744 lines
18 KiB
Erlang
744 lines
18 KiB
Erlang
-module(gleam@float).
|
|
-compile([no_auto_import, nowarn_unused_vars, nowarn_unused_function, nowarn_nomatch, inline]).
|
|
-define(FILEPATH, "src/gleam/float.gleam").
|
|
-export([parse/1, to_string/1, compare/2, min/2, max/2, clamp/3, ceiling/1, floor/1, truncate/1, absolute_value/1, loosely_compare/3, loosely_equals/3, power/2, square_root/1, negate/1, round/1, to_precision/2, sum/1, product/1, random/0, modulo/2, divide/2, add/2, multiply/2, subtract/2, logarithm/1, exponential/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(
|
|
" Functions for working with floats.\n"
|
|
"\n"
|
|
" ## Float representation\n"
|
|
"\n"
|
|
" Floats are represented as 64 bit floating point numbers on both the Erlang\n"
|
|
" and JavaScript runtimes. The floating point behaviour is native to their\n"
|
|
" respective runtimes, so their exact behaviour will be slightly different on\n"
|
|
" the two runtimes.\n"
|
|
"\n"
|
|
" ### Infinity and NaN\n"
|
|
"\n"
|
|
" Under the JavaScript runtime, exceeding the maximum (or minimum)\n"
|
|
" representable value for a floating point value will result in Infinity (or\n"
|
|
" -Infinity). Should you try to divide two infinities you will get NaN as a\n"
|
|
" result.\n"
|
|
"\n"
|
|
" When running on BEAM, exceeding the maximum (or minimum) representable\n"
|
|
" value for a floating point value will raise an error.\n"
|
|
"\n"
|
|
" ## Division by zero\n"
|
|
"\n"
|
|
" Gleam runs on the Erlang virtual machine, which does not follow the IEEE\n"
|
|
" 754 standard for floating point arithmetic and does not have an `Infinity`\n"
|
|
" value. In Erlang division by zero results in a crash, however Gleam does\n"
|
|
" not have partial functions and operators in core so instead division by zero\n"
|
|
" returns zero, a behaviour taken from Pony, Coq, and Lean.\n"
|
|
"\n"
|
|
" This may seem unexpected at first, but it is no less mathematically valid\n"
|
|
" than crashing or returning a special value. Division by zero is undefined\n"
|
|
" in mathematics.\n"
|
|
).
|
|
|
|
-file("src/gleam/float.gleam", 51).
|
|
?DOC(
|
|
" Attempts to parse a string as a `Float`, returning `Error(Nil)` if it was\n"
|
|
" not possible.\n"
|
|
"\n"
|
|
" ## Examples\n"
|
|
"\n"
|
|
" ```gleam\n"
|
|
" parse(\"2.3\")\n"
|
|
" // -> Ok(2.3)\n"
|
|
" ```\n"
|
|
"\n"
|
|
" ```gleam\n"
|
|
" parse(\"ABC\")\n"
|
|
" // -> Error(Nil)\n"
|
|
" ```\n"
|
|
).
|
|
-spec parse(binary()) -> {ok, float()} | {error, nil}.
|
|
parse(String) ->
|
|
gleam_stdlib:parse_float(String).
|
|
|
|
-file("src/gleam/float.gleam", 64).
|
|
?DOC(
|
|
" Returns the string representation of the provided `Float`.\n"
|
|
"\n"
|
|
" ## Examples\n"
|
|
"\n"
|
|
" ```gleam\n"
|
|
" to_string(2.3)\n"
|
|
" // -> \"2.3\"\n"
|
|
" ```\n"
|
|
).
|
|
-spec to_string(float()) -> binary().
|
|
to_string(X) ->
|
|
gleam_stdlib:float_to_string(X).
|
|
|
|
-file("src/gleam/float.gleam", 95).
