How to use true/false inside definitions?

Clash Royale CLAN TAG#URR8PPP

up vote
3
down vote

favorite

Suppose you want to define page style depending on a boolean value.

I think both constructions below have equivalent output (or not?), but which is better/more indicated/professional/elegant?

if@mybool
 defps@myps
 % definition here
 
else
 defps@myps
 % definition here
 
fi

or

defps@myps
 if@mybool
 % definition here
 else
 % definition here
 fi

conditionals sourcecode pagestyle

share|improve this question

edited 1 hour ago

asked 1 hour ago

Sigur

22.7k353134

• 
  
  
  

  
  1
  

  
  
  
  
  
  

  
  They aren't equivalent. The former tests if@mybool at definition time, the latter at call time.
  – egreg
  1 hour ago
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  @egreg, oh, I see. But do you have some reason to choose one? I mean, could I get some bug or problem if I choose wrong?
  – Sigur
  1 hour ago
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  The two constructs do different things, so generally only one is correct according to what you need to do.
  – egreg
  1 hour ago
  

  
  
  
  

add a comment | 

up vote
3
down vote

favorite

Suppose you want to define page style depending on a boolean value.

I think both constructions below have equivalent output (or not?), but which is better/more indicated/professional/elegant?

if@mybool
 defps@myps
 % definition here
 
else
 defps@myps
 % definition here
 
fi

or

defps@myps
 if@mybool
 % definition here
 else
 % definition here
 fi

conditionals sourcecode pagestyle

share|improve this question

edited 1 hour ago

asked 1 hour ago

Sigur

22.7k353134

• 
  
  
  

  
  1
  

  
  
  
  
  
  

  
  They aren't equivalent. The former tests if@mybool at definition time, the latter at call time.
  – egreg
  1 hour ago
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  @egreg, oh, I see. But do you have some reason to choose one? I mean, could I get some bug or problem if I choose wrong?
  – Sigur
  1 hour ago
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  The two constructs do different things, so generally only one is correct according to what you need to do.
  – egreg
  1 hour ago
  

  
  
  
  

add a comment | 

up vote
3
down vote

favorite

up vote
3
down vote

favorite

Suppose you want to define page style depending on a boolean value.

I think both constructions below have equivalent output (or not?), but which is better/more indicated/professional/elegant?

if@mybool
 defps@myps
 % definition here
 
else
 defps@myps
 % definition here
 
fi

or

defps@myps
 if@mybool
 % definition here
 else
 % definition here
 fi

conditionals sourcecode pagestyle

share|improve this question

edited 1 hour ago

asked 1 hour ago

Sigur

22.7k353134

Suppose you want to define page style depending on a boolean value.

I think both constructions below have equivalent output (or not?), but which is better/more indicated/professional/elegant?

if@mybool
 defps@myps
 % definition here
 
else
 defps@myps
 % definition here
 
fi

or

defps@myps
 if@mybool
 % definition here
 else
 % definition here
 fi

conditionals sourcecode pagestyle

conditionals sourcecode pagestyle

share|improve this question

edited 1 hour ago

asked 1 hour ago

Sigur

22.7k353134

share|improve this question

edited 1 hour ago

asked 1 hour ago

Sigur

22.7k353134

share|improve this question

share|improve this question

edited 1 hour ago

edited 1 hour ago

edited 1 hour ago

asked 1 hour ago

Sigur

22.7k353134

asked 1 hour ago

Sigur

22.7k353134

asked 1 hour ago

Sigur

22.7k353134

22.7k353134

• 
  
  
  

  
  1
  

  
  
  
  
  
  

  
  They aren't equivalent. The former tests if@mybool at definition time, the latter at call time.
  – egreg
  1 hour ago
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  @egreg, oh, I see. But do you have some reason to choose one? I mean, could I get some bug or problem if I choose wrong?
  – Sigur
  1 hour ago
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  The two constructs do different things, so generally only one is correct according to what you need to do.
  – egreg
  1 hour ago
  

  
  
  
  

add a comment | 

• 
  
  
  

  
  1
  

  
  
  
  
  
  

  
  They aren't equivalent. The former tests if@mybool at definition time, the latter at call time.
  – egreg
  1 hour ago
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  @egreg, oh, I see. But do you have some reason to choose one? I mean, could I get some bug or problem if I choose wrong?
  – Sigur
  1 hour ago
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  The two constructs do different things, so generally only one is correct according to what you need to do.
  – egreg
  1 hour ago
  

