small patternMatching template

patternm.d

// returns where the pattern matched 
uint[] match(T)(T[] elems, T[] pattern) {
	uint[] positionsMatched;
	uint posInPattern;
	uint posInElems;

	while (elems.length - posInElems >= pattern.length - posInPattern) {

		if (pattern[posInPattern] == elems[posInElems]) {
			if (posInPattern == pattern.length-1) {
				positionsMatched ~= (posInElems - posInPattern);
				posInPattern = 0;
				posInElems++;
			} else {
				posInElems++;
				posInPattern++;
			}

		} else {
			posInPattern = 0;
			posInElems++;
		}
	}

	
	return positionsMatched;
}