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How can I check if the current code is inside a certain environment?

How can I check if the current code is inside a tikzpicture?Detecting if inside a tikzpictureHow to test if I'm currently in a footnote or notHow can I center arbitrary content between two horizontal lines?Checking environment in order to end itHow to access name of environment in its own definitionpassing options to the newenvironmentUse column-separator & (ampersand) inside newenvironmentHow can I create a customized environment?Environments with matched parens in begin and endAllow only certain commands in own environmentCompiler Error when Creating a Macro/EnvironmentHow can I know if I am inside an equation environment if it's nested with others?Symbol at the end of an environmentHow to delete the contents of the current paragraph and “re-start” from the beginning?Using a split environment inside every equation environment

20

6

I would like to define a command which checks if it is executed inside a certain environment. Like this:

documentclassarticle

newenvironmentmyenv[0]at start at end

newcommandinner[0]%
 % if iside a myenv
 (inner)
 % else
 beginmyenv
 (inner)%
 endmyenv
 % end


begindocument

beginmyenv
 inner
endmyenv

inner

enddocument

See the definition of inner. Is an if-condition of this form possible?

environments conditionals

share|improve this question

edited May 20 '11 at 14:15

lockstep

192k53593723

asked May 20 '11 at 8:17

Nickolay KolevNickolay Kolev

1,70641731

• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  Related Question: Detecting if inside a tikzpicture
  
  – Peter Grill
  Nov 7 '18 at 23:30
  

  
  
  
  

add a comment | 

20

6

I would like to define a command which checks if it is executed inside a certain environment. Like this:

documentclassarticle

newenvironmentmyenv[0]at start at end

newcommandinner[0]%
 % if iside a myenv
 (inner)
 % else
 beginmyenv
 (inner)%
 endmyenv
 % end


begindocument

beginmyenv
 inner
endmyenv

inner

enddocument

See the definition of inner. Is an if-condition of this form possible?

environments conditionals

share|improve this question

edited May 20 '11 at 14:15

lockstep

192k53593723

asked May 20 '11 at 8:17

Nickolay KolevNickolay Kolev

1,70641731

• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  Related Question: Detecting if inside a tikzpicture
  
  – Peter Grill
  Nov 7 '18 at 23:30
  

  
  
  
  

add a comment | 

I would like to define a command which checks if it is executed inside a certain environment. Like this:

documentclassarticle

newenvironmentmyenv[0]at start at end

newcommandinner[0]%
 % if iside a myenv
 (inner)
 % else
 beginmyenv
 (inner)%
 endmyenv
 % end


begindocument

beginmyenv
 inner
endmyenv

inner

enddocument

See the definition of inner. Is an if-condition of this form possible?

environments conditionals

share|improve this question

edited May 20 '11 at 14:15

lockstep

192k53593723

asked May 20 '11 at 8:17

Nickolay KolevNickolay Kolev

1,70641731

documentclassarticle

newenvironmentmyenv[0]at start at end

newcommandinner[0]%
 % if iside a myenv
 (inner)
 % else
 beginmyenv
 (inner)%
 endmyenv
 % end


begindocument

beginmyenv
 inner
endmyenv

inner

enddocument

share|improve this question

edited May 20 '11 at 14:15

lockstep

192k53593723

asked May 20 '11 at 8:17

Nickolay KolevNickolay Kolev

1,70641731

share|improve this question

edited May 20 '11 at 14:15

lockstep

192k53593723

asked May 20 '11 at 8:17

Nickolay KolevNickolay Kolev

1,70641731

edited May 20 '11 at 14:15

lockstep

192k53593723

edited May 20 '11 at 14:15

lockstep

192k53593723

asked May 20 '11 at 8:17

Nickolay KolevNickolay Kolev

1,70641731

asked May 20 '11 at 8:17

Nickolay KolevNickolay Kolev

1,70641731

2 Answers
2

active

oldest

votes

20

LaTeX keeps the current environment in the macro @currenvir

makeatletter
newcommandinner%
 ifx@currenvir@myenvname
 (inner)
 else
 beginmyenv(inner)endmyenv
 fi
newcommand*@myenvnamemyenv
makeatother

Another approach would be to define a global conditional that's set to true by myenv start code and to false by myenv end code. It depends mostly on what you are expecting from the myenv environment: can it appear nested inside itself?

share|improve this answer

edited 20 mins ago

answered May 20 '11 at 8:32

egregegreg

729k8819263235

• 
  
  
  

  
  2
  

  
  
  
  
  
  

  
  
  @Nickoley: Note that this doesn't work any longer when inner is used inside another environment inside the myenv environment, e.g. beginmyenvbegincenterinnerendcenterendmyenv. Then @currenvir` will be center when inner is expanded.
  
