-module(prng@random).
-compile([no_auto_import, nowarn_unused_vars, nowarn_unused_function, nowarn_nomatch, inline]).
-define(FILEPATH, "src/prng/random.gleam").
-export([new_seed/1, step/2, sample/2, to_yielder/2, int/2, random_sample/1, to_random_yielder/1, float/2, constant/1, fixed_size_list/2, then/2, list/1, map/2, weighted/2, try_weighted/1, map2/3, pair/2, uniform/2, try_uniform/1, choose/2, map3/4, map4/5, map5/6, fixed_size_string/1, string/0, bit_array/0, set/1, fixed_size_set/2, dict/2, fixed_size_dict/3]).
-export_type([generator/1]).
-if(?OTP_RELEASE >= 27).
-define(MODULEDOC(Str), -moduledoc(Str)).
-define(DOC(Str), -doc(Str)).
-else.
-define(MODULEDOC(Str), -compile([])).
-define(DOC(Str), -compile([])).
-endif.
?MODULEDOC(
" This package provides many building blocks that can be used to define\n"
" pure generators of pseudo-random values.\n"
"\n"
" This is based on the great\n"
" [Elm implementation](https://package.elm-lang.org/packages/elm/random/1.0.0/)\n"
" of [Permuted Congruential Generators](https://www.pcg-random.org).\n"
"\n"
" _It is not cryptographically secure!_\n"
"\n"
" You can use this cheatsheet to navigate the module documentation:\n"
"\n"
"
\n"
" \n"
" | Building generators | \n"
" \n"
" int,\n"
" float,\n"
" string,\n"
" fixed_size_string,\n"
" bit_array,\n"
" uniform,\n"
" weighted,\n"
" choose,\n"
" constant\n"
" | \n"
"
\n"
" \n"
" | Transform and compose generators | \n"
" \n"
" map,\n"
" then,\n"
" pair\n"
" | \n"
"
\n"
" \n"
" | Generating common data structures | \n"
" \n"
" fixed_size_list,\n"
" list,\n"
" fixed_size_dict,\n"
" dict\n"
" fixed_size_set,\n"
" set\n"
" | \n"
"
\n"
" \n"
" | Getting values out of a generator | \n"
" \n"
" step\n"
" | \n"
"
\n"
"
\n"
"\n"
).
-opaque generator(EVL) :: {generator,
fun((prng@seed:seed()) -> {EVL, prng@seed:seed()})}.
-file("src/prng/random.gleam", 120).
-spec new_seed(integer()) -> prng@seed:seed().
new_seed(Int) ->
prng_ffi:new_seed(Int).
-file("src/prng/random.gleam", 149).
?DOC(
" Steps a `Generator(a)` producing a random value of type `a` using the given\n"
" seed as the source of randomness.\n"
"\n"
" The stepping logic is completely deterministic. This means that, given a\n"
" seed and a generator, you'll always get the same result.\n"
"\n"
" This is why this function also returns a new seed that can be used to make\n"
" subsequent calls to `step` to get other random values.\n"
"\n"
" Stepping a generator by hand can be quite cumbersome, so I recommend you\n"
" try [`to_yielder`](#to_yielder),\n"
" [`to_random_yielder`](#to_random_yielder), or [`sample`](#sample) instead.\n"
"\n"
" ## Examples\n"
"\n"
" ```gleam\n"
" let initial_seed = seed.new(11)\n"
" let dice_roll = random.int(1, 6)\n"
" let #(first_roll, new_seed) = random.step(dice_roll, initial_seed)\n"
" let #(second_roll, _) = random.step(dice_roll, new_seed)\n"
"\n"
" #(first_roll, second_roll)\n"
" // -> #(3, 2)\n"
" ```\n"
).
-spec step(generator(EVM), prng@seed:seed()) -> {EVM, prng@seed:seed()}.
step(Generator, Seed) ->
(erlang:element(2, Generator))(Seed).
-file("src/prng/random.gleam", 160).
?DOC(
" Generates a single value using the given generator and seed.\n"
"\n"
" This is just a shorthand for the `step` function that drops the new\n"
" seed. It can be useful if you just need to get a single value out of\n"
" a generator and need the result to be reproducible.\n"
).