  
  
  
  

1

1

They aren't equivalent. The former tests if@mybool at definition time, the latter at call time.
– egreg
1 hour ago

They aren't equivalent. The former tests if@mybool at definition time, the latter at call time.
– egreg
1 hour ago

@egreg, oh, I see. But do you have some reason to choose one? I mean, could I get some bug or problem if I choose wrong?
– Sigur
1 hour ago

@egreg, oh, I see. But do you have some reason to choose one? I mean, could I get some bug or problem if I choose wrong?
– Sigur
1 hour ago

The two constructs do different things, so generally only one is correct according to what you need to do.
– egreg
1 hour ago

The two constructs do different things, so generally only one is correct according to what you need to do.
– egreg
1 hour ago

add a comment | 

1 Answer
1

active

oldest

votes

up vote
5
down vote



accepted

The two constructs aren't equivalent.

With

if@mybool
 defps@myps...T...%
else
 defps@myps...F...%
fi

you test if@mybool and define ps@myps according to its truth value. Changing the value later in the document will not change the definition of ps@myps.

To the contrary,

defps@myps%
 if@mybool
 ...A...%
 else
 ...B...%
 fi

will yield ...A... or ...B... according the the truth value of if@mybool at the time the macro is expanded.

Which one to use depends on what you need to achieve.

---

With the first definition, if issued when if@mybool is true,

@myboolfalse
ps@myps
@myboolfalse
ps@myps

will produce ...A... twice.

With the second definition, the above code would produce first ...B... and then ...A....

If you are writing a package and if@mybool is set by a package options at runtime, most likely you want to use the first model, as the macro name suggests you're trying to define a page style that probably shouldn't change mid document.

---

The situation is quite similar to let and def. With letmymacroanother you define mymacro to be the same another is at the time the let instruction is performed.

With defmymacroanother, the meaning of another current at the moment mymacro is called will be used, which can have changed in the meantime.

share|improve this answer

edited 1 hour ago

answered 1 hour ago

egreg

695k8518453102

• 
  
  
  

  
  1
  

  
  
  
  
  
  

  
  Changing the value later in the document will not change the definition of ps@myps explained a lot to me. Very nice!
  – Sigur
  1 hour ago
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  @Sigur I added some more comments
  – egreg
  1 hour ago
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  I got it. That is the point, mybool will not change, because it comes from an option within the class. Thanks.
  – Sigur
  1 hour ago
  

  
  
  
  

add a comment | 

Your Answer

StackExchange.ready(function()
var channelOptions =
tags: "".split(" "),
id: "85"
;
initTagRenderer("".split(" "), "".split(" "), channelOptions);

StackExchange.using("externalEditor", function()
// Have to fire editor after snippets, if snippets enabled
if (StackExchange.settings.snippets.snippetsEnabled)
StackExchange.using("snippets", function()
createEditor();
);

else
createEditor();

);

function createEditor()
StackExchange.prepareEditor(
heartbeatType: 'answer',
convertImagesToLinks: false,
noModals: true,
showLowRepImageUploadWarning: true,
reputationToPostImages: null,
bindNavPrevention: true,
postfix: "",
imageUploader:
brandingHtml: "Powered by u003ca class="icon-imgur-white" href="https://imgur.com/"u003eu003c/au003e",
contentPolicyHtml: "User contributions licensed under u003ca href="https://creativecommons.org/licenses/by-sa/3.0/"u003ecc by-sa 3.0 with attribution requiredu003c/au003e u003ca href="https://stackoverflow.com/legal/content-policy"u003e(content policy)u003c/au003e",
allowUrls: true
,
onDemand: true,
discardSelector: ".discard-answer"
,immediatelyShowMarkdownHelp:true
);



);

 

draft saved

draft discarded

Sign up or log in

StackExchange.ready(function ()
StackExchange.helpers.onClickDraftSave('#login-link');
);

Sign up using Google

Sign up using Facebook

Sign up using Email and Password

Post as a guest

Name Email

StackExchange.ready(
function ()
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2ftex.stackexchange.com%2fquestions%2f458967%2fhow-to-use-true-false-inside-definitions%23new-answer', 'question_page');

);

Post as a guest

Name Email

1 Answer
1

active

oldest

votes

1 Answer
1

active

oldest

votes

active

oldest

votes

active

oldest

votes

up vote
5
down vote



accepted

The two constructs aren't equivalent.

