Testing for a “if not defined” boolean

Clash Royale CLAN TAG#URR8PPP

up vote
3
down vote

favorite

How can I test for a not defined boolean?

I want to have

usepackagexr-hyper
usepackagehyperref

provideboolis_single_book
booltrueis_single_book

in my main.tex and in each of the chapter TeX files.

if not defined is_single_book
 externaldocumentvolume1[http://mybook.com/volume1.pdf]
fi

So when I compile the entire book, externaldocumentvolume1[http://mybook.com/volume1.pdf] isn't executed.

It doesn't have to be a boolean if something else is simpler or doesn't require an extra package.

conditionals

share|improve this question

edited Aug 16 at 19:14

Peter Mortensen

48336

asked Aug 16 at 11:04

Sandra Schlichting

294410

• 
  
  
  

  
  

  
  
  
  
  
  

  
  Why do you want "is not defined" rather than "true" and "false"? Does a package specify that boolean?
  – TeXnician
  Aug 16 at 11:06
  
  

  
  
  
  


• 
  
  
  

  
  3
  

  
  
  
  
  
  

  
  So you essentially want a three-way switch: boolean undefined, boolean true and boolean false? Or can you simplify this to a simple two-valued logic with a true and false boolean? Since you use etoolbox commands you can use ifcsundefifis_single_book<undef><def> to check if the boolean is_single_book is undefined. Note that providebool makes sure the boolean is defined, so ifcsundefifis_single_book will execute the false branch.
  – moewe
  Aug 16 at 11:06
  
  

  
  
  
  

add a comment | 

up vote
3
down vote

favorite

How can I test for a not defined boolean?

I want to have

usepackagexr-hyper
usepackagehyperref

provideboolis_single_book
booltrueis_single_book

in my main.tex and in each of the chapter TeX files.

if not defined is_single_book
 externaldocumentvolume1[http://mybook.com/volume1.pdf]
fi

So when I compile the entire book, externaldocumentvolume1[http://mybook.com/volume1.pdf] isn't executed.

It doesn't have to be a boolean if something else is simpler or doesn't require an extra package.

conditionals

share|improve this question

edited Aug 16 at 19:14

Peter Mortensen

48336

asked Aug 16 at 11:04

Sandra Schlichting

294410

• 
  
  
  

  
  

  
  
  
  
  
  

  
  Why do you want "is not defined" rather than "true" and "false"? Does a package specify that boolean?
  – TeXnician
  Aug 16 at 11:06
  
  

  
  
  
  


• 
  
  
  

  
  3
  

  
  
  
  
  
  

  
  So you essentially want a three-way switch: boolean undefined, boolean true and boolean false? Or can you simplify this to a simple two-valued logic with a true and false boolean? Since you use etoolbox commands you can use ifcsundefifis_single_book<undef><def> to check if the boolean is_single_book is undefined. Note that providebool makes sure the boolean is defined, so ifcsundefifis_single_book will execute the false branch.
  – moewe
  Aug 16 at 11:06
  
  

  
  
  
  

add a comment | 

up vote
3
down vote

favorite

up vote
3
down vote

favorite

How can I test for a not defined boolean?

I want to have

usepackagexr-hyper
usepackagehyperref

provideboolis_single_book
booltrueis_single_book

in my main.tex and in each of the chapter TeX files.

if not defined is_single_book
 externaldocumentvolume1[http://mybook.com/volume1.pdf]
fi

So when I compile the entire book, externaldocumentvolume1[http://mybook.com/volume1.pdf] isn't executed.

It doesn't have to be a boolean if something else is simpler or doesn't require an extra package.

conditionals

share|improve this question

edited Aug 16 at 19:14

Peter Mortensen

48336

asked Aug 16 at 11:04

Sandra Schlichting

294410

How can I test for a not defined boolean?

I want to have

usepackagexr-hyper
usepackagehyperref

provideboolis_single_book
booltrueis_single_book

in my main.tex and in each of the chapter TeX files.

if not defined is_single_book
 externaldocumentvolume1[http://mybook.com/volume1.pdf]
fi

So when I compile the entire book, externaldocumentvolume1[http://mybook.com/volume1.pdf] isn't executed.