-spec sample(generator(EVO), prng@seed:seed()) -> EVO.
sample(Generator, Seed) ->
erlang:element(1, step(Generator, Seed)).
-file("src/prng/random.gleam", 222).
?DOC(
" Turns the given generator into an infinite stream of random values generated\n"
" with it.\n"
"\n"
" `seed` is the seed used to get the initial random value and start the\n"
" infinite sequence.\n"
"\n"
" If you don't care about the initial seed and reproducibility is not your\n"
" goal, you can use `to_random_yielder` which works like this function and\n"
" randomly picks the initial seed.\n"
).
-spec to_yielder(generator(EVV), prng@seed:seed()) -> gleam@yielder:yielder(EVV).
to_yielder(Generator, Seed) ->
gleam@yielder:unfold(
Seed,
fun(Seed@1) ->
{Value, New_seed} = step(Generator, Seed@1),
{next, Value, New_seed}
end
).
-file("src/prng/random.gleam", 262).
-spec sort_ascending(EVZ, EVZ, fun((EVZ, EVZ) -> gleam@order:order())) -> {EVZ,
EVZ}.
sort_ascending(One, Other, Compare) ->
case Compare(One, Other) of
lt ->
{One, Other};
eq ->
{One, Other};
gt ->
{Other, One}
end.
-file("src/prng/random.gleam", 256).
?DOC(
" Generates integers in the given inclusive range.\n"
"\n"
" ## Examples\n"
"\n"
" Say you want to model the outcome of a dice, you could use `int` like this:\n"
"\n"
" ```gleam\n"
" let dice_roll = random.int(1, 6)\n"
" ```\n"
).
-spec int(integer(), integer()) -> generator(integer()).
int(From, To) ->
{generator,
fun(Seed) ->
{Low, High} = sort_ascending(From, To, fun gleam@int:compare/2),
prng_ffi:random_int(Seed, Low, High)
end}.
-file("src/prng/random.gleam", 188).
?DOC(
" Generates a single value using the given generator.\n"
"\n"
" The initial seed is chosen randomly so you won't have control over which\n"
" value is generated and may get different results each time you call this\n"
" function.\n"
"\n"
" This is useful if you want to quickly get a value out of a generator and\n"
" do not care about reproducibility (if you want to decide which seed is\n"
" used for the generation process you'll have to use `random.step`).\n"
"\n"
" ## Examples\n"
"\n"
" Imagine you want to perform some action, say only 40% of the times.\n"
" Your code may look like this:\n"
"\n"
" ```gleam\n"
" let probability = random.float(0.0, 1.0)\n"
" case random.random_sample(probability) <= 0.4 {\n"
" True -> perform_action()\n"
" False -> Nil // do nothing\n"
" }\n"
" ```\n"
).
-spec random_sample(generator(EVQ)) -> EVQ.
random_sample(Generator) ->
erlang:element(
1,
step(Generator, prng_ffi:new_seed(gleam@int:random(4294967296)))
).
-file("src/prng/random.gleam", 203).
?DOC(
" Turns the given generator into an infinite stream of random values generated\n"
" with it.\n"
"\n"
" The initial seed is chosen randomly so you won't have control over which\n"
" values are generated and may get different results each time you call this\n"
" function.\n"
"\n"
" If you want to have control over the initial seed used to get the infinite\n"
" sequence of values, you can use `to_yielder`.\n"
).
-spec to_random_yielder(generator(EVS)) -> gleam@yielder:yielder(EVS).
to_random_yielder(Generator) ->
gleam@yielder:unfold(
prng_ffi:new_seed(gleam@int:random(4294967296)),
fun(Seed) ->
{Value, New_seed} = step(Generator, Seed),
{next, Value, New_seed}
end
).
-file("src/prng/random.gleam", 281).
?DOC(
" Generates floating point numbers in the given inclusive range.\n"
"\n"
" ## Examples\n"
"\n"
" ```gleam\n"
" let probability = random.float(0.0, 1.0)\n"
" ```\n"
).
