473,383 Members | 1,984 Online
Bytes | Software Development & Data Engineering Community
Post Job

Home Posts Topics Members FAQ

Join Bytes to post your question to a community of 473,383 software developers and data experts.

creating a compile time error... is it possible?

Hi,
I'd like to create a compile time error in my class... maybe there's a way
already built in in the framework so I can achieve what I want... I have 2
constructors in my class. One of them has mandatory parameters, I mean, they
should not be null nor empty (for strings). So I'd make the validation in
the constructor and generate a compile-time error if the validation does not
match...

Is there a way to achieve this or to specify mandatory parameters? (I'm
using C#)

thanks

ThunderMusic

Aug 21 '06 #1
9 3473
ThunderMusic,

That's easy, just create a syntax error, forget a semi-colon somewhere.

I think what you really want is a run-time error. If you have a
compile-time error, then your code doesn't compile, and it certainly doesn't
run.

Basically, what you want to do is throw an exception. In the case of an
argument being null, you want to do something like this:

public class MyClass
{
public MyClass()
{
}

public MyClass(SomeOtherClass other)
{
// If other is null, throw an exception.
if (other == null)
{
// Throw an exception.
throw new ArgumentNullException();
}
}
}

Hope this helps.
--
- Nicholas Paldino [.NET/C# MVP]
- mv*@spam.guard.caspershouse.com

"ThunderMusic" <No*************************@NoSpAm.comwrote in message
news:uT**************@TK2MSFTNGP03.phx.gbl...
Hi,
I'd like to create a compile time error in my class... maybe there's a
way already built in in the framework so I can achieve what I want... I
have 2 constructors in my class. One of them has mandatory parameters, I
mean, they should not be null nor empty (for strings). So I'd make the
validation in the constructor and generate a compile-time error if the
validation does not match...

Is there a way to achieve this or to specify mandatory parameters? (I'm
using C#)

thanks

ThunderMusic

Aug 21 '06 #2
What I wanted to do is to have the user (developer) of my class have a
compile-time error when it supplies null as the value of a parameter when he
compiles.... like myMethod(param1, null, param3,...) so param2 should
generate a compile-time error because it's explicitly null... Is there a
way to make this validation or I must go with the NullReferenceException?
Sure, runtime exceptions will have to be implemented because param1 or
param3 could also be null without being explicit, but as a first time
validation, I would like to implement compile-time error if possible...

thanks

ThunderMusic
"Nicholas Paldino [.NET/C# MVP]" <mv*@spam.guard.caspershouse.comwrote in
message news:e%****************@TK2MSFTNGP05.phx.gbl...
ThunderMusic,

That's easy, just create a syntax error, forget a semi-colon somewhere.

I think what you really want is a run-time error. If you have a
compile-time error, then your code doesn't compile, and it certainly
doesn't run.

Basically, what you want to do is throw an exception. In the case of
an argument being null, you want to do something like this:

public class MyClass
{
public MyClass()
{
}

public MyClass(SomeOtherClass other)
{
// If other is null, throw an exception.
if (other == null)
{
// Throw an exception.
throw new ArgumentNullException();
}
}
}

Hope this helps.
--
- Nicholas Paldino [.NET/C# MVP]
- mv*@spam.guard.caspershouse.com

"ThunderMusic" <No*************************@NoSpAm.comwrote in message
news:uT**************@TK2MSFTNGP03.phx.gbl...
>Hi,
I'd like to create a compile time error in my class... maybe there's a
way already built in in the framework so I can achieve what I want... I
have 2 constructors in my class. One of them has mandatory parameters, I
mean, they should not be null nor empty (for strings). So I'd make the
validation in the constructor and generate a compile-time error if the
validation does not match...

