fix: replace .english.md extension with .md

curriculum/challenges/english/10-coding-interview-prep/rosetta-code/s-expressions.md

@@ -0,0 +1,99 @@
+---
+title: S-Expressions
+id: 59667989bf71cf555dd5d2ff
+challengeType: 5
+forumTopicId: 302303
+---
+
+## Description
+<section id='description'>
+<a href="https://en.wikipedia.org/wiki/S-Expression" title="wp: S-Expression" target="_blank">S-Expressions</a> are one convenient way to parse and store data.
+</section>
+
+## Instructions
+<section id='instructions'>
+Write a simple reader/parser for S-Expressions that handles quoted and unquoted strings, integers and floats.
+The function should read a single but nested S-Expression from a string and return it as a (nested) array.
+Newlines and other whitespace may be ignored unless contained within a quoted string.
+"<tt>()</tt>"  inside quoted strings are not interpreted, but treated as part of the string.
+Handling escaped quotes inside a string is optional; thus "<tt>(foo"bar)</tt>" may be treated as a string "<tt>foo"bar</tt>", or as an error.
+For this, the reader need not recognize "<tt>\</tt>" for escaping, but should, in addition, recognize numbers if the language has appropriate data types.
+Note that with the exception of "<tt>()"</tt>" ("<tt>\</tt>" if escaping is supported) and whitespace there are no special characters. Anything else is allowed without quotes.
+The reader should be able to read the following input
+<pre>
+((data "quoted data" 123 4.5)
+(data (!@# (4.5) "(more" "data)")))
+</pre>
+and turn it into a native data structure. (See the <a href="https://rosettacode.org/wiki/S-Expressions#Pike" title="#Pike" target="_blank">Pike</a>, <a href="https://rosettacode.org/wiki/S-Expressions#Python" title="#Python" target="_blank">Python</a> and <a href="https://rosettacode.org/wiki/S-Expressions#Ruby" title="#Ruby" target="_blank">Ruby</a> implementations for examples of native data structures.)
+</section>
+
+## Tests
+<section id='tests'>
+
+```yml
+tests:
+  - text: <code>parseSexpr</code> should be a function.
+    testString: assert(typeof parseSexpr === 'function');
+  - text: <code>parseSexpr('(data1 data2 data3)')</code> should return <code>['data1', 'data2', 'data3']</code>
+    testString: assert.deepEqual(parseSexpr(simpleSExpr), simpleSolution);
+  - text: <code>parseSexpr('(data1 data2 data3)')</code> should return an array with 3 elements.
+    testString: assert.deepEqual(parseSexpr(basicSExpr), basicSolution);
+
+```
+
+</section>
+
+## Challenge Seed
+<section id='challengeSeed'>
+
+<div id='js-seed'>
+
+```js
+function parseSexpr(str) {
+
+  return true;
+}
+```
+
+</div>
+
+
+### After Test
+<div id='js-teardown'>
+
+```js
+const simpleSExpr = '(data1 data2 data3)';
+const simpleSolution = ['data1', 'data2', 'data3'];
+
+const basicSExpr = '((data "quoted data" 123 4.5) (data (!@# (4.5) "(more" "data)")))';
+const basicSolution = [["data","\"quoted data\"",123,4.5],["data",["!@#",[4.5],"\"(more\"","\"data)\""]]];
+```
+
+</div>
+
+</section>
+
+## Solution
+<section id='solution'>
+
+
+```js
+function parseSexpr(str) {
+  const t = str.match(/\s*("[^"]*"|\(|\)|"|[^\s()"]+)/g);
+  for (var o, c = 0, i = t.length - 1; i >= 0; i--) {
+    var n,
+      ti = t[i].trim();
+    if (ti == '"') return;
+    else if (ti == '(') t[i] = '[', c += 1;
+    else if (ti == ')') t[i] = ']', c -= 1;
+    else if ((n = +ti) == ti) t[i] = n;
+    else t[i] = `'${ti.replace('\'', '\\\'')}'`;
+    if (i > 0 && ti != ']' && t[i - 1].trim() != '(') t.splice(i, 0, ',');
+    if (!c) if (!o) o = true; else return;
+  }
+  return c ? undefined : eval(t.join(''));
+}
+
+```
+
+</section>