-spec float(float(), float()) -> generator(float()).
float(From, To) ->
{generator,
fun(Seed) ->
{Low, High} = sort_ascending(From, To, fun gleam@float:compare/2),
prng_ffi:random_float(Seed, Low, High)
end}.
-file("src/prng/random.gleam", 303).
?DOC(
" Always generates the given value, no matter the seed used.\n"
"\n"
" ## Examples\n"
"\n"
" ```gleam\n"
" let always_eleven = random.constant(11)\n"
" random.random_sample(always_eleven)\n"
" // -> 11\n"
" ```\n"
).
-spec constant(EWB) -> generator(EWB).
constant(Value) ->
{generator, fun(Seed) -> {Value, Seed} end}.
-file("src/prng/random.gleam", 463).
-spec get_by_weight({float(), EWT}, list({float(), EWT}), float()) -> EWT.
get_by_weight(First, Others, Countdown) ->
{Weight, Value} = First,
case Others of
[] ->
Value;
[Second | Rest] ->
Positive_weight = gleam@float:absolute_value(Weight),
case gleam@float:compare(Countdown, Positive_weight) of
lt ->
Value;
eq ->
Value;
gt ->
get_by_weight(Second, Rest, Countdown - Positive_weight)
end
end.
-file("src/prng/random.gleam", 550).
-spec do_fixed_size_list(list(EXG), prng@seed:seed(), generator(EXG), integer()) -> {list(EXG),
prng@seed:seed()}.
do_fixed_size_list(Acc, Seed, Generator, Length) ->
case Length =< 0 of
true ->
{Acc, Seed};
false ->
{Value, Seed@1} = step(Generator, Seed),
do_fixed_size_list([Value | Acc], Seed@1, Generator, Length - 1)
end.
-file("src/prng/random.gleam", 542).
?DOC(
" Generates a lists of a fixed size; its values are generated using the\n"
" given generator.\n"
"\n"
" ## Examples\n"
"\n"
" Imagine you're modelling a game of\n"
" [Risk](https://en.wikipedia.org/wiki/Risk_(game)); when a player \"attacks\"\n"
" they can roll three dice. You may model that outcome using `fixed_size_list`\n"
" like this:\n"
"\n"
" ```gleam\n"
" let dice_roll = random.int(1, 6)\n"
" let attack_outcome = random.fixed_size_list(dice_roll, 3)\n"
" ```\n"
).
-spec fixed_size_list(generator(EXC), integer()) -> generator(list(EXC)).
fixed_size_list(Generator, Length) ->
{generator,
fun(Seed) -> do_fixed_size_list([], Seed, Generator, Length) end}.
-file("src/prng/random.gleam", 744).
?DOC(
" Transforms a generator into another one based on its generated values.\n"
"\n"
" The random value generated by the given generator is fed into the `do`\n"
" function and the returned generator is used as the new generator.\n"
"\n"
" ## Examples\n"
"\n"
" `then` is a really powerful function, almost all functions exposed by this\n"
" library could be defined in term of it!\n"
" Take as an example `map`, it can be implemented like this:\n"
"\n"
" ```gleam\n"
" fn map(generator: Generator(a), with fun: fn(a) -> b) -> Generator(b) {\n"
" random.then(generator, fn(value) {\n"
" random.constant(fun(value))\n"
" })\n"
" }\n"
" ```\n"
"\n"
" Notice how the `do` function needs to return a `Generator(b)`, you can\n"
" achieve that by wrapping any constant value with the `random.constant`\n"
" generator.\n"
"\n"
" > Code written with `then` can gain a lot in readability if you use the\n"
" > `use` syntax, especially if it has some deep nesting. As an example, this\n"
" > is how you can rewrite the previous example taking advantage of `use`:\n"
" >\n"
" > ```gleam\n"
" > fn map(generator: Generator(a), with fun: fn(a) -> b) -> Generator(b) {\n"
" > use value <- random.then(generator)\n"
" > random.constant(fun(value))\n"
" > }\n"
" > ```\n"
).
