How do I avoid eval and parse? The Next CEO of Stack OverflowAvoiding the infamous “eval(parse())” constructR: eval(parse(…)) is often suboptimalWhy is using the JavaScript eval function a bad idea?When is JavaScript's eval() not evil?How to sort a dataframe by multiple column(s)?How to join (merge) data frames (inner, outer, left, right)What's the difference between eval, exec, and compile?How to make a great R reproducible exampleWhat does Python's eval() do? Avoiding the infamous “eval(parse())” constructUse argument value as variable name in R during function runR: eval parse function call not accessing correct environments

Is it my responsibility to learn a new technology in my own time my employer wants to implement?

Unreliable Magic - Is it worth it?

Several mode to write the symbol of a vector

Why is the US ranked as #45 in Press Freedom ratings, despite its extremely permissive free speech laws?

Is there a difference between "Fahrstuhl" and "Aufzug"

What connection does MS Office have to Netscape Navigator?

If the heap is initialized for security, then why is the stack uninitialized?

If a black hole is created from light, can this black hole then move at speed of light?

sp_blitzCache results Memory grants

What benefits would be gained by using human laborers instead of drones in deep sea mining?

Sending manuscript to multiple publishers

Why does the UK parliament need a vote on the political declaration?

Anatomically Correct Strange Women In Ponds Distributing Swords

What can we do to stop prior company from asking us questions?

Rotate a column

What happens if you roll doubles 3 times then land on "Go to jail?"

Limits on contract work without pre-agreed price/contract (UK)

How to invert MapIndexed on a ragged structure? How to construct a tree from rules?

Should I tutor a student who I know has cheated on their homework?

Between two walls

Do I need to enable Dev Hub in my PROD Org?

Non-deterministic sum of floats

MessageLevel in QGIS3

Why has the US not been more assertive in confronting Russia in recent years?



How do I avoid eval and parse?



The Next CEO of Stack OverflowAvoiding the infamous “eval(parse())” constructR: eval(parse(…)) is often suboptimalWhy is using the JavaScript eval function a bad idea?When is JavaScript's eval() not evil?How to sort a dataframe by multiple column(s)?How to join (merge) data frames (inner, outer, left, right)What's the difference between eval, exec, and compile?How to make a great R reproducible exampleWhat does Python's eval() do? Avoiding the infamous “eval(parse())” constructUse argument value as variable name in R during function runR: eval parse function call not accessing correct environments










11















I have written a function that sources files that contain scripts for other functions and stores these functions in an alternative environment so that they aren't cluttering up the global environment. The code works, but contains two instances of eval(parse(...)):



# sourceFunctionHidden ---------------------------
# source a function and hide the function from the global environment
sourceFunctionHidden <- function(functions, environment = "env", ...)
if (environment %in% search())
while (environment %in% search())
if (!exists("counter", inherits = F)) counter <- 0
eval(parse(text = paste0("detach(", environment, ")")))
counter <- counter + 1

cat("detached", counter, environment, "sn")
else cat("no", environment, "attachedn")
if (!environment %in% ls(.GlobalEnv, all.names = T))
assign(environment, new.env(), pos = .GlobalEnv)
cat("created", environment, "n")
else cat(environment, "already existsn")
sapply(functions, function(func)
# source(paste0("C:/Users/JT/R/Functions/", func, ".R"), .env)
source(paste0("C:/Users/JT/R/Functions/", func, ".R"))
eval(parse(text = paste0(environment, "$", func," <- ", func)))
cat(func, "created in", environment, "n")
)
# rm(list = functions, pos = .GlobalEnv)
eval(parse(text = paste0("attach(", environment, ")")))
cat("attached", environment, "nn")



Much has been written about the sub-optimality of the eval(parse(...)) construction (see here and here). However, the discussions that I've found mostly deal with alternate strategies for subsetting. The first instance of eval(parse(...)) in my code doesn't involve subsetting (the second instance might be related to subsetting).



Is there a way to call new.env(...) and [environment name]$[function name] <- [function name] without resorting to eval(parse(...))? Thanks.



N.B.: I don't want to change the names of my functions to .name to hide them in the global environment










share|improve this question






















  • Just discovered that eval(parse(text = paste0("detach(", environment, ")"))) can be replaced with detach(environment, character.only = T). The question about improving eval(parse(text = paste0("attach(", environment, ")"))) remains.

