Merge pull request #623 from Goju-Ryu/unit_list-utillity-functions

Add (unit) list utillity functions

book/src/list-functions-lists.md

@@ -284,7 +284,7 @@ sort_by_key(last_digit, [701, 313, 9999, 4])
 </details>
 
 ### `sort`
-Sort a list of quantities.
+Sort a list of quantities in ascending order.
 
 ```nbt
 fn sort<D: Dim>(xs: List<D>) -> List<D>
@@ -300,6 +300,45 @@ fn sort<D: Dim>(xs: List<D>) -> List<D>
 
 </details>
 
+### `contains`
+Returns true if the element `x` is in the list `xs`.
+
+```nbt
+fn contains<A>(x: A, xs: List<A>) -> Bool
+```
+
+<details>
+<summary>Examples</summary>
+
+<pre><div class="buttons"><button class="fa fa-play play-button" title="Run this code" aria-label="Run this code"  onclick=" window.open('https://numbat.dev/?q=%5B3%2C%202%2C%207%2C%208%2C%20%2D4%2C%200%2C%20%2D5%5D%20%7C%3E%20contains%280%29')""></button></div><code class="language-nbt hljs numbat">>>> [3, 2, 7, 8, -4, 0, -5] |> contains(0)
+
+    = true    [Bool]
+</code></pre>
+
+<pre><div class="buttons"><button class="fa fa-play play-button" title="Run this code" aria-label="Run this code"  onclick=" window.open('https://numbat.dev/?q=%5B3%2C%202%2C%207%2C%208%2C%20%2D4%2C%200%2C%20%2D5%5D%20%7C%3E%20contains%281%29')""></button></div><code class="language-nbt hljs numbat">>>> [3, 2, 7, 8, -4, 0, -5] |> contains(1)
+
+    = false    [Bool]
+</code></pre>
+
+</details>
+
+### `unique`
+Remove duplicates from a given list.
+
+```nbt
+fn unique<A>(xs: List<A>) -> List<A>
+```
+
+<details>
+<summary>Examples</summary>
+
+<pre><div class="buttons"><button class="fa fa-play play-button" title="Run this code" aria-label="Run this code"  onclick=" window.open('https://numbat.dev/?q=unique%28%5B1%2C%202%2C%202%2C%203%2C%203%2C%203%5D%29')""></button></div><code class="language-nbt hljs numbat">>>> unique([1, 2, 2, 3, 3, 3])
+
+    = [1, 2, 3]    [List<Scalar>]
+</code></pre>
+
+</details>
+
 ### `intersperse`
 Add an element between each pair of elements in a list.
 

book/src/list-functions-other.md

@@ -85,6 +85,50 @@ fn is_finite<T: Dim>(n: T) -> Bool
 
 </details>
 
+### `is_zero`
+Returns true if the input is 0 (zero).
+
+```nbt
+fn is_zero<D: Dim>(value: D) -> Bool
+```
+
+<details>
+<summary>Examples</summary>
+
+<pre><div class="buttons"><button class="fa fa-play play-button" title="Run this code" aria-label="Run this code"  onclick=" window.open('https://numbat.dev/?q=is%5Fzero%2837%29')""></button></div><code class="language-nbt hljs numbat">>>> is_zero(37)
+
+    = false    [Bool]
+</code></pre>
+
+<pre><div class="buttons"><button class="fa fa-play play-button" title="Run this code" aria-label="Run this code"  onclick=" window.open('https://numbat.dev/?q=is%5Fzero%280%29')""></button></div><code class="language-nbt hljs numbat">>>> is_zero(0)
+
+    = true    [Bool]
+</code></pre>
+
+</details>
+
+### `is_nonzero`
+Returns true unless the input is 0 (zero).
+
+```nbt
+fn is_nonzero<D: Dim>(value: D) -> Bool
+```
+
+<details>
+<summary>Examples</summary>
+
+<pre><div class="buttons"><button class="fa fa-play play-button" title="Run this code" aria-label="Run this code"  onclick=" window.open('https://numbat.dev/?q=is%5Fnonzero%2837%29')""></button></div><code class="language-nbt hljs numbat">>>> is_nonzero(37)
+
+    = true    [Bool]
+</code></pre>
+
+<pre><div class="buttons"><button class="fa fa-play play-button" title="Run this code" aria-label="Run this code"  onclick=" window.open('https://numbat.dev/?q=is%5Fnonzero%280%29')""></button></div><code class="language-nbt hljs numbat">>>> is_nonzero(0)
+
+    = false    [Bool]
+</code></pre>
+
+</details>
+
 ## Quantities
 
 Defined in: `core::quantities`

examples/tests/lists.nbt

@@ -70,6 +70,29 @@ fn negate(x) = -x
 assert_eq(sort_by_key(negate, [1, 2, 3]), [3, 2, 1])
 assert_eq(sort_by_key(str_length, ["aa", "", "aaaa", "aaa"]), ["", "aa", "aaa", "aaaa"])
 
+# contains:
+assert(contains(1, [1]))
+
+assert(contains(1, [1, 2, 3]))
+assert(contains(1, [3, 2, 1]))
+assert(contains(1, [3, 1, 2]))
+
+assert(!contains(10, [1, 2, 3]))
+
+assert(contains("1", ["1", "2", "3"]))
+
+# unique:
+assert_eq(unique([]), [])
+
+assert_eq(unique([1, 2, 3]), [1, 2, 3])
+
+assert_eq(unique([1, 2, 2, 3, 3, 3]), [1, 2, 3])
+assert_eq(unique([3, 3, 3, 2, 2, 1]), [3, 2, 1])
