The domain is air traffic control and I need to generate 12-tuples for aircraft that are within a particular radius of the tower. When I evaluate that expression with 'take 4' it works fine. When I evaluate it with 'take 6' it works as well. But, when I evaluate it with 'take 5' I get the following runtime error from H# in Visual Studio (it runs fine on the command line). This is particularly odd because I'm not using Sql. The type initializer for 'System.Data.SqlClient.SqlConnection' threw an exception. Exception (TypeInitializationException): Source=System.Data; Target=null; Tag=null; TypeName=System.Data.SqlClient.SqlConnection; Message = The type initializer for 'System.Data.SqlClient.SqlConnection' threw an exception. InnerException (TypeInitializationException): Source=System.Data; Target=null; Tag=null; Message = The type initializer for 'System.Data.SqlClient.SqlConnectionFactory' threw an exception. StackTrace = at System.Data.SqlClient.SqlConnection..cctor() InnerException (TypeInitializationException): Source=System.Data; Target=null; Tag=null; Message = The type initializer for 'System.Data.SqlClient.SqlPerformanceCounters' threw an exception. StackTrace = at System.Data.SqlClient.SqlConnectionFactory..ctor() at System.Data.SqlClient.SqlConnectionFactory..cctor() InnerException (ConfigurationErrorsException): Source=System.Configuration; Target=null; Tag=null; Line=21; Message = The value of the property 'traceOutputOptions' cannot be parsed. The error is: The enumeration value must be one of the following: None, LogicalOperationStack, DateTime, Timestamp, ProcessId, ThreadId, Callstack. (C:\Documents and Settings\Paey\Desktop\Projects\RPMC\bin\Debug\RPMC.vshost.exe.config line 21) StackTrace = at System.Configuration.BaseConfigurationRecord.EvaluateOne(String[] keys, SectionInput input, Boolean isTrusted, FactoryRecord factoryRecord, SectionRecord sectionRecord, Object parentResult) at System.Configuration.BaseConfigurationRecord.Evaluate(FactoryRecord factoryRecord, SectionRecord sectionRecord, Object parentResult, Boolean getLkg, Boolean getRuntimeObject, Object result, Object resultRuntimeObject) at System.Configuration.BaseConfigurationRecord.GetSectionRecursive(String configKey, Boolean getLkg, Boolean checkPermission, Boolean getRuntimeObject, Boolean requestIsHere, Object result, Object resultRuntimeObject) at System.Configuration.BaseConfigurationRecord.GetSectionRecursive(String configKey, Boolean getLkg, Boolean checkPermission, Boolean getRuntimeObject, Boolean requestIsHere, Object result, Object resultRuntimeObject) at System.Configuration.BaseConfigurationRecord.GetSectionRecursive(String configKey, Boolean getLkg, Boolean ch... (truncated) ...olean checkPermission) at System.Configuration.BaseConfigurationRecord.GetSection(String configKey) at System.Configuration.ClientConfigurationSystem.System.Configuration.Internal.IInternalConfigSystem.GetSection(String sectionName) at System.Configuration.ConfigurationManager.GetSection(String sectionName) at System.Configuration.PrivilegedConfigurationManager.GetSection(String sectionName) at System.Diagnostics.DiagnosticsConfiguration.GetConfigSection() at System.Diagnostics.DiagnosticsConfiguration.Initialize() at System.Diagnostics.Switch.InitializeConfigSettings() at System.Diagnostics.Switch.InitializeWithStatus() at System.Diagnostics.Switch.get_SwitchSetting() at
Re: [Haskell-cafe] Having trouble with zip12..