-spec then(generator(EYV), fun((EYV) -> generator(EYX))) -> generator(EYX).
then(Generator, Generator_from) ->
{generator,
fun(Seed) ->
{Value, Seed@1} = step(Generator, Seed),
_pipe = Generator_from(Value),
step(_pipe, Seed@1)
end}.
-file("src/prng/random.gleam", 571).
?DOC(
" Generates a list with a random size with at most 32 items.\n"
" Each item is generated using the given generator.\n"
"\n"
" This is similar to `fixed_size_list` with the difference that the size\n"
" is chosen randomly.\n"
).
-spec list(generator(EXK)) -> generator(list(EXK)).
list(Generator) ->
then(int(0, 32), fun(Size) -> fixed_size_list(Generator, Size) end).
-file("src/prng/random.gleam", 771).
?DOC(
" Transforms the values produced by a generator using the given function.\n"
"\n"
" ## Examples\n"
"\n"
" Imagine you want to make a generator for boolean values that returns\n"
" `True` and `False` with the same probability. You could do that using `map`\n"
" like this:\n"
"\n"
" ```gleam\n"
" let bool_generator = random.int(1, 2) |> random.map(fn(n) { n == 1 })\n"
" ```\n"
"\n"
" Here `map` allows you to transform the values produced by the initial\n"
" integer generator - either 1 or 2 - into boolean values: when the original\n"
" generator produces a 1, `bool_generator` will produce `True`; when the\n"
" original generator produces a 2, `bool_generator` will produce `False`.\n"
).
-spec map(generator(EZA), fun((EZA) -> EZC)) -> generator(EZC).
map(Generator, Fun) ->
{generator,
fun(Seed) ->
{Value, Seed@1} = step(Generator, Seed),
{Fun(Value), Seed@1}
end}.
-file("src/prng/random.gleam", 418).
?DOC(
" Generates values from the given ones with a weighted probability.\n"
"\n"
" This generator can guarantee to produce values since it always takes at\n"
" least one item (as its first argument); if it were to accept just a list of\n"
" options, it could be called like this:\n"
"\n"
" ```gleam\n"
" weighted([])\n"
" ```\n"
"\n"
" In which case it would be impossible to actually produce any value: none was\n"
" provided!\n"
"\n"
" ## Examples\n"
"\n"
" Given the following type to model the outcome of a coin flip:\n"
"\n"
" ```gleam\n"
" pub type CoinFlip {\n"
" Heads\n"
" Tails\n"
" }\n"
" ```\n"
"\n"
" You could write a generator for a loaded coin that lands on head 75% of the\n"
" times like this:\n"
"\n"
" ```gleam\n"
" let loaded_coin = random.weighted(#(0.75, Heads), [#(0.25, Tails)])\n"
" ```\n"
"\n"
" In this example the weights add up to 1, but you could use any number: the\n"
" weights get added up to a `total` and the probability of each option is its\n"
" `weight` / `total`.\n"
).
-spec weighted({float(), EWL}, list({float(), EWL})) -> generator(EWL).
weighted(First, Others) ->
Normalise = fun(Pair) ->
gleam@float:absolute_value(gleam@pair:first(Pair))
end,
Total = Normalise(First) + gleam@float:sum(
gleam@list:map(Others, Normalise)
),
map(
float(+0.0, Total),
fun(_capture) -> get_by_weight(First, Others, _capture) end
).
-file("src/prng/random.gleam", 456).
?DOC(
" This function works exactly like `weighted` but will return an `Error(Nil)`\n"
" if the provided argument is an empty list since the generator wouldn't be\n"
" able to produce any value in that case.\n"
"\n"
" It generates values from the given list with a weighted probability.\n"
"\n"
" ## Examples\n"
"\n"
" ```gleam\n"
" random.try_weighted([])\n"
" // -> Error(Nil)\n"
" ```\n"
"\n"
" For example if you consider the following type definition to model color:\n"
"\n"
" ```gleam\n"
" type CoinFlip {\n"
" Heads\n"
" Tails\n"
" }\n"
" ```\n"
"\n"
" This call of `try_weighted` will produce a generator wrapped in an `Ok`:\n"
"\n"
" ```gleam\n"
" let assert Ok(coin_1) =\n"
" random.try_weighted([#(0.75, Heads), #(0.25, Tails)])\n"
" let coin_2 = random.uniform(#(0.75, Heads), [#(0.25, Tails)])\n"
" ```\n"
"\n"
" The generators `coin_1` and `coin_2` will behave exactly the same.\n"
).