Is there a way to achieve this or to specify mandatory parameters? (I'm
using C#)

thanks

ThunderMusic


Aug 21 '06 #3
Hi,

"ThunderMusic" <No*************************@NoSpAm.comwrote in message
news:uE**************@TK2MSFTNGP05.phx.gbl...
What I wanted to do is to have the user (developer) of my class have a
compile-time error when it supplies null as the value of a parameter when
he compiles


There is no way to do this. The only moment where you can evaluate your
parameters is at runtime, you cannot know the possible values at
compile-time
--
--
Ignacio Machin,
ignacio.machin AT dot.state.fl.us
Florida Department Of Transportation
Aug 21 '06 #4
ok, thanks... ;) after your first post, I realized that, but I thought "hey,
what if it's possible in a way I don't know..." ;) I'll use the
exceptions...
"Ignacio Machin ( .NET/ C# MVP )" <ignacio.machin AT dot.state.fl.uswrote
in message news:e9****************@TK2MSFTNGP06.phx.gbl...
Hi,

"ThunderMusic" <No*************************@NoSpAm.comwrote in message
news:uE**************@TK2MSFTNGP05.phx.gbl...
>What I wanted to do is to have the user (developer) of my class have a
compile-time error when it supplies null as the value of a parameter when
he compiles

There is no way to do this. The only moment where you can evaluate your
parameters is at runtime, you cannot know the possible values at
compile-time
--
--
Ignacio Machin,
ignacio.machin AT dot.state.fl.us
Florida Department Of Transportation

Aug 21 '06 #5
ThunderMusic,

What you are looking for is a static analysis tool, which will analyze
the possible code paths. Needless to say such tools are difficult to get
right (since they can't possibly get ALL possible code paths for larger,
more complex applications).
--
- Nicholas Paldino [.NET/C# MVP]
- mv*@spam.guard.caspershouse.com

"ThunderMusic" <No*************************@NoSpAm.comwrote in message
news:uw**************@TK2MSFTNGP04.phx.gbl...
ok, thanks... ;) after your first post, I realized that, but I thought
"hey, what if it's possible in a way I don't know..." ;) I'll use the
exceptions...
"Ignacio Machin ( .NET/ C# MVP )" <ignacio.machin AT dot.state.fl.us>
wrote in message news:e9****************@TK2MSFTNGP06.phx.gbl...
>Hi,

"ThunderMusic" <No*************************@NoSpAm.comwrote in message
news:uE**************@TK2MSFTNGP05.phx.gbl...
>>What I wanted to do is to have the user (developer) of my class have a
compile-time error when it supplies null as the value of a parameter
when he compiles

There is no way to do this. The only moment where you can evaluate your
parameters is at runtime, you cannot know the possible values at
compile-time
--
--
Ignacio Machin,
ignacio.machin AT dot.state.fl.us
Florida Department Of Transportation


Aug 21 '06 #6
Spec# does a great job of handling this case :)

Cheers,

Greg
"Nicholas Paldino [.NET/C# MVP]" <mv*@spam.guard.caspershouse.comwrote in
message news:ey**************@TK2MSFTNGP02.phx.gbl...
ThunderMusic,

What you are looking for is a static analysis tool, which will analyze
the possible code paths. Needless to say such tools are difficult to get
right (since they can't possibly get ALL possible code paths for larger,
more complex applications).
--
- Nicholas Paldino [.NET/C# MVP]
- mv*@spam.guard.caspershouse.com

"ThunderMusic" <No*************************@NoSpAm.comwrote in message
news:uw**************@TK2MSFTNGP04.phx.gbl...
>ok, thanks... ;) after your first post, I realized that, but I thought
"hey, what if it's possible in a way I don't know..." ;) I'll use the
exceptions...
"Ignacio Machin ( .NET/ C# MVP )" <ignacio.machin AT dot.state.fl.us>
wrote in message news:e9****************@TK2MSFTNGP06.phx.gbl...
>>Hi,

"ThunderMusic" <No*************************@NoSpAm.comwrote in message
news:uE**************@TK2MSFTNGP05.phx.gbl...
What I wanted to do is to have the user (developer) of my class have a
compile-time error when it supplies null as the value of a parameter
when he compiles

There is no way to do this. The only moment where you can evaluate your
parameters is at runtime, you cannot know the possible values at
compile-time
--
--
Ignacio Machin,
ignacio.machin AT dot.state.fl.us
Florida Department Of Transportation



Aug 21 '06 #7
You should probably also look at #error directive, here is the msdn
link:
http://msdn2.microsoft.com/en-us/library/x5hedts0.aspx

Take care
Naveed

Aug 21 '06 #8
The ref keyword might be able to help you here.