Wow. Where did you come up with the stack trace? That's...impressive. On Sun, Jul 6, 2008 at 5:07 PM, Don Stewart [EMAIL PROTECTED] wrote: I win, almost ... 13:13:18 dons dolio: yeah, it was ... almost ... an April 1 style post :) And yes, this was truly shocking on a number of levels. However, we have people doing a lot of weird things with Haskell these days, so its not as absurd that someone would be hacking up a zip12 for an air traffic control system on some MS platform, with SQL in the backend, as it might have been a few years ago :) mfeathers: Sorry guys. I was just bored on a Sunday afternoon so I thought I'd type up a little joke. I thought to myself Gee, how outrageous can I make it? 1) Using and debugging a zip12 function. 2) That fails only on 'take 5' (Brubeck fans take note) 3) Has some absurd arguments like (nub . nub) 4) Is embedded in an air traffic control system 5) Is written in a Microsoft variant of Haskell called H# 6) Silently makes SQL calls when evaluating a pure function 7) Yields an mile long stack trace Sorry all. Boredom made me do it, Michael Paul Visschers wrote: You're zipping 12 lists here, so how about testing each list individually? This will narrow down the problem considerably. Michael Feathers wrote: I have some code that looks like this and I'm having trouble with it: zip12 ((tails . nub) flightPaths) wayPoints etopsPackets (hd geoCaches) groundSpeeds headings (map windShift headings) (regulations !! 2) (foldr (\|/) (tail pathDistances)) [ghy x | x - [1..], full x] (nub . nub) arrivalSchedule The domain is air traffic control and I need to generate 12-tuples for aircraft that are within a particular radius of the tower. When I evaluate that expression with 'take 4' it works fine. When I evaluate it with 'take 6' it works as well. But, when I evaluate it with 'take 5' I get the following runtime error from H# in Visual Studio (it runs fine on the command line). This is particularly odd because I'm not using Sql. The type initializer for 'System.Data.SqlClient.SqlConnection' threw an exception. Exception (TypeInitializationException): Source=System.Data; Target=null; Tag=null; TypeName=System.Data.SqlClient.SqlConnection; Message = The type initializer for 'System.Data.SqlClient.SqlConnection' threw an exception. InnerException (TypeInitializationException): Source=System.Data; Target=null; Tag=null; Message = The type initializer for 'System.Data.SqlClient.SqlConnectionFactory' threw an exception. StackTrace = at System.Data.SqlClient.SqlConnection..cctor() InnerException (TypeInitializationException): Source=System.Data; Target=null; Tag=null; Message = The type initializer for 'System.Data.SqlClient.SqlPerformanceCounters' threw an exception. StackTrace = at System.Data.SqlClient.SqlConnectionFactory..ctor() at System.Data.SqlClient.SqlConnectionFactory..cctor() InnerException (ConfigurationErrorsException): Source=System.Configuration; Target=null; Tag=null; Line=21; Message = The value of the property 'traceOutputOptions' cannot be parsed. The error is: The enumeration value must be one of the following: None, LogicalOperationStack, DateTime, Timestamp, ProcessId, ThreadId, Callstack. (C:\Documents and Settings\Paey\Desktop\Projects\RPMC\bin\Debug\RPMC.vshost.exe.config line 21) StackTrace = at System.Configuration.BaseConfigurationRecord.EvaluateOne(String[] keys, SectionInput input, Boolean isTrusted, FactoryRecord factoryRecord, SectionRecord sectionRecord, Object parentResult) at System.Configuration.BaseConfigurationRecord.Evaluate(FactoryRecord factoryRecord, SectionRecord sectionRecord, Object parentResult, Boolean getLkg, Boolean getRuntimeObject, Object result, Object resultRuntimeObject) at System.Configuration.BaseConfigurationRecord.GetSectionRecursive(String configKey, Boolean getLkg, Boolean checkPermission, Boolean getRuntimeObject, Boolean requestIsHere, Object result, Object resultRuntimeObject) at System.Configuration.BaseConfigurationRecord.GetSectionRecursive(String configKey, Boolean getLkg, Boolean checkPermission, Boolean getRuntimeObject, Boolean requestIsHere, Object result, Object resultRuntimeObject) at System.Configuration.BaseConfigurationRecord.GetSectionRecursive(String configKey, Boolean getLkg, Boolean ch... (truncated) ...olean checkPermission) at System.Configuration.BaseConfigurationRecord.GetSection(String configKey) at System.Configuration.ClientConfigurationSystem.System.Configuration.Internal.IInternalConfigSystem.GetSection(String sectionName) at System.Configuration.ConfigurationManager.GetSection(String sectionName) at System.Configuration.PrivilegedConfigurationManager.GetSection(String sectionName) at System.Diagnostics.DiagnosticsConfiguration.GetConfigSection() at System.Diagnostics.DiagnosticsConfiguration.Initialize() at
Re: [Haskell-cafe] Having trouble with zip12..