|
|
?DOC(
|
|
" Compares two `Float`s, returning an `Order`:\n"
|
|
" `Lt` for lower than, `Eq` for equals, or `Gt` for greater than.\n"
|
|
"\n"
|
|
" ## Examples\n"
|
|
"\n"
|
|
" ```gleam\n"
|
|
" compare(2.0, 2.3)\n"
|
|
" // -> Lt\n"
|
|
" ```\n"
|
|
"\n"
|
|
" To handle\n"
|
|
" [Floating Point Imprecision](https://en.wikipedia.org/wiki/Floating-point_arithmetic#Accuracy_problems)\n"
|
|
" you may use [`loosely_compare`](#loosely_compare) instead.\n"
|
|
).
|
|
-spec compare(float(), float()) -> gleam@order:order().
|
|
compare(A, B) ->
|
|
case A =:= B of
|
|
true ->
|
|
eq;
|
|
|
|
false ->
|
|
case A < B of
|
|
true ->
|
|
lt;
|
|
|
|
false ->
|
|
gt
|
|
end
|
|
end.
|
|
|
|
-file("src/gleam/float.gleam", 176).
|
|
?DOC(
|
|
" Compares two `Float`s, returning the smaller of the two.\n"
|
|
"\n"
|
|
" ## Examples\n"
|
|
"\n"
|
|
" ```gleam\n"
|
|
" min(2.0, 2.3)\n"
|
|
" // -> 2.0\n"
|
|
" ```\n"
|
|
).
|
|
-spec min(float(), float()) -> float().
|
|
min(A, B) ->
|
|
case A < B of
|
|
true ->
|
|
A;
|
|
|
|
false ->
|
|
B
|
|
end.
|
|
|
|
-file("src/gleam/float.gleam", 192).
|
|
?DOC(
|
|
" Compares two `Float`s, returning the larger of the two.\n"
|
|
"\n"
|
|
" ## Examples\n"
|
|
"\n"
|
|
" ```gleam\n"
|
|
" max(2.0, 2.3)\n"
|
|
" // -> 2.3\n"
|
|
" ```\n"
|
|
).
|
|
-spec max(float(), float()) -> float().
|
|
max(A, B) ->
|
|
case A > B of
|
|
true ->
|
|
A;
|
|
|
|
false ->
|
|
B
|
|
end.
|
|
|
|
-file("src/gleam/float.gleam", 75).
|
|
?DOC(
|
|
" Restricts a `Float` between a lower and upper bound.\n"
|
|
"\n"
|
|
" ## Examples\n"
|
|
"\n"
|
|
" ```gleam\n"
|
|
" clamp(1.2, min: 1.4, max: 1.6)\n"
|
|
" // -> 1.4\n"
|
|
" ```\n"
|
|
).
|
|
-spec clamp(float(), float(), float()) -> float().
|
|
clamp(X, Min_bound, Max_bound) ->
|
|
_pipe = X,
|
|
_pipe@1 = min(_pipe, Max_bound),
|
|
max(_pipe@1, Min_bound).
|
|
|
|
-file("src/gleam/float.gleam", 210).
|
|
?DOC(
|
|
" Rounds the value to the next highest whole number as a `Float`.\n"
|
|
"\n"
|
|
" ## Examples\n"
|
|
"\n"
|
|
" ```gleam\n"
|
|
" ceiling(2.3)\n"
|
|
" // -> 3.0\n"
|
|
" ```\n"
|
|
).
|
|
-spec ceiling(float()) -> float().
|
|
ceiling(X) ->
|
|
math:ceil(X).
|
|
|
|
-file("src/gleam/float.gleam", 223).
|
|
?DOC(
|
|
" Rounds the value to the next lowest whole number as a `Float`.\n"
|
|
"\n"
|
|
" ## Examples\n"
|
|
"\n"
|
|
" ```gleam\n"
|
|
" floor(2.3)\n"
|
|
" // -> 2.0\n"
|
|
" ```\n"
|
|
).
|
|
-spec floor(float()) -> float().
|
|
floor(X) ->
|
|
math:floor(X).
|
|
|
|
-file("src/gleam/float.gleam", 261).
|
|
?DOC(
|
|
" Returns the value as an `Int`, truncating all decimal digits.\n"
|
|
"\n"
|
|
" ## Examples\n"
|
|
"\n"
|
|
" ```gleam\n"
|
|
" truncate(2.4343434847383438)\n"
|
|
" // -> 2\n"
|
|
" ```\n"
|
|
).