  – Martin Scharrer♦
  May 20 '11 at 10:28
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  This does not seem to work on my end. It produces the "else" output both inside and outside a myenv environment. However, both @currenvir and @myenvname display the correct (and the same) output when placed inside the environment.
  
  – Danny Hansen
  29 mins ago
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  @DannyHansen Right: in some update during the last eight years, the LaTeX kernel changed @currenvir to not be long as it used to be. Fixed by adding a *.
  
  – egreg
  20 mins ago
  

  
  
  
  

add a comment | 

4

If you use pdftex, etex or xetex (I mean engine), you can define a fully expandable test:

makeatletter defIfEnvir #1%
% implicit #2 "what if true"
% implicit #3 "what if false"
%
 ifnum strcmp@currenvir#1=0
 expandafter@firstoftwo
 else
 expandafter@secondoftwo
 fi


makeatother

Such a conditional is defined in the gmutils package: @ifenvir, but there it's protected for some reason.

share|improve this answer

edited May 20 '11 at 9:40

Martin Scharrer♦

203k47651825

answered May 20 '11 at 9:01

NatrorNatror

612

• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  If you prefer the if… … else … fi form, just replace expandafter@first/secondoftwo with your stuff, but i'd suggest the arguments-form because it's robust to unbalanced if's.
  
  – Natror
  May 20 '11 at 9:06
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  Please indent your code with four spaces (or use the '101010' button to do this) so that it is properly highlighted. Please don't use HTML for code formatting. Thanks.
  
  – Martin Scharrer♦
  May 20 '11 at 9:39
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  the command is strcmp in XeTeX and pdfstrcmp in pdfTeX. One can load pdftexcmds and use pdf@strcmp in all engines (including LuaTeX).
  
  – egreg
  May 20 '11 at 10:04
  

  
  
  
  

add a comment | 

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20

LaTeX keeps the current environment in the macro @currenvir

makeatletter
newcommandinner%
 ifx@currenvir@myenvname
 (inner)
 else
 beginmyenv(inner)endmyenv
 fi
newcommand*@myenvnamemyenv
makeatother

Another approach would be to define a global conditional that's set to true by myenv start code and to false by myenv end code. It depends mostly on what you are expecting from the myenv environment: can it appear nested inside itself?

share|improve this answer

edited 20 mins ago

answered May 20 '11 at 8:32

egregegreg

729k8819263235

• 
  
  
  

  
  2
  

  
  
  
  
  
  

  
  
  @Nickoley: Note that this doesn't work any longer when inner is used inside another environment inside the myenv environment, e.g. beginmyenvbegincenterinnerendcenterendmyenv. Then @currenvir` will be center when inner is expanded.
  
  – Martin Scharrer♦
  May 20 '11 at 10:28
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  This does not seem to work on my end. It produces the "else" output both inside and outside a myenv environment. However, both @currenvir and @myenvname display the correct (and the same) output when placed inside the environment.
  
  – Danny Hansen
  29 mins ago
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  @DannyHansen Right: in some update during the last eight years, the LaTeX kernel changed @currenvir to not be long as it used to be. Fixed by adding a *.
  
  – egreg
  20 mins ago
  

  
  
  
  

add a comment | 

20

LaTeX keeps the current environment in the macro @currenvir

makeatletter
newcommandinner%
 ifx@currenvir@myenvname
 (inner)
 else
 beginmyenv(inner)endmyenv
 fi
newcommand*@myenvnamemyenv
makeatother

Another approach would be to define a global conditional that's set to true by myenv start code and to false by myenv end code. It depends mostly on what you are expecting from the myenv environment: can it appear nested inside itself?

share|improve this answer

edited 20 mins ago

answered May 20 '11 at 8:32

egregegreg

729k8819263235

• 
  
  
  

  
  2
  

  
  
  
  
  
  

  
  
  @Nickoley: Note that this doesn't work any longer when inner is used inside another environment inside the myenv environment, e.g. beginmyenvbegincenterinnerendcenterendmyenv. Then @currenvir` will be center when inner is expanded.
  
  – Martin Scharrer♦
  May 20 '11 at 10:28
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  This does not seem to work on my end. It produces the "else" output both inside and outside a myenv environment. However, both @currenvir and @myenvname display the correct (and the same) output when placed inside the environment.
  
  – Danny Hansen
  29 mins ago
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  @DannyHansen Right: in some update during the last eight years, the LaTeX kernel changed @currenvir to not be long as it used to be. Fixed by adding a *.
  