Don Stewart wrote: I win, almost ... 13:13:18 dons dolio: yeah, it was ... almost ... an April 1 style post :) And yes, this was truly shocking on a number of levels. However, we have people doing a lot of weird things with Haskell these days, so its not as absurd that someone would be hacking up a zip12 for an air traffic control system on some MS platform, with SQL in the backend, as it might have been a few years ago :) :-) Was that IRC? Oh boy, now I have a reputation. Michael mfeathers: Sorry guys. I was just bored on a Sunday afternoon so I thought I'd type up a little joke. I thought to myself Gee, how outrageous can I make it? 1) Using and debugging a zip12 function. 2) That fails only on 'take 5' (Brubeck fans take note) 3) Has some absurd arguments like (nub . nub) 4) Is embedded in an air traffic control system 5) Is written in a Microsoft variant of Haskell called H# 6) Silently makes SQL calls when evaluating a pure function 7) Yields an mile long stack trace Sorry all. Boredom made me do it, Michael Paul Visschers wrote: You're zipping 12 lists here, so how about testing each list individually? This will narrow down the problem considerably. Michael Feathers wrote: I have some code that looks like this and I'm having trouble with it: zip12 ((tails . nub) flightPaths) wayPoints etopsPackets (hd geoCaches) groundSpeeds headings (map windShift headings) (regulations !! 2) (foldr (\|/) (tail pathDistances)) [ghy x | x - [1..], full x] (nub . nub) arrivalSchedule The domain is air traffic control and I need to generate 12-tuples for aircraft that are within a particular radius of the tower. When I evaluate that expression with 'take 4' it works fine. When I evaluate it with 'take 6' it works as well. But, when I evaluate it with 'take 5' I get the following runtime error from H# in Visual Studio (it runs fine on the command line). This is particularly odd because I'm not using Sql. The type initializer for 'System.Data.SqlClient.SqlConnection' threw an exception. Exception (TypeInitializationException): Source=System.Data; Target=null; Tag=null; TypeName=System.Data.SqlClient.SqlConnection; Message = The type initializer for 'System.Data.SqlClient.SqlConnection' threw an exception. InnerException (TypeInitializationException): Source=System.Data; Target=null; Tag=null; Message = The type initializer for 'System.Data.SqlClient.SqlConnectionFactory' threw an exception. StackTrace = at System.Data.SqlClient.SqlConnection..cctor() InnerException (TypeInitializationException): Source=System.Data; Target=null; Tag=null; Message = The type initializer for 'System.Data.SqlClient.SqlPerformanceCounters' threw an exception. StackTrace = at System.Data.SqlClient.SqlConnectionFactory..ctor() at System.Data.SqlClient.SqlConnectionFactory..cctor() InnerException (ConfigurationErrorsException): Source=System.Configuration; Target=null; Tag=null; Line=21; Message = The value of the property 'traceOutputOptions' cannot be parsed. The error is: The enumeration value must be one of the following: None, LogicalOperationStack, DateTime, Timestamp, ProcessId, ThreadId, Callstack. (C:\Documents and Settings\Paey\Desktop\Projects\RPMC\bin\Debug\RPMC.vshost.exe.config line 21) StackTrace = at System.Configuration.BaseConfigurationRecord.EvaluateOne(String[] keys, SectionInput input, Boolean isTrusted, FactoryRecord factoryRecord, SectionRecord sectionRecord, Object parentResult) at System.Configuration.BaseConfigurationRecord.Evaluate(FactoryRecord factoryRecord, SectionRecord sectionRecord, Object parentResult, Boolean getLkg, Boolean getRuntimeObject, Object result, Object resultRuntimeObject) at System.Configuration.BaseConfigurationRecord.GetSectionRecursive(String configKey, Boolean getLkg, Boolean checkPermission, Boolean getRuntimeObject, Boolean requestIsHere, Object result, Object resultRuntimeObject) at System.Configuration.BaseConfigurationRecord.GetSectionRecursive(String configKey, Boolean getLkg, Boolean checkPermission, Boolean getRuntimeObject, Boolean requestIsHere, Object result, Object resultRuntimeObject) at System.Configuration.BaseConfigurationRecord.GetSectionRecursive(String configKey, Boolean getLkg, Boolean ch... (truncated) ...olean checkPermission) at System.Configuration.BaseConfigurationRecord.GetSection(String configKey) at System.Configuration.ClientConfigurationSystem.System.Configuration.Internal.IInternalConfigSystem.GetSection(String sectionName) at System.Configuration.ConfigurationManager.GetSection(String sectionName) at System.Configuration.PrivilegedConfigurationManager.GetSection(String sectionName) at System.Diagnostics.DiagnosticsConfiguration.GetConfigSection() at System.Diagnostics.DiagnosticsConfiguration.Initialize() at System.Diagnostics.Switch.InitializeConfigSettings() at System.Diagnostics.Switch.InitializeWithStatus() at System.Diagnostics.Switch.get_SwitchSetting() at System.Diagnostics.TraceSwitch.get_Level() at
Re: [Haskell-cafe] Having trouble with zip12..