|
|
-spec truncate(float()) -> integer().
|
|
truncate(X) ->
|
|
erlang:trunc(X).
|
|
|
|
-file("src/gleam/float.gleam", 311).
|
|
?DOC(
|
|
" Returns the absolute value of the input as a `Float`.\n"
|
|
"\n"
|
|
" ## Examples\n"
|
|
"\n"
|
|
" ```gleam\n"
|
|
" absolute_value(-12.5)\n"
|
|
" // -> 12.5\n"
|
|
" ```\n"
|
|
"\n"
|
|
" ```gleam\n"
|
|
" absolute_value(10.2)\n"
|
|
" // -> 10.2\n"
|
|
" ```\n"
|
|
).
|
|
-spec absolute_value(float()) -> float().
|
|
absolute_value(X) ->
|
|
case X >= +0.0 of
|
|
true ->
|
|
X;
|
|
|
|
false ->
|
|
+0.0 - X
|
|
end.
|
|
|
|
-file("src/gleam/float.gleam", 125).
|
|
?DOC(
|
|
" Compares two `Float`s within a tolerance, returning an `Order`:\n"
|
|
" `Lt` for lower than, `Eq` for equals, or `Gt` for greater than.\n"
|
|
"\n"
|
|
" This function allows Float comparison while handling\n"
|
|
" [Floating Point Imprecision](https://en.wikipedia.org/wiki/Floating-point_arithmetic#Accuracy_problems).\n"
|
|
"\n"
|
|
" Notice: For `Float`s the tolerance won't be exact:\n"
|
|
" `5.3 - 5.0` is not exactly `0.3`.\n"
|
|
"\n"
|
|
" ## Examples\n"
|
|
"\n"
|
|
" ```gleam\n"
|
|
" loosely_compare(5.0, with: 5.3, tolerating: 0.5)\n"
|
|
" // -> Eq\n"
|
|
" ```\n"
|
|
"\n"
|
|
" If you want to check only for equality you may use\n"
|
|
" [`loosely_equals`](#loosely_equals) instead.\n"
|
|
).
|
|
-spec loosely_compare(float(), float(), float()) -> gleam@order:order().
|
|
loosely_compare(A, B, Tolerance) ->
|
|
Difference = absolute_value(A - B),
|
|
case Difference =< Tolerance of
|
|
true ->
|
|
eq;
|
|
|
|
false ->
|
|
compare(A, B)
|
|
end.
|
|
|
|
-file("src/gleam/float.gleam", 158).
|
|
?DOC(
|
|
" Checks for equality of two `Float`s within a tolerance,\n"
|
|
" returning an `Bool`.\n"
|
|
"\n"
|
|
" This function allows Float comparison while handling\n"
|
|
" [Floating Point Imprecision](https://en.wikipedia.org/wiki/Floating-point_arithmetic#Accuracy_problems).\n"
|
|
"\n"
|
|
" Notice: For `Float`s the tolerance won't be exact:\n"
|
|
" `5.3 - 5.0` is not exactly `0.3`.\n"
|
|
"\n"
|
|
" ## Examples\n"
|
|
"\n"
|
|
" ```gleam\n"
|
|
" loosely_equals(5.0, with: 5.3, tolerating: 0.5)\n"
|
|
" // -> True\n"
|
|
" ```\n"
|
|
"\n"
|
|
" ```gleam\n"
|
|
" loosely_equals(5.0, with: 5.1, tolerating: 0.1)\n"
|
|
" // -> False\n"
|
|
" ```\n"
|
|
).
|
|
-spec loosely_equals(float(), float(), float()) -> boolean().
|
|
loosely_equals(A, B, Tolerance) ->
|
|
Difference = absolute_value(A - B),
|
|
Difference =< Tolerance.
|
|
|
|
-file("src/gleam/float.gleam", 348).