It doesn't have to be a boolean if something else is simpler or doesn't require an extra package.

conditionals

share|improve this question

edited Aug 16 at 19:14

Peter Mortensen

48336

asked Aug 16 at 11:04

Sandra Schlichting

294410

share|improve this question

share|improve this question

edited Aug 16 at 19:14

Peter Mortensen

48336

edited Aug 16 at 19:14

Peter Mortensen

48336

edited Aug 16 at 19:14

Peter Mortensen

48336

48336

asked Aug 16 at 11:04

Sandra Schlichting

294410

asked Aug 16 at 11:04

Sandra Schlichting

294410

asked Aug 16 at 11:04

Sandra Schlichting

294410

294410

• 
  
  
  

  
  

  
  
  
  
  
  

  
  Why do you want "is not defined" rather than "true" and "false"? Does a package specify that boolean?
  – TeXnician
  Aug 16 at 11:06
  
  

  
  
  
  


• 
  
  
  

  
  3
  

  
  
  
  
  
  

  
  So you essentially want a three-way switch: boolean undefined, boolean true and boolean false? Or can you simplify this to a simple two-valued logic with a true and false boolean? Since you use etoolbox commands you can use ifcsundefifis_single_book<undef><def> to check if the boolean is_single_book is undefined. Note that providebool makes sure the boolean is defined, so ifcsundefifis_single_book will execute the false branch.
  – moewe
  Aug 16 at 11:06
  
  

  
  
  
  

add a comment | 

• 
  
  
  

  
  

  
  
  
  
  
  

  
  Why do you want "is not defined" rather than "true" and "false"? Does a package specify that boolean?
  – TeXnician
  Aug 16 at 11:06
  
  

  
  
  
  


• 
  
  
  

  
  3
  

  
  
  
  
  
  

  
  So you essentially want a three-way switch: boolean undefined, boolean true and boolean false? Or can you simplify this to a simple two-valued logic with a true and false boolean? Since you use etoolbox commands you can use ifcsundefifis_single_book<undef><def> to check if the boolean is_single_book is undefined. Note that providebool makes sure the boolean is defined, so ifcsundefifis_single_book will execute the false branch.
  – moewe
  Aug 16 at 11:06
  
  

  
  
  
  

Why do you want "is not defined" rather than "true" and "false"? Does a package specify that boolean?
– TeXnician
Aug 16 at 11:06

Why do you want "is not defined" rather than "true" and "false"? Does a package specify that boolean?
– TeXnician
Aug 16 at 11:06

3

3

So you essentially want a three-way switch: boolean undefined, boolean true and boolean false? Or can you simplify this to a simple two-valued logic with a true and false boolean? Since you use etoolbox commands you can use ifcsundefifis_single_book<undef><def> to check if the boolean is_single_book is undefined. Note that providebool makes sure the boolean is defined, so ifcsundefifis_single_book will execute the false branch.
– moewe
Aug 16 at 11:06

So you essentially want a three-way switch: boolean undefined, boolean true and boolean false? Or can you simplify this to a simple two-valued logic with a true and false boolean? Since you use etoolbox commands you can use ifcsundefifis_single_book<undef><def> to check if the boolean is_single_book is undefined. Note that providebool makes sure the boolean is defined, so ifcsundefifis_single_book will execute the false branch.
– moewe
Aug 16 at 11:06

add a comment | 

3 Answers
3

active

oldest

votes

up vote
6
down vote



accepted

While you could check if a bool is defined by using ifcsundefif... (see comment from moewe), it looks as if you actually want a boolean which is always false if you are in a chapter tex file.

This can be archived by using providebool, which defines the bool as false, iff is is not defined already:

Use

newboolis_single_book
booltrueis_single_book

in your main file and

provideboolis_single_book
ifboolis_single_book%
 externaldocumentvolume1[http://mybook.com/volume1.pdf]%

in your chapter files.

Even better would be to use toggles. They are almost the same but avoid name clashes and provide slightly better performance:

To use them, insert

newtoggleis_single_book
toggletrueis_single_book

in your main file and

providetoggleis_single_book
iftoggleis_single_book%
 externaldocumentvolume1[http://mybook.com/volume1.pdf]%

in the chapters.

share|improve this answer

answered Aug 16 at 11:19

Marcel Krüger

10.4k11032

• 
  
  
  

  
  

  
  
  
  
  
  

  
  +1 for toggles.
  – moewe
  Aug 16 at 11:28
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  Something seams to be wrong for the chapters part. externaldocumentvolume1[http://mybook.com/volume1.pdf] isn't being executed. Is is_single_book true or fasle right after providetoggleis_single_book?
  – Sandra Schlichting
  Aug 16 at 12:34
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  externaldocumentvolume1[http://mybook.com/volume1.pdf] should be executed if is_single_book is false or undefined.
  – Sandra Schlichting
  Aug 16 at 12:37
  

  
  
  
  

add a comment | 

up vote
6
down vote

providebool and booltrue makes me think you are using etoolbox.

etoolbox booleans are just a thin wrapper around TeX's newif.