Andrew Wagner wrote: Wow. Where did you come up with the stack trace? That's...impressive. Pulled it from a blog. I was actually looking for a creepy VB4 or VB5 stack trace I saw years ago that ripped through their dynamic type resolution layer. Now that would've been funny. :-) Michael On Sun, Jul 6, 2008 at 5:07 PM, Don Stewart [EMAIL PROTECTED] wrote: I win, almost ... 13:13:18 dons dolio: yeah, it was ... almost ... an April 1 style post :) And yes, this was truly shocking on a number of levels. However, we have people doing a lot of weird things with Haskell these days, so its not as absurd that someone would be hacking up a zip12 for an air traffic control system on some MS platform, with SQL in the backend, as it might have been a few years ago :) mfeathers: Sorry guys. I was just bored on a Sunday afternoon so I thought I'd type up a little joke. I thought to myself Gee, how outrageous can I make it? 1) Using and debugging a zip12 function. 2) That fails only on 'take 5' (Brubeck fans take note) 3) Has some absurd arguments like (nub . nub) 4) Is embedded in an air traffic control system 5) Is written in a Microsoft variant of Haskell called H# 6) Silently makes SQL calls when evaluating a pure function 7) Yields an mile long stack trace Sorry all. Boredom made me do it, Michael Paul Visschers wrote: You're zipping 12 lists here, so how about testing each list individually? This will narrow down the problem considerably. Michael Feathers wrote: I have some code that looks like this and I'm having trouble with it: zip12 ((tails . nub) flightPaths) wayPoints etopsPackets (hd geoCaches) groundSpeeds headings (map windShift headings) (regulations !! 2) (foldr (\|/) (tail pathDistances)) [ghy x | x - [1..], full x] (nub . nub) arrivalSchedule The domain is air traffic control and I need to generate 12-tuples for aircraft that are within a particular radius of the tower. When I evaluate that expression with 'take 4' it works fine. When I evaluate it with 'take 6' it works as well. But, when I evaluate it with 'take 5' I get the following runtime error from H# in Visual Studio (it runs fine on the command line). This is particularly odd because I'm not using Sql. The type initializer for 'System.Data.SqlClient.SqlConnection' threw an exception. Exception (TypeInitializationException): Source=System.Data; Target=null; Tag=null; TypeName=System.Data.SqlClient.SqlConnection; Message = The type initializer for 'System.Data.SqlClient.SqlConnection' threw an exception. InnerException (TypeInitializationException): Source=System.Data; Target=null; Tag=null; Message = The type initializer for 'System.Data.SqlClient.SqlConnectionFactory' threw an exception. StackTrace = at System.Data.SqlClient.SqlConnection..cctor() InnerException (TypeInitializationException): Source=System.Data; Target=null; Tag=null; Message = The type initializer for 'System.Data.SqlClient.SqlPerformanceCounters' threw an exception. StackTrace = at System.Data.SqlClient.SqlConnectionFactory..ctor() at System.Data.SqlClient.SqlConnectionFactory..cctor() InnerException (ConfigurationErrorsException): Source=System.Configuration; Target=null; Tag=null; Line=21; Message = The value of the property 'traceOutputOptions' cannot be parsed. The error is: The enumeration value must be one of the following: None, LogicalOperationStack, DateTime, Timestamp, ProcessId, ThreadId, Callstack. (C:\Documents and Settings\Paey\Desktop\Projects\RPMC\bin\Debug\RPMC.vshost.exe.config line 21) StackTrace = at System.Configuration.BaseConfigurationRecord.EvaluateOne(String[] keys, SectionInput input, Boolean isTrusted, FactoryRecord factoryRecord, SectionRecord sectionRecord, Object parentResult) at System.Configuration.BaseConfigurationRecord.Evaluate(FactoryRecord factoryRecord, SectionRecord sectionRecord, Object parentResult, Boolean getLkg, Boolean getRuntimeObject, Object result, Object resultRuntimeObject) at System.Configuration.BaseConfigurationRecord.GetSectionRecursive(String configKey, Boolean getLkg, Boolean checkPermission, Boolean getRuntimeObject, Boolean requestIsHere, Object result, Object resultRuntimeObject) at System.Configuration.BaseConfigurationRecord.GetSectionRecursive(String configKey, Boolean getLkg, Boolean checkPermission, Boolean getRuntimeObject, Boolean requestIsHere, Object result, Object resultRuntimeObject) at System.Configuration.BaseConfigurationRecord.GetSectionRecursive(String configKey, Boolean getLkg, Boolean ch... (truncated) ...olean checkPermission) at System.Configuration.BaseConfigurationRecord.GetSection(String configKey) at System.Configuration.ClientConfigurationSystem.System.Configuration.Internal.IInternalConfigSystem.GetSection(String sectionName) at System.Configuration.ConfigurationManager.GetSection(String sectionName) at System.Configuration.PrivilegedConfigurationManager.GetSection(String sectionName) at
Re: [Haskell-cafe] Having trouble with zip12..