|
|
?DOC(
|
|
" Returns the results of the base being raised to the power of the\n"
|
|
" exponent, as a `Float`.\n"
|
|
"\n"
|
|
" ## Examples\n"
|
|
"\n"
|
|
" ```gleam\n"
|
|
" power(2.0, -1.0)\n"
|
|
" // -> Ok(0.5)\n"
|
|
" ```\n"
|
|
"\n"
|
|
" ```gleam\n"
|
|
" power(2.0, 2.0)\n"
|
|
" // -> Ok(4.0)\n"
|
|
" ```\n"
|
|
"\n"
|
|
" ```gleam\n"
|
|
" power(8.0, 1.5)\n"
|
|
" // -> Ok(22.627416997969522)\n"
|
|
" ```\n"
|
|
"\n"
|
|
" ```gleam\n"
|
|
" 4.0 |> power(of: 2.0)\n"
|
|
" // -> Ok(16.0)\n"
|
|
" ```\n"
|
|
"\n"
|
|
" ```gleam\n"
|
|
" power(-1.0, 0.5)\n"
|
|
" // -> Error(Nil)\n"
|
|
" ```\n"
|
|
).
|
|
-spec power(float(), float()) -> {ok, float()} | {error, nil}.
|
|
power(Base, Exponent) ->
|
|
Fractional = (math:ceil(Exponent) - Exponent) > +0.0,
|
|
case ((Base < +0.0) andalso Fractional) orelse ((Base =:= +0.0) andalso (Exponent
|
|
< +0.0)) of
|
|
true ->
|
|
{error, nil};
|
|
|
|
false ->
|
|
{ok, math:pow(Base, Exponent)}
|
|
end.
|
|
|
|
-file("src/gleam/float.gleam", 380).
|
|
?DOC(
|
|
" Returns the square root of the input as a `Float`.\n"
|
|
"\n"
|
|
" ## Examples\n"
|
|
"\n"
|
|
" ```gleam\n"
|
|
" square_root(4.0)\n"
|
|
" // -> Ok(2.0)\n"
|
|
" ```\n"
|
|
"\n"
|
|
" ```gleam\n"
|
|
" square_root(-16.0)\n"
|
|
" // -> Error(Nil)\n"
|
|
" ```\n"
|
|
).
|
|
-spec square_root(float()) -> {ok, float()} | {error, nil}.
|
|
square_root(X) ->
|
|
power(X, 0.5).
|
|
|
|
-file("src/gleam/float.gleam", 393).
|
|
?DOC(
|
|
" Returns the negative of the value provided.\n"
|
|
"\n"
|
|
" ## Examples\n"
|
|
"\n"
|
|
" ```gleam\n"
|
|
" negate(1.0)\n"
|
|
" // -> -1.0\n"
|
|
" ```\n"
|
|
).
|
|
-spec negate(float()) -> float().
|
|
negate(X) ->
|
|
-1.0 * X.
|
|
|
|
-file("src/gleam/float.gleam", 240).
|
|
?DOC(
|
|
" Rounds the value to the nearest whole number as an `Int`.\n"
|
|
"\n"
|
|
" ## Examples\n"
|
|
"\n"
|
|
" ```gleam\n"
|
|
" round(2.3)\n"
|
|
" // -> 2\n"
|
|
" ```\n"
|
|
"\n"
|
|
" ```gleam\n"
|
|
" round(2.5)\n"
|
|
" // -> 3\n"
|
|
" ```\n"
|
|
).
|
|
-spec round(float()) -> integer().
|
|
round(X) ->
|
|
erlang:round(X).
|
|
|
|
-file("src/gleam/float.gleam", 280).
|
|
?DOC(
|
|
" Converts the value to a given precision as a `Float`.\n"
|
|
" The precision is the number of allowed decimal places.\n"
|
|
" Negative precisions are allowed and force rounding\n"
|
|
" to the nearest tenth, hundredth, thousandth etc.\n"
|
|
"\n"
|
|
" ## Examples\n"
|
|
"\n"
|
|
" ```gleam\n"
|
|
" to_precision(2.43434348473, precision: 2)\n"
|
|
" // -> 2.43\n"
|
|
" ```\n"
|
|
"\n"
|
|
" ```gleam\n"
|
|
" to_precision(547890.453444, precision: -3)\n"
|
|
" // -> 548000.0\n"
|
|
" ```\n"
|
|
).
