我在stack.yaml中包含github的包.当我运行堆栈解算器时,我收到消息:No extra-dep setting found for package at URL:
对于这种情况,我在堆栈文档中找不到文档.警告表示什么？采取什么纠正措施？
flags: {}
extra-package-dbs: []
packages:
- '.'
- location: /home/frank/Workspace8/repo8/uniform/uniform-algebras
extra-dep: true
- location: /home/frank/Workspace8/repo8/uniform/uniform-time
extra-dep: true
- location:
git: https://github.com/andrewufrank/uniform-strings.git
commit: ba8bd37567758c1807bf470b3dda4f471cee0f5f
extra-dep: true
- location:
git: https://github.com/andrewufrank/uniform-error.git
commit: 46c62fcf8b4d6b7a5a9a3622c724ab573fce295d
extra-dep: true
extra-deps:
- data-easy-0.7.0
- pipes-4.3.2
resolver: lts-8.13
我想得出的anyclass策略class Zeros.为此我需要一个默认实现和泛型的相应实例:
import GHC.Generics
class Zeros z where
zero :: z
default zero :: (Generic z, Gzero (Rep z)) => z
zero = gzero (from z)
class Gzero f where
gzero :: f a -> a
instance Gzero (Rec0 Int) where
gzero (Rec0 i a) = a
data B1 = B1 Int
deriving stock (Show, Read, Eq, Ord, Generic)
deriving instance Zeros B1
instance Zeros Int where zero = 0
我收到错误消息(堆栈LTS 10.8 - GHC 8.2.2):
Not …我有一个JSON-LD文档,其中基本前缀没有像我期望的那样扩展,但首先缩短到它的根,然后@id附加数据:
{
"@context": {
"tag": "@type",
"@base": "http://example.com/base#auth-1/",
"Line": "lit:Line",
"load": "book:load",
"book": "http://gerastree.at/auth-1/",
"lnum": "lit:lnum",
"lline": {
"@language": "deu",
"@id": "lit:lines"
},
"lit": "http://gerastree.at/lit_2014#",
"lid": "@id"
},
"loadid": "loadIDstring",
"load": [
{
"tag": "Line",
"lnum": 1,
"lline": "asdf1",
"lid": "1"
},
{
"tag": "Line",
"lnum": 2,
"lline": "asdf2",
"lid": "2"
}
]
}
然后RIOT(或操场)给出:
riot --syntax=jsonld --output=turtle lines.jsonld
@prefix lit: <http://gerastree.at/lit_2014#> .
@prefix book: <http://gerastree.at/auth-1/> .
_:b0 book:load <http://example.com/1> ;
book:load <http://example.com/2> .
<http://example.com/1>
<http://www.w3.org/1999/02/22-rdf-syntax-ns#type> lit:Line ; …我已经安装了fuseki并启动了服务器
#!/bin/sh
cd /home/frank/localInstall/jena/apache-jena-fuseki-2.5.0
exec /home/frank/localInstall/jena/apache-jena-fuseki-2.5.0/fuseki-server -v --update --mem /testDB
服务器正在运行,程序可以将数据存储在/ testDB中,但是Web界面不显示数据集,我无法添加数据集.当我尝试查询界面时说Please select a dataset.
我想我之前遇到过这个问题,并通过重新安装fuseki文件夹解决了这个问题.我想了解我做错了什么以及如何避免这个问题.谢谢!
配置文件是自动生成的文件.它是:
# Licensed under the terms of http://www.apache.org/licenses/LICENSE-2.0
## Fuseki Server configuration file.
@prefix : <#> .
@prefix fuseki: <http://jena.apache.org/fuseki#> .
@prefix rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#> .
@prefix rdfs: <http://www.w3.org/2000/01/rdf-schema#> .
@prefix ja: <http://jena.hpl.hp.com/2005/11/Assembler#> .
[] rdf:type fuseki:Server ;
# Example::
# Server-wide query timeout.
#
# Timeout - server-wide default: milliseconds.
# Format 1: "1000" -- 1 second timeout
# Format 2: "10000,60000" -- …我有数据结构(这里B和T),其中包括一个monad作为类型参数(这里m)(它是一个简化的形式Data.Binding.Simple),它在类(这里Variables3)中使用具有相同monad类型的函数.在使用数据的类的实例中,monad的类型参数(比如m)出现两次(这里Variable3 (T m) m a).这个编译,但是当我使用代码中的函数时,对于某些类型的参数(这里test3),我得到一个错误(could not deduce ... m ..m1),表明编译器将类型变量的两次出现视为不同.
我找到了一个解决方案:用不同的类型参数命名两个匹配项(比如说m和m1)并添加等价m ~ m1(使用TypeFamilies扩展名).编译并运行.
这里有一些非常简化的代码,它会产生错误 test3
class (Monad m) => Variable3 v m a where
newVar3 :: a -> m (v a)
readVar3 :: v a -> m a
writeVar3 :: v a -> a -> m ()
data B a m = B {f1 :: a …我编写了一些简单的代码来调用C库中的函数.代码编译(以及类似的部分适用于标准C库)但是当我编译和链接时,ghc找不到C库.我的cabal文件是:
executable ttclient
main-is: MainFFI4TT.hs
build-depends: base
default-language: Haskell2010
hs-source-dirs: src
other-modules:
Include-dirs: treetaggerSourceC
Includes: tagger-api.h
extra-libraries: libtreetagger
extra-lib-dirs: /usr/lib
该文件libtreetagger.so已存在/usr/lib但无法找到.还有什么需要什么？使用stack build或cabal install(8.0.2或8.0.1)是没有区别的.cabal是版本1.24.0.0,系统是linux debian stretch.
我宁愿将库保留在用户目录而不是系统目录中.这可以实现吗？
haskell代码是:
foreign import ccall "tagger-api.h init_treetagger"
c_initTreeTagger :: CString -> IO ()
-- void init_treetagger(char *param_file_name);
mainFFItest :: IO ()
mainFFItest = do
c_initTreeTagger "german-utf8.par"
当前包间接导入构造函数Path(..)，该构造函数在更靠近源的导入链的模块中可用于派生，Read但是当我稍后尝试在独立的派生子句中使用它时，我得到
• Can't make a derived instance of ‘Read (Path Abs Dir)’:
The data constructors of ‘Path’ are not all in scope
so you cannot derive an instance for it
• In the stand-alone deriving instance for ‘Read (Path Abs Dir)’
模块代码没有给出错误和导入Path(..)。导入中缺少什么？
{-# LANGUAGE FlexibleContexts #-}
{-# LANGUAGE FlexibleInstances #-}
{-# LANGUAGE MultiParamTypeClasses #-}
{-# LANGUAGE OverloadedStrings #-}
{-# LANGUAGE TypeSynonymInstances #-}
{-# LANGUAGE StandaloneDeriving #-}
module Uniform.Convenience.StartApp(
module Uniform.Convenience.StartApp
) where
import UniformBase …我有以下代码与管道没有第二个管道(>-> P.mapM ( fillMD5)).fillMD5是一项行动a -> IO a.
runSafeT $ runEffect $
every (senseRecursive5 startfpo)
>-> P.mapM ( fillMD5)
>-> P.map fp2rdf
>-> toNTriple houtfile
错误是:
Couldn't match type `IO' with `Pipes.Safe.SafeT IO'
Expected type: Pipes.Safe.SafeT IO ()
Actual type: IO ()
In the second argument of `($)', namely
`runEffect
我明白的类型mapM是
mapM :: Monad m => (a -> m b) -> Pipe a b m r
但我不明白如何将其提升到Safe.SafeT？