+assert_eq(unique([1, 3, 2, 3, 2, 3]), [1, 3, 2])
+
+assert_eq(unique([1, 3, 2, 3, 2, 3]), unique(unique([1, 3, 2, 3, 2, 3,])))
+
+# intersperse:
 assert_eq(intersperse(0, []), [])
 assert_eq(intersperse(0, [1]), [1])
 assert_eq(intersperse(0, [1, 2, 3]), [1, 0, 2, 0, 3])

examples/tests/mixed_units.nbt

@@ -47,5 +47,3 @@ let test2 = 12 degree + 34 arcminute + 5 arcsec
 assert_eq(test2 |> unit_list([degree]) |> head, test2)
 assert_eq(test2 |> unit_list([degree, arcmin]) |> sum, test2)
 assert_eq(test2 |> unit_list([degree, arcmin, arcsec]) |> sum, test2)
-
-

numbat/modules/core/lists.nbt

@@ -114,10 +114,33 @@ fn sort_by_key<A, D: Dim>(key: Fn[(A) -> D], xs: List<A>) -> List<A> =
                   sort_by_key(key, drop(floor(len(xs) / 2), xs)),
                   key)
 
-@description("Sort a list of quantities")
+@description("Sort a list of quantities in ascending order")
 @example("sort([3, 2, 7, 8, -4, 0, -5])")
 fn sort<D: Dim>(xs: List<D>) -> List<D> = sort_by_key(id, xs)
 
+@description("Returns true if the element `x` is in the list `xs`.")
+@example("[3, 2, 7, 8, -4, 0, -5] |> contains(0)")
+@example("[3, 2, 7, 8, -4, 0, -5] |> contains(1)")
+fn contains<A>(x: A, xs: List<A>) -> Bool = 
+  if is_empty(xs)
+    then false
+    else if x == head(xs)
+      then true
+      else contains(x, tail(xs))
+
+fn _unique<A>(acc: List<A>, xs: List<A>) -> List<A> = 
+  if is_empty(xs)
+    then acc
+    else if is_empty(acc)
+      then _unique([head(xs)], tail(xs))
+      else if (acc |> contains(head(xs)))
+        then _unique(acc, tail(xs))
+        else _unique((cons_end(head(xs), acc)), tail(xs))
+
+@description("Remove duplicates from a given list.")
+@example("unique([1, 2, 2, 3, 3, 3])")
+fn unique<A>(xs: List<A>) -> List<A> = xs |> _unique([])
+
 @description("Add an element between each pair of elements in a list")
 @example("intersperse(0, [1, 1, 1, 1])")
 fn intersperse<A>(sep: A, xs: List<A>) -> List<A> =

numbat/modules/core/mixed_units.nbt

@@ -1,5 +1,7 @@
 use core::strings
 use core::lists
+use core::numbers
+use core::quantities
 
 # Helper functions for mixed-unit conversions. See units::mixed for more.
 
@@ -15,3 +17,11 @@ fn _mixed_unit_list<D: Dim>(val: D, units: List<D>, acc: List<D>) -> List<D> =
     if (len(units) > 0)
       then (val |> trunc_in(head(units)))
       else error("Units list cannot be empty")
+
+fn _negate<D: Dim>(x: D) = -x
+
+fn _sort_descending<D: Dim>(xs: List<D>) -> List<D> = sort_by_key(_negate, xs)
+
+fn _clean_units<D: Dim>(units: List<D>) -> List<D> = units |> unique() |> _sort_descending()
+
+fn _unit_list<D: Dim>(units: List<D>, value: D) -> List<D> = _mixed_unit_list(value, _clean_units(units), [])

numbat/modules/core/numbers.nbt

@@ -14,3 +14,13 @@ fn is_infinite<T: Dim>(n: T) -> Bool
 @example("is_finite(37)")
 @example("is_finite(-inf)")
 fn is_finite<T: Dim>(n: T) -> Bool = !is_nan(n) && !is_infinite(n)
+
+@description("Returns true if the input is 0 (zero).")
+@example("is_zero(37)")
+@example("is_zero(0)")
+fn is_zero<D: Dim>(value: D) -> Bool = value == 0
+
+@description("Returns true unless the input is 0 (zero).")
+@example("is_nonzero(37)")
+@example("is_nonzero(0)")
+fn is_nonzero<D: Dim>(value: D) -> Bool = !is_zero(value)

numbat/modules/prelude.nbt

@@ -7,6 +7,7 @@ use core::strings
 use core::error
 use core::random
 use core::numbers
+use core::mixed_units
 
 use math::constants
 use math::transcendental

numbat/modules/units/mixed.nbt

@@ -5,7 +5,7 @@ use units::imperial
 @name("Unit list")
 @description("Convert a value to a mixed representation using the provided units.")
 @example("5500 m |> unit_list([miles, yards, feet, inches])")
-fn unit_list<D: Dim>(units: List<D>, value: D) -> List<D> = _mixed_unit_list(value, units, [])
+fn unit_list<D: Dim>(units: List<D>, value: D) -> List<D> = _unit_list(units, value)
 
 @name("Degrees, minutes, seconds")
 @description("Convert an angle to a mixed degrees, (arc)minutes, and (arc)seconds representation. Also called sexagesimal degree notation.")
@@ -33,5 +33,4 @@ fn feet_and_inches(length: Length) -> List<Length> =
 @url("https://en.wikipedia.org/wiki/Pound_(mass)")
 @example("1 kg -> pounds_and_ounces")
 fn pounds_and_ounces(mass: Mass) -> List<Mass> =
-  unit_list([pound, ounce], mass)
-
+  unit_list([pound, ounce], mass)