|
|
-spec to_precision(float(), integer()) -> float().
|
|
to_precision(X, Precision) ->
|
|
case Precision =< 0 of
|
|
true ->
|
|
Factor = math:pow(10.0, erlang:float(- Precision)),
|
|
erlang:float(erlang:round(case Factor of
|
|
+0.0 -> +0.0;
|
|
-0.0 -> -0.0;
|
|
Gleam@denominator -> X / Gleam@denominator
|
|
end)) * Factor;
|
|
|
|
false ->
|
|
Factor@1 = math:pow(10.0, erlang:float(Precision)),
|
|
case Factor@1 of
|
|
+0.0 -> +0.0;
|
|
-0.0 -> -0.0;
|
|
Gleam@denominator@1 -> erlang:float(erlang:round(X * Factor@1))
|
|
/ Gleam@denominator@1
|
|
end
|
|
end.
|
|
|
|
-file("src/gleam/float.gleam", 410).
|
|
-spec sum_loop(list(float()), float()) -> float().
|
|
sum_loop(Numbers, Initial) ->
|
|
case Numbers of
|
|
[First | Rest] ->
|
|
sum_loop(Rest, First + Initial);
|
|
|
|
[] ->
|
|
Initial
|
|
end.
|
|
|
|
-file("src/gleam/float.gleam", 406).
|
|
?DOC(
|
|
" Sums a list of `Float`s.\n"
|
|
"\n"
|
|
" ## Example\n"
|
|
"\n"
|
|
" ```gleam\n"
|
|
" sum([1.0, 2.2, 3.3])\n"
|
|
" // -> 6.5\n"
|
|
" ```\n"
|
|
).
|
|
-spec sum(list(float())) -> float().
|
|
sum(Numbers) ->
|
|
sum_loop(Numbers, +0.0).
|
|
|
|
-file("src/gleam/float.gleam", 430).
|
|
-spec product_loop(list(float()), float()) -> float().
|
|
product_loop(Numbers, Initial) ->
|
|
case Numbers of
|
|
[First | Rest] ->
|
|
product_loop(Rest, First * Initial);
|
|
|
|
[] ->
|
|
Initial
|
|
end.
|
|
|
|
-file("src/gleam/float.gleam", 426).
|
|
?DOC(
|
|
" Multiplies a list of `Float`s and returns the product.\n"
|
|
"\n"
|
|
" ## Example\n"
|
|
"\n"
|
|
" ```gleam\n"
|
|
" product([2.5, 3.2, 4.2])\n"
|
|
" // -> 33.6\n"
|
|
" ```\n"
|
|
).
|
|
-spec product(list(float())) -> float().
|
|
product(Numbers) ->
|
|
product_loop(Numbers, 1.0).
|
|
|
|
-file("src/gleam/float.gleam", 452).
|
|
?DOC(
|
|
" Generates a random float between the given zero (inclusive) and one\n"
|
|
" (exclusive).\n"
|
|
"\n"
|
|
" On Erlang this updates the random state in the process dictionary.\n"
|
|
" See: <https://www.erlang.org/doc/man/rand.html#uniform-0>\n"
|
|
"\n"
|
|
" ## Examples\n"
|
|
"\n"
|
|
" ```gleam\n"
|
|
" random()\n"
|
|
" // -> 0.646355926896028\n"
|
|
" ```\n"
|
|
).
|
|
-spec random() -> float().
|
|
random() ->
|
|
rand:uniform().
|
|
|
|
-file("src/gleam/float.gleam", 481).