  – egreg
  20 mins ago
  

  
  
  
  

add a comment | 

LaTeX keeps the current environment in the macro @currenvir

makeatletter
newcommandinner%
 ifx@currenvir@myenvname
 (inner)
 else
 beginmyenv(inner)endmyenv
 fi
newcommand*@myenvnamemyenv
makeatother

Another approach would be to define a global conditional that's set to true by myenv start code and to false by myenv end code. It depends mostly on what you are expecting from the myenv environment: can it appear nested inside itself?

share|improve this answer

edited 20 mins ago

answered May 20 '11 at 8:32

egregegreg

729k8819263235

makeatletter
newcommandinner%
 ifx@currenvir@myenvname
 (inner)
 else
 beginmyenv(inner)endmyenv
 fi
newcommand*@myenvnamemyenv
makeatother

share|improve this answer

edited 20 mins ago

answered May 20 '11 at 8:32

egregegreg

729k8819263235

answered May 20 '11 at 8:32

egregegreg

729k8819263235

answered May 20 '11 at 8:32

egregegreg

729k8819263235

4

If you use pdftex, etex or xetex (I mean engine), you can define a fully expandable test:

makeatletter defIfEnvir #1%
% implicit #2 "what if true"
% implicit #3 "what if false"
%
 ifnum strcmp@currenvir#1=0
 expandafter@firstoftwo
 else
 expandafter@secondoftwo
 fi


makeatother

Such a conditional is defined in the gmutils package: @ifenvir, but there it's protected for some reason.

share|improve this answer

edited May 20 '11 at 9:40

Martin Scharrer♦

203k47651825

answered May 20 '11 at 9:01

NatrorNatror

612

• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  If you prefer the if… … else … fi form, just replace expandafter@first/secondoftwo with your stuff, but i'd suggest the arguments-form because it's robust to unbalanced if's.
  
  – Natror
  May 20 '11 at 9:06
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  Please indent your code with four spaces (or use the '101010' button to do this) so that it is properly highlighted. Please don't use HTML for code formatting. Thanks.
  
  – Martin Scharrer♦
  May 20 '11 at 9:39
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  the command is strcmp in XeTeX and pdfstrcmp in pdfTeX. One can load pdftexcmds and use pdf@strcmp in all engines (including LuaTeX).
  
  – egreg
  May 20 '11 at 10:04
  

  
  
  
  

add a comment | 

4

If you use pdftex, etex or xetex (I mean engine), you can define a fully expandable test:

makeatletter defIfEnvir #1%
% implicit #2 "what if true"
% implicit #3 "what if false"
%
 ifnum strcmp@currenvir#1=0
 expandafter@firstoftwo
 else
 expandafter@secondoftwo
 fi


makeatother

Such a conditional is defined in the gmutils package: @ifenvir, but there it's protected for some reason.

share|improve this answer

edited May 20 '11 at 9:40

Martin Scharrer♦

203k47651825

answered May 20 '11 at 9:01

NatrorNatror

612

• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  If you prefer the if… … else … fi form, just replace expandafter@first/secondoftwo with your stuff, but i'd suggest the arguments-form because it's robust to unbalanced if's.
  
  – Natror
  May 20 '11 at 9:06
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  Please indent your code with four spaces (or use the '101010' button to do this) so that it is properly highlighted. Please don't use HTML for code formatting. Thanks.
  
  – Martin Scharrer♦
  May 20 '11 at 9:39
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  the command is strcmp in XeTeX and pdfstrcmp in pdfTeX. One can load pdftexcmds and use pdf@strcmp in all engines (including LuaTeX).
  
  – egreg
  May 20 '11 at 10:04
  

  
  
  
  

add a comment | 

If you use pdftex, etex or xetex (I mean engine), you can define a fully expandable test:

makeatletter defIfEnvir #1%
% implicit #2 "what if true"
% implicit #3 "what if false"
%
 ifnum strcmp@currenvir#1=0
 expandafter@firstoftwo
 else
 expandafter@secondoftwo
 fi


makeatother

Such a conditional is defined in the gmutils package: @ifenvir, but there it's protected for some reason.

share|improve this answer

edited May 20 '11 at 9:40

Martin Scharrer♦

203k47651825

answered May 20 '11 at 9:01

NatrorNatror

612

makeatletter defIfEnvir #1%
% implicit #2 "what if true"
% implicit #3 "what if false"
%
 ifnum strcmp@currenvir#1=0
 expandafter@firstoftwo
 else
 expandafter@secondoftwo
 fi


makeatother

share|improve this answer

edited May 20 '11 at 9:40

Martin Scharrer♦

203k47651825

answered May 20 '11 at 9:01

NatrorNatror

612

edited May 20 '11 at 9:40

Martin Scharrer♦

203k47651825

edited May 20 '11 at 9:40

Martin Scharrer♦

203k47651825

answered May 20 '11 at 9:01

NatrorNatror

612

answered May 20 '11 at 9:01

NatrorNatror

612