parser

Documentation

Index

• Variables
• func IntervalString(s string, defaultSign int) (int32, error)
• func IsNameChar(r byte) bool
• 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 ParseExpr(e string) (Expr, string, error)
• type ExprType
• type MetricRequest
• type NamedArgs
• type ParseError
  • func (p ParseError) Error() string

Variables

var (
	// ErrMissingExpr is a parse error returned when an expression is missing.
	ErrMissingExpr = ParseError("missing expression")
	// ErrMissingComma is a parse error returned when an expression is missing a comma.
	ErrMissingComma = ParseError("missing comma")
	// ErrMissingQuote is a parse error returned when an expression is missing a quote.
	ErrMissingQuote = ParseError("missing quote")
	// ErrUnexpectedCharacter is a parse error returned when an expression contains an unexpected character.
	ErrUnexpectedCharacter = ParseError("unexpected character")
	// ErrMissingBracket is a parse error returned when an expression is missing an opening or closing bracket.
	ErrMissingBracket = ParseError("missing opening or closing bracket []")
	// ErrMissingBrace is a parse error returned when an expression is missing an opening or closing brace.
	ErrMissingBrace = ParseError("missing opening or closing brace {}")
	// ErrCommaInBrackets is a parse error returned when an expression has comma within brackets.
	ErrCommaInBrackets = ParseError("comma within brackets")
	// ErrSpacesInMetricName is a parse error returned when an expression has space in metric name.
	ErrSpacesInMetricName = ParseError("space in metric name")
	// ErrSpacesInBraces is a parse error returned when an expression has space in braces.
	ErrSpacesInBraces = ParseError("space in braces")
	// ErrSpacesInBrackets is a parse error returned when an expression has space in brackets.
	ErrSpacesInBrackets = ParseError("space in brackets")
	// ErrBraceInBrackets is a parse error returned when an expression has brace within brackets.
	ErrBraceInBrackets = ParseError("brace within brackets")
	// ErrNestedBrackets is a parse error returned when an expression has nested brackets.
	ErrNestedBrackets = ParseError("nested brackets")
	// ErrBadType is an eval error returned when a argument has wrong type.
	ErrBadType = ParseError("bad type")
	// ErrMissingArgument is an eval error returned when a argument is missing.
	ErrMissingArgument = ParseError("missing argument")
	// ErrMissingTimeseries is an eval error returned when a time series argument is missing.
	ErrMissingTimeseries = ParseError("missing time series argument")
	// ErrSeriesDoesNotExist is an eval error returned when a requested time series argument does not exist.
	