|
|
?DOC(
|
|
" Computes the modulo of an float division of inputs as a `Result`.\n"
|
|
"\n"
|
|
" Returns division of the inputs as a `Result`: If the given divisor equals\n"
|
|
" `0`, this function returns an `Error`.\n"
|
|
"\n"
|
|
" ## Examples\n"
|
|
"\n"
|
|
" ```gleam\n"
|
|
" modulo(13.3, by: 3.3)\n"
|
|
" // -> Ok(0.1)\n"
|
|
" ```\n"
|
|
"\n"
|
|
" ```gleam\n"
|
|
" modulo(-13.3, by: 3.3)\n"
|
|
" // -> Ok(3.2)\n"
|
|
" ```\n"
|
|
"\n"
|
|
" ```gleam\n"
|
|
" modulo(13.3, by: -3.3)\n"
|
|
" // -> Ok(-3.2)\n"
|
|
" ```\n"
|
|
"\n"
|
|
" ```gleam\n"
|
|
" modulo(-13.3, by: -3.3)\n"
|
|
" // -> Ok(-0.1)\n"
|
|
" ```\n"
|
|
).
|
|
-spec modulo(float(), float()) -> {ok, float()} | {error, nil}.
|
|
modulo(Dividend, Divisor) ->
|
|
case Divisor of
|
|
+0.0 ->
|
|
{error, nil};
|
|
|
|
_ ->
|
|
{ok, Dividend - (math:floor(case Divisor of
|
|
+0.0 -> +0.0;
|
|
-0.0 -> -0.0;
|
|
Gleam@denominator -> Dividend / Gleam@denominator
|
|
end) * Divisor)}
|
|
end.
|
|
|
|
-file("src/gleam/float.gleam", 502).
|
|
?DOC(
|
|
" Returns division of the inputs as a `Result`.\n"
|
|
"\n"
|
|
" ## Examples\n"
|
|
"\n"
|
|
" ```gleam\n"
|
|
" divide(0.0, 1.0)\n"
|
|
" // -> Ok(0.0)\n"
|
|
" ```\n"
|
|
"\n"
|
|
" ```gleam\n"
|
|
" divide(1.0, 0.0)\n"
|
|
" // -> Error(Nil)\n"
|
|
" ```\n"
|
|
).
|
|
-spec divide(float(), float()) -> {ok, float()} | {error, nil}.
|
|
divide(A, B) ->
|
|
case B of
|
|
+0.0 ->
|
|
{error, nil};
|
|
|
|
B@1 ->
|
|
{ok, case B@1 of
|
|
+0.0 -> +0.0;
|
|
-0.0 -> -0.0;
|
|
Gleam@denominator -> A / Gleam@denominator
|
|
end}
|
|
end.
|
|
|
|
-file("src/gleam/float.gleam", 533).
|
|
?DOC(
|
|
" Adds two floats together.\n"
|
|
"\n"
|
|
" It's the function equivalent of the `+.` operator.\n"
|
|
" This function is useful in higher order functions or pipes.\n"
|
|
"\n"
|
|
" ## Examples\n"
|
|
"\n"
|
|
" ```gleam\n"
|
|
" add(1.0, 2.0)\n"
|
|
" // -> 3.0\n"
|
|
" ```\n"
|
|
"\n"
|
|
" ```gleam\n"
|
|
" import gleam/list\n"
|
|
"\n"
|
|
" list.fold([1.0, 2.0, 3.0], 0.0, add)\n"
|
|
" // -> 6.0\n"
|
|
" ```\n"
|
|
"\n"
|
|
" ```gleam\n"
|
|
" 3.0 |> add(2.0)\n"
|
|
" // -> 5.0\n"
|
|
" ```\n"
|
|
).
|
|
-spec add(float(), float()) -> float().
|
|
add(A, B) ->
|
|
A + B.
|
|
|
|
-file("src/gleam/float.gleam", 561).
|
|
?DOC(
|
|
" Multiplies two floats together.\n"
|
|
"\n"
|
|
" It's the function equivalent of the `*.` operator.\n"
|
|
" This function is useful in higher order functions or pipes.\n"
|
|
"\n"
|
|
" ## Examples\n"
|
|
"\n"
|
|
" ```gleam\n"
|
|
" multiply(2.0, 4.0)\n"
|
|
" // -> 8.0\n"
|
|
" ```\n"
|
|
"\n"
|
|
" ```gleam\n"
|
|
" import gleam/list\n"
|
|
"\n"
|
|
" list.fold([2.0, 3.0, 4.0], 1.0, multiply)\n"
|
|
" // -> 24.0\n"
|
|
" ```\n"
|
|
"\n"
|
|
" ```gleam\n"
|
|
" 3.0 |> multiply(2.0)\n"
|
|
" // -> 6.0\n"
|
|
" ```\n"
|
|
).
