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How do I avoid eval and parse?
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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
add a comment |
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
1
Just discovered thateval(parse(text = paste0("detach(", environment, ")")))
can be replaced withdetach(environment, character.only = T)
. The question about improvingeval(parse(text = paste0("attach(", environment, ")")))
remains.
– Josh
39 mins ago
add a comment |
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
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
r eval
edited 8 mins ago
Josh
asked 4 hours ago
JoshJosh
300113
300113
1
Just discovered thateval(parse(text = paste0("detach(", environment, ")")))
can be replaced withdetach(environment, character.only = T)
. The question about improvingeval(parse(text = paste0("attach(", environment, ")")))
remains.
– Josh
39 mins ago
add a comment |
1
Just discovered thateval(parse(text = paste0("detach(", environment, ")")))
can be replaced withdetach(environment, character.only = T)
. The question about improvingeval(parse(text = paste0("attach(", environment, ")")))
remains.
– Josh
39 mins ago
1
1
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
39 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
39 mins ago
add a comment |
2 Answers
2
active
oldest
votes
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)
Thank you, I missed that aspect ofsource()
. However, if I change that line of code tosource(paste0("C:/Users/JT/R/Functions/", func, ".R"), local = environment)
I get the errorError 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 fromenvironment
toenv
?
– Josh
31 mins ago
You should create an environment to save into. For example as I demonstrated withenv = 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 useassign(environment, new.env())
– dww
8 mins ago
add a comment |
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.
I agree. I eventually need to learn how to do this.
– Josh
38 mins ago
add a comment |
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2 Answers
2
active
oldest
votes
2 Answers
2
active
oldest
votes
active
oldest
votes
active
oldest
votes
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)
Thank you, I missed that aspect ofsource()
. However, if I change that line of code tosource(paste0("C:/Users/JT/R/Functions/", func, ".R"), local = environment)
I get the errorError 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 fromenvironment
toenv
?
– Josh
31 mins ago
You should create an environment to save into. For example as I demonstrated withenv = 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 useassign(environment, new.env())
– dww
8 mins ago
add a comment |
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$test('hello', 'world')
# [1] "hello world"
ls(pattern = 'test')
# character(0)
And an example test.r
file to use this on:
test = function(a,b) paste(a,b)
Thank you, I missed that aspect ofsource()
. However, if I change that line of code tosource(paste0("C:/Users/JT/R/Functions/", func, ".R"), local = environment)
I get the errorError in source(paste0("C:/Users/JT/R/Functions/", func, ".R"), local = environment) : 'local' must be TRUE, FALSE or an environment
. Is there a way to convert the"env"
that comes fromenvironment
toenv
?
– Josh
31 mins ago
You should create an environment to save into. For example as I demonstrated withenv = new.env()
. Then pass the environment as your argument. If you need to name the new environement using a character string (environemt
in your example - although it is bad practice to use reserved words as names), you can useassign(environment, new.env())
– dww
8 mins ago
add a comment |
For what its worth, the function source
actually uses eval(parse(...))
, albeit in a somewhat subtle way. First, .Internal(parse(...))
is used to create expressions, which after more processing are later passed to eval
. So eval(parse(...))
seems to be good enough for the R core team in this instance.
That said, you don't need to jump through hoops to source functions into a new environment. source
provides an argument local
that can be used for precisely this.
local: TRUE, FALSE or an environment, determining where the parsed expressions are evaluated.
An example:
env = new.env()
source('test.r', local = env)
testing it works:
env$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)
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)
answered 2 hours ago
dwwdww
15.9k32659
15.9k32659
Thank you, I missed that aspect ofsource()
. However, if I change that line of code tosource(paste0("C:/Users/JT/R/Functions/", func, ".R"), local = environment)
I get the errorError 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 fromenvironment
toenv
?
– Josh
31 mins ago
You should create an environment to save into. For example as I demonstrated withenv = 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 useassign(environment, new.env())
– dww
8 mins ago
add a comment |
Thank you, I missed that aspect ofsource()
. However, if I change that line of code tosource(paste0("C:/Users/JT/R/Functions/", func, ".R"), local = environment)
I get the errorError 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 fromenvironment
toenv
?
– Josh
31 mins ago
You should create an environment to save into. For example as I demonstrated withenv = 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 useassign(environment, new.env())
– dww
8 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
31 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
31 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
8 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
8 mins ago
add a comment |
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.
I agree. I eventually need to learn how to do this.
– Josh
38 mins ago
add a comment |
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.
I agree. I eventually need to learn how to do this.
– Josh
38 mins ago
add a comment |
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.
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.
answered 4 hours ago
thcthc
5,37611224
5,37611224
I agree. I eventually need to learn how to do this.
– Josh
38 mins ago
add a comment |
I agree. I eventually need to learn how to do this.
– Josh
38 mins ago
I agree. I eventually need to learn how to do this.
– Josh
38 mins ago
I agree. I eventually need to learn how to do this.
– Josh
38 mins ago
add a comment |
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1
Just discovered that
eval(parse(text = paste0("detach(", environment, ")")))
can be replaced withdetach(environment, character.only = T)
. The question about improvingeval(parse(text = paste0("attach(", environment, ")")))
remains.– Josh
39 mins ago