Put in skip list causing some -E- DXL: incorrect arguments for (if)

Hello,

I came accross some issue with if with the following sample code (interesting part start after comment "HERE!!":

Module m = current
AttrType at = find(m, "Good or bad")
 
if (null at) then{
  string codes[]={
      "good",
          "bad"}
  int values[] ={0,1}
  int colors[] ={realColor_Green,
                                 realColor_Red}
 
  string descs[]={
          "This is good",
          "This is bad"}
  string errmess = ""
  setRealColourOptionForTypes(true)
  at  = create("Good or bad", codes,values, colors,descs,errmess)
  
}
 
AttrDef ad = find(m,"Good or bad")
if (null ad) then{
                ad = create object type "Good or bad" attribute "Good or bad"
}
 
// HERE!!! ------------------------------
Object o = create m
 
bool b = true
Skip ooo = create
if b == true then
   put(ooo,o,o)
else
   o . "Good or bad" = "bad"
delete ooo

In this code I get the error -E- DXL: incorrect arguments for (if)

If I do the following then it works without error:

if b == true then
   o . "Good or bad" = "good"
else
   o . "Good or bad" = "bad"

Or if I do this,it also works without error

if b == true then
   put(ooo,o,o)
else{
   o . "Good or bad" = "bad"
}

That looks very strange, as some bug in DXL.

Any feedback welcome, I personally think that the only things to do is to file a bug report.

Vincent.

SystemAdmin - Wed Oct 26 04:25:38 EDT 2011

Re: Put in skip list causing some -E- DXL: incorrect arguments for (if)
OurGuest - Wed Oct 26 07:58:04 EDT 2011

I think most people would just put: if(b){}

Re: Put in skip list causing some -E- DXL: incorrect arguments for (if)
Mathias Mamsch - Wed Oct 26 12:50:47 EDT 2011

That is really funny. It seems with that "put()" on the if statement any assignment in the else clause fails parsing ...

That code fails parsing:

Skip sk = create()
if (true) put(sk,0,0) else sk = null

That code does not fail parsing:

Skip sk = create()
if (true) put(sk,0,0) else { sk = null }

That code does also not fail parsing:

Skip sk = create()
if (true) put(sk,0,0) else print "Hallo" 
sk = null

So that is definitly a bug ;-) Maybe we should finally file all those DXL bugs. Maybe that is the straw that broke the camels back. We took it since version 5. Now we are fed up! ;-)

Regards, Mathias

Mathias Mamsch, IT-QBase GmbH, Consultant for Requirement Engineering and D00RS

Re: Put in skip list causing some -E- DXL: incorrect arguments for (if)
llandale - Wed Oct 26 13:20:19 EDT 2011

Mathias Mamsch - Wed Oct 26 12:50:47 EDT 2011

That is really funny. It seems with that "put()" on the if statement any assignment in the else clause fails parsing ...

That code fails parsing:

Skip sk = create()
if (true) put(sk,0,0) else sk = null

That code does not fail parsing:

Skip sk = create()
if (true) put(sk,0,0) else { sk = null }

That code does also not fail parsing:

Skip sk = create()
if (true) put(sk,0,0) else print "Hallo" 
sk = null

Mathias Mamsch, IT-QBase GmbH, Consultant for Requirement Engineering and D00RS

I run into that pretty regularly forcing me to use braces around an else statement that "should" not need one. Just today:

if (canModify(in_obj)) //
then in_obj."Interface_SE-Analyst" = NameFull
else {g_CountFail++}

Never got around to narrowing down the exact causes, something Telelogic always insisted I do for them before they would even consider having development reject my suggestion there was a bug. Never occurred to me it was the "then" clause, now maybe I'll pay more attention. Like putting the braces around the "then" clause and seeing if that fixes it.