-spec try_weighted(list({float(), EWO})) -> {ok, generator(EWO)} | {error, nil}.
try_weighted(Options) ->
case Options of
[First | Rest] ->
{ok, weighted(First, Rest)};
[] ->
{error, nil}
end.
-file("src/prng/random.gleam", 815).
?DOC(
" Combines two generators into a single one. The resulting generator produces\n"
" values obtained by applying `fun` to the values generated by the given\n"
" generators.\n"
"\n"
" ## Examples\n"
"\n"
" Imagine you need to generate random points in a 2D space:\n"
"\n"
" ```gleam\n"
" pub type Point {\n"
" Point(x: Float, y: Float)\n"
" }\n"
" ```\n"
"\n"
" You can compose two basic generators into a `Point` generator using `map2`:\n"
"\n"
" ```gleam\n"
" let x_generator = random.float(-1.0, 1.0)\n"
" let y_generator = random.float(-1.0, 1.0)\n"
" let point_generator = map2(x_generator, y_generator, Point)\n"
" ```\n"
"\n"
" > Notice how you could get the same result using `then`:\n"
" >\n"
" > ```gleam\n"
" > pub fn point_generator() -> Generator(Point) {\n"
" > use x <- random.then(random.float(-1.0, 1.0))\n"
" > use y <- random.then(random.float(-1.0, 1.0))\n"
" > random.constant(Point(x, y))\n"
" > }\n"
" > ```\n"
" >\n"
" > the `use` syntax paired with `then` may be confusing for other people\n"
" > reading your code, especially Gleam newcomers.\n"
" >\n"
" > Usually `map2`/`map3`/... will be more than enough if you just need to\n"
" > combine simple generators into more complex ones.\n"
).
-spec map2(generator(EZE), generator(EZG), fun((EZE, EZG) -> EZI)) -> generator(EZI).
map2(One, Other, Fun) ->
{generator,
fun(Seed) ->
{A, Seed@1} = step(One, Seed),
{B, Seed@2} = step(Other, Seed@1),
{Fun(A, B), Seed@2}
end}.
-file("src/prng/random.gleam", 523).
?DOC(
" Generates pairs of values obtained by combining the values produced by the\n"
" given generators.\n"
"\n"
" ## Examples\n"
"\n"
" ```gleam\n"
" let one_to_five = random.int(1, 5)\n"
" let probability = random.float(0.0, 1.0)\n"
" let ints_and_floats = random.pair(one_to_five, probability)\n"
"\n"
" random.random_sample(ints_and_floats)\n"
" // -> #(3, 0.22)\n"
" ```\n"
).
-spec pair(generator(EWX), generator(EWZ)) -> generator({EWX, EWZ}).
pair(One, Other) ->
map2(One, Other, fun gleam@pair:new/2).
-file("src/prng/random.gleam", 340).
?DOC(
" Generates values from the given ones with an equal probability.\n"
"\n"
" This generator can guarantee to produce values since it always takes at\n"
" least one item (as its first argument); if it were to accept just a list of\n"
" options, it could be called like this:\n"
"\n"
" ```gleam\n"
" uniform([])\n"
" ```\n"
"\n"
" In which case it would be impossible to actually produce any value: none was\n"
" provided!\n"
"\n"
" ## Examples\n"
"\n"
" Given the following type to model colors:\n"
"\n"
" ```gleam\n"
" pub type Color {\n"
" Red\n"
" Green\n"
" Blue\n"
" }\n"
" ```\n"
"\n"
" You could write a generator that returns each color with an equal\n"
" probability (~33%) each color like this:\n"
"\n"
" ```gleam\n"
" let color = random.uniform(Red, [Green, Blue])\n"
" ```\n"
).
-spec uniform(EWD, list(EWD)) -> generator(EWD).
uniform(First, Others) ->
weighted(
{1.0, First},
gleam@list:map(
Others,
fun(_capture) -> gleam@pair:new(1.0, _capture) end
)
).