That means that newbool<name> defines if<name>, so you can check if a boolean is defined by checking if if<name> is defined.

documentclass[british]article
usepackage[T1]fontenc
usepackage[utf8]inputenc
usepackagebabel
usepackageetoolbox

newcommand*ifboolundef[1]ifcsundefif#1

newcommand*sabooleantest[1]%
 bool ttfamily#1 is
 ifboolundef#1
 undefined
 ifbool#1
 true
 false

begindocument
sabooleantestflobbel

newboolglobbel
boolfalseglobbel
sabooleantestglobbel

newboolhobbel
booltruehobbel
sabooleantesthobbel
enddocument

bool flobbel is undefined

bool globbel is false

bool hobbel is true

The question is whether you really need something that comes down to a three-valued logic. Is a two-valued boolean not enough?

If you want to avoid problems in case the boolean is undefined, you could just check if a macro is undefined or defined. This also has two states, but unlike with booleans there are no errors if the thing is not defined.

newcommand*mybool
ifcsundefmybool
 not defined
 defined

You could also define 'permissive toggles' that are false if they don't exist

documentclass[british]article
usepackage[T1]fontenc
usepackage[utf8]inputenc
usepackagebabel
usepackageetoolbox

newcommand*permissivetoggletrue[1]csletcssa@ptogl@#1@empty
newcommand*permissivetogglefalse[1]csundefsa@ptogl@#1
newcommand*ifpermissivetoggle[1]ifcsdefsa@ptogl@#1

begindocument
flobbel
ifpermissivetoggleflobbel
 true
 false

permissivetoggletrueglobbel
globbel
ifpermissivetoggleglobbel
 true
 false
enddocument

This can also be done without etoolbox if you like those sort of things

makeatletter
newcommand*permissivetoggletrue[1]%
 expandafterletcsname sa@ptogl@#1endcsname@empty
newcommand*permissivetogglefalse[1]%
 expandafterletcsname sa@ptogl@#1endcsname@sa@undef% this assumes @sa@undef is undefined
newcommand*ifpermissivetoggle[1]%
 ifcsname sa@ptogl@#1endcsname
 expandafter@firstoftwo
 else
 expandafter@secondoftwo
 fi
makeatother

share|improve this answer

edited Aug 16 at 13:18

answered Aug 16 at 11:28

moewe

74.8k797285

• 
  
  
  

  
  

  
  
  
  
  
  

  
  I were only using etoolbox for this one thing, so if this package can be avoided, then it would be much appreciated.
  – Sandra Schlichting
  Aug 16 at 11:34
  

  
  
  
  


• 
  
  
  

  
  2
  

  
  
  
  
  
  

  
  @SandraSchlichting Theoretically especially in my last two examples we could do away with etoolbox, but I would end up essentially copying (a bit of) code from that package, so why not load it?
  – moewe
  Aug 16 at 11:38
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  I see. Good point.
  – Sandra Schlichting
  Aug 16 at 11:42
  

  
  
  
  

add a comment | 

up vote
0
down vote

It doesn't have to be a boolean, if something else is simpler or doesn't require an extra package.

I think ifdefined and def provide what you're looking for. You don't need an extra package or any definition.

In your main document, write

defisSingleBook

or, alternatively, newcommandisSingleBook or providecommandisSingleBook.

Then you can check with:

ifdefinedisSingleBook
 %% you're in the book
else
 %% you're not in the book
fi

share|improve this answer

answered Aug 16 at 13:19

Scz

1,213512

add a comment | 

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3 Answers
3

active

oldest

votes

3 Answers
3

active

oldest

votes

active

oldest

votes

active

oldest

votes

up vote
6
down vote



accepted

While you could check if a bool is defined by using ifcsundefif... (see comment from moewe), it looks as if you actually want a boolean which is always false if you are in a chapter tex file.

This can be archived by using providebool, which defines the bool as false, iff is is not defined already:

Use

newboolis_single_book
booltrueis_single_book

in your main file and

provideboolis_single_book
ifboolis_single_book%
 externaldocumentvolume1[http://mybook.com/volume1.pdf]%

in your chapter files.

