✨ add ḳ (keep); addresses part of #3

README.md

@@ -38,6 +38,7 @@ The intending way of using Jellyfish is through the [Jello REPL](https://github.
 * `ṕ` (Q's `prior`)
 * `É` (dual to `odd?` i.e. `even?`)
 * `①` (`bits` aka `bit_count`, `pop_count` or `ones_count`)
+* `ḳ` (Uiua's `keep` and BQN/APL's `compress`/`replicate`)
 
 ### Changes
 

jelly/interpreter.py

@@ -16,9 +16,9 @@
 
 code_page  = '''¡¢£¤¥¦©¬®µ½¿€ÆÇÐÑ×ØŒÞßæçðıȷñ÷øœþ !"#$%&'()*+,-./0123456789:;<=>?@ABCDEFGHIJKLMNOPQRSTUVWXYZ[\]^_`abcdefghijklmnopqrstuvwxyz{|}~¶''' # noqa: Q001 W605
 code_page += '''°¹²³⁴⁵⁶⁷⁸⁹⁺⁻⁼⁽⁾ƁƇƊƑƓƘⱮƝƤƬƲȤɓƈɗƒɠɦƙɱɲƥʠɼʂƭʋȥẠḄḌẸḤỊḲḶṂṆỌṚṢṬỤṾẈỴẒȦḂĊḊĖḞĠḢİĿṀṄȮṖṘṠṪẆẊẎŻạḅḍẹḥịḳḷṃṇọṛṣṭ§Äẉỵẓȧḃċḋėḟġḣŀṁṅȯṗṙṡṫẇẋẏż«»‘’“”'''    # noqa: Q001
-code_page += "ṕṔÉ①" # jellyfish specific
+code_page += "ṕṔÉ①ḳ" # jellyfish specific
 
-# Unused symbols for single-byte atoms/quicks: (quƁƘȤėɦɱɲƥʠʂȥḥḳṇẉỵẓġṅẏ
+# Unused symbols for single-byte atoms/quicks: (quƁƘȤėɦɱɲƥʠʂȥḥṇẉỵẓġṅẏ
 
 str_digit = "0123456789"
 str_lower = "abcdefghijklmnopqrstuvwxyz"
@@ -370,6 +370,9 @@ def partition(array):
     array = iterable(array, make_digits = True)
     return list(filter(lambda x: x[0] > 0, group_equal(array)))
 
+def keep(mask, array):
+    return [val for val, m in zip(array, mask) if m]
+
 def group_lengths(array):
     array = iterable(array, make_digits = True)
     lengths = []
@@ -1614,6 +1617,10 @@ def zip_ragged(array):
         arity = 2,
         call = lambda x, y: partition_at(x, y, border = 2)
     ),
+    "ḳ": attrdict(
+        arity = 2,
+        call = lambda x, y: keep(x, y)
+    ),
     "L": attrdict(
         arity = 1,
         call = lambda z: len(iterable(z))