parser

Documentation

Index

• Variables
• func Define(name, tmpl string) error
• func IntervalString(s string, defaultSign int) (int32, error)
• func IsDigit(r byte) bool
• func IsNameChar(r byte) bool
• func StartAlignTo(start int64, alignTo string) (int64, error)
• func TruthyBool(s string) bool
• type ArgName
• type ArgValue
• type Expr
  • func NewConstExpr(value float64) Expr
  • func NewExpr(target string, vaArgs ...interface{}) Expr
  • func NewExprTyped(target string, args []Expr) Expr
  • func NewNameExpr(name string) Expr
  • func NewTargetExpr(target string) Expr
  • func NewValueExpr(value string) Expr
  • func Parse(e string) (Expr, string, error)
  • func ParseExpr(e string) (Expr, string, error)
• type ExprType
• type IntOrInf
• type MetricRequest
• type NamedArgs
• type NodeOrTag

Variables

var (
	// ErrMissingExpr is a parse error returned when an expression is missing.
	ErrMissingExpr = errors.New("missing expression")
	// ErrMissingComma is a parse error returned when an expression is missing a comma.
	ErrMissingComma = errors.New("missing comma")
	// ErrMissingQuote is a parse error returned when an expression is missing a quote.
	ErrMissingQuote = errors.New("missing quote")
	// ErrUnexpectedCharacter is a parse error returned when an expression contains an unexpected character.
	ErrUnexpectedCharacter = errors.New("unexpected character")
	// ErrBadType is an eval error returned when a argument has wrong type.
	ErrBadType = errors.New("bad type")
	// ErrMissingArgument is an eval error returned when a argument is missing.
	ErrMissingArgument = errors.New("missing argument")
	// ErrMissingTimeseries is an eval error returned when a time series argument is missing.
	ErrMissingTimeseries = errors.New("missing time series argument")
	// ErrMissingValues is an eval error returned when an empty time series is returned but is expected to be non-empty.
	ErrMissingValues = errors.New("unexpected empty time series")
	// ErrUnknownTimeUnits is an eval error returned when a time unit is unknown to system
	ErrUnknownTimeUnits = errors.New("unknown time units")
	// ErrInvalidArg is eval error for invalid or mismatch function arg
	ErrInvalidArg = errors.New("invalid function arg")
	// ErrInvalidInterval is an eval error returned when an interval is set to 0
	ErrInvalidInterval = errors.New("invalid interval arg")
)

var RangeTables []*unicode.RangeTable

RangeTables is an array of *unicode.RangeTable

Functions

func Define

func Define(name, tmpl string) error

Define new template

func IntervalString

func IntervalString(s string, defaultSign int) (int32, error)

IntervalString converts a sign and string into a number of seconds

func IsDigit

func IsDigit(r byte) bool

func IsNameChar

func IsNameChar(r byte) bool

IsNameChar checks if specified char is actually a valid (from graphite's protocol point of view)

func StartAlignTo

func StartAlignTo(start int64, alignTo string) (int64, error)

func TruthyBool

func TruthyBool(s string) bool

Types

type ArgName

type ArgName string

ArgName is a type for Name Argument

type ArgValue

type ArgValue string

ArgValue is a type for Value Argument

type Expr

type Expr interface {
	// IsName checks if Expression is 'Series Name' expression
	IsName() bool
	// IsFunc checks if Expression is 'Function' expression
	IsFunc() bool
	// IsConst checks if Expression is 'Constant' expression
	IsConst() bool
	// IsString checks if Expression is 'String' expression
	IsString() bool
	// IsBool checks if Expression is 'Bool' expression
	IsBool() bool
	// Type returns type of the expression
	Type() ExprType
	// Target returns target value for expression
	Target() string
	// SetTarget changes target for the expression
	SetTarget(string)
	// MutateTarget changes target for the expression and returns new interface. Please note that it doesn't copy object yet
	MutateTarget(string) Expr
	// ToString returns string representation of expression
	ToString() string

	// FloatValue returns float value for expression.
	FloatValue() float64

	// StringValue returns value of String-typed expression (will return empty string for ConstExpr for example).
	StringValue() string
	// SetValString changes value of String-typed expression
	SetValString(string)
	// MutateValString changes ValString for the expression and returns new interface. Please note that it doesn't copy object yet
	MutateValString(string) Expr

	// Arg returns argument with index (parsed, as Expr interface as well)
	Arg(int) Expr
	// Args returns slice of arguments (parsed, as Expr interface as well)
	Args() []Expr
	// ArgsLen return arguments count
	ArgsLen() int
	// NamedArgs returns map of named arguments. E.x. for nonNegativeDerivative(metric1,maxValue=32) it will return map{"maxValue": constExpr(32)}
	NamedArgs() map[string]Expr
	// NamedArg returns named argument and boolean flag for check arg exist.
	NamedArg(string) (Expr, bool)
	// RawArgs returns string that contains all arguments of expression exactly the same order they appear
	RawArgs() string
	// SetRawArgs changes raw argument list for current expression.
	SetRawArgs(args string)
	// MutateRawArgs changes raw argument list for the expression and returns new interface. Please note that it doesn't copy object yet
	MutateRawArgs(args string) Expr

	// Metrics returns list of metric requests
	Metrics(from, until int64) []MetricRequest

	// GetIntervalArg returns interval typed argument.
	GetIntervalArg(n int, defaultSign int) (int32, error)

	// GetIntervalNamedOrPosArgDefault returns interval typed argument that can be passed as a named argument or as position or replace it with default if none found.
	GetIntervalNamedOrPosArgDefault(k string, n, defaultSign int, v int64) (int64, error)