    – Josh
    18 mins ago
















11















I have written a function that sources files that contain scripts for other functions and stores these functions in an alternative environment so that they aren't cluttering up the global environment. The code works, but contains two instances of eval(parse(...)):



# sourceFunctionHidden ---------------------------
# source a function and hide the function from the global environment
sourceFunctionHidden <- function(functions, environment = "env", ...)
if (environment %in% search())
while (environment %in% search())
if (!exists("counter", inherits = F)) counter <- 0
eval(parse(text = paste0("detach(", environment, ")")))
counter <- counter + 1

cat("detached", counter, environment, "sn")
else cat("no", environment, "attachedn")
if (!environment %in% ls(.GlobalEnv, all.names = T))
assign(environment, new.env(), pos = .GlobalEnv)
cat("created", environment, "n")
else cat(environment, "already existsn")
sapply(functions, function(func)
# source(paste0("C:/Users/JT/R/Functions/", func, ".R"), .env)
source(paste0("C:/Users/JT/R/Functions/", func, ".R"))
eval(parse(text = paste0(environment, "$", func," <- ", func)))
cat(func, "created in", environment, "n")
)
# rm(list = functions, pos = .GlobalEnv)
eval(parse(text = paste0("attach(", environment, ")")))
cat("attached", environment, "nn")



Much has been written about the sub-optimality of the eval(parse(...)) construction (see here and here). However, the discussions that I've found mostly deal with alternate strategies for subsetting. The first instance of eval(parse(...)) in my code doesn't involve subsetting (the second instance might be related to subsetting).



Is there a way to call new.env(...) and [environment name]$[function name] <- [function name] without resorting to eval(parse(...))? Thanks.



N.B.: I don't want to change the names of my functions to .name to hide them in the global environment










share|improve this question






















  • Just discovered that eval(parse(text = paste0("detach(", environment, ")"))) can be replaced with detach(environment, character.only = T). The question about improving eval(parse(text = paste0("attach(", environment, ")"))) remains.

    – Josh
    18 mins ago














11












11








11








I have written a function that sources files that contain scripts for other functions and stores these functions in an alternative environment so that they aren't cluttering up the global environment. The code works, but contains two instances of eval(parse(...)):



# sourceFunctionHidden ---------------------------
# source a function and hide the function from the global environment
sourceFunctionHidden <- function(functions, environment = "env", ...)
if (environment %in% search())
while (environment %in% search())
if (!exists("counter", inherits = F)) counter <- 0
eval(parse(text = paste0("detach(", environment, ")")))
counter <- counter + 1

cat("detached", counter, environment, "sn")
else cat("no", environment, "attachedn")
if (!environment %in% ls(.GlobalEnv, all.names = T))
assign(environment, new.env(), pos = .GlobalEnv)
cat("created", environment, "n")
else cat(environment, "already existsn")
sapply(functions, function(func)
# source(paste0("C:/Users/JT/R/Functions/", func, ".R"), .env)
source(paste0("C:/Users/JT/R/Functions/", func, ".R"))
eval(parse(text = paste0(environment, "$", func," <- ", func)))
cat(func, "created in", environment, "n")
)
# rm(list = functions, pos = .GlobalEnv)
eval(parse(text = paste0("attach(", environment, ")")))
cat("attached", environment, "nn")



Much has been written about the sub-optimality of the eval(parse(...)) construction (see here and here). However, the discussions that I've found mostly deal with alternate strategies for subsetting. The first instance of eval(parse(...)) in my code doesn't involve subsetting (the second instance might be related to subsetting).



Is there a way to call new.env(...) and [environment name]$[function name] <- [function name] without resorting to eval(parse(...))? Thanks.



N.B.: I don't want to change the names of my functions to .name to hide them in the global environment










share|improve this question














I have written a function that sources files that contain scripts for other functions and stores these functions in an alternative environment so that they aren't cluttering up the global environment. The code works, but contains two instances of eval(parse(...)):



# sourceFunctionHidden ---------------------------
# source a function and hide the function from the global environment
sourceFunctionHidden <- function(functions, environment = "env", ...)
if (environment %in% search())
while (environment %in% search())
if (!exists("counter", inherits = F)) counter <- 0
eval(parse(text = paste0("detach(", environment, ")")))
counter <- counter + 1

cat("detached", counter, environment, "sn")
else cat("no", environment, "attachedn")
if (!environment %in% ls(.GlobalEnv, all.names = T))
assign(environment, new.env(), pos = .GlobalEnv)
cat("created", environment, "n")
else cat(environment, "already existsn")
sapply(functions, function(func)
# source(paste0("C:/Users/JT/R/Functions/", func, ".R"), .env)
source(paste0("C:/Users/JT/R/Functions/", func, ".R"))
eval(parse(text = paste0(environment, "$", func," <- ", func)))
cat(func, "created in", environment, "n")
)
# rm(list = functions, pos = .GlobalEnv)
eval(parse(text = paste0("attach(", environment, ")")))
cat("attached", environment, "nn")



Much has been written about the sub-optimality of the eval(parse(...)) construction (see here and here). However, the discussions that I've found mostly deal with alternate strategies for subsetting. The first instance of eval(parse(...)) in my code doesn't involve subsetting (the second instance might be related to subsetting).