On 2008 Jul 6, at 16:47, Tony Morris wrote: -BEGIN PGP SIGNED MESSAGE- Hash: SHA1 Michael Feathers wrote: zip12 ((tails . nub) flightPaths) wayPoints etopsPackets (hd geoCaches) groundSpeeds headings (map windShift headings) (regulations !! 2) (foldr (\|/) (tail pathDistances)) [ghy x | x - [1..], full x] (nub . nub) arrivalSchedule Hi Michael, Sorry to distract from your issue, but I note that (nub . nub) can be replaced with just 'nub' since the function nub is idempotent (f . f == f). Or even better, with a custom nub: in order to handle some special cases the Prelude nub is rather inefficient. -- brandon s. allbery [solaris,freebsd,perl,pugs,haskell] [EMAIL PROTECTED] system administrator [openafs,heimdal,too many hats] [EMAIL PROTECTED] electrical and computer engineering, carnegie mellon universityKF8NH ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] Is there a nicer way to do this?
segment :: Int - [a] - [[a]] segment 0 _ = [] segment _ [] = [] segment n x = (take n x) : segment n (drop n x) I did a version of this which used splitAt but I wasn't sure whether it was going to buy me anything re performance that would justify its ugliness. Michael ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Is there a nicer way to do this?
mfeathers: segment :: Int - [a] - [[a]] segment 0 _ = [] segment _ [] = [] segment n x = (take n x) : segment n (drop n x) The first set of parens can go, segment n x = take n x : segment n (drop n x) I did a version of this which used splitAt but I wasn't sure whether it was going to buy me anything re performance that would justify its ugliness. Besides, splitAt n xs = (take n xs, drop n xs) -- Don ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Is there a nicer way to do this?
On Sun, Jul 6, 2008 at 16:45, Michael Feathers [EMAIL PROTECTED] wrote: segment :: Int - [a] - [[a]] segment 0 _ = [] segment _ [] = [] segment n x = (take n x) : segment n (drop n x) I did a version of this which used splitAt but I wasn't sure whether it was going to buy me anything re performance that would justify its ugliness. You can use segment n = takeWhile (not . null) . unfoldr (Just . splitAt n) I don't know how it compares in performance. It's from http://www.haskell.org/haskellwiki/Blow_your_mind - John ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] extensible data types in Haskell?
Hi all, SML conveniently contains the type exn which is an instance of an extensible data type. In other words, unlike normal data types that are closed (can't admit new constructors once defined), SML's exn type is open, allowing programmers to keep adding new alternatives as often as they choose. Like normal datatypes, the elimination form for an extensible data type is a case statement (or match function). Friends have told me that Haskell doesn't have extensible data types. However, it seems fairly straightforward to code them up using type classesthough the solution I'm thinking of has a little bit of boilerplate I'd like to scrap (you have to define a new type declaration *and* an instance of a type class with a match method) and matching occurs through a string comparison (which can lead to silly programmer errors if there is accidentally a typo in the string). Anyway, it's possible with some thought I could come up with a better solution, but before worrying about it, I figured I'd ask if anybody else already has a package that does this. It seems like a pretty natural feature to want to have. Thanks in advance, Dave ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Is there a nicer way to do this?
