There are two main types of expand variable-expanding algorithms for ''variable interpolation'':<ref>[https://code.google.com/p/smallest-template-system/wiki/SimplestAlgorithm "smallest-template-system/Simplest algorithms"], an online tutorial for placeholder-template-systems.</ref>
# ''Replace and expand placeholders'': creating a new string from the original one, by find-replacefind–replace operations. Find variable- reference (placeholder), replace it by its variable- value. This algorithm offers no cache strategy.
# ''Split and join string'': splitting the string into an array, and merging it with the corresponding array of values;, then joinjoining items by concatenation. The split string can be cached tofor reuse.
