rename binary-search to binary-chop

config.json

@@ -979,9 +979,9 @@
         "difficulty": 3
       },
       {
-        "slug": "binary-search",
+        "slug": "binary-chop",
         "name": "Binary Search",
-        "uuid": "ea3a619c-0d03-4688-821a-22379470d7e1",
+        "uuid": "49cc7b5c-d2fc-4332-89a5-9890c340f25f",
         "practices": [
           "recursion"
         ],
@@ -993,6 +993,15 @@
         ],
         "difficulty": 3
       },
+      {
+        "slug": "binary-search",
+        "name": "Binary Search (deprecated)",
+        "uuid": "ea3a619c-0d03-4688-821a-22379470d7e1",
+        "practices": [],
+        "prerequisites": [],
+        "difficulty": 3,
+        "status": "deprecated"
+      },
       {
         "slug": "bob",
         "name": "Bob",

exercises/practice/binary-chop/.docs/instructions.md

@@ -0,0 +1,29 @@
+# Instructions
+
+Your task is to implement a binary search algorithm.
+
+A binary search algorithm finds an item in a list by repeatedly splitting it in half, only keeping the half which contains the item we're looking for.
+It allows us to quickly narrow down the possible locations of our item until we find it, or until we've eliminated all possible locations.
+
+~~~~exercism/caution
+Binary search only works when a list has been sorted.
+~~~~
+
+The algorithm looks like this:
+
+- Find the middle element of a _sorted_ list and compare it with the item we're looking for.
+- If the middle element is our item, then we're done!
+- If the middle element is greater than our item, we can eliminate that element and all the elements **after** it.
+- If the middle element is less than our item, we can eliminate that element and all the elements **before** it.
+- If every element of the list has been eliminated then the item is not in the list.
+- Otherwise, repeat the process on the part of the list that has not been eliminated.
+
+Here's an example:
+
+Let's say we're looking for the number 23 in the following sorted list: `[4, 8, 12, 16, 23, 28, 32]`.
+
+- We start by comparing 23 with the middle element, 16.
+- Since 23 is greater than 16, we can eliminate the left half of the list, leaving us with `[23, 28, 32]`.
+- We then compare 23 with the new middle element, 28.
+- Since 23 is less than 28, we can eliminate the right half of the list: `[23]`.
+- We've found our item.

exercises/practice/binary-chop/.docs/introduction.md

@@ -0,0 +1,13 @@
+# Introduction
+
+You have stumbled upon a group of mathematicians who are also singer-songwriters.
+They have written a song for each of their favorite numbers, and, as you can imagine, they have a lot of favorite numbers (like [0][zero] or [73][seventy-three] or [6174][kaprekars-constant]).
+
+You are curious to hear the song for your favorite number, but with so many songs to wade through, finding the right song could take a while.
+Fortunately, they have organized their songs in a playlist sorted by the title — which is simply the number that the song is about.
+
+You realize that you can use a binary search algorithm to quickly find a song given the title.
+
+[zero]: https://en.wikipedia.org/wiki/0
+[seventy-three]: https://en.wikipedia.org/wiki/73_(number)
+[kaprekars-constant]: https://en.wikipedia.org/wiki/6174_(number)

exercises/practice/binary-chop/.meta/config.json

@@ -0,0 +1,19 @@
+{
+  "authors": [
+    "keiravillekode"
+  ],
+  "files": {
+    "solution": [
+      "binary-chop/binary-chop.factor"
+    ],
+    "test": [
+      "binary-chop/binary-chop-tests.factor"
+    ],
+    "example": [
+      ".meta/example.factor"
+    ]
+  },
+  "blurb": "Implement a binary search algorithm.",
+  "source": "Wikipedia",
+  "source_url": "https://en.wikipedia.org/wiki/Binary_search_algorithm"
+}

exercises/practice/binary-chop/.meta/example.factor

@@ -0,0 +1,18 @@
+USING: combinators kernel locals math sequences ;
+IN: binary-chop
+
+ERROR: value-not-in-array ;
+
+:: search-range ( array value low high -- index )
+    low high > [ value-not-in-array ] [
+        low high + 2 /i :> mid
+        mid array nth :> probe
+        {
+            { [ probe value = ] [ mid ] }
+            { [ probe value < ] [ array value mid 1 + high search-range ] }
+            [ array value low mid 1 - search-range ]
+        } cond
+    ] if ;
+
+: find ( array value -- index )
+    over length 1 - [ 0 ] dip search-range ;