On Sun, Jul 6, 2008 at 5:25 PM, John Hamilton [EMAIL PROTECTED] wrote: On Sun, Jul 6, 2008 at 16:45, Michael Feathers [EMAIL PROTECTED] wrote: segment :: Int - [a] - [[a]] segment 0 _ = [] segment _ [] = [] segment n x = (take n x) : segment n (drop n x) I did a version of this which used splitAt but I wasn't sure whether it was going to buy me anything re performance that would justify its ugliness. You can use segment n = takeWhile (not . null) . unfoldr (Just . splitAt n) I don't know how it compares in performance. It's from http://www.haskell.org/haskellwiki/Blow_your_mind Watch out for negative numbers, though. ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Is there a nicer way to do this?
mfeathers: Don Stewart wrote: mfeathers: segment :: Int - [a] - [[a]] segment 0 _ = [] segment _ [] = [] segment n x = (take n x) : segment n (drop n x) The first set of parens can go, segment n x = take n x : segment n (drop n x) I did a version of this which used splitAt but I wasn't sure whether it was going to buy me anything re performance that would justify its ugliness. Besides, splitAt n xs = (take n xs, drop n xs) Thanks. That is odd, though. It makes me wonder what to expect re optimization. Would the compiler/runtime know that splitAt could be done in a single pass? Not with that definition. It would require some moderately unusual fusion combining the take and drop into a single fold with the (,) on the inside, rather than on the outside. However, GHC actually implements splitAt as: splitAt (I n) ls | n 0 = ([], ls) | otherwise = splitAt' n ls where splitAt' :: Int - [a] - ([a], [a]) splitAt' 0 xs = ([], xs) splitAt' _ [EMAIL PROTECTED] = (xs, xs) splitAt' m (x:xs) = (x:xs', xs'') where (xs', xs'') = splitAt' (m - 1) xs So there may be some benefit. -- Don ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] Is there anything manifestly stupid about this code?
Decided a while ago to write some code to calculate the Mandelbrot set using the escape iterations algorithm. Discovered after mulling it about that I could just built it as an infinite list of infinite lists and then extract any rectangle of values that I wanted: type Point = (Double, Double) sq :: Double - Double sq x = x ^ 2 translate :: Point - Point - Point translate (r0, i0) (r1, i1) = (r0 + r1, i0 + i1) mandel :: Point - Point mandel (r, i) = (sq r + sq i, 2 * r * i) notEscaped :: Point - Bool notEscaped (r, i) = (sq r + sq i) = 4.0 trajectory :: (Point - Point) - [Point] trajectory pointFunction = takeWhile notEscaped $ iterate pointFunction seed where seed = (0.0, 0.0) escapeIterations :: (Point - Point) - Int escapeIterations = length . tail . take 1024 . trajectory mandelbrot :: Double - [[Int]] mandelbrot incrementSize = [[ escapeIterations $ translate (x, y) . mandel | x - increments] | y - increments] where increments = [0.0, incrementSize .. ] window :: (Int, Int) - (Int, Int) - [[a]] - [[a]] window (x0, y0) (x1, y1) = range x0 x1 . map (range y0 y1) where range m n = take (n - m) . drop m ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Is there anything manifestly stupid about this code?
To answer the question in your subject, yes! We have a complex type. Not only does that make the code simpler and more obvious and idiomatic, but it's also more efficient because for this use you'd really prefer a strict pair type for Point, and complex is strict in it's components. On Sun, 2008-07-06 at 21:02 -0400, Michael Feathers wrote: Decided a while ago to write some code to calculate the Mandelbrot set using the escape iterations algorithm. Discovered after mulling it about that I could just built it as an infinite list of infinite lists and then extract any rectangle of values that I wanted: type Point = (Double, Double) sq :: Double - Double sq x = x ^ 2 translate :: Point - Point - Point translate (r0, i0) (r1, i1) = (r0 + r1, i0 + i1) mandel :: Point - Point mandel (r, i) = (sq r + sq i, 2 * r * i) notEscaped :: Point - Bool notEscaped (r, i) = (sq r + sq i) = 4.0 trajectory :: (Point - Point) - [Point] trajectory pointFunction = takeWhile notEscaped $ iterate pointFunction seed where seed = (0.0, 0.0) escapeIterations :: (Point - Point) - Int escapeIterations = length . tail . take 1024 . trajectory mandelbrot :: Double - [[Int]] mandelbrot incrementSize = [[ escapeIterations $ translate (x, y) . mandel | x - increments] | y - increments] where increments = [0.0, incrementSize .. ] window :: (Int, Int) - (Int, Int) - [[a]] - [[a]] window (x0, y0) (x1, y1) = range x0 x1 . map (range y0 y1) where range m n = take (n - m) . drop m ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] extensible data types in Haskell?
