summaryrefslogtreecommitdiff
blob: 26c45b3b64ae67febe0ce8b68a36c4b47ee5e777 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE pkgmetadata SYSTEM "https://www.gentoo.org/dtd/metadata.dtd">
<pkgmetadata>
	<maintainer type="project">
		<email>haskell@gentoo.org</email>
		<name>Gentoo Haskell</name>
	</maintainer>
	<longdescription>
		Common debugging/error/exception functions that give file location information
		
		&gt; $(err "OH NO!")
		&gt;
		&gt; main:Main main.hs:16:1 OH NO!
		
		Notice how it displays package:module file:line:character
		It exposes the functions err (error), undef (undefined), and trc (Debug.Trace.trace). All of these behave the same as their normal counterpart but also spit out a location.
		
		Here is my favorite helper, debug, which is like trace but just show the value.
		
		&gt; debug [1,2,3]
		&gt;
		&gt; DEBUG: [1,2,3]
		&gt; [1,2,3]
		
		And The Template Haskell version.
		
		&gt; $(dbg) [1,2,3]
		&gt;
		&gt; DEBUG main:Main main.hs:1:3 [1,2,3]
		&gt; [1,2,3]
		
		Also there is a version of thrwIO that gives location information
		&gt; ($(thrwIO) $ AException) `catch` \e -&gt; putStrLn ("Caught " ++ show (e :: AException))
		&gt;
		&gt; Caught AException "main:Main test/main.hs:25:6"
		
		See module for a listing of all the functions with short descriptions, and the homepage for some more examples https://github.com/gregwebs/ErrorLocation.hs
	</longdescription>
	<upstream>
		<remote-id type="github">gregwebs/FileLocation.hs</remote-id>
	</upstream>
</pkgmetadata>