	// GetStringArg returns n-th argument as string.
	GetStringArg(n int) (string, error)
	// GetStringArgs returns n-th argument as slice of strings.
	GetStringArgs(n int) ([]string, error)
	// GetStringArgDefault returns n-th argument as string. It will replace it with Default value if none present.
	GetStringArgDefault(n int, s string) (string, error)
	// GetStringNamedOrPosArgDefault returns specific positioned string-typed argument or replace it with default if none found.
	GetStringNamedOrPosArgDefault(k string, n int, s string) (string, error)

	// GetFloatArg returns n-th argument as float-typed (if it's convertible to float)
	GetFloatArg(n int) (float64, error)
	// GetFloatArgDefault returns n-th argument as float. It will replace it with Default value if none present.
	GetFloatArgDefault(n int, v float64) (float64, error)
	// GetFloatNamedOrPosArgDefault returns specific positioned float64-typed argument or replace it with default if none found.
	GetFloatNamedOrPosArgDefault(k string, n int, v float64) (float64, error)

	// GetIntArg returns n-th argument as int-typed
	GetIntArg(n int) (int, error)
	// GetIntArgs returns n-th argument as slice of ints
	GetIntArgs(n int) ([]int, error)
	// GetIntArgDefault returns n-th argument as int. It will replace it with Default value if none present.
	GetIntArgDefault(n int, d int) (int, error)
	// GetIntArgWithIndication returns n-th argument as int. If argument wasn't present, second return value will be `false`. Even if there was error in parsing data, but it was there, second value will be `true`
	GetIntArgWithIndication(n int) (int, bool, error)
	// GetIntNamedOrPosArgWithIndication returns specific positioned int-typed argument. If argument wasn't present, second return value will be `false`. Even if there was error in parsing data, but it was there, second value will be `true`
	GetIntNamedOrPosArgWithIndication(k string, n int) (int, bool, error)
	// GetIntNamedOrPosArgDefault returns specific positioned int-typed argument or replace it with default if none found.
	GetIntNamedOrPosArgDefault(k string, n int, d int) (int, error)

	GetIntOrInfArg(n int) (IntOrInf, error)
	GetIntOrInfArgDefault(n int, d IntOrInf) (IntOrInf, error)
	GetIntOrInfNamedOrPosArgDefault(k string, n int, d IntOrInf) (IntOrInf, error)

	GetNamedArg(name string) Expr

	// GetBoolArgDefault returns n-th argument as bool. It will replace it with Default value if none present.
	GetBoolArgDefault(n int, b bool) (bool, error)
	// GetBoolNamedOrPosArgDefault returns specific positioned bool-typed argument or replace it with default if none found.
	GetBoolNamedOrPosArgDefault(k string, n int, b bool) (bool, error)

	// GetNodeOrTagArgs returns the last arguments starting from the n-th as a slice of NodeOrTag structures. If `single` is `true`, only the n-th argument is taken.
	GetNodeOrTagArgs(n int, single bool) ([]NodeOrTag, error)

	IsInterfaceNil() bool
	// contains filtered or unexported methods
}

Expr defines an interface to talk with expressions

func NewConstExpr

func NewConstExpr(value float64) Expr

NewConstExpr Creates new Constant expression.

func NewExpr

func NewExpr(target string, vaArgs ...interface{}) Expr

NewExpr creates a new expression with specified target and arguments. It will do best it can to identify type of argument

func NewExprTyped

func NewExprTyped(target string, args []Expr) Expr

NewExprTyped creates a new expression with specified target and arguments. Strictly typed one.

func NewNameExpr

func NewNameExpr(name string) Expr

NewNameExpr Creates new expression with specified name only.

func NewTargetExpr

func NewTargetExpr(target string) Expr

NewTargetExpr Creates new expression with specified target only.

func NewValueExpr

func NewValueExpr(value string) Expr

NewValueExpr Creates new Value expression.

func Parse

func Parse(e string) (Expr, string, error)

Parse parses string as an expression.

func ParseExpr

func ParseExpr(e string) (Expr, string, error)

ParseExpr actually do all the parsing. It returns expression, original string and error (if any)

type ExprType

type ExprType int

ExprType defines a type for expression types constants (e.x. functions, values, constants, parameters, strings)

const (
	// EtName is a const for 'Series Name' type expression
	EtName ExprType = iota
	// EtFunc is a const for 'Function' type expression
	EtFunc
	// EtConst is a const for 'Constant' type expression
	EtConst
	// EtString is a const for 'String' type expression
	EtString
	// EtBool is a constant for 'Bool' type expression
	EtBool
)

type IntOrInf

type IntOrInf struct {
	IsInf  bool
	IntVal int
}

IntOrInf is either positive infinity or an integer value. They are distinguished by "IsInf" = true if it is positive infinity.

type MetricRequest

type MetricRequest struct {
	Metric            string
	ConsolidationFunc string // explicitly use function for consolidation. Check https://graphite.readthedocs.io/en/latest/functions.html?highlight=consolidateBy#graphite.render.functions.consolidateBy
	From              int64
	Until             int64
}

MetricRequest contains all necessary data to request a metric.

type NamedArgs

type NamedArgs map[string]interface{}

NamedArgs is a type for Hashmap of Named Arguments.

type NodeOrTag

type NodeOrTag struct {
	IsTag bool
	Value interface{}
}

NodeOrTag structure contains either Node (=integer) or Tag (=string) They are distinguished by "IsTag" = true in case it's tag.