princedpw: Hi all, SML conveniently contains the type exn which is an instance of an extensible data type. In other words, unlike normal data types that are closed (can't admit new constructors once defined), SML's exn type is open, allowing programmers to keep adding new alternatives as often as they choose. Like normal datatypes, the elimination form for an extensible data type is a case statement (or match function). Friends have told me that Haskell doesn't have extensible data types. However, it seems fairly straightforward to code them up using type classesthough the solution I'm thinking of has a little bit of boilerplate I'd like to scrap (you have to define a new type declaration *and* an instance of a type class with a match method) and matching occurs through a string comparison (which can lead to silly programmer errors if there is accidentally a typo in the string). You should probably use Typeable here, for the type matching, rather than a custom matcher. class Typeable a = Extensible a, this leads to a fairly straighforward extensible data type, where the open instance definition lets you add variants on the fly. Anyway, it's possible with some thought I could come up with a better solution, but before worrying about it, I figured I'd ask if anybody else already has a package that does this. It seems like a pretty natural feature to want to have. There's a number of ways to do this, including fully statically via type classes and existential types, or via the Dynamic type. Googling for expression problem Haskell will turn up some things. Some implementions of open data types in use can be found in xmonad, and the extensible exceptions proposal here, http://209.85.173.104/search?q=cache:xeXhle5KAqkJ:www.haskell.org/~simonmar/papers/ext-exceptions.pdf -- Don ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] Associative Commutative Unification
I'd like to write an obviously correct implementation of a unifier, a program that when given two terms, finds a substitution that makes the two terms equal. The phrase obviously correct is meant to imply that the clarity of the code trumps efficiency. As near as I can tell, high performance unifiers are full of side-effects, and achieving the same performance without side-effects in Haskell is difficult or impossible. In contrast, it is easy to write obviously correct Hasklell implementations of unifiers for freely generated term algebras. One can use Lawrence Paulson's code in ML for the Working Programmer as a template or follow Martelli and Montanari's simple set of rules. My problem is one of my operators is multiplication, which is associative and commutative. These two properties make unification much more difficult. Mark Stickel described a complete unification algorithm for this problem, but the task of translating his description into an obviously correct Haskell program appears to be difficult. For example, the algorithm requires the generation of the basis of solutions to linear homogeneous diophantine equations. I haven't located an algorithm for this part yet. If you have experience implemented equational unification in Haskell, please share it. John ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Associative Commutative Unification
ramsdell0: I'd like to write an obviously correct implementation of a unifier, a program that when given two terms, finds a substitution that makes the two terms equal. The phrase obviously correct is meant to imply that the clarity of the code trumps efficiency. As near as I can tell, high performance unifiers are full of side-effects, and achieving the same performance without side-effects in Haskell is difficult or impossible. In contrast, it is easy to write obviously correct Hasklell implementations of unifiers for freely generated term algebras. One can use Lawrence Paulson's code in ML for the Working Programmer as a template or follow Martelli and Montanari's simple set of rules. My problem is one of my operators is multiplication, which is associative and commutative. These two properties make unification much more difficult. Mark Stickel described a complete unification algorithm for this problem, but the task of translating his description into an obviously correct Haskell program appears to be difficult. For example, the algorithm requires the generation of the basis of solutions to linear homogeneous diophantine equations. I haven't located an algorithm for this part yet. If you have experience implemented equational unification in Haskell, please share it. Typing Haskell in Haskell lives here, http://hackage.haskell.org/cgi-bin/hackage-scripts/package/thih a Haskell program that implements a Haskell typechecker, thus providing a mathematically rigorous specification in a notation that is familiar to Haskell users. We expect this program to fill a serious gap in current descriptions of Haskell, both as a starting point for discussions about existing features of the type system, and as a platform from which to explore new proposals Might be useful as a starting point. -- Don ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] The state of database libraries
