matcher

type Engine interface {
	Compile(pattern string, flags int) (Regexp, error)
	Quote(s string) string

	FlagDotAll() int
	FlagExtended() int
	FlagUnicode() int
	FlagCaseInsensitive() int
	FlagMultiline() int
}

type Match interface {
	// Groups returns the number of capturing groups in the pattern
	Groups() int
	// GroupByIdx returns the value of a group by index
	// Important: GroupByIdx(0) returns the full match, the first group has index 1
	GroupByIdx(idx int) string
	// GroupPresentByIdx returns whether the specified group is present in the succesful match
	GroupPresentByIdx(idx int) bool
	// GroupByName returns the value of a group by name
	GroupByName(name string) string
	// GroupPresentByName returns whether the specified group is present in the succesful match
	GroupPresentByName(name string) bool
	// Next tries to find a next match, returns true if it succeeds;
	// after calling this method all info about the previous match gets lost
	Next() bool
}

type Regexp interface {
	// Search returns the leftmost successful match or nil if the pattern failed to match
	Search(subject string) Match
	// Replace replaces every occurrence of the pattern with repl
	// (group references in repl are in Perl/Java style: $0, $1, $2, ..)
	Replace(subject, repl string) string
	// ReplaceFunc replaces every occurrence of the pattern with
	// replacements produced by invoking the replacer on every match
	ReplaceFunc(subject string, replacer Replacer) string
}

type Replacer interface {
	Replacement(match Match) string
}