Is there a way to call new.env(...) and [environment name]$[function name] <- [function name] without resorting to eval(parse(...))? Thanks.



N.B.: I don't want to change the names of my functions to .name to hide them in the global environment







r eval






share|improve this question













share|improve this question











share|improve this question




share|improve this question










asked 4 hours ago









JoshJosh

300112




300112












  • Just discovered that eval(parse(text = paste0("detach(", environment, ")"))) can be replaced with detach(environment, character.only = T). The question about improving eval(parse(text = paste0("attach(", environment, ")"))) remains.

    – Josh
    18 mins ago


















  • Just discovered that eval(parse(text = paste0("detach(", environment, ")"))) can be replaced with detach(environment, character.only = T). The question about improving eval(parse(text = paste0("attach(", environment, ")"))) remains.

    – Josh
    18 mins ago

















Just discovered that eval(parse(text = paste0("detach(", environment, ")"))) can be replaced with detach(environment, character.only = T). The question about improving eval(parse(text = paste0("attach(", environment, ")"))) remains.

– Josh
18 mins ago






Just discovered that eval(parse(text = paste0("detach(", environment, ")"))) can be replaced with detach(environment, character.only = T). The question about improving eval(parse(text = paste0("attach(", environment, ")"))) remains.

– Josh
18 mins ago













2 Answers
2






active

oldest

votes


















4














For what its worth, the function source actually uses eval(parse(...)), albeit in a somewhat subtle way. First, .Internal(parse(...)) is used to create expressions, which after more processing are later passed to eval. So eval(parse(...)) seems to be good enough for the R core team in this instance.



That said, you don't need to jump through hoops to source functions into a new environment. source provides an argument local that can be used for precisely this.




local: TRUE, FALSE or an environment, determining where the parsed expressions are evaluated.




An example:



env = new.env()
source('test.r', local = env)


testing it works:



env$test('hello', 'world')
# [1] "hello world"
ls(pattern = 'test')
# character(0)


And an example test.r file to use this on:



test = function(a,b) paste(a,b)





share|improve this answer























  • Thank you, I missed that aspect of source(). However, if I change that line of code to source(paste0("C:/Users/JT/R/Functions/", func, ".R"), local = environment) I get the error Error in source(paste0("C:/Users/JT/R/Functions/", func, ".R"), local = environment) : 'local' must be TRUE, FALSE or an environment. Is there a way to convert the "env" that comes from environment to env?

    – Josh
    9 mins ago



















3














If you want to keep it off global_env, put it into a package. It's common for people in the R community to put a bunch of frequently used helper functions into their own personal package.






share|improve this answer























  • I agree. I eventually need to learn how to do this.

    – Josh
    16 mins ago











Your Answer






StackExchange.ifUsing("editor", function ()
StackExchange.using("externalEditor", function ()
StackExchange.using("snippets", function ()
StackExchange.snippets.init();
);
);
, "code-snippets");

StackExchange.ready(function()
var channelOptions =
tags: "".split(" "),
id: "1"
;
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',
autoActivateHeartbeat: false,
convertImagesToLinks: true,
noModals: true,
showLowRepImageUploadWarning: true,
reputationToPostImages: 10,
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


















StackExchange.ready(
function ()
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fstackoverflow.com%2fquestions%2f55426015%2fhow-do-i-avoid-eval-and-parse%23new-answer', 'question_page');

);

Post as a guest















Required, but never shown

























2 Answers
2






active

oldest

votes








2 Answers
2






active

oldest

votes









active

oldest

votes






active

oldest

votes









4














For what its worth, the function source actually uses eval(parse(...)), albeit in a somewhat subtle way. First, .Internal(parse(...)) is used to create expressions, which after more processing are later passed to eval. So eval(parse(...)) seems to be good enough for the R core team in this instance.



That said, you don't need to jump through hoops to source functions into a new environment. source provides an argument local that can be used for precisely this.




local: TRUE, FALSE or an environment, determining where the parsed expressions are evaluated.