Even better would be to use toggles. They are almost the same but avoid name clashes and provide slightly better performance:

To use them, insert

newtoggleis_single_book
toggletrueis_single_book

in your main file and

providetoggleis_single_book
iftoggleis_single_book%
 externaldocumentvolume1[http://mybook.com/volume1.pdf]%

in the chapters.

share|improve this answer

answered Aug 16 at 11:19

Marcel Krüger

10.4k11032

• 
  
  
  

  
  

  
  
  
  
  
  

  
  +1 for toggles.
  – moewe
  Aug 16 at 11:28
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  Something seams to be wrong for the chapters part. externaldocumentvolume1[http://mybook.com/volume1.pdf] isn't being executed. Is is_single_book true or fasle right after providetoggleis_single_book?
  – Sandra Schlichting
  Aug 16 at 12:34
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  externaldocumentvolume1[http://mybook.com/volume1.pdf] should be executed if is_single_book is false or undefined.
  – Sandra Schlichting
  Aug 16 at 12:37
  

  
  
  
  

add a comment | 

up vote
6
down vote



accepted

While you could check if a bool is defined by using ifcsundefif... (see comment from moewe), it looks as if you actually want a boolean which is always false if you are in a chapter tex file.

This can be archived by using providebool, which defines the bool as false, iff is is not defined already:

Use

newboolis_single_book
booltrueis_single_book

in your main file and

provideboolis_single_book
ifboolis_single_book%
 externaldocumentvolume1[http://mybook.com/volume1.pdf]%

in your chapter files.

Even better would be to use toggles. They are almost the same but avoid name clashes and provide slightly better performance:

To use them, insert

newtoggleis_single_book
toggletrueis_single_book

in your main file and

providetoggleis_single_book
iftoggleis_single_book%
 externaldocumentvolume1[http://mybook.com/volume1.pdf]%

in the chapters.

share|improve this answer

answered Aug 16 at 11:19

Marcel Krüger

10.4k11032

• 
  
  
  

  
  

  
  
  
  
  
  

  
  +1 for toggles.
  – moewe
  Aug 16 at 11:28
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  Something seams to be wrong for the chapters part. externaldocumentvolume1[http://mybook.com/volume1.pdf] isn't being executed. Is is_single_book true or fasle right after providetoggleis_single_book?
  – Sandra Schlichting
  Aug 16 at 12:34
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  externaldocumentvolume1[http://mybook.com/volume1.pdf] should be executed if is_single_book is false or undefined.
  – Sandra Schlichting
  Aug 16 at 12:37
  

  
  
  
  

add a comment | 

up vote
6
down vote



accepted

up vote
6
down vote



accepted

While you could check if a bool is defined by using ifcsundefif... (see comment from moewe), it looks as if you actually want a boolean which is always false if you are in a chapter tex file.

This can be archived by using providebool, which defines the bool as false, iff is is not defined already:

Use

newboolis_single_book
booltrueis_single_book

in your main file and

provideboolis_single_book
ifboolis_single_book%
 externaldocumentvolume1[http://mybook.com/volume1.pdf]%

in your chapter files.

Even better would be to use toggles. They are almost the same but avoid name clashes and provide slightly better performance:

To use them, insert

newtoggleis_single_book
toggletrueis_single_book

in your main file and

providetoggleis_single_book
iftoggleis_single_book%
 externaldocumentvolume1[http://mybook.com/volume1.pdf]%

in the chapters.

share|improve this answer

answered Aug 16 at 11:19

Marcel Krüger

10.4k11032

While you could check if a bool is defined by using ifcsundefif... (see comment from moewe), it looks as if you actually want a boolean which is always false if you are in a chapter tex file.

This can be archived by using providebool, which defines the bool as false, iff is is not defined already:

Use

newboolis_single_book
booltrueis_single_book

in your main file and

provideboolis_single_book
ifboolis_single_book%
 externaldocumentvolume1[http://mybook.com/volume1.pdf]%

in your chapter files.

Even better would be to use toggles. They are almost the same but avoid name clashes and provide slightly better performance:

To use them, insert

newtoggleis_single_book
toggletrueis_single_book

in your main file and

providetoggleis_single_book
iftoggleis_single_book%
 externaldocumentvolume1[http://mybook.com/volume1.pdf]%

in the chapters.

share|improve this answer

answered Aug 16 at 11:19

Marcel Krüger

10.4k11032

share|improve this answer

share|improve this answer

answered Aug 16 at 11:19

Marcel Krüger

10.4k11032

answered Aug 16 at 11:19

Marcel Krüger

10.4k11032

answered Aug 16 at 11:19

Marcel Krüger

10.4k11032

10.4k11032

• 
  
  
  

  
  

  
  
  
  
  
  

