Add matrix exercise

config.json

@@ -321,6 +321,14 @@
         "prerequisites": [],
         "difficulty": 4
       },
+      {
+        "slug": "matrix",
+        "name": "Matrix",
+        "uuid": "213bf83a-3a6b-44c5-b145-439b262cbd3d",
+        "practices": [],
+        "prerequisites": [],
+        "difficulty": 4
+      },
       {
         "slug": "perfect-numbers",
         "name": "Perfect Numbers",

exercises/practice/matrix/.docs/instructions.md

@@ -0,0 +1,38 @@
+# Instructions
+
+Given a string representing a matrix of numbers, return the rows and columns of that matrix.
+
+So given a string with embedded newlines like:
+
+```text
+9 8 7
+5 3 2
+6 6 7
+```
+
+representing this matrix:
+
+```text
+    1  2  3
+  |---------
+1 | 9  8  7
+2 | 5  3  2
+3 | 6  6  7
+```
+
+your code should be able to spit out:
+
+- A list of the rows, reading each row left-to-right while moving top-to-bottom across the rows,
+- A list of the columns, reading each column top-to-bottom while moving from left-to-right.
+
+The rows for our example matrix:
+
+- 9, 8, 7
+- 5, 3, 2
+- 6, 6, 7
+
+And its columns:
+
+- 9, 5, 6
+- 8, 3, 6
+- 7, 2, 7

exercises/practice/matrix/.meta/config.json

@@ -0,0 +1,19 @@
+{
+  "authors": [
+    "keiravillekode"
+  ],
+  "files": {
+    "solution": [
+      "matrix.fut"
+    ],
+    "test": [
+      "test.fut"
+    ],
+    "example": [
+      ".meta/example.fut"
+    ]
+  },
+  "blurb": "Given a string representing a matrix of numbers, return the rows and columns of that matrix.",
+  "source": "Exercise by the JumpstartLab team for students at The Turing School of Software and Design.",
+  "source_url": "https://turing.edu"
+}

exercises/practice/matrix/.meta/example.fut

@@ -0,0 +1,20 @@
+def select [n] (string: [n]u8) (required_row: i32) (required_column: i32): []i32 =
+  let (a, count, _, _, _, _) = loop (a, count, current_row, current_column, i, number) = (replicate n 0, 0, 1, 1, 0, 0) while i < n do
+    let ch = string[i]
+    in
+      if ch == ' ' then (a, count, current_row, current_column + 1, i + 1, 0)
+      else if ch == '\n' then (a, count, current_row + 1, 1, i + 1, 0)
+      else
+        let number = 10 * number + i32.u8(ch - '0')
+        in
+          if i + 1 < n && string[i + 1] > ' ' then (a, count, current_row, current_column, i + 1, number)
+          else if current_row != required_row && current_column != required_column then (a, count, current_row, current_column, i + 1, 0)
+          else (a with [count] = number, count + 1, current_row, current_column, i + 1, 0)
+  in
+    a[0:count]
+
+def row (string: []u8) (index: i32): []i32 =
+  select string index 0
+
+def column (string: []u8) (index: i32): []i32 =
+  select string 0 index

exercises/practice/matrix/.meta/tests.toml

@@ -0,0 +1,34 @@
+# 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.
+
+[ca733dab-9d85-4065-9ef6-a880a951dafd]
+description = "extract row from one number matrix"
+
+[5c93ec93-80e1-4268-9fc2-63bc7d23385c]
+description = "can extract row"
+
+[2f1aad89-ad0f-4bd2-9919-99a8bff0305a]
+description = "extract row where numbers have different widths"
+
+[68f7f6ba-57e2-4e87-82d0-ad09889b5204]
+description = "can extract row from non-square matrix with no corresponding column"
+
+[e8c74391-c93b-4aed-8bfe-f3c9beb89ebb]
+description = "extract column from one number matrix"
+
+[7136bdbd-b3dc-48c4-a10c-8230976d3727]
+description = "can extract column"
+
+[ad64f8d7-bba6-4182-8adf-0c14de3d0eca]
+description = "can extract column from non-square matrix with no corresponding row"
+
+[9eddfa5c-8474-440e-ae0a-f018c2a0dd89]
+description = "extract column where numbers have different widths"

exercises/practice/matrix/matrix.fut

@@ -0,0 +1,3 @@
+def row (string: []u8) (index: i32): []i32 = ???
+
+def column (string: []u8) (index: i32): []i32 = ???

exercises/practice/matrix/test.fut

@@ -0,0 +1,55 @@
+import "matrix"
+
+-- extract row from one number matrix
+-- ==
+-- entry: test_row
+-- input { "1" 1 }
+-- output { [1] }
+
+-- can extract row
+-- ==
+-- entry: test_row
+-- input { "1 2\n3 4" 2 }
+-- output { [3, 4] }
+
+-- extract row where numbers have different widths
+-- ==
+-- entry: test_row
+-- input { "1 2\n10 20" 2 }
+-- output { [10, 20] }
+
+-- can extract row from non-square matrix with no corresponding column
+-- ==
+-- entry: test_row
+-- input { "1 2 3\n4 5 6\n7 8 9\n8 7 6" 4 }
+-- output { [8, 7, 6] }
+
+-- extract column from one number matrix
+-- ==
+-- entry: test_column
+-- input { "1" 1 }
+-- output { [1] }
+
+-- can extract column
+-- ==
+-- entry: test_column
+-- input { "1 2 3\n4 5 6\n7 8 9" 3 }
+-- output { [3, 6, 9] }
+
+-- can extract column from non-square matrix with no corresponding row
+-- ==
+-- entry: test_column
+-- input { "1 2 3 4\n5 6 7 8\n9 8 7 6" 4 }
+-- output { [4, 8, 6] }
+
+-- extract column where numbers have different widths
+-- ==
+-- entry: test_column
+-- input { "89 1903 3\n18 3 1\n9 4 800" 2 }
+-- output { [1903, 3, 4] }
+
+entry test_row (string: []u8) (index: i32): []i32 =
+  row string index
+
+entry test_column (string: []u8) (index: i32): []i32 =
+  column string index

generators/exercises/matrix.py

@@ -0,0 +1,21 @@
+def gen_test_case(prop, description, inp, expected, f):
+    string = inp["string"].replace("\n", "\\n")
+    index = inp["index"]
+    if expected == []:
+        expected = "empty([0]i32)"
+    else:
+        expected = str(expected)
+
+    f.write(f"-- {description}\n")
+    f.write("-- ==\n")
+    f.write(f"-- entry: test_{prop}\n")
+    f.write(f'-- input {{ "{string}" {index} }}\n')
+    f.write(f"-- output {{ {expected} }}\n\n")
+
+
+def gen_main(f):
+    f.write("entry test_row (string: []u8) (index: i32): []i32 =\n")
+    f.write("  row string index\n\n")
+
+    f.write("entry test_column (string: []u8) (index: i32): []i32 =\n")
+    f.write("  column string index\n")