[alexdavey]

Ok, I haven't written any PHP for ages, so I can't help you there, but I have written some JavaScript that does what you want.

The concept is very simple, split the string into an array containing groups and single letters (so

'extreme'

would become

['e', 'xtr', 'e', 'm', 'e]'

), then shuffle the array.

Unfortunately though, what could have been a 5 line regex function (if JavaScript's regex functions weren't so haphazard) turned into a ungodly 40 line function (To be fair, it is only 30 solid lines of code). Here it is:

var groups = ['er', 'ing', 'xtr', 'an', 'or', 'es'];

// Determines whether the string is a prefix of any of the groups
function groupPrefix(prefix, groups) {
	for (var i = 0, l = groups.length; i < l; i++) { // Test each group
		if (groups[i].indexOf(prefix) === 0) return true;
	}
	return false;
}

// Splits a string into an array of characters and groups.
// Essentially, it traverses the string, and checks to see
// whether that character is part of a group. If so, it adds
// it to a stack until it cannot. Then it pushes that group onto
// the new array. If the character is not part of a group, it
// simply pushes it onto the array.
function split(string, groups) {
	var array = [], // Array of characters and groups
		character, // Character being inspected
		match = '', // Characters so far that match a group
		isMatch; // Whether the current pass resulted in a match

	for (var i = 0, l = string.length; i < l; i++) { // Loop over the string

		isMatch = true;
		character = string.charAt(i);

		if (groupPrefix(match + character, groups)) { // If it is a prefix,
			match += character;                      // push it onto the stack
		} else if (groupPrefix(character, groups)) { // Special test for 
			array.push(match);                       // adjacent groups
			match = character;
		} else {
			isMatch = false;
		}

		// If there was a match, then jump to the next character
		if (isMatch) continue;
		
		// If there was no match, but there are characters in the 'match'
		// string, the previous character must have completed the match, 
		// so push in onto the array
		if (match) {
			array.push(match);
			match = '';
		}

		// Push the current character onto the 
		array.push(character);

	}

	// If characters are left in the match, check if it is a complete match,
	// and if so, push it onto the array. If it is of length one, it could also
	// be the last character
	if (match && (groups.indexOf(match) !== -1 || match.length == 1)) array.push(match); 

	return array;
}

// Generic shuffle function
function shuffle(array) {
	var newArray = [],
		random;
	for (var i = 0, l = array.length; i < l; i++) {
		random = Math.floor(Math.random() * array.length);
		newArray.push(array.splice(random, 1)[0]);
	}
	return newArray;
}

function scrambleWord(word) {
	var middle = word.slice(1, -1),
		array = split(middle, groups);
		array = shuffle(array);
	// return first charater + new middle + last character
	return word.charAt(0) + array.join('') + word.charAt(word.length - 1);
}

There is also a fiddle.

I would love it if someone could come up with a shorter function (as I am sure there must be, i'm probably not thinking straight).

[HeartLess]

alexdavey, on 20 August 2012 - 02:07 PM, said:

*snip*

The code looks great. I'm using the same concept as you, but the problem I'm running into is the indexof() part. It returns true if the whole "group" is found, but it returns false if only part of it is found.

e.g.

input "er" : you get true
input "e" : you get false


EDIT: nvm. It was a mistake on my part while porting to PHP >:]