  
  +1 for toggles.
  – moewe
  Aug 16 at 11:28
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  Something seams to be wrong for the chapters part. externaldocumentvolume1[http://mybook.com/volume1.pdf] isn't being executed. Is is_single_book true or fasle right after providetoggleis_single_book?
  – Sandra Schlichting
  Aug 16 at 12:34
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  externaldocumentvolume1[http://mybook.com/volume1.pdf] should be executed if is_single_book is false or undefined.
  – Sandra Schlichting
  Aug 16 at 12:37
  

  
  
  
  

add a comment | 

• 
  
  
  

  
  

  
  
  
  
  
  

  
  +1 for toggles.
  – moewe
  Aug 16 at 11:28
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  Something seams to be wrong for the chapters part. externaldocumentvolume1[http://mybook.com/volume1.pdf] isn't being executed. Is is_single_book true or fasle right after providetoggleis_single_book?
  – Sandra Schlichting
  Aug 16 at 12:34
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  externaldocumentvolume1[http://mybook.com/volume1.pdf] should be executed if is_single_book is false or undefined.
  – Sandra Schlichting
  Aug 16 at 12:37
  

  
  
  
  

+1 for toggles.
– moewe
Aug 16 at 11:28

+1 for toggles.
– moewe
Aug 16 at 11:28

Something seams to be wrong for the chapters part. externaldocumentvolume1[http://mybook.com/volume1.pdf] isn't being executed. Is is_single_book true or fasle right after providetoggleis_single_book?
– Sandra Schlichting
Aug 16 at 12:34

Something seams to be wrong for the chapters part. externaldocumentvolume1[http://mybook.com/volume1.pdf] isn't being executed. Is is_single_book true or fasle right after providetoggleis_single_book?
– Sandra Schlichting
Aug 16 at 12:34

externaldocumentvolume1[http://mybook.com/volume1.pdf] should be executed if is_single_book is false or undefined.
– Sandra Schlichting
Aug 16 at 12:37

externaldocumentvolume1[http://mybook.com/volume1.pdf] should be executed if is_single_book is false or undefined.
– Sandra Schlichting
Aug 16 at 12:37

add a comment | 

up vote
6
down vote

providebool and booltrue makes me think you are using etoolbox.

etoolbox booleans are just a thin wrapper around TeX's newif.

That means that newbool<name> defines if<name>, so you can check if a boolean is defined by checking if if<name> is defined.

documentclass[british]article
usepackage[T1]fontenc
usepackage[utf8]inputenc
usepackagebabel
usepackageetoolbox

newcommand*ifboolundef[1]ifcsundefif#1

newcommand*sabooleantest[1]%
 bool ttfamily#1 is
 ifboolundef#1
 undefined
 ifbool#1
 true
 false

begindocument
sabooleantestflobbel

newboolglobbel
boolfalseglobbel
sabooleantestglobbel

newboolhobbel
booltruehobbel
sabooleantesthobbel
enddocument

bool flobbel is undefined

bool globbel is false

bool hobbel is true

The question is whether you really need something that comes down to a three-valued logic. Is a two-valued boolean not enough?

If you want to avoid problems in case the boolean is undefined, you could just check if a macro is undefined or defined. This also has two states, but unlike with booleans there are no errors if the thing is not defined.

newcommand*mybool
ifcsundefmybool
 not defined
 defined

You could also define 'permissive toggles' that are false if they don't exist

documentclass[british]article
usepackage[T1]fontenc
usepackage[utf8]inputenc
usepackagebabel
usepackageetoolbox

newcommand*permissivetoggletrue[1]csletcssa@ptogl@#1@empty
newcommand*permissivetogglefalse[1]csundefsa@ptogl@#1
newcommand*ifpermissivetoggle[1]ifcsdefsa@ptogl@#1

begindocument
flobbel
ifpermissivetoggleflobbel
 true
 false

permissivetoggletrueglobbel
globbel
ifpermissivetoggleglobbel
 true
 false
enddocument

This can also be done without etoolbox if you like those sort of things

makeatletter
newcommand*permissivetoggletrue[1]%
 expandafterletcsname sa@ptogl@#1endcsname@empty
newcommand*permissivetogglefalse[1]%
 expandafterletcsname sa@ptogl@#1endcsname@sa@undef% this assumes @sa@undef is undefined
newcommand*ifpermissivetoggle[1]%
 ifcsname sa@ptogl@#1endcsname
 expandafter@firstoftwo
 else
 expandafter@secondoftwo
 fi
makeatother

share|improve this answer

edited Aug 16 at 13:18

answered Aug 16 at 11:28

moewe

74.8k797285

• 
  
  
  

