Add matching-brackets exercise (#75)

config.json

@@ -356,6 +356,14 @@
         "prerequisites": [],
         "difficulty": 2
       },
+      {
+        "slug": "matching-brackets",
+        "name": "Matching Brackets",
+        "uuid": "d77e2cae-6aff-494c-bd92-d8fc3ab09c16",
+        "practices": [],
+        "prerequisites": [],
+        "difficulty": 4
+      },
       {
         "slug": "pascals-triangle",
         "name": "Pascal's Triangle",

exercises/practice/matching-brackets/.docs/instructions.md

@@ -0,0 +1,5 @@
+# Instructions
+
+Given a string containing brackets `[]`, braces `{}`, parentheses `()`, or any combination thereof, verify that any and all pairs are matched and nested correctly.
+Any other characters should be ignored.
+For example, `"{what is (42)}?"` is balanced and `"[text}"` is not.

exercises/practice/matching-brackets/.docs/introduction.md

@@ -0,0 +1,8 @@
+# Introduction
+
+You're given the opportunity to write software for the Bracketeer™, an ancient but powerful mainframe.
+The software that runs on it is written in a proprietary language.
+Much of its syntax is familiar, but you notice _lots_ of brackets, braces and parentheses.
+Despite the Bracketeer™ being powerful, it lacks flexibility.
+If the source code has any unbalanced brackets, braces or parentheses, the Bracketeer™ crashes and must be rebooted.
+To avoid such a scenario, you start writing code that can verify that brackets, braces, and parentheses are balanced before attempting to run it on the Bracketeer™.

exercises/practice/matching-brackets/.meta/config.json

@@ -0,0 +1,18 @@
+{
+  "authors": [
+    "erikschierboom"
+  ],
+  "files": {
+    "solution": [
+      "src/matching-brackets.art"
+    ],
+    "test": [
+      "tests/test-matching-brackets.art"
+    ],
+    "example": [
+      ".meta/src/example.art"
+    ]
+  },
+  "blurb": "Make sure the brackets and braces all match.",
+  "source": "Ginna Baker"
+}

exercises/practice/matching-brackets/.meta/src/example.art

@@ -0,0 +1,16 @@
+paired?: function [str][
+    expected: []
+
+    loop str [c][
+        switch c = '[' -> append 'expected ']' ->
+        switch c = '(' -> append 'expected ')' ->
+        switch c = '{' -> append 'expected '}' -> 
+        switch in? c [']' ')' '}'] [
+            if c <> last expected -> return false
+            chop 'expected
+         ]
+        -> []
+    ]
+
+    empty? expected
+]

exercises/practice/matching-brackets/.meta/tests.toml

@@ -0,0 +1,70 @@
+# 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.
+
+[81ec11da-38dd-442a-bcf9-3de7754609a5]
+description = "paired square brackets"
+
+[287f0167-ac60-4b64-8452-a0aa8f4e5238]
+description = "empty string"
+
+[6c3615a3-df01-4130-a731-8ef5f5d78dac]
+description = "unpaired brackets"
+
+[9d414171-9b98-4cac-a4e5-941039a97a77]
+description = "wrong ordered brackets"
+
+[f0f97c94-a149-4736-bc61-f2c5148ffb85]
+description = "wrong closing bracket"
+
+[754468e0-4696-4582-a30e-534d47d69756]
+description = "paired with whitespace"
+
+[ba84f6ee-8164-434a-9c3e-b02c7f8e8545]
+description = "partially paired brackets"
+
+[3c86c897-5ff3-4a2b-ad9b-47ac3a30651d]
+description = "simple nested brackets"
+
+[2d137f2c-a19e-4993-9830-83967a2d4726]
+description = "several paired brackets"
+
+[2e1f7b56-c137-4c92-9781-958638885a44]
+description = "paired and nested brackets"
+
+[84f6233b-e0f7-4077-8966-8085d295c19b]
+description = "unopened closing brackets"
+
+[9b18c67d-7595-4982-b2c5-4cb949745d49]
+description = "unpaired and nested brackets"
+
+[a0205e34-c2ac-49e6-a88a-899508d7d68e]
+description = "paired and wrong nested brackets"
+
+[1d5c093f-fc84-41fb-8c2a-e052f9581602]
+description = "paired and wrong nested brackets but innermost are correct"
+
+[ef47c21b-bcfd-4998-844c-7ad5daad90a8]
+description = "paired and incomplete brackets"
+
+[a4675a40-a8be-4fc2-bc47-2a282ce6edbe]
+description = "too many closing brackets"
+
+[a345a753-d889-4b7e-99ae-34ac85910d1a]
+description = "early unexpected brackets"
+
+[21f81d61-1608-465a-b850-baa44c5def83]
+description = "early mismatched brackets"
+
+[99255f93-261b-4435-a352-02bdecc9bdf2]
+description = "math expression"
+
+[8e357d79-f302-469a-8515-2561877256a1]
+description = "complex latex expression"