An example:



env = new.env()
source('test.r', local = env)


testing it works:



env$test('hello', 'world')
# [1] "hello world"
ls(pattern = 'test')
# character(0)


And an example test.r file to use this on:



test = function(a,b) paste(a,b)





share|improve this answer























  • Thank you, I missed that aspect of source(). However, if I change that line of code to source(paste0("C:/Users/JT/R/Functions/", func, ".R"), local = environment) I get the error Error in source(paste0("C:/Users/JT/R/Functions/", func, ".R"), local = environment) : 'local' must be TRUE, FALSE or an environment. Is there a way to convert the "env" that comes from environment to env?

    – Josh
    9 mins ago
















4














For what its worth, the function source actually uses eval(parse(...)), albeit in a somewhat subtle way. First, .Internal(parse(...)) is used to create expressions, which after more processing are later passed to eval. So eval(parse(...)) seems to be good enough for the R core team in this instance.



That said, you don't need to jump through hoops to source functions into a new environment. source provides an argument local that can be used for precisely this.




local: TRUE, FALSE or an environment, determining where the parsed expressions are evaluated.




An example:



env = new.env()
source('test.r', local = env)


testing it works:



env$test('hello', 'world')
# [1] "hello world"
ls(pattern = 'test')
# character(0)


And an example test.r file to use this on:



test = function(a,b) paste(a,b)





share|improve this answer























  • Thank you, I missed that aspect of source(). However, if I change that line of code to source(paste0("C:/Users/JT/R/Functions/", func, ".R"), local = environment) I get the error Error in source(paste0("C:/Users/JT/R/Functions/", func, ".R"), local = environment) : 'local' must be TRUE, FALSE or an environment. Is there a way to convert the "env" that comes from environment to env?

    – Josh
    9 mins ago














4












4








4







For what its worth, the function source actually uses eval(parse(...)), albeit in a somewhat subtle way. First, .Internal(parse(...)) is used to create expressions, which after more processing are later passed to eval. So eval(parse(...)) seems to be good enough for the R core team in this instance.



That said, you don't need to jump through hoops to source functions into a new environment. source provides an argument local that can be used for precisely this.




local: TRUE, FALSE or an environment, determining where the parsed expressions are evaluated.




An example:



env = new.env()
source('test.r', local = env)


testing it works:



env$test('hello', 'world')
# [1] "hello world"
ls(pattern = 'test')
# character(0)


And an example test.r file to use this on:



test = function(a,b) paste(a,b)





share|improve this answer













For what its worth, the function source actually uses eval(parse(...)), albeit in a somewhat subtle way. First, .Internal(parse(...)) is used to create expressions, which after more processing are later passed to eval. So eval(parse(...)) seems to be good enough for the R core team in this instance.



That said, you don't need to jump through hoops to source functions into a new environment. source provides an argument local that can be used for precisely this.




local: TRUE, FALSE or an environment, determining where the parsed expressions are evaluated.




An example:



env = new.env()
source('test.r', local = env)


testing it works:



env$test('hello', 'world')
# [1] "hello world"
ls(pattern = 'test')
# character(0)


And an example test.r file to use this on:



test = function(a,b) paste(a,b)






share|improve this answer












share|improve this answer



share|improve this answer










answered 2 hours ago









dwwdww

15.9k32659




15.9k32659












  • Thank you, I missed that aspect of source(). However, if I change that line of code to source(paste0("C:/Users/JT/R/Functions/", func, ".R"), local = environment) I get the error Error in source(paste0("C:/Users/JT/R/Functions/", func, ".R"), local = environment) : 'local' must be TRUE, FALSE or an environment. Is there a way to convert the "env" that comes from environment to env?

    – Josh
    9 mins ago


















  • Thank you, I missed that aspect of source(). However, if I change that line of code to source(paste0("C:/Users/JT/R/Functions/", func, ".R"), local = environment) I get the error Error in source(paste0("C:/Users/JT/R/Functions/", func, ".R"), local = environment) : 'local' must be TRUE, FALSE or an environment. Is there a way to convert the "env" that comes from environment to env?

    – Josh
    9 mins ago

















Thank you, I missed that aspect of source(). However, if I change that line of code to source(paste0("C:/Users/JT/R/Functions/", func, ".R"), local = environment) I get the error Error in source(paste0("C:/Users/JT/R/Functions/", func, ".R"), local = environment) : 'local' must be TRUE, FALSE or an environment. Is there a way to convert the "env" that comes from environment to env?

– Josh
9 mins ago






Thank you, I missed that aspect of source(). However, if I change that line of code to source(paste0("C:/Users/JT/R/Functions/", func, ".R"), local = environment) I get the error Error in source(paste0("C:/Users/JT/R/Functions/", func, ".R"), local = environment) : 'local' must be TRUE, FALSE or an environment. Is there a way to convert the "env" that comes from environment to env?

