<div dir="ltr"><div>Hi,</div><div><br></div>You will need to create instances of type Gen for your data types to specify how you can build expressions of your language. I have a simple interpreter for gradually-typed lambda calculus (still in development) and I am using quickcheck to verify it, here is the quickcheck code:<div><a href="https://github.com/deyaaeldeen/GTLC/blob/master/interps/Testing.hs">https://github.com/deyaaeldeen/GTLC/blob/master/interps/Testing.hs</a><br><div class="gmail_extra"><br clear="all"><div><div class="gmail_signature"><div dir="rtl"><div style="text-align:left">Deyaa<br></div></div></div></div>
<br><div class="gmail_quote">On Mon, Feb 16, 2015 at 12:33 PM, Maurizio Vitale <span dir="ltr"><<a href="mailto:mrz.vtl@gmail.com" target="_blank">mrz.vtl@gmail.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-color:rgb(204,204,204);border-left-style:solid;padding-left:1ex"><div dir="ltr">By 'test size reduction' I mean the 'shrink' function. It seems to me (as I said, first Haskell program and no experience with quickcheck) that it works nicely with a topdown generation of the test, but I don't see how to easily generate correct programs that way.<div><br></div><div>Even if you cannot release your tests, maybe you can help me with a very simple case. Consider a trivial AST. A program is a possibly nested block. Each block is a bunch of declarations of variables and some use of them</div><div><br></div><blockquote style="margin:0px 0px 0px 40px;border:none;padding:0px"><div><div>data Block = Block [Declaration] [Statement]</div></div><div><div><br></div></div><div><div>data Declaration = Var String String</div></div><div><div><br></div></div><div><div>data Statement = Statement Block | Use String</div></div></blockquote><div><br></div><div>How one would generate things like:</div><div><br></div><blockquote style="margin:0px 0px 0px 40px;border:none;padding:0px"><div>Block [Var "a" "int"] [Use "a"] -- here a is declared in the same block</div><div><br></div><div>Block [] [Statement Block [Var "s" "int"] [Statement Block [] [Use "s"]]] -- here s is declared in some other visible scope</div></blockquote><div><br></div><div>etc.</div><div><br></div><div>Or am I trying to approach the problem from the wrong angle?</div><div><br></div><div> </div></div><div class=""><div class="h5"><div class="gmail_extra"><br><div class="gmail_quote">On Mon, Feb 16, 2015 at 12:02 PM, Andrey Chudnov <span dir="ltr"><<a href="mailto:achudnov@gmail.com" target="_blank">achudnov@gmail.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-color:rgb(204,204,204);border-left-style:solid;padding-left:1ex">
<div bgcolor="#FFFFFF" text="#000000">
I use QuichCheck for compiler testing where I generate random, but
well-formed programs and check some high-level syntactic properties
on results. The QuickCheck instance is open-source (see
language-ecmascript), but the compiler-test code is closed-source at
this time. Still, I found that it's not the ultimate answer: many
properties are hard to formalize, so I have to resort to unit tests.
I'm not sure what you mean by "how this would play with test size
reduction". I think it's worth giving a try, but keep in mind that
you might still need to use unit tests.<br>
<br>
Let me know if you have any questions.<br>
<br>
/Andrey<div><div><br>
<br>
<div>On 02/16/2015 11:53 AM, Maurizio Vitale
wrote:<br>
</div>
</div></div><blockquote type="cite"><div><div>
<div dir="ltr">I'm starting to work on my first real haskell
program (I've only RWH exercises under my belt) and wondering
whether people use quickcheck at all for compiler testing.
<div><br>
</div>
<div>I've seen uses of quickcheck for testing parsers, but I'm
interested in generating well-formed programs (e.g. random
programs with all declarations in reasonable random places).
This could be used to test passes other than parsing (or even
parsing, for languages that needs to distinguish identifiers,
like the 'typedef' problem in C/C++).</div>
<div><br>
</div>
<div>The only thing I can think of, is to use quickcheck for
randomly generating statements, go over them and figure out
free variables (incl. functions) and generate declarations in
random places for them. But I'm not sure how this would play
with test size reduction and doesn't look like a nice solution
anyhow.</div>
<div><br>
</div>
<div>Any idea or pointers to examples? or should I give up on
quickcheck for this and just do direct testing?</div>
<div><br>
</div>
<div>Thanks,</div>
<div><br>
</div>
<div> Maurizio</div>
</div>
<br>
<fieldset></fieldset>
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