-file("src/prng/random.gleam", 376).
?DOC(
" This function works exactly like `uniform` but will return an `Error(Nil)`\n"
" if the provided argument is an empty list since the generator wouldn't be\n"
" able to produce any value in that case.\n"
"\n"
" It generates values from the given list with equal probability.\n"
"\n"
" ## Examples\n"
"\n"
" ```gleam\n"
" random.try_uniform([])\n"
" // -> Error(Nil)\n"
" ```\n"
"\n"
" For example if you consider the following type definition to model color:\n"
"\n"
" ```gleam\n"
" type Color {\n"
" Red\n"
" Green\n"
" Blue\n"
" }\n"
" ```\n"
"\n"
" This call of `try_uniform` will produce a generator wrapped in an `Ok`:\n"
"\n"
" ```gleam\n"
" let assert Ok(color_1) = random.try_uniform([Red, Green, Blue])\n"
" let color_2 = random.uniform(Red, [Green, Blue])\n"
" ```\n"
"\n"
" The generators `color_1` and `color_2` will behave exactly the same.\n"
).
-spec try_uniform(list(EWG)) -> {ok, generator(EWG)} | {error, nil}.
try_uniform(Options) ->
case Options of
[First | Rest] ->
{ok, uniform(First, Rest)};
[] ->
{error, nil}
end.
-file("src/prng/random.gleam", 503).
?DOC(
" Generates two values with equal probability.\n"
"\n"
" This is a shorthand for `random.uniform(one, [other])`, but can read better\n"
" when there's only two choices.\n"
"\n"
" ## Examples\n"
"\n"
" Given the following type to model the outcome of a coin flip:\n"
"\n"
" ```gleam\n"
" pub type CoinFlip {\n"
" Heads\n"
" Tails\n"
" }\n"
" ```\n"
"\n"
" You can write a generator for coin flip outcomes like this:\n"
"\n"
" ```gleam\n"
" let flip = random.choose(Heads, Tails)\n"
" ```\n"
).
-spec choose(EWV, EWV) -> generator(EWV).
choose(One, Other) ->
uniform(One, [Other]).
-file("src/prng/random.gleam", 859).
?DOC(
" Combines three generators into a single one. The resulting generator\n"
" produces values obtained by applying `fun` to the values generated by the\n"
" given generators.\n"
"\n"
" ## Examples\n"
"\n"
" Imagine you're writing a generator for random enemies in a game you're\n"
" making:\n"
"\n"
" ```gleam\n"
" pub type Enemy {\n"
" Enemy(health: Int, attack: Int, defense: Int)\n"
" }\n"
" ```\n"
"\n"
" Each enemy starts with a random health (that can go from 50 to 100) and\n"
" random values for the `attack` and `defense` stats (each can be in a range\n"
" from 1 to 5):\n"
"\n"
" ```gleam\n"
" let health_generator = random.int(50, 100)\n"
" let attack_generator = random.int(1, 5)\n"
" let defense_generator = random.int(1, 5)\n"
"\n"
" let enemy_generator =\n"
" random.map3(\n"
" health_generator,\n"
" attack_generator,\n"
" defense_generator,\n"
" Enemy,\n"
" )\n"
" ```\n"
).
-spec map3(
generator(EZK),
generator(EZM),
generator(EZO),
fun((EZK, EZM, EZO) -> EZQ)
) -> generator(EZQ).
map3(One, Two, Three, Fun) ->
{generator,
fun(Seed) ->
{A, Seed@1} = step(One, Seed),
{B, Seed@2} = step(Two, Seed@1),
{C, Seed@3} = step(Three, Seed@2),
{Fun(A, B, C), Seed@3}
end}.
-file("src/prng/random.gleam", 876).
?DOC(
" Combines four generators into a single one. The resulting generator\n"
" produces values obtained by applying `fun` to the values generated by the\n"
" given generators.\n"
).