On Jul 4, 2008, at 7:54 AM, Chris Eidhof wrote: 1. hdbc. I'd like to connect to MySQL, so I need the ODBC backend. I couldn't get this to work under OS X, while I installed myodbc, which seems to be broken. FWIW, I've had good luck with the SQLite3 bindings for HDBC on MacOS X. I had a bit of a hiccup with Linux, but that was only because the version of SQLite on the Linux box was a bit too old. (3.2.x versus 3.4.x on the MacOS box.) With 3.5.9 on the Linux box, everything worked swimmingly. I haven't tried the MySQL support, but I don't need it. The timestamps on the other packages were old enough (~2007 IIRC) that I didn't even try 'em. Depending on what your application is, you might get more mileage out of a binding to CouchDB or some other post-relational storage system. -- Paul ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] OpenSSL.Digest linking error: EVP_mdc2
I'm using hopenssl 1.0 from hackage. What am I doing wrong here? $ cat test-hopenssl.hs import OpenSSL.Digest main=undefined $ ghc --make test-hopenssl.hs -lcrypto [1 of 1] Compiling Main ( test-hopenssl.hs, test-hopenssl.o ) Linking test-hopenssl ... /tmp/ken/lib/hopenssl-1.0/ghc-6.8.2/libHShopenssl-1.0.a(Digest.o): In function `s2O8_info': (.text+0xf3a): undefined reference to `EVP_mdc2' /tmp/ken/lib/hopenssl-1.0/ghc-6.8.2/libHShopenssl-1.0.a(Digest.o): In function `s2TQ_info': (.text+0x1435): undefined reference to `EVP_mdc2' collect2: ld returned 1 exit status $ dpkg-query -S /usr/lib/libcrypto.a libssl-dev: /usr/lib/libcrypto.a $ dpkg-query -l libssl-dev Desired=Unknown/Install/Remove/Purge/Hold | Status=Not/Inst/Cfg-files/Unpacked/Failed-cfg/Half-inst/trig-aWait/Trig-pend |/ Err?=(none)/Hold/Reinst-required/X=both-problems (Status,Err: uppercase=bad) ||/ Name VersionDescription +++-==-==- ii libssl-dev 0.9.8g-10.1SSL development libraries, header files and documentation $ ghc --version The Glorious Glasgow Haskell Compilation System, version 6.8.2 $ uname -a Linux localhost 2.6.24-1-686 #1 SMP Thu May 8 02:16:39 UTC 2008 i686 GNU/Linux ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] The state of database libraries
prb: On Jul 4, 2008, at 7:54 AM, Chris Eidhof wrote: 1. hdbc. I'd like to connect to MySQL, so I need the ODBC backend. I couldn't get this to work under OS X, while I installed myodbc, which seems to be broken. FWIW, I've had good luck with the SQLite3 bindings for HDBC on MacOS X. I had a bit of a hiccup with Linux, but that was only because the version of SQLite on the Linux box was a bit too old. (3.2.x versus 3.4.x on the MacOS box.) With 3.5.9 on the Linux box, everything worked swimmingly. I haven't tried the MySQL support, but I don't need it. The timestamps on the other packages were old enough (~2007 IIRC) that I didn't even try 'em. Depending on what your application is, you might get more mileage out of a binding to CouchDB or some other post-relational storage system. The YHC guys have a simple CouchDB binding too. I was thinking this might be a nice project to actually polish up into a comprehensive system. -- Don ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] not for me, guv!
So I wrote a big email about this mysterious message I was getting, but then after some research and poking and debugging tracked it down to a dangling pointer in C that was causing a callback to point to an invalid address, which somehow worked anyway 99% of the time. That all said, I'm not totally convinced that freeHaskellFunctionPtr: not for me, guv! 0x23143f0 is the clearest error message ever. Now, if it were in a more contemporary American idiom such as wtf this ptr ain't from MY house lol!!! I probably would have found the bug in half the time. Anyway, I fixed my bug and I'm happy about that, but I didn't want to waste a chance to send an email with this title... ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] OpenSSL.Digest linking error: EVP_mdc2
Quoth Ken Takusagawa [EMAIL PROTECTED]: | $ ghc --make test-hopenssl.hs -lcrypto | [1 of 1] Compiling Main ( test-hopenssl.hs, test-hopenssl.o ) | Linking test-hopenssl ... | /tmp/ken/lib/hopenssl-1.0/ghc-6.8.2/libHShopenssl-1.0.a(Digest.o): In | function `s2O8_info': | (.text+0xf3a): undefined reference to `EVP_mdc2' | /tmp/ken/lib/hopenssl-1.0/ghc-6.8.2/libHShopenssl-1.0.a(Digest.o): In | function `s2TQ_info': | (.text+0x1435): undefined reference to `EVP_mdc2' | collect2: ld returned 1 exit status I see the following in the Configure file for openssl-0.9.8h: my $default_depflags = -DOPENSSL_NO_CAMELLIA -DOPENSSL_NO_CMS -DOPENSSL_NO_GMP -DOPENSSL_NO_MDC2 -DOPENSSL_NO_RC5 -DOPENSSL_NO_RFC3779 -DOPENSSL_NO_SEED -DOPENSSL_NO_TLSEXT ;my $default_depflags = -DOPENSSL_NO_CAMELLIA -DOPENSSL_NO_CMS -DOPENSSL_NO_GMP I don't know why this would be, but I infer that the function hopenssl was looking for is commonly missing in SSL builds. Donn Cave, [EMAIL PROTECTED] ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