exercises/practice/matching-brackets/src/matching-brackets.art

@@ -0,0 +1,3 @@
+paired?: function [str][
+    panic "Please implement the paired? function"
+]

exercises/practice/matching-brackets/tester.art

@@ -0,0 +1,3 @@
+import {unitt}!
+
+runTests.failFast findTests "tests"

exercises/practice/matching-brackets/tests/test-matching-brackets.art

@@ -0,0 +1,105 @@
+import {unitt}!
+import {src/matching-brackets}!
+
+suite "Matching Brackets"[
+    test "paired square brackets" [
+        result: paired? "[]"
+        assert -> true = result
+    ]
+
+    test.skip "empty string" [
+        result: paired? ""
+        assert -> true = result
+    ]
+
+    test.skip "unpaired brackets" [
+        result: paired? "[["
+        assert -> false = result
+    ]
+
+    test.skip "wrong ordered brackets" [
+        result: paired? "}{"
+        assert -> false = result
+    ]
+
+    test.skip "wrong closing bracket" [
+        result: paired? "{]"
+        assert -> false = result
+    ]
+
+    test.skip "paired with whitespace" [
+        result: paired? "{ }"
+        assert -> true = result
+    ]
+
+    test.skip "partially paired brackets" [
+        result: paired? "{[])"
+        assert -> false = result
+    ]
+
+    test.skip "simple nested brackets" [
+        result: paired? "{[]}"
+        assert -> true = result
+    ]
+
+    test.skip "several paired brackets" [
+        result: paired? "{}[]"
+        assert -> true = result
+    ]
+
+    test.skip "paired and nested brackets" [
+        result: paired? "([{}({}[])])"
+        assert -> true = result
+    ]
+
+    test.skip "unopened closing brackets" [
+        result: paired? "{[)][]}"
+        assert -> false = result
+    ]
+
+    test.skip "unpaired and nested brackets" [
+        result: paired? "([{])"
+        assert -> false = result
+    ]
+
+    test.skip "paired and wrong nested brackets" [
+        result: paired? "[({]})"
+        assert -> false = result
+    ]
+
+    test.skip "paired and wrong nested brackets but innermost are correct" [
+        result: paired? "[({}])"
+        assert -> false = result
+    ]
+
+    test.skip "paired and incomplete brackets" [
+        result: paired? "{}["
+        assert -> false = result
+    ]
+
+    test.skip "too many closing brackets" [
+        result: paired? "[]]"
+        assert -> false = result
+    ]
+
+    test.skip "early unexpected brackets" [
+        result: paired? ")()"
+        assert -> false = result
+    ]
+
+    test.skip "early mismatched brackets" [
+        result: paired? "{)()"
+        assert -> false = result
+    ]
+
+    test.skip "math expression" [
+        result: paired? "(((185 + 223.85) * 15) - 543)/2"
+        assert -> true = result
+    ]
+
+    test.skip "complex latex expression" [
+        result: paired? "\left(\begin{array}{cc} \frac{1}{3} & x\\ \mathrm{e}^{x} &... x^2 \end{array}\right)"
+        assert -> true = result
+    ]
+
+]