-spec map4(
generator(EZS),
generator(EZU),
generator(EZW),
generator(EZY),
fun((EZS, EZU, EZW, EZY) -> FAA)
) -> generator(FAA).
map4(One, Two, Three, Four, Fun) ->
{generator,
fun(Seed) ->
{A, Seed@1} = step(One, Seed),
{B, Seed@2} = step(Two, Seed@1),
{C, Seed@3} = step(Three, Seed@2),
{D, Seed@4} = step(Four, Seed@3),
{Fun(A, B, C, D), Seed@4}
end}.
-file("src/prng/random.gleam", 898).
?DOC(
" Combines five generators into a single one. The resulting generator\n"
" produces values obtained by applying `fun` to the values generated by the\n"
" given generators.\n"
"\n"
" > There's no `map6`, `map7`, and so on. If you feel like you need to compose\n"
" > together even more generators, you can use the `random.then` function.\n"
).
-spec map5(
generator(FAC),
generator(FAE),
generator(FAG),
generator(FAI),
generator(FAK),
fun((FAC, FAE, FAG, FAI, FAK) -> FAM)
) -> generator(FAM).
map5(One, Two, Three, Four, Five, Fun) ->
{generator,
fun(Seed) ->
{A, Seed@1} = step(One, Seed),
{B, Seed@2} = step(Two, Seed@1),
{C, Seed@3} = step(Three, Seed@2),
{D, Seed@4} = step(Four, Seed@3),
{E, Seed@5} = step(Five, Seed@4),
{Fun(A, B, C, D, E), Seed@5}
end}.
-file("src/prng/random.gleam", 935).
?DOC(
" Generates Strings with the given number number of UTF code points.\n"
"\n"
" > ⚠️ The generated codepoints will be in the range from 0 (inclusive) to\n"
" > 1023 (inclusive). If you feel like these strings are not enough for your\n"
" > needs, please open an issue! I'd love to hear your use case and improve\n"
" > the package.\n"
).
-spec fixed_size_string(integer()) -> generator(binary()).
fixed_size_string(Size) ->
_pipe = fixed_size_list(utf_codepoint_in_range(0, 1023), Size),
map(_pipe, fun gleam_stdlib:utf_codepoint_list_to_string/1).
-file("src/prng/random.gleam", 946).
?DOC(
" I'm not exposing this function because, if one is not careful with the range,\n"
" it might lead to a nasty infinite loop.\n"
" When I come up with a better alternative I might make a similar API public,\n"
" for now, if someone wants to do something unsafe they will have to\n"
" manually reimplement it.\n"
).
-spec utf_codepoint_in_range(integer(), integer()) -> generator(integer()).
utf_codepoint_in_range(Lower, Upper) ->
then(
int(Lower, Upper),
fun(Raw_codepoint) -> case gleam@string:utf_codepoint(Raw_codepoint) of
{ok, Codepoint} ->
constant(Codepoint);
{error, _} ->
utf_codepoint_in_range(Lower, Upper)
end end
).
-file("src/prng/random.gleam", 923).
?DOC(
" Generates Strings with a random number of UTF code points, between\n"
" 0 (included) and 32 (included).\n"
"\n"
" This is similar to `fixed_size_string`, with the difference that the\n"
" size is randomly generated as well.\n"
).
-spec string() -> generator(binary()).
string() ->
then(int(0, 32), fun(Size) -> fixed_size_string(Size) end).
-file("src/prng/random.gleam", 704).
?DOC(" Generates `BitArray`s with a random size.\n").
-spec bit_array() -> generator(bitstring()).
bit_array() ->
map(string(), fun gleam_stdlib:identity/1).
-file("src/prng/random.gleam", 697).
?DOC(
" Generates a `Set(a)` where each item is generated using the provided\n"
" generator.\n"
"\n"
" This is similar to `fixed_size_set` with the difference that the set is\n"
" going to have a random size between 0 (inclusive) and 32 (inclusive).\n"
).
-spec set(generator(EYQ)) -> generator(gleam@set:set(EYQ)).
set(Generator) ->
then(int(0, 32), fun(Size) -> fixed_size_set(Generator, Size) end).
-file("src/prng/random.gleam", 649).
