# datastructures: Implementation of core datastructures for R.
#
# Copyright (C) Simon Dirmeier
#
# This file is part of datastructures.
#
# datastructures is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# datastructures is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with datastructures. If not, see <http://www.gnu.org/licenses/>.
#' @include ds_map.R
#' @include methods_insert.R
#' @include methods_at.R
#' @include methods_keys.R
#' @include methods_values.R
#' @include methods_erase.R
NULL
#' @title Bimap class
#'
#' @export
#' @name bimap-class
#' @rdname bimap-class
#'
#' @description Implementation of a bimap data structure, i.e. an unordered
#' collection of key-value pairs. The notable difference to
#' \code{\linkS4class{hashmap}} is that the mapping is not only
#' \deqn{f: keys -> values,}
#' but also
#' \deqn{f: values -> keys.}
#' Inserting and accessing is amortized in \emph{O(1)}.
#' \code{bimap} wraps a \code{boost::bimap} using Rcpp modules.
#'
#' @slot .map \code{C++} object representing a mapping
#' @slot .key.class the class of the keys
#' @slot .value.class the class of the values
#'
#' @seealso \code{\link{bimap}} for creating a new \code{bimap} object
#'
setClass(
"bimap",
contains = "map",
slots = list(.value.class = "character"),
prototype = prototype(.value.class = NA_character_)
)
#' @title Create a new \code{bimap}
#'
#' @export
#' @importFrom methods new
#'
#' @description Instantiates a new \code{\linkS4class{bimap}} object,
#' i.e. an unordered collection of key-value pairs with mappings
#' \deqn{f: keys -> values,}
#' and
#' \deqn{f: values -> keys.}
#'
#' @param key.class the primitive class type of the keys
#' @param value.class the primitive class type of the values
#'
#' @return returns a new \code{bimap} object
#'
#' @examples
#' # create a bimap with character <-> character bi-mapping
#' b <- bimap()
#'
#' # create a bimap with character <-> integer bi-mapping
#' b <- bimap("character", "integer")
#'
#' # create a bimap with integer <-> integer bi-mapping
#' b <- bimap("integer", "numeric")
bimap <- function(key.class = c("character", "numeric", "integer"),
value.class = c("character", "numeric", "integer")) {
key.class <- match.arg(key.class)
value.class <- match.arg(value.class)
if (key.class == "character") {
if (value.class == "character") {
map <- methods::new(bimap_ss)
} else if (value.class == "integer") {
map <- methods::new(bimap_si)
} else {
map <- methods::new(bimap_sd)
}
}
else if (key.class == "numeric") {
if (value.class == "character") {
map <- methods::new(bimap_ds)
} else if (value.class == "integer") {
map <- methods::new(bimap_di)
} else {
map <- methods::new(bimap_dd)
}
}
else {
if (value.class == "character") {
map <- methods::new(bimap_is)
} else if (value.class == "integer") {
map <- methods::new(bimap_ii)
} else {
map <- methods::new(bimap_id)
}
}
methods::new("bimap",
.key.class = key.class,
.value.class = value.class,
.map = map
)
}
#' @noRd
.insert.bimap <- function(obj, x, y) {
.check.key.value.classes(obj, x, y)
erase(obj, x)
obj@.map$insert(x, y)
obj
}
#' @noRd
.erase.bimap.values <- function(obj, value) {
.check.value.class(obj, value)
obj@.map$remove_value(value)
obj
}
#' Insert parts to an object
#'
#' @description Inserts <key, value> pairs to a bimap.
#'
#' @param x a \code{map} object
#' @param i a vector of keys
#' @param value a vector of values for the keys
setMethod(
"[<-",
signature = signature(
x = "bimap", i = "vector", j = "missing", value = "vector"
),
function(x, i, value) .insert.bimap(x, i, value)
)
#' @rdname insert-methods
setMethod(
"insert",
signature = signature(obj = "bimap", x = "vector", y = "vector"),
function(obj, x, y) .insert.bimap(obj, x, y)
)
#' @rdname at-methods
setMethod(
"at",
signature = signature(obj = "bimap", x = "vector", which = "character"),
function(obj, x, which = c("values", "keys")) {
which <- match.arg(which)
kc <- ifelse(which == "values", obj@.key.class, obj@.value.class)
.check.key.class(obj, x, kc = kc)
if (which == "keys") {
obj@.map$get_left(x)
} else {
obj@.map$get_right(x)
}
}
)
#' @rdname at-methods
setMethod(
"at",
signature = signature(obj = "bimap", x = "vector", which = "missing"),
function(obj, x) {
.check.key.class(obj, x)
obj@.map$get_right(x)
}
)
#' @rdname keys-methods
setMethod("keys", "bimap", function(obj) {
obj@.map$lefts()
})
#' @rdname values-methods
setMethod("values", "bimap", function(obj) {
obj@.map$rights()
})
#' @rdname erase-methods
setMethod(
"erase",
signature = signature(obj = "bimap", key = "missing", value = "vector"),
function(obj, value) .erase.bimap.values(obj, value)
)
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