exercises/practice/binary-chop/.meta/generator.jl

@@ -0,0 +1,13 @@
+module BinarySearch
+
+function gen_test_case(case)
+    array = format_int_array(case["input"]["array"])
+    value = to_int_str(case["input"]["value"])
+    expected = case["expected"]
+    if expected isa AbstractDict && haskey(expected, "error")
+        return """[ $(array) $(value) find ] [ value-not-in-array? ] must-fail-with"""
+    end
+    return "{ $(to_int_str(expected)) }\n[ $(array) $(value) find ] unit-test"
+end
+
+end

exercises/practice/binary-chop/.meta/tests.toml

@@ -0,0 +1,43 @@
+# This is an auto-generated file.
+#
+# Regenerating this file via `configlet sync` will:
+# - Recreate every `description` key/value pair
+# - Recreate every `reimplements` key/value pair, where they exist in problem-specifications
+# - Remove any `include = true` key/value pair (an omitted `include` key implies inclusion)
+# - Preserve any other key/value pair
+#
+# As user-added comments (using the # character) will be removed when this file
+# is regenerated, comments can be added via a `comment` key.
+
+[b55c24a9-a98d-4379-a08c-2adcf8ebeee8]
+description = "finds a value in an array with one element"
+
+[73469346-b0a0-4011-89bf-989e443d503d]
+description = "finds a value in the middle of an array"
+
+[327bc482-ab85-424e-a724-fb4658e66ddb]
+description = "finds a value at the beginning of an array"
+
+[f9f94b16-fe5e-472c-85ea-c513804c7d59]
+description = "finds a value at the end of an array"
+
+[f0068905-26e3-4342-856d-ad153cadb338]
+description = "finds a value in an array of odd length"
+
+[fc316b12-c8b3-4f5e-9e89-532b3389de8c]
+description = "finds a value in an array of even length"
+
+[da7db20a-354f-49f7-a6a1-650a54998aa6]
+description = "identifies that a value is not included in the array"
+
+[95d869ff-3daf-4c79-b622-6e805c675f97]
+description = "a value smaller than the array's smallest value is not found"
+
+[8b24ef45-6e51-4a94-9eac-c2bf38fdb0ba]
+description = "a value larger than the array's largest value is not found"
+
+[f439a0fa-cf42-4262-8ad1-64bf41ce566a]
+description = "nothing is found in an empty array"
+
+[2c353967-b56d-40b8-acff-ce43115eed64]
+description = "nothing is found when the left and right bounds cross"

exercises/practice/binary-chop/binary-chop/binary-chop-tests.factor

@@ -0,0 +1,43 @@
+USING: binary-chop exercism-tools io kernel tools.test unicode ;
+IN: binary-chop.tests
+
+"finds a value in an array with one element" description
+{ 0 }
+[ { 6 } 6 find ] unit-test
+
+STOP-HERE
+
+"finds a value in the middle of an array" description
+{ 3 }
+[ { 1 3 4 6 8 9 11 } 6 find ] unit-test
+
+"finds a value at the beginning of an array" description
+{ 0 }
+[ { 1 3 4 6 8 9 11 } 1 find ] unit-test
+
+"finds a value at the end of an array" description
+{ 6 }
+[ { 1 3 4 6 8 9 11 } 11 find ] unit-test
+
+"finds a value in an array of odd length" description
+{ 9 }
+[ { 1 3 5 8 13 21 34 55 89 144 233 377 634 } 144 find ] unit-test
+
+"finds a value in an array of even length" description
+{ 5 }
+[ { 1 3 5 8 13 21 34 55 89 144 233 377 } 21 find ] unit-test
+
+"identifies that a value is not included in the array" description
+[ { 1 3 4 6 8 9 11 } 7 find ] [ value-not-in-array? ] must-fail-with
+
+"a value smaller than the array's smallest value is not found" description
+[ { 1 3 4 6 8 9 11 } 0 find ] [ value-not-in-array? ] must-fail-with
+
+"a value larger than the array's largest value is not found" description
+[ { 1 3 4 6 8 9 11 } 13 find ] [ value-not-in-array? ] must-fail-with
+
+"nothing is found in an empty array" description
+[ {  } 1 find ] [ value-not-in-array? ] must-fail-with
+
+"nothing is found when the left and right bounds cross" description
+[ { 1 2 } 0 find ] [ value-not-in-array? ] must-fail-with

