regexutil

Documentation

Index

• func GetOrValuesPromRegex(expr string) []string
• func GetOrValuesRegex(expr string) []string
• func RemoveStartEndAnchors(expr string) string
• func SimplifyPromRegex(expr string) (string, string)
• func SimplifyRegex(expr string) (string, string)
• type PromRegex
  • func NewPromRegex(expr string) (*PromRegex, error)
  • func (pr *PromRegex) MatchString(s string) bool
  • func (pr *PromRegex) String() string
• type Regex
  • func NewRegex(expr string) (*Regex, error)
  • func (r *Regex) GetLiterals() []string
  • func (r *Regex) MatchString(s string) bool
  • func (r *Regex) String() string

Functions

func GetOrValuesPromRegex

func GetOrValuesPromRegex(expr string) []string

GetOrValuesPromRegex returns "or" values from the given Prometheus-like regexp expr.

It ignores start and end anchors ('^') and ('$') at the start and the end of expr. It returns ["foo", "bar"] for "foo|bar" regexp. It returns ["foo"] for "foo" regexp. It returns [""] for "" regexp. It returns an empty list if it is impossible to extract "or" values from the regexp.

func GetOrValuesRegex

func GetOrValuesRegex(expr string) []string

GetOrValuesRegex returns "or" values from the given regexp expr.

It returns ["foo", "bar"] for "foo|bar" regexp. It returns ["foo"] for "foo" regexp. It returns [""] for "" regexp. It returns an empty list if it is impossible to extract "or" values from the regexp.

func RemoveStartEndAnchors

func RemoveStartEndAnchors(expr string) string

RemoveStartEndAnchors removes '^' at the start of expr and '$' at the end of the expr.

func SimplifyPromRegex

func SimplifyPromRegex(expr string) (string, string)

SimplifyPromRegex simplifies the given Prometheus-like expr.

It returns plaintext prefix and the remaining regular expression with dropped '^' and '$' anchors at the beginning and at the end of the regular expression.

The function removes capturing parens from the expr, so it cannot be used when capturing parens are necessary.

func SimplifyRegex

func SimplifyRegex(expr string) (string, string)

SimplifyRegex simplifies the given regexp expr.

It returns plaintext pefix and the remaining regular expression without capturing parens.

Types

type PromRegex

type PromRegex struct {
	// contains filtered or unexported fields
}

PromRegex implements an optimized string matching for Prometheus-like regex.

The following regexs are optimized:

- plain string such as "foobar" - alternate strings such as "foo|bar|baz" - prefix match such as "foo.*" or "foo.+" - substring match such as ".*foo.*" or ".+bar.+"

The rest of regexps are also optimized by returning cached match results for the same input strings.

func NewPromRegex

func NewPromRegex(expr string) (*PromRegex, error)

NewPromRegex returns PromRegex for the given expr.

func (*PromRegex) MatchString

func (pr *PromRegex) MatchString(s string) bool

MatchString returns true if s matches pr.

The pr is automatically anchored to the beginning and to the end of the matching string with '^' and '$'.

func (*PromRegex) String

func (pr *PromRegex) String() string

String returns string representation of pr.

type Regex

type Regex struct {
	// contains filtered or unexported fields
}

Regex implements an optimized string matching for Go regex.

The following regexs are optimized:

- plain string such as "foobar" - alternate strings such as "foo|bar|baz" - prefix match such as "foo.*" or "foo.+" - substring match such as ".*foo.*" or ".+bar.+"

func NewRegex

func NewRegex(expr string) (*Regex, error)

NewRegex returns Regex for the given expr.

func (*Regex) GetLiterals

func (r *Regex) GetLiterals() []string

GetLiterals returns literals for r.

func (*Regex) MatchString

func (r *Regex) MatchString(s string) bool

MatchString returns true if s matches r.

func (*Regex) String

func (r *Regex) String() string

String returns string represetnation for r