Louie

Re: Put in skip list causing some -E- DXL: incorrect arguments for (if)
Doug.Zawacki - Thu Oct 27 13:50:20 EDT 2011

llandale - Wed Oct 26 13:20:19 EDT 2011
I run into that pretty regularly forcing me to use braces around an else statement that "should" not need one. Just today:

if (canModify(in_obj)) //
then in_obj."Interface_SE-Analyst" = NameFull
else {g_CountFail++}

Never got around to narrowing down the exact causes, something Telelogic always insisted I do for them before they would even consider having development reject my suggestion there was a bug. Never occurred to me it was the "then" clause, now maybe I'll pay more attention. Like putting the braces around the "then" clause and seeing if that fixes it.

Louie

Interestingly enough...

This works

int i = 2, j = 2 
 
if i == j then j = 22

But this does not..

int i = 2, j = 2 
 
if i == j else j = 22

Re: Put in skip list causing some -E- DXL: incorrect arguments for (if)
Doug.Zawacki - Thu Oct 27 13:56:18 EDT 2011

Doug.Zawacki - Thu Oct 27 13:50:20 EDT 2011

Interestingly enough...

This works

int i = 2, j = 2 
 
if i == j then j = 22

But this does not..

int i = 2, j = 2 
 
if i == j else j = 22

Ugh. Sorry...bad post..

Re: Put in skip list causing some -E- DXL: incorrect arguments for (if)
Doug.Zawacki - Thu Oct 27 14:01:04 EDT 2011

Doug.Zawacki - Thu Oct 27 13:56:18 EDT 2011
Ugh. Sorry...bad post..

Sorry, was reading the DXL help and my paste didn't work as expected.

The then form does not work with a condition that starts with a component in parenthesis, for example:

if (2 + 3) == 4 then print "no"

generates a syntax error.

Re: Put in skip list causing some -E- DXL: incorrect arguments for (if)
Doug.Zawacki - Thu Oct 27 14:15:30 EDT 2011

Doug.Zawacki - Thu Oct 27 14:01:04 EDT 2011

Sorry, was reading the DXL help and my paste didn't work as expected.

The then form does not work with a condition that starts with a component in parenthesis, for example:

if (2 + 3) == 4 then print "no"

generates a syntax error.

Does anyone have a list of order of precendence evaluation?
I'm assuming the equal sign is why this doesn't work

int a
Skip sk = create()
if (true) put(sk,0,0) else a = 1

And there is no precendence evaluation needed in the statement below

Skip sk = create()
if (true) put(sk,0,0) else print "Hi"

Alas, I have learned to use paranthesis and brackets consistently to reduce frustration and confusion. It would seem to be a parsing error.

Re: Put in skip list causing some -E- DXL: incorrect arguments for (if)
Doug.Zawacki - Thu Oct 27 14:37:40 EDT 2011

Doug.Zawacki - Thu Oct 27 14:15:30 EDT 2011

Does anyone have a list of order of precendence evaluation?
I'm assuming the equal sign is why this doesn't work

int a
Skip sk = create()
if (true) put(sk,0,0) else a = 1

And there is no precendence evaluation needed in the statement below

Skip sk = create()
if (true) put(sk,0,0) else print "Hi"

Alas, I have learned to use paranthesis and brackets consistently to reduce frustration and confusion. It would seem to be a parsing error.

ok. This is really messed up. I'm done looking at this...

This statement fails parsing...

int a = 0
Skip sk = create()
if (true) put(sk,0,0) else a = 1

This statement does not fail

string str = ""
Skip sk = create()
if (true) put(sk,0,0) else str = "x"

So, forget everything you've ever thought to be true Arrgghh!

Re: Put in skip list causing some -E- DXL: incorrect arguments for (if)
llandale - Thu Oct 27 15:53:28 EDT 2011

Doug.Zawacki - Thu Oct 27 14:37:40 EDT 2011

ok. This is really messed up. I'm done looking at this...