  
  

  
  
  
  
  
  

  
  I were only using etoolbox for this one thing, so if this package can be avoided, then it would be much appreciated.
  – Sandra Schlichting
  Aug 16 at 11:34
  

  
  
  
  


• 
  
  
  

  
  2
  

  
  
  
  
  
  

  
  @SandraSchlichting Theoretically especially in my last two examples we could do away with etoolbox, but I would end up essentially copying (a bit of) code from that package, so why not load it?
  – moewe
  Aug 16 at 11:38
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  I see. Good point.
  – Sandra Schlichting
  Aug 16 at 11:42
  

  
  
  
  

add a comment | 

up vote
6
down vote

providebool and booltrue makes me think you are using etoolbox.

etoolbox booleans are just a thin wrapper around TeX's newif.

That means that newbool<name> defines if<name>, so you can check if a boolean is defined by checking if if<name> is defined.

documentclass[british]article
usepackage[T1]fontenc
usepackage[utf8]inputenc
usepackagebabel
usepackageetoolbox

newcommand*ifboolundef[1]ifcsundefif#1

newcommand*sabooleantest[1]%
 bool ttfamily#1 is
 ifboolundef#1
 undefined
 ifbool#1
 true
 false

begindocument
sabooleantestflobbel

newboolglobbel
boolfalseglobbel
sabooleantestglobbel

newboolhobbel
booltruehobbel
sabooleantesthobbel
enddocument

bool flobbel is undefined

bool globbel is false

bool hobbel is true

The question is whether you really need something that comes down to a three-valued logic. Is a two-valued boolean not enough?

If you want to avoid problems in case the boolean is undefined, you could just check if a macro is undefined or defined. This also has two states, but unlike with booleans there are no errors if the thing is not defined.

newcommand*mybool
ifcsundefmybool
 not defined
 defined

You could also define 'permissive toggles' that are false if they don't exist

documentclass[british]article
usepackage[T1]fontenc
usepackage[utf8]inputenc
usepackagebabel
usepackageetoolbox

newcommand*permissivetoggletrue[1]csletcssa@ptogl@#1@empty
newcommand*permissivetogglefalse[1]csundefsa@ptogl@#1
newcommand*ifpermissivetoggle[1]ifcsdefsa@ptogl@#1

begindocument
flobbel
ifpermissivetoggleflobbel
 true
 false

permissivetoggletrueglobbel
globbel
ifpermissivetoggleglobbel
 true
 false
enddocument

This can also be done without etoolbox if you like those sort of things

makeatletter
newcommand*permissivetoggletrue[1]%
 expandafterletcsname sa@ptogl@#1endcsname@empty
newcommand*permissivetogglefalse[1]%
 expandafterletcsname sa@ptogl@#1endcsname@sa@undef% this assumes @sa@undef is undefined
newcommand*ifpermissivetoggle[1]%
 ifcsname sa@ptogl@#1endcsname
 expandafter@firstoftwo
 else
 expandafter@secondoftwo
 fi
makeatother

share|improve this answer

edited Aug 16 at 13:18

answered Aug 16 at 11:28

moewe

74.8k797285

• 
  
  
  

  
  

  
  
  
  
  
  

  
  I were only using etoolbox for this one thing, so if this package can be avoided, then it would be much appreciated.
  – Sandra Schlichting
  Aug 16 at 11:34
  

  
  
  
  


• 
  
  
  

  
  2
  

  
  
  
  
  
  

  
  @SandraSchlichting Theoretically especially in my last two examples we could do away with etoolbox, but I would end up essentially copying (a bit of) code from that package, so why not load it?
  – moewe
  Aug 16 at 11:38
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  I see. Good point.
  – Sandra Schlichting
  Aug 16 at 11:42
  

  
  
  
  

add a comment | 

up vote
6
down vote

up vote
6
down vote

providebool and booltrue makes me think you are using etoolbox.

etoolbox booleans are just a thin wrapper around TeX's newif.

That means that newbool<name> defines if<name>, so you can check if a boolean is defined by checking if if<name> is defined.

documentclass[british]article
usepackage[T1]fontenc
usepackage[utf8]inputenc
usepackagebabel
usepackageetoolbox

newcommand*ifboolundef[1]ifcsundefif#1

newcommand*sabooleantest[1]%
 bool ttfamily#1 is
 ifboolundef#1
 undefined
 ifbool#1
 true
 false

begindocument
sabooleantestflobbel

newboolglobbel
boolfalseglobbel
sabooleantestglobbel

newboolhobbel
booltruehobbel
sabooleantesthobbel
enddocument

bool flobbel is undefined

bool globbel is false

bool hobbel is true

The question is whether you really need something that comes down to a three-valued logic. Is a two-valued boolean not enough?