– Josh
9 mins ago














3














If you want to keep it off global_env, put it into a package. It's common for people in the R community to put a bunch of frequently used helper functions into their own personal package.






share|improve this answer























  • I agree. I eventually need to learn how to do this.

    – Josh
    16 mins ago















3














If you want to keep it off global_env, put it into a package. It's common for people in the R community to put a bunch of frequently used helper functions into their own personal package.






share|improve this answer























  • I agree. I eventually need to learn how to do this.

    – Josh
    16 mins ago













3












3








3







If you want to keep it off global_env, put it into a package. It's common for people in the R community to put a bunch of frequently used helper functions into their own personal package.






share|improve this answer













If you want to keep it off global_env, put it into a package. It's common for people in the R community to put a bunch of frequently used helper functions into their own personal package.







share|improve this answer












share|improve this answer



share|improve this answer










answered 3 hours ago









thcthc

5,37611224




5,37611224












  • I agree. I eventually need to learn how to do this.

    – Josh
    16 mins ago

















  • I agree. I eventually need to learn how to do this.

    – Josh
    16 mins ago
















I agree. I eventually need to learn how to do this.

– Josh
16 mins ago





I agree. I eventually need to learn how to do this.

– Josh
16 mins ago

















draft saved

draft discarded
















































Thanks for contributing an answer to Stack Overflow!


  • Please be sure to answer the question. Provide details and share your research!

But avoid


  • Asking for help, clarification, or responding to other answers.

  • Making statements based on opinion; back them up with references or personal experience.

To learn more, see our tips on writing great answers.




draft saved


draft discarded














StackExchange.ready(
function ()
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fstackoverflow.com%2fquestions%2f55426015%2fhow-do-i-avoid-eval-and-parse%23new-answer', 'question_page');

);

Post as a guest















Required, but never shown





















































Required, but never shown














Required, but never shown












Required, but never shown







Required, but never shown

































Required, but never shown














Required, but never shown












Required, but never shown







Required, but never shown







Popular posts from this blog

Disable / Remove link to Product Items in Cart Planned maintenance scheduled April 23, 2019 at 23:30 UTC (7:30pm US/Eastern) Announcing the arrival of Valued Associate #679: Cesar Manara Unicorn Meta Zoo #1: Why another podcast?How can I limit products that can be bought / added to cart?Remove item from cartHide “Add to Cart” button if specific products are already in cart“Prettifying” the custom options in cart pageCreate link in cart sidebar to view all added items After limit reachedLink products together in checkout/cartHow to Get product from cart and add it againHide action-edit on cart page if simple productRemoving Cart items - ObserverRemove wishlist items when added to cart

Helsingin valtaus Sisällysluettelo Taustaa | Yleistä sotatoimista | Osapuolet | Taistelut Helsingin ympäristössä | Punaisten antautumissuunnitelma | Taistelujen kulku Helsingissä | Valtauksen jälkeen | Tappiot | Muistaminen | Kirjallisuutta | Lähteet | Aiheesta muualla | NavigointivalikkoTeoksen verkkoversioTeoksen verkkoversioGoogle BooksSisällissota Helsingissä päättyi tasan 95 vuotta sittenSaksalaisten ylivoima jyräsi punaisen HelsinginSuomalaiset kuvaavat sotien jälkiä kaupungeissa – katso kuvat ja tarinat tutuilta kulmiltaHelsingin valtaus 90 vuotta sittenSaksalaiset valtasivat HelsinginHyökkäys HelsinkiinHelsingin valtaus 12.–13.4. 1918Saksalaiset käyttivät ihmiskilpiä Helsingin valtauksessa 1918Teoksen verkkoversioTeoksen verkkoversioSaksalaiset hyökkäävät Etelä-SuomeenTaistelut LeppävaarassaSotilaat ja taistelutLeppävaara 1918 huhtikuussa. KapinatarinaHelsingin taistelut 1918Saksalaisten voitonparaati HelsingissäHelsingin valtausta juhlittiinSaksalaisten Helsinki vuonna 1918Helsingin taistelussa kaatuneet valkokaartilaisetHelsinkiin haudatut taisteluissa kaatuneet punaiset12.4.1918 Helsingin valtauksessa saksalaiset apujoukot vapauttavat kaupunginVapaussodan muistomerkkejä Helsingissä ja pääkaupunkiseudullaCrescendo / Vuoden 1918 Kansalaissodan uhrien muistomerkkim

Adjektiivitarina Tarinan tekeminen | Esimerkki: ennen | Esimerkki: jälkeen | Navigointivalikko