exercises/practice/binary-chop/binary-chop/binary-chop.factor

@@ -0,0 +1,7 @@
+USING: kernel ;
+IN: binary-chop
+
+ERROR: value-not-in-array ;
+
+: find ( array value -- index )
+    "unimplemented" throw ;

exercises/practice/binary-chop/exercism-tools/exercism-tools.factor

@@ -0,0 +1,35 @@
+USING: accessors command-line continuations debugger io kernel
+       lexer namespaces prettyprint.config sequences
+       source-files.errors.debugger system tools.test vocabs
+       vocabs.loader ;
+IN: exercism-tools
+
+SYNTAX: STOP-HERE
+    lexer get [ text>> length ] keep line<< ;
+
+SYNTAX: TASK:
+    lexer get next-line ;
+
+! Label the test that follows with its description.
+: description ( str -- )
+    "###DESC### " write print ;
+
+! Print one failure block in a stable, parser-friendly form.
+:: print-failure ( failure -- )
+    "###FAIL_BEGIN###" print
+    failure error-location print
+    [ failure error>> [ error. ] [ 2drop ] recover ] without-limits
+    "###FAIL_END###" print
+    flush ;
+
+: print-failures ( -- )
+    test-failures get [ print-failure ] each ;
+
+: run-exercism-tests ( -- )
+    vocab-roots [ "." prefix ] change-global
+    command-line get first
+    [ require ] [ test ] bi
+    test-failures get empty?
+    [ 0 exit ] [ print-failures 1 exit ] if ;
+
+MAIN: run-exercism-tests

generator/generate.jl

@@ -4,14 +4,28 @@ using JSON3, TOML
 const GENERATOR_DIR = @__DIR__
 const TRACK_DIR = dirname(GENERATOR_DIR)
 
-function read_canonical_data(exercise)
+function specification_for(slug)
+    # A Practice Exercise may set an optional `specification` key in the track
+    # `config.json` to sync from a differently-named `problem-specifications`
+    # exercise (e.g. slug `binary-chop` <- specification `binary-search`).
+    # When the key is absent, the slug doubles as the specification name.
+    config = JSON3.read(read(joinpath(TRACK_DIR, "config.json"), String))
+    for ex in config.exercises.practice
+        if String(ex.slug) == slug
+            return haskey(ex, :specification) ? String(ex.specification) : slug
+        end
+    end
+    return slug
+end
+
+function read_canonical_data(specification)
     prefix = "Using cached 'problem-specifications' dir: "
     info = readchomp(Cmd(`$(joinpath(TRACK_DIR, "bin", "configlet")) info -o -v d`))
     lines = split(info, '\n')
     cache_lines = filter(l -> startswith(l, prefix), lines)
     length(cache_lines) == 1 || error("Could not determine 'problem-specifications' dir")
     cache_dir = cache_lines[1][length(prefix)+1:end]
-    path = joinpath(cache_dir, "exercises", exercise, "canonical-data.json")
+    path = joinpath(cache_dir, "exercises", specification, "canonical-data.json")
     return JSON3.read(read(path, String))
 end
 
@@ -123,7 +137,9 @@ function render_test_file(mod, cases, slug)
 end
 
 function generate(exercise)
-    data = read_canonical_data(exercise)
+    # The canonical data is read using the `specification` (which may differ
+    # from the slug); everything else stays keyed on the track `exercise` slug.
+    data = read_canonical_data(specification_for(exercise))
     cases = flatten_cases(data)
     cases = filter_by_toml(cases, exercise)
     extra = load_extra_cases(exercise)