|
|
-spec multiply(float(), float()) -> float().
|
|
multiply(A, B) ->
|
|
A * B.
|
|
|
|
-file("src/gleam/float.gleam", 594).
|
|
?DOC(
|
|
" Subtracts one float from another.\n"
|
|
"\n"
|
|
" It's the function equivalent of the `-.` operator.\n"
|
|
" This function is useful in higher order functions or pipes.\n"
|
|
"\n"
|
|
" ## Examples\n"
|
|
"\n"
|
|
" ```gleam\n"
|
|
" subtract(3.0, 1.0)\n"
|
|
" // -> 2.0\n"
|
|
" ```\n"
|
|
"\n"
|
|
" ```gleam\n"
|
|
" import gleam/list\n"
|
|
"\n"
|
|
" list.fold([1.0, 2.0, 3.0], 10.0, subtract)\n"
|
|
" // -> 4.0\n"
|
|
" ```\n"
|
|
"\n"
|
|
" ```gleam\n"
|
|
" 3.0 |> subtract(_, 2.0)\n"
|
|
" // -> 1.0\n"
|
|
" ```\n"
|
|
"\n"
|
|
" ```gleam\n"
|
|
" 3.0 |> subtract(2.0, _)\n"
|
|
" // -> -1.0\n"
|
|
" ```\n"
|
|
).
|
|
-spec subtract(float(), float()) -> float().
|
|
subtract(A, B) ->
|
|
A - B.
|
|
|
|
-file("src/gleam/float.gleam", 623).
|
|
?DOC(
|
|
" Returns the natural logarithm (base e) of the given as a `Result`. If the\n"
|
|
" input is less than or equal to 0, returns `Error(Nil)`.\n"
|
|
"\n"
|
|
" ## Examples\n"
|
|
"\n"
|
|
" ```gleam\n"
|
|
" logarithm(1.0)\n"
|
|
" // -> Ok(0.0)\n"
|
|
" ```\n"
|
|
"\n"
|
|
" ```gleam\n"
|
|
" logarithm(2.718281828459045) // e\n"
|
|
" // -> Ok(1.0)\n"
|
|
" ```\n"
|
|
"\n"
|
|
" ```gleam\n"
|
|
" logarithm(0.0)\n"
|
|
" // -> Error(Nil)\n"
|
|
" ```\n"
|
|
"\n"
|
|
" ```gleam\n"
|
|
" logarithm(-1.0)\n"
|
|
" // -> Error(Nil)\n"
|
|
" ```\n"
|
|
).
|
|
-spec logarithm(float()) -> {ok, float()} | {error, nil}.
|
|
logarithm(X) ->
|
|
case X =< +0.0 of
|
|
true ->
|
|
{error, nil};
|
|
|
|
false ->
|
|
{ok, math:log(X)}
|
|
end.
|
|
|
|
-file("src/gleam/float.gleam", 661).
|
|
?DOC(
|
|
" Returns e (Euler's number) raised to the power of the given exponent, as\n"
|
|
" a `Float`.\n"
|
|
"\n"
|
|
" ## Examples\n"
|
|
"\n"
|
|
" ```gleam\n"
|
|
" exponential(0.0)\n"
|
|
" // -> Ok(1.0)\n"
|
|
" ```\n"
|
|
"\n"
|
|
" ```gleam\n"
|
|
" exponential(1.0)\n"
|
|
" // -> Ok(2.718281828459045)\n"
|
|
" ```\n"
|
|
"\n"
|
|
" ```gleam\n"
|
|
" exponential(-1.0)\n"
|
|
" // -> Ok(0.36787944117144233)\n"
|
|
" ```\n"
|
|
).
|
|
-spec exponential(float()) -> float().
|
|
exponential(X) ->
|
|
math:exp(X).
|