NewParamParser receives a "src" of a single parameter and returns a new ParamParser, ready to Parse.

Parse takes a route "fullpath" and returns its param statements and an error on failure.

DefaultParamErrorCode is the default http error code, 404 not found, per-parameter.

DefaultParamType when parameter type is missing use this param type, defaults to string and it should be remains unless earth split in two.

ParamParser is the parser which is being used by the Parse function to parse path segments one by one and return their parsed parameter statements (param name, param type its functions and the inline route's functions).