If you want to avoid problems in case the boolean is undefined, you could just check if a macro is undefined or defined. This also has two states, but unlike with booleans there are no errors if the thing is not defined.

newcommand*mybool
ifcsundefmybool
 not defined
 defined

You could also define 'permissive toggles' that are false if they don't exist

documentclass[british]article
usepackage[T1]fontenc
usepackage[utf8]inputenc
usepackagebabel
usepackageetoolbox

newcommand*permissivetoggletrue[1]csletcssa@ptogl@#1@empty
newcommand*permissivetogglefalse[1]csundefsa@ptogl@#1
newcommand*ifpermissivetoggle[1]ifcsdefsa@ptogl@#1

begindocument
flobbel
ifpermissivetoggleflobbel
 true
 false

permissivetoggletrueglobbel
globbel
ifpermissivetoggleglobbel
 true
 false
enddocument

This can also be done without etoolbox if you like those sort of things

makeatletter
newcommand*permissivetoggletrue[1]%
 expandafterletcsname sa@ptogl@#1endcsname@empty
newcommand*permissivetogglefalse[1]%
 expandafterletcsname sa@ptogl@#1endcsname@sa@undef% this assumes @sa@undef is undefined
newcommand*ifpermissivetoggle[1]%
 ifcsname sa@ptogl@#1endcsname
 expandafter@firstoftwo
 else
 expandafter@secondoftwo
 fi
makeatother

share|improve this answer

edited Aug 16 at 13:18

answered Aug 16 at 11:28

moewe

74.8k797285

providebool and booltrue makes me think you are using etoolbox.

etoolbox booleans are just a thin wrapper around TeX's newif.

That means that newbool<name> defines if<name>, so you can check if a boolean is defined by checking if if<name> is defined.

documentclass[british]article
usepackage[T1]fontenc
usepackage[utf8]inputenc
usepackagebabel
usepackageetoolbox

newcommand*ifboolundef[1]ifcsundefif#1

newcommand*sabooleantest[1]%
 bool ttfamily#1 is
 ifboolundef#1
 undefined
 ifbool#1
 true
 false

begindocument
sabooleantestflobbel

newboolglobbel
boolfalseglobbel
sabooleantestglobbel

newboolhobbel
booltruehobbel
sabooleantesthobbel
enddocument

bool flobbel is undefined

bool globbel is false

bool hobbel is true

The question is whether you really need something that comes down to a three-valued logic. Is a two-valued boolean not enough?

If you want to avoid problems in case the boolean is undefined, you could just check if a macro is undefined or defined. This also has two states, but unlike with booleans there are no errors if the thing is not defined.

newcommand*mybool
ifcsundefmybool
 not defined
 defined

You could also define 'permissive toggles' that are false if they don't exist

documentclass[british]article
usepackage[T1]fontenc
usepackage[utf8]inputenc
usepackagebabel
usepackageetoolbox

newcommand*permissivetoggletrue[1]csletcssa@ptogl@#1@empty
newcommand*permissivetogglefalse[1]csundefsa@ptogl@#1
newcommand*ifpermissivetoggle[1]ifcsdefsa@ptogl@#1

begindocument
flobbel
ifpermissivetoggleflobbel
 true
 false

permissivetoggletrueglobbel
globbel
ifpermissivetoggleglobbel
 true
 false
enddocument

This can also be done without etoolbox if you like those sort of things

makeatletter
newcommand*permissivetoggletrue[1]%
 expandafterletcsname sa@ptogl@#1endcsname@empty
newcommand*permissivetogglefalse[1]%
 expandafterletcsname sa@ptogl@#1endcsname@sa@undef% this assumes @sa@undef is undefined
newcommand*ifpermissivetoggle[1]%
 ifcsname sa@ptogl@#1endcsname
 expandafter@firstoftwo
 else
 expandafter@secondoftwo
 fi
makeatother

share|improve this answer

edited Aug 16 at 13:18

answered Aug 16 at 11:28

moewe

74.8k797285

share|improve this answer

share|improve this answer

edited Aug 16 at 13:18

edited Aug 16 at 13:18

edited Aug 16 at 13:18

answered Aug 16 at 11:28

moewe

74.8k797285

answered Aug 16 at 11:28

moewe

74.8k797285

answered Aug 16 at 11:28

moewe

74.8k797285

74.8k797285

• 
  
  
  