This statement fails parsing...

int a = 0
Skip sk = create()
if (true) put(sk,0,0) else a = 1

This statement does not fail

string str = ""
Skip sk = create()
if (true) put(sk,0,0) else str = "x"

So, forget everything you've ever thought to be true Arrgghh!

Yes, most of my trouble with this syntax is assocated with print statements and integer assignments as you have discovered. So I get the error, put it in braces, and move on. There are far bigger fish to "Arrgghh" about. And I do. In this case it won't help me to understand it since I'm going to continue to try to have nice pretty if-then-else blocks of single lines of code.

It helps a lot to accept DXL as "quirky" than to accuse it of being "buggy". Serenity ... change what you can ... bla bla bla.

Louie

"forget everything you've ever thought to be true". Got that advise years ago from my Zen Poker Master from Pluto who then told me what was really true; but I forgot.

Re: Put in skip list causing some -E- DXL: incorrect arguments for (if)
PDU - Fri Oct 28 02:08:41 EDT 2011

llandale - Thu Oct 27 15:53:28 EDT 2011
Yes, most of my trouble with this syntax is assocated with print statements and integer assignments as you have discovered. So I get the error, put it in braces, and move on. There are far bigger fish to "Arrgghh" about. And I do. In this case it won't help me to understand it since I'm going to continue to try to have nice pretty if-then-else blocks of single lines of code.

It helps a lot to accept DXL as "quirky" than to accuse it of being "buggy". Serenity ... change what you can ... bla bla bla.

Louie

"forget everything you've ever thought to be true". Got that advise years ago from my Zen Poker Master from Pluto who then told me what was really true; but I forgot.

Hi all,

i think the solution is to use a style comparable to what is required in C (C++) developpement with quality constraints (see MISRA for example). In the example, use always brackets and embraces :

int a = 0
Skip sk = create()
if (true)
{
  put(sk, 0, 0)
}
else
{
  a = 1
}

Pierre

Re: Put in skip list causing some -E- DXL: incorrect arguments for (if)
Tony_Goodman - Fri Oct 28 09:17:30 EDT 2011

PDU - Fri Oct 28 02:08:41 EDT 2011

int a = 0
Skip sk = create()
if (true)
{
  put(sk, 0, 0)
}
else
{
  a = 1
}

Pierre

I second what PDU said.

I ALWAYS use braces around every code block, no matter how small.

And I always use parentheses, even if they are "not required", especially after parameter-less functions.

These rules help make the code more readable and more robust.

I recommend everyone looks at the MISRA standards and takes on board good practice.

PS I gave up being surprised long ago. As Louie said, you learn the workarounds by heart and move on...

Tony Goodman, www.smartdxl.com

Re: Put in skip list causing some -E- DXL: incorrect arguments for (if)
llandale - Fri Oct 28 10:37:33 EDT 2011

Tony_Goodman - Fri Oct 28 09:17:30 EDT 2011
I second what PDU said.

I ALWAYS use braces around every code block, no matter how small.

And I always use parentheses, even if they are "not required", especially after parameter-less functions.

These rules help make the code more readable and more robust.

I recommend everyone looks at the MISRA standards and takes on board good practice.

PS I gave up being surprised long ago. As Louie said, you learn the workarounds by heart and move on...

Tony Goodman, www.smartdxl.com

I use the parens as it makes it easier to clarify what is and what is not a function, something the reader needs to know. And of course because I'm somewhat weak in this area and need to break it up visually and rely heavily on matching-pairs feature of Crimson.

But I think the 1st of the following is a lot easier to read than the 2nd.

int a = 0
Skip sk = create()
 
if (true) //
then put(sk, 0, 0)
else  a = 1
 
DoMoreWork()
//-------------------------
if (true)
{
  put(sk, 0, 0)
}
else
{
  a = 1
}
 
DoMoreWork()

I argue that visually its easier to tell that this represents simple processing. It also takes less vertical space, 3 lines instead of 8, which generally helps the reader overall.

But yes, it doesn't matter much one way or the other.

Louie