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digitalmars.D - error messages that could be better

reply "Adam D. Ruppe" <destructionator gmail.com> writes:
Yesterday, I was working on a socket code and wrote this:

this(string host, uint port) {
     socket.connect(new InternetAddress(host, port));
}

and got this:

server.d(109): Error: constructor std.socket.InternetAddress.this 
() is not callable using argument types (string, uint)
server.d(109): Error: no constructor for InternetAddress


It took me several minutes to realize my real mistake: I wrote 
"uint" when I meant "ushort". The error message was less than 
helpful because I was quite certain this was how it worked, but 
it was complaining about this() rather than this(string, ushort), 
so maybe I forgot how to construct this thing.



The error messages can catch simple spelling errors with a 
distance of one edit from the correct name, but here it couldn't 
catch a type mismatch with a similar distance of one from the 
real thing.

If it did that, I would have spent 5 seconds on this rather than 
5 minutes.
Jun 16 2013
next sibling parent Andrej Mitrovic <andrej.mitrovich gmail.com> writes:
On 6/16/13, Adam D. Ruppe <destructionator gmail.com> wrote:

 Yesterday, I was working on a socket code and wrote this:

 this(string host, uint port) {
      socket.connect(new InternetAddress(host, port));
 }

 and got this:

 server.d(109): Error: constructor std.socket.InternetAddress.this
 () is not callable using argument types (string, uint)
 server.d(109): Error: no constructor for InternetAddress


This is entirely Walter's fault. He removed extra messages from the
error message (despite my objections), leading to confusing errors
like this one.

Otherwise you would have gotten:

test.d(10): Error: constructor std.socket.InternetAddress.this () is
not callable using argument types (string,uint)
test.d(10): Error: expected 1 arguments, not 2 for non-variadic
function type InternetAddress(ushort port)

And this would make it at least informative enough that you can see
the wrong constructor is being called.

Here's another error that went bad:

-----
import core.sys.windows.windows;

pragma(lib, "Advapi32.lib");

void main()
{
    HKEY hKey;
    DWORD dwIndex;
    LPSTR lpValueName;
    LPDWORD lpcbValueName;
    LPDWORD lpReserved;
    LPDWORD lpType;
    LPBYTE lpData;
    LPDWORD lpcbData;
    wchar* valueName = "foo\0"w.dup.ptr;

    RegEnumValueA(hKey, dwIndex, valueName, lpcbValueName, lpReserved,
lpType, lpData, lpcbData);
}
-----

2.063:

test.d(19): Error: function core.sys.windows.windows.RegEnumValueA
(const(void*) hKey, uint dwIndex, char* lpValueName, uint*
lpcbValueName, uint* lpReserved, uint* lpType, ubyte* lpData, uint*
lpcbData) is not callable using argument types
(void*,uint,wchar*,uint*,uint*,uint*,ubyte*,uint*)

Can you spot what's wrong? Try using an earlier compiler:

2.062:

test.d(19): Error: function core.sys.windows.windows.RegEnumValueA
(const(void*) hKey, uint dwIndex, char* lpValueName, uint*
lpcbValueName, uint* lpReserved, uint* lpType, ubyte* lpData, uint*
lpcbData) is not callable using argument types
(void*,uint,wchar*,uint*,uint*,uint*,ubyte*,uint*)
test.d(19): Error: cannot implicitly convert expression (valueName) of
type wchar* to char*

How Walter can argue that the second error isn't useful is beyond
comprehension. He clearly doesn't use D as much as we do to understand
the need for this message.
Jun 16 2013
prev sibling next sibling parent Andrei Alexandrescu <SeeWebsiteForEmail erdani.org> writes:
On 6/16/13 9:04 AM, Adam D. Ruppe wrote:

 Yesterday, I was working on a socket code and wrote this:

 this(string host, uint port) {
 socket.connect(new InternetAddress(host, port));
 }

 and got this:

 server.d(109): Error: constructor std.socket.InternetAddress.this () is
 not callable using argument types (string, uint)
 server.d(109): Error: no constructor for InternetAddress


 It took me several minutes to realize my real mistake: I wrote "uint"
 when I meant "ushort". The error message was less than helpful because I
 was quite certain this was how it worked, but it was complaining about
 this() rather than this(string, ushort), so maybe I forgot how to
 construct this thing.



 The error messages can catch simple spelling errors with a distance of
 one edit from the correct name, but here it couldn't catch a type
 mismatch with a similar distance of one from the real thing.

 If it did that, I would have spent 5 seconds on this rather than 5 minutes.


At a minimum the full signature should be in the error message.

server.d(109): Error: constructor 
std.socket.InternetAddress.this(string, ushort) is not callable using 
argument types (string, uint)


Andrei
Jun 16 2013
prev sibling parent reply "Adam D. Ruppe" <destructionator gmail.com> writes:
Here's another bad one:

admin.d(53): Error: not a property ta.innerHTML


I assigned an int to it instead of a string, but the error 
message doesn't say that, it makes me think I have the entirely 
wrong name, or ta isn't the type I think it is.


The error messages in general seem to have been moving backward 
the last few releases.
Jun 19 2013
parent reply Andrej Mitrovic <andrej.mitrovich gmail.com> writes:
On 6/20/13, Adam D. Ruppe <destructionator gmail.com> wrote:

 Here's another bad one:

 admin.d(53): Error: not a property ta.innerHTML


File it, please. Once it's fixed it'll go into diagnostic tests and
should not become bad again in new releases.
Jun 19 2013
parent "Adam D. Ruppe" <destructionator gmail.com> writes:
On Wednesday, 19 June 2013 at 23:03:50 UTC, Andrej Mitrovic wrote:

 File it, please.


http://d.puremagic.com/issues/show_bug.cgi?id=10418

The same principle applies to this and the constructor one I 
complained about before, and I think it can to overloaded 
functions in general.
Jun 19 2013