The high-level API operates directly on native JavaScript RegExp instances.
The low-level API provides the same functions but operates on the custom data
types StdRegex (standard regex) and ExtRegex (extended regex).
Most of the additional functions are just a
DSL
for constructing instances of these types.
ExtRegex is a super-type of StdRegex and extends it with complement and
intersection operators which have no direct representation in standard regular
expressions. Some operations like size and enumerate only work on StdRegex.
ExtRegex can always be "compiled down" to StdRegex using toStdRegex.
But note that most computational cost is concentrated in this transformation.
The high-level API operates directly on native JavaScript
RegExpinstances. The low-level API provides the same functions but operates on the custom data typesStdRegex(standard regex) andExtRegex(extended regex). Most of the additional functions are just a DSL for constructing instances of these types.ExtRegexis a super-type ofStdRegexand extends it with complement and intersection operators which have no direct representation in standard regular expressions. Some operations likesizeandenumerateonly work onStdRegex.ExtRegexcan always be "compiled down" toStdRegexusingtoStdRegex. But note that most computational cost is concentrated in this transformation.