With

if@mybool
 defps@myps...T...%
else
 defps@myps...F...%
fi

you test if@mybool and define ps@myps according to its truth value. Changing the value later in the document will not change the definition of ps@myps.

To the contrary,

defps@myps%
 if@mybool
 ...A...%
 else
 ...B...%
 fi

will yield ...A... or ...B... according the the truth value of if@mybool at the time the macro is expanded.

Which one to use depends on what you need to achieve.

---

With the first definition, if issued when if@mybool is true,

@myboolfalse
ps@myps
@myboolfalse
ps@myps

will produce ...A... twice.

With the second definition, the above code would produce first ...B... and then ...A....

If you are writing a package and if@mybool is set by a package options at runtime, most likely you want to use the first model, as the macro name suggests you're trying to define a page style that probably shouldn't change mid document.

---

The situation is quite similar to let and def. With letmymacroanother you define mymacro to be the same another is at the time the let instruction is performed.

With defmymacroanother, the meaning of another current at the moment mymacro is called will be used, which can have changed in the meantime.

share|improve this answer

edited 1 hour ago

answered 1 hour ago

egreg

695k8518453102

• 
  
  
  

  
  1
  

  
  
  
  
  
  

  
  Changing the value later in the document will not change the definition of ps@myps explained a lot to me. Very nice!
  – Sigur
  1 hour ago
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  @Sigur I added some more comments
  – egreg
  1 hour ago
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  I got it. That is the point, mybool will not change, because it comes from an option within the class. Thanks.
  – Sigur
  1 hour ago
  

  
  
  
  

add a comment | 

up vote
5
down vote



accepted

The two constructs aren't equivalent.

With

if@mybool
 defps@myps...T...%
else
 defps@myps...F...%
fi

you test if@mybool and define ps@myps according to its truth value. Changing the value later in the document will not change the definition of ps@myps.

To the contrary,

defps@myps%
 if@mybool
 ...A...%
 else
 ...B...%
 fi

will yield ...A... or ...B... according the the truth value of if@mybool at the time the macro is expanded.

Which one to use depends on what you need to achieve.

---

With the first definition, if issued when if@mybool is true,

@myboolfalse
ps@myps
@myboolfalse
ps@myps

will produce ...A... twice.

With the second definition, the above code would produce first ...B... and then ...A....

If you are writing a package and if@mybool is set by a package options at runtime, most likely you want to use the first model, as the macro name suggests you're trying to define a page style that probably shouldn't change mid document.

---

The situation is quite similar to let and def. With letmymacroanother you define mymacro to be the same another is at the time the let instruction is performed.

With defmymacroanother, the meaning of another current at the moment mymacro is called will be used, which can have changed in the meantime.

share|improve this answer

edited 1 hour ago

answered 1 hour ago

egreg

695k8518453102

• 
  
  
  

  
  1
  

  
  
  
  
  
  

  
  Changing the value later in the document will not change the definition of ps@myps explained a lot to me. Very nice!
  – Sigur
  1 hour ago
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  @Sigur I added some more comments
  – egreg
  1 hour ago
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  I got it. That is the point, mybool will not change, because it comes from an option within the class. Thanks.
  – Sigur
  1 hour ago
  

  
  
  
  

add a comment | 

up vote
5
down vote



accepted

up vote
5
down vote



accepted

The two constructs aren't equivalent.

With

if@mybool
 defps@myps...T...%
else
 defps@myps...F...%
fi

you test if@mybool and define ps@myps according to its truth value. Changing the value later in the document will not change the definition of ps@myps.

To the contrary,

defps@myps%
 if@mybool
 ...A...%
 else
 ...B...%
 fi

will yield ...A... or ...B... according the the truth value of if@mybool at the time the macro is expanded.

Which one to use depends on what you need to achieve.

---

With the first definition, if issued when if@mybool is true,

@myboolfalse
ps@myps
@myboolfalse
ps@myps

will produce ...A... twice.

With the second definition, the above code would produce first ...B... and then ...A....

If you are writing a package and if@mybool is set by a package options at runtime, most likely you want to use the first model, as the macro name suggests you're trying to define a page style that probably shouldn't change mid document.

---

The situation is quite similar to let and def. With letmymacroanother you define mymacro to be the same another is at the time the let instruction is performed.