?DOC(
" Generates a `Set(a)` where each item is generated using the provided\n"
" generator.\n"
"\n"
" > ⚠️ This function makes a best effort at generating a set with exactly the\n"
" > specified number of items, but beware that it may contain less items if\n"
" > the given generator cannot generate enough distinct values.\n"
).
-spec fixed_size_set(generator(EYH), integer()) -> generator(gleam@set:set(EYH)).
fixed_size_set(Generator, Size) ->
_pipe = gleam@int:max(Size, 0),
do_fixed_size_set(Generator, _pipe, 0, 0, gleam@set:new()).
-file("src/prng/random.gleam", 657).
-spec do_fixed_size_set(
generator(EYL),
integer(),
integer(),
integer(),
gleam@set:set(EYL)
) -> generator(gleam@set:set(EYL)).
do_fixed_size_set(Generator, Size, Unique_items, Consecutive_attempts, Acc) ->
Has_required_size = Unique_items =:= Size,
gleam@bool:guard(
Has_required_size,
constant(Acc),
fun() ->
Has_reached_maximum_attempts = Consecutive_attempts >= 10,
gleam@bool:guard(
Has_reached_maximum_attempts,
constant(Acc),
fun() ->
then(
Generator,
fun(Item) -> case gleam@set:contains(Acc, Item) of
true ->
_pipe = (Consecutive_attempts + 1),
do_fixed_size_set(
Generator,
Size,
Unique_items,
_pipe,
Acc
);
false ->
_pipe@1 = gleam@set:insert(Acc, Item),
do_fixed_size_set(
Generator,
Size,
Unique_items + 1,
0,
_pipe@1
)
end end
)
end
)
end
).
-file("src/prng/random.gleam", 637).
?DOC(
" Generates a `Map(k, v)` where each key value pair is generated using the\n"
" provided generators.\n"
"\n"
" This is similar to `fixed_size_dict` with the difference that the map is\n"
" going to have a random number of key-value pairs between 0 (inclusive) and\n"
" 32 (inclusive).\n"
).
-spec dict(generator(any()), generator(any())) -> generator(gleam@dict:dict(any(), any())).
dict(Keys, Values) ->
then(int(0, 32), fun(Size) -> fixed_size_dict(Keys, Values, Size) end).
-file("src/prng/random.gleam", 586).
?DOC(
" Generates a `Dict(k, v)` where each key value pair is generated using the\n"
" provided generators.\n"
"\n"
" > ⚠️ This function makes a best effort at generating a map with exactly the\n"
" > specified number of keys, but beware that it may contain less items if\n"
" > the keys generator cannot generate enough distinct keys.\n"
).
-spec fixed_size_dict(generator(EXO), generator(EXQ), integer()) -> generator(gleam@dict:dict(EXO, EXQ)).
fixed_size_dict(Keys, Values, Size) ->
_pipe = gleam@int:max(Size, 0),
do_fixed_size_dict(Keys, Values, _pipe, 0, 0, maps:new()).
-file("src/prng/random.gleam", 595).
-spec do_fixed_size_dict(
generator(EXT),
generator(EXV),
integer(),
integer(),
integer(),
gleam@dict:dict(EXT, EXV)
) -> generator(gleam@dict:dict(EXT, EXV)).
do_fixed_size_dict(Keys, Values, Size, Unique_keys, Consecutive_attempts, Acc) ->
Has_required_size = Unique_keys =:= Size,
gleam@bool:guard(
Has_required_size,
constant(Acc),
fun() ->
Has_reached_maximum_attempts = Consecutive_attempts >= 10,
gleam@bool:guard(
Has_reached_maximum_attempts,
constant(Acc),
fun() ->
then(Keys, fun(Key) -> case gleam@dict:has_key(Acc, Key) of
true ->
_pipe = (Consecutive_attempts + 1),
do_fixed_size_dict(
Keys,
Values,
Size,
Unique_keys,
_pipe,
Acc
);
false ->
then(
Values,
fun(Value) ->
_pipe@1 = gleam@dict:insert(
Acc,
Key,
Value
),
do_fixed_size_dict(
Keys,
Values,
Size,
Unique_keys + 1,
0,
_pipe@1
)
end
)
end end)
end
)
end
).