  
  

  
  
  
  
  
  

  
  I were only using etoolbox for this one thing, so if this package can be avoided, then it would be much appreciated.
  – Sandra Schlichting
  Aug 16 at 11:34
  

  
  
  
  


• 
  
  
  

  
  2
  

  
  
  
  
  
  

  
  @SandraSchlichting Theoretically especially in my last two examples we could do away with etoolbox, but I would end up essentially copying (a bit of) code from that package, so why not load it?
  – moewe
  Aug 16 at 11:38
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  I see. Good point.
  – Sandra Schlichting
  Aug 16 at 11:42
  

  
  
  
  

add a comment | 

• 
  
  
  

  
  

  
  
  
  
  
  

  
  I were only using etoolbox for this one thing, so if this package can be avoided, then it would be much appreciated.
  – Sandra Schlichting
  Aug 16 at 11:34
  

  
  
  
  


• 
  
  
  

  
  2
  

  
  
  
  
  
  

  
  @SandraSchlichting Theoretically especially in my last two examples we could do away with etoolbox, but I would end up essentially copying (a bit of) code from that package, so why not load it?
  – moewe
  Aug 16 at 11:38
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  I see. Good point.
  – Sandra Schlichting
  Aug 16 at 11:42
  

  
  
  
  

I were only using etoolbox for this one thing, so if this package can be avoided, then it would be much appreciated.
– Sandra Schlichting
Aug 16 at 11:34

I were only using etoolbox for this one thing, so if this package can be avoided, then it would be much appreciated.
– Sandra Schlichting
Aug 16 at 11:34

2

2

@SandraSchlichting Theoretically especially in my last two examples we could do away with etoolbox, but I would end up essentially copying (a bit of) code from that package, so why not load it?
– moewe
Aug 16 at 11:38

@SandraSchlichting Theoretically especially in my last two examples we could do away with etoolbox, but I would end up essentially copying (a bit of) code from that package, so why not load it?
– moewe
Aug 16 at 11:38

I see. Good point.
– Sandra Schlichting
Aug 16 at 11:42

I see. Good point.
– Sandra Schlichting
Aug 16 at 11:42

add a comment | 

up vote
0
down vote

It doesn't have to be a boolean, if something else is simpler or doesn't require an extra package.

I think ifdefined and def provide what you're looking for. You don't need an extra package or any definition.

In your main document, write

defisSingleBook

or, alternatively, newcommandisSingleBook or providecommandisSingleBook.

Then you can check with:

ifdefinedisSingleBook
 %% you're in the book
else
 %% you're not in the book
fi

share|improve this answer

answered Aug 16 at 13:19

Scz

1,213512

add a comment | 

up vote
0
down vote

It doesn't have to be a boolean, if something else is simpler or doesn't require an extra package.

I think ifdefined and def provide what you're looking for. You don't need an extra package or any definition.

In your main document, write

defisSingleBook

or, alternatively, newcommandisSingleBook or providecommandisSingleBook.

Then you can check with:

ifdefinedisSingleBook
 %% you're in the book
else
 %% you're not in the book
fi

share|improve this answer

answered Aug 16 at 13:19

Scz

1,213512

add a comment | 

up vote
0
down vote

up vote
0
down vote

It doesn't have to be a boolean, if something else is simpler or doesn't require an extra package.

I think ifdefined and def provide what you're looking for. You don't need an extra package or any definition.

In your main document, write

defisSingleBook

or, alternatively, newcommandisSingleBook or providecommandisSingleBook.

Then you can check with:

ifdefinedisSingleBook
 %% you're in the book
else
 %% you're not in the book
fi

share|improve this answer

answered Aug 16 at 13:19

Scz

1,213512

It doesn't have to be a boolean, if something else is simpler or doesn't require an extra package.

I think ifdefined and def provide what you're looking for. You don't need an extra package or any definition.

In your main document, write

defisSingleBook

or, alternatively, newcommandisSingleBook or providecommandisSingleBook.

Then you can check with:

ifdefinedisSingleBook
 %% you're in the book
else
 %% you're not in the book
fi

share|improve this answer

answered Aug 16 at 13:19

Scz

1,213512

share|improve this answer

share|improve this answer

answered Aug 16 at 13:19

Scz

1,213512

answered Aug 16 at 13:19

Scz

1,213512

answered Aug 16 at 13:19

Scz

1,213512

1,213512

add a comment | 

add a comment | 

 

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