With defmymacroanother, the meaning of another current at the moment mymacro is called will be used, which can have changed in the meantime.

share|improve this answer

edited 1 hour ago

answered 1 hour ago

egreg

695k8518453102

The two constructs aren't equivalent.

With

if@mybool
 defps@myps...T...%
else
 defps@myps...F...%
fi

you test if@mybool and define ps@myps according to its truth value. Changing the value later in the document will not change the definition of ps@myps.

To the contrary,

defps@myps%
 if@mybool
 ...A...%
 else
 ...B...%
 fi

will yield ...A... or ...B... according the the truth value of if@mybool at the time the macro is expanded.

Which one to use depends on what you need to achieve.

---

With the first definition, if issued when if@mybool is true,

@myboolfalse
ps@myps
@myboolfalse
ps@myps

will produce ...A... twice.

With the second definition, the above code would produce first ...B... and then ...A....

If you are writing a package and if@mybool is set by a package options at runtime, most likely you want to use the first model, as the macro name suggests you're trying to define a page style that probably shouldn't change mid document.

---

The situation is quite similar to let and def. With letmymacroanother you define mymacro to be the same another is at the time the let instruction is performed.

With defmymacroanother, the meaning of another current at the moment mymacro is called will be used, which can have changed in the meantime.

share|improve this answer

edited 1 hour ago

answered 1 hour ago

egreg

695k8518453102

share|improve this answer

share|improve this answer

edited 1 hour ago

edited 1 hour ago

edited 1 hour ago

answered 1 hour ago

egreg

695k8518453102

answered 1 hour ago

egreg

695k8518453102

answered 1 hour ago

egreg

695k8518453102

695k8518453102

• 
  
  
  

  
  1
  

  
  
  
  
  
  

  
  Changing the value later in the document will not change the definition of ps@myps explained a lot to me. Very nice!
  – Sigur
  1 hour ago
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  @Sigur I added some more comments
  – egreg
  1 hour ago
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  I got it. That is the point, mybool will not change, because it comes from an option within the class. Thanks.
  – Sigur
  1 hour ago
  

  
  
  
  

add a comment | 

• 
  
  
  

  
  1
  

  
  
  
  
  
  

  
  Changing the value later in the document will not change the definition of ps@myps explained a lot to me. Very nice!
  – Sigur
  1 hour ago
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  @Sigur I added some more comments
  – egreg
  1 hour ago
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  I got it. That is the point, mybool will not change, because it comes from an option within the class. Thanks.
  – Sigur
  1 hour ago
  

  
  
  
  

1

1

Changing the value later in the document will not change the definition of ps@myps explained a lot to me. Very nice!
– Sigur
1 hour ago

Changing the value later in the document will not change the definition of ps@myps explained a lot to me. Very nice!
– Sigur
1 hour ago

@Sigur I added some more comments
– egreg
1 hour ago

@Sigur I added some more comments
– egreg
1 hour ago

I got it. That is the point, mybool will not change, because it comes from an option within the class. Thanks.
– Sigur
1 hour ago

I got it. That is the point, mybool will not change, because it comes from an option within the class. Thanks.
– Sigur
1 hour ago

add a comment | 

 

draft saved

draft discarded

 

draft saved

draft discarded

Sign up or log in

StackExchange.ready(function ()
StackExchange.helpers.onClickDraftSave('#login-link');
);

Sign up using Google

Sign up using Facebook

Sign up using Email and Password

Post as a guest

Name Email

StackExchange.ready(
function ()
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2ftex.stackexchange.com%2fquestions%2f458967%2fhow-to-use-true-false-inside-definitions%23new-answer', 'question_page');

);

Post as a guest

Name Email

Sign up or log in

StackExchange.ready(function ()
StackExchange.helpers.onClickDraftSave('#login-link');
);

Sign up using Google

Sign up using Facebook

Sign up using Email and Password

Post as a guest

Name Email

Sign up or log in

StackExchange.ready(function ()
StackExchange.helpers.onClickDraftSave('#login-link');
);

Sign up using Google

Sign up using Facebook

Sign up using Email and Password

Post as a guest

Name Email

Sign up or log in

StackExchange.ready(function ()
StackExchange.helpers.onClickDraftSave('#login-link');
);

Sign up using Google

Sign up using Facebook

Sign up using Email and Password

Sign up using Google

Sign up using Facebook

Sign up using Email and Password

Post as a guest

Name Email

Name Email

Name

Email

Name Email

Name

Email