add matching-brackets (#288)

config.json

@@ -522,6 +522,14 @@
         "prerequisites": [],
         "difficulty": 3
       },
+      {
+        "slug": "matching-brackets",
+        "name": "matching brackets",
+        "uuid": "c3fe6f2a-cb23-4f1e-8e80-67c36b387d15",
+        "practices": [],
+        "prerequisites": [],
+        "difficulty": 2
+      },
       {
         "slug": "robot-simulator",
         "name": "Robot Simulator",

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": [
+    "BNAndras"
+  ],
+  "files": {
+    "solution": [
+      "matching_brackets.bal"
+    ],
+    "test": [
+      "tests/matching_brackets_test.bal"
+    ],
+    "example": [
+      ".meta/reference/matching_brackets.bal"
+    ]
+  },
+  "blurb": "Make sure the brackets and braces all match.",
+  "source": "Ginna Baker"
+}

exercises/practice/matching-brackets/.meta/reference/matching_brackets.bal

@@ -0,0 +1,46 @@
+map<string> pairs = {
+    "[": "]",
+    "{": "}",
+    "(": ")"
+};
+
+string[] closers = pairs.keys().map(k => pairs.get(k));
+
+#
+# Check whether the brackets in a given string are balanced.
+# 
+# + value - the string to check
+# + return - true if the brackets are balanced, false otherwise
+function isPaired(string value) returns boolean {
+    string:Char[] stack = [];
+
+    foreach string:Char chr in value {
+        if pairs.hasKey(chr) {
+            stack.push(chr);
+        }
+        else if closers.indexOf(chr) is int  {
+            if stack.length() == 0 {
+                return false;
+            }
+
+            string:Char last = stack.pop();
+
+            match [last, chr] {
+                ["[", _] if chr != "]" => {
+                    return false;
+                }
+                ["{", _] if chr != "}" => {
+                    return false;
+                }
+                ["(", _] if chr != ")" => {
+                    return false;
+                }
+                _ => {
+                    continue;
+                }
+            }
+        }
+    }
+
+    return stack.length() == 0;
+}

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/Ballerina.toml

@@ -0,0 +1,5 @@
+[package]
+org = "ballerina_exercism"
+name = "matching_brackets"
+version = "0.1.0"
+distribution = "2201.5.0"

exercises/practice/matching-brackets/Dependencies.toml

@@ -0,0 +1,38 @@
+# AUTO-GENERATED FILE. DO NOT MODIFY.
+
+# This file is auto-generated by Ballerina for managing dependency versions.
+# It should not be modified by hand.
+
+[ballerina]
+dependencies-toml-version = "2"
+distribution-version = "2201.5.0"
+
+[[package]]
+org = "ballerina"
+name = "jballerina.java"
+version = "0.0.0"
+scope = "testOnly"
+
+[[package]]
+org = "ballerina"
+name = "test"
+version = "0.0.0"
+scope = "testOnly"
+dependencies = [
+	{org = "ballerina", name = "jballerina.java"}
+]
+modules = [
+	{org = "ballerina", packageName = "test", moduleName = "test"}
+]
+
+[[package]]
+org = "ballerina_exercism"
+name = "matching_brackets"
+version = "0.1.0"
+dependencies = [
+	{org = "ballerina", name = "test"}
+]
+modules = [
+	{org = "ballerina_exercism", packageName = "matching_brackets", moduleName = "matching_brackets"}
+]
+

exercises/practice/matching-brackets/matching_brackets.bal

@@ -0,0 +1,3 @@
+function isPaired(string value) returns boolean {
+    //TODO: Implement this function
+}

exercises/practice/matching-brackets/tests/matching_brackets_test.bal

@@ -0,0 +1,159 @@
+import ballerina/test;
+
+@test:Config
+function testPairedSquareBrackets() {
+    string value = "[]";
+    test:assertTrue(isPaired(value));
+}
+
+@test:Config {
+    enable: false
+}
+function testEmptyString() {
+    string value = "";
+    test:assertTrue(isPaired(value));
+}
+
+@test:Config {
+    enable: false
+}
+function testUnpairedBrackets() {
+    string value = "[[";
+    test:assertFalse(isPaired(value));
+}
+
+@test:Config {
+    enable: false
+}
+function testWrongOrderedBrackets() {
+    string value = "}{";
+    test:assertFalse(isPaired(value));
+}
+
+@test:Config {
+    enable: false
+}
+function testWrongClosingBracket() {
+    string value = "{]";
+    test:assertFalse(isPaired(value));
+}
+
+@test:Config {
+    enable: false
+}
+function testPairedWithWhitespace() {
+    string value = "{ }";
+    test:assertTrue(isPaired(value));
+}
+
+@test:Config {
+    enable: false
+}
+function testPartiallyPairedBrackets() {
+    string value = "{[])";
+    test:assertFalse(isPaired(value));
+}
+
+@test:Config {
+    enable: false
+}
+function testSimpleNestedBrackets() {
+    string value = "{[]}";
+    test:assertTrue(isPaired(value));
+}
+
+@test:Config {
+    enable: false
+}
+function testSeveralPairedBrackets() {
+    string value = "{}[]";
+    test:assertTrue(isPaired(value));
+}
+
+@test:Config {
+    enable: false
+}
+function testPairedAndNestedBrackets() {
+    string value = "([{}({}[])])";
+    test:assertTrue(isPaired(value));
+}
+
+@test:Config {
+    enable: false
+}
+function testUnopenedClosingBrackets() {
+    string value = "{[)][]}";
+    test:assertFalse(isPaired(value));
+}
+
+@test:Config {
+    enable: false
+}
+function testUnpairedAndNestedBrackets() {
+    string value = "([{])";
+    test:assertFalse(isPaired(value));
+}
+
+@test:Config {
+    enable: false
+}
+function testPairedAndWrongNestedBrackets() {
+    string value = "[({]})";
+    test:assertFalse(isPaired(value));
+}
+
+@test:Config {
+    enable: false
+}
+function testPairedAndWrongNestedBracketsButInnermostAreCorrect() {
+    string value = "[({}])";
+    test:assertFalse(isPaired(value));
+}
+
+@test:Config {
+    enable: false
+}
+function testPairedAndIncompleteBrackets() {
+    string value = "{}[";
+    test:assertFalse(isPaired(value));
+}
+
+@test:Config {
+    enable: false
+}
+function testTooManyClosingBrackets() {
+    string value = "[]]";
+    test:assertFalse(isPaired(value));
+}
+
+@test:Config {
+    enable: false
+}
+function testEarlyUnexpectedBrackets() {
+    string value = ")()";
+    test:assertFalse(isPaired(value));
+}
+
+@test:Config {
+    enable: false
+}
+function testEarlyMismatchedBrackets() {
+    string value = "{)()";
+    test:assertFalse(isPaired(value));
+}
+
+@test:Config {
+    enable: false
+}
+function testMathExpression() {
+    string value = "(((185 + 223.85) * 15) - 543)/2";
+    test:assertTrue(isPaired(value));
+}
+
+@test:Config {
+    enable: false
+}
+function testComplexLatexExpression() {
+    string value = "\\left(\\begin{array}{cc} \\frac{1}{3} & x\\\\ \\mathrm{e}^{x} &... x^2 \\end{array}\\right)";
+    test:assertTrue(isPaired(value));
+}