How do I avoid eval and parse?












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 three 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 and third instances of eval(parse(...)) in my code don't involve subsetting (the second instance might be related to subsetting).



Is there a way to call new.env(...), [environment name]$[function name] <- [function name], and attach(...) 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
    32 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 three 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 and third instances of eval(parse(...)) in my code don't involve subsetting (the second instance might be related to subsetting).



Is there a way to call new.env(...), [environment name]$[function name] <- [function name], and attach(...) 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
    32 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 three 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 and third instances of eval(parse(...)) in my code don't involve subsetting (the second instance might be related to subsetting).



Is there a way to call new.env(...), [environment name]$[function name] <- [function name], and attach(...) 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 three 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 and third instances of eval(parse(...)) in my code don't involve subsetting (the second instance might be related to subsetting).



Is there a way to call new.env(...), [environment name]$[function name] <- [function name], and attach(...) 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













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edited 1 min ago







Josh

















asked 4 hours ago









JoshJosh

300113




300113













  • 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
    32 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
    32 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
32 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
32 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
    24 mins ago













  • You should create an environment to save into. For example as I demonstrated with env = new.env(). Then pass the environment as your argument. If you need to name the new environement using a character string (environemt in your example - although it is bad practice to use reserved words as names), you can use assign(environment, new.env())

    – dww
    1 min 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
    31 mins ago












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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
    24 mins ago













  • You should create an environment to save into. For example as I demonstrated with env = new.env(). Then pass the environment as your argument. If you need to name the new environement using a character string (environemt in your example - although it is bad practice to use reserved words as names), you can use assign(environment, new.env())

    – dww
    1 min 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
    24 mins ago













  • You should create an environment to save into. For example as I demonstrated with env = new.env(). Then pass the environment as your argument. If you need to name the new environement using a character string (environemt in your example - although it is bad practice to use reserved words as names), you can use assign(environment, new.env())

    – dww
    1 min 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
    24 mins ago













  • You should create an environment to save into. For example as I demonstrated with env = new.env(). Then pass the environment as your argument. If you need to name the new environement using a character string (environemt in your example - although it is bad practice to use reserved words as names), you can use assign(environment, new.env())

    – dww
    1 min 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
    24 mins ago













  • You should create an environment to save into. For example as I demonstrated with env = new.env(). Then pass the environment as your argument. If you need to name the new environement using a character string (environemt in your example - although it is bad practice to use reserved words as names), you can use assign(environment, new.env())

    – dww
    1 min 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
24 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
24 mins ago















You should create an environment to save into. For example as I demonstrated with env = new.env(). Then pass the environment as your argument. If you need to name the new environement using a character string (environemt in your example - although it is bad practice to use reserved words as names), you can use assign(environment, new.env())

– dww
1 min ago





You should create an environment to save into. For example as I demonstrated with env = new.env(). Then pass the environment as your argument. If you need to name the new environement using a character string (environemt in your example - although it is bad practice to use reserved words as names), you can use assign(environment, new.env())

– dww
1 min 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
    31 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
    31 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 4 hours ago









thcthc

5,37611224




5,37611224













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

    – Josh
    31 mins ago



















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

    – Josh
    31 mins ago

















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

– Josh
31 mins ago





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

– Josh
31 mins ago


















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