"An argument passed to a ref parameter must first be initialized"

Aug 22 '06 #9
Well, if it is null, then it *is* initialized; and the OP was talking about
*explicitely* passing null, in which case the relevant error would be "A ref
or out argument must be an assignable variable", but I personally wouldn't
advocate making this change; it would preclude, for instance, passing
(inline) consts, readonly fields, properties, method results, etc; all sorts
of things.

Marc
Aug 22 '06 #10

This thread has been closed and replies have been disabled. Please start a new discussion.

Similar topics

6
by: Ben Ingram | last post by:
Hi all, I am writing a template matrix class in which the template parameters are the number of rows and number of columns. There are a number of reasons why this is an appropriate tradeoff for...
2
by: Abhishek Saksena | last post by:
Is it possible using Boost mpl library:- Assume any class implementing a function "connect" with two arugments of fixed types class protocol1 { connect(T0 & t0, T1 &t1 ){..} //fixed types...
5
by: Carmine Cairo | last post by:
Hi, I'm working on a project and today I've note a little problem during the compile fase. Here a little piece of code: // 1st version welldone = 0; size = p->getSize(); backbone = new...
5
by: Brice Prunier | last post by:
Here under 4 schemas i'm working with ( it may be long: sorry...) The context is the following : Resident.xsd imports Person.xsd and includes Common.xsd ( anonimous schema: no TargetNamespace )...
10
by: Bart Goeman | last post by:
Hi, I have a question about how to put redundant information in data structures, initialized at compile time. This is often necessary for performance reasons and can't be done at run time (data...
13
by: Adam Blair | last post by:
Is it possible to bind a switch statement to an Enum such that a compile-time error is raised if not all values within the Enum are handled in the switch statement? I realise you can use default:...
4
by: John Smith | last post by:
Hi I'm porting some C++ code to new platforms and have some 1-byte aligned structures which need a specific size. Since datatypes can vary on different platforms (which I found out the hard way...
9
by: ThunderMusic | last post by:
Hi, I'd like to create a compile time error in my class... maybe there's a way already built in in the framework so I can achieve what I want... I have 2 constructors in my class. One of them...
11
by: Bryan Crouse | last post by:
I am looking a way to do error checking on a string at compile time, and if the string isn't the correct length have then have the compiler throw an error. I am working an embedded software that...
0
isladogs
by: isladogs | last post by:
The next Access Europe User Group meeting will be on Wednesday 3 Apr 2024 starting at 18:00 UK time (6PM UTC+1) and finishing by 19:30 (7.30PM). In this session, we are pleased to welcome former...
0
by: ryjfgjl | last post by:
In our work, we often need to import Excel data into databases (such as MySQL, SQL Server, Oracle) for data analysis and processing. Usually, we use database tools like Navicat or the Excel import...
0
by: taylorcarr | last post by:
A Canon printer is a smart device known for being advanced, efficient, and reliable. It is designed for home, office, and hybrid workspace use and can also be used for a variety of purposes. However,...
0
by: Charles Arthur | last post by:
How do i turn on java script on a villaon, callus and itel keypad mobile phone
0
by: aa123db | last post by:
Variable and constants Use var or let for variables and const fror constants. Var foo ='bar'; Let foo ='bar';const baz ='bar'; Functions function $name$ ($parameters$) { } ...
0
by: ryjfgjl | last post by:
If we have dozens or hundreds of excel to import into the database, if we use the excel import function provided by database editors such as navicat, it will be extremely tedious and time-consuming...
0
by: ryjfgjl | last post by:
In our work, we often receive Excel tables with data in the same format. If we want to analyze these data, it can be difficult to analyze them because the data is spread across multiple Excel files...
0
by: emmanuelkatto | last post by:
Hi All, I am Emmanuel katto from Uganda. I want to ask what challenges you've faced while migrating a website to cloud. Please let me know. Thanks! Emmanuel
1
by: nemocccc | last post by:
hello, everyone, I want to develop a software for my android phone for daily needs, any suggestions?

By using Bytes.com and it's services, you agree to our Privacy Policy and Terms of Use.

To disable or enable advertisements and analytics tracking please visit the manage ads & tracking page.