Invoke the Active Binding in a Thing

Description

Invoke the Active Binding in a Thing

Usage

## S3 method for class 'thing'
x[...]

Arguments

Value

the return value of the active binding in a thing

Use a Package as if a Module

Description

Use a Package as if a Module

Usage

as_module(package)

Arguments

Value

a module that contains a package's exported objects

Examples

tcltk <- as_module("tcltk")
ls(tcltk)

tcltk$is.tclObj(NULL)

Drop a Module

Description

Detach a named module from the search path. If no arguments is supplied, detach the most recently attached module.

Usage

drop(name)

Arguments

Value

TRUE if successful; invisible

Examples

use(mod::ule({
   a <- 1
}), as = "my_module")

use(mod::ule({
   b <- 2
}), as = "my_other_module")

search()

# by name
drop("my_module")

# and at the head position
drop()

search()

Test if an Object is a Module

Description

Test if an Object is a Module

Usage

is_module(x)

Arguments

Value

TRUE if the object is a module, FALSE otherwise

Test if an Object is a Thing

Description

Test if an Object is a Thing

Usage

is_thing(x)

Arguments

Value

TRUE if the object is a thing, FALSE otherwise

Make a Module

Description

Institute a module object inline or from a file. mod::ule() is a useful shorthand for module() when this package is not attached.

Usage

module(..., parent = parent.frame(), lock = TRUE,
  expose_private = FALSE)

ule(..., parent = parent.frame(), lock = TRUE,
  expose_private = FALSE)

acquire(module, parent = baseenv(), lock = TRUE,
  expose_private = FALSE)

Arguments

Value

an environment of class module containing defined objects

Examples

# from file
module_path <- system.file("misc", "example_module.R", package = "mod")
example_module <- acquire(module_path)

example_module$e(123)

# inline
my_module <- mod::ule({
    a <- 1
    .a <- 2
    f <- function(){.a}
})

my_module$a
my_module$f

Name a Module

Description

Name a Module

Usage

name(name)

Arguments

Value

the input

Print a Module

Description

Print a Module

Usage

## S3 method for class 'module'
print(x, ...)

Arguments

Value

the object itself; invisible

Provide Objects from a Module

Description

Can only be used inside a module expression. If this function is used, only the names included as argument are public. If not used, every name in the module will be public.

Usage

provide(...)

Arguments

Value

NULL; invisible

Examples

mod_a <- mod::ule({
    # names included in provide() are public, however...
    mod:::provide(var,.var, ..var)
    # It is suggested to omit mod::: when using
    var <- 1
    .var <- 2
    ..var <- 3 # objects denoted by .. prefix are always private.
    another_var <- 4 # objects not included in provide() are also private.
})

mod_b <- mod::ule({
    # if no call to provide(), all objects are public, except...
    var <- 1
    .var <- 2
    ..var <- 3 # objects denoted by .. prefix are always private.
})

ls(mod_a)
ls(mod_b)

Copy Bindings from a Module to Another

Description

Can only be used inside a module expression. Makes reference to objects from one module, with specified filters.

Usage

refer(..., include = c(), exclude = c(), prefix = "", sep = ".")

Arguments

Value

NULL; invisible

Examples

mod_a <- mod::ule(number <- 1)
mod_b <- mod::ule(number <- 2)

mod_c <- mod::ule({
    mod:::refer(mod_a, mod_b, prefix = .)
    # It is suggested to omit mod::: when using
    number <- mod_a.number + mod_b.number
})

mod_c$number

Load/Attach Package to Local Search Path

Description

Can only be used in a module expression. Emulates the effect of base::require() in its containing module, making functions and their chain of environment availab.e Masks base::require() inside a module context.

Usage

require(package)

Arguments

Value

NULL; invisible

Examples

mod_tcl <- mod::ule({
    mod:::require(tcltk)
    # It is suggested to omit mod::: when using
    f <- tcl
})

identical(mod_tcl$f, tcltk::tcl)

Make a Thing

Description

A "thing" is a special object made based on a module. Contains an active binding, defined with the 'dot' argument.

Usage

thing(..., dot, parent = parent.frame(), lock = TRUE,
  expose_private = FALSE)

Arguments

Value

a module containing an active binding

Examples

my_thing <- mod::thing({
    a <- 1
}, dot = function() a)

my_thing$.

my_thing[]

Load/Attach a Module to the Search Path

Description

Load/Attach a Module to the Search Path

Usage

use(module, as, parent = baseenv(), lock = TRUE,
  expose_private = FALSE)

Arguments

Value

TRUE if successful; invisible

Examples

module_path <- system.file("misc", "example_module.R", package = "mod")
example_module <- acquire(module_path)

# Attach module object to search path
use(example_module)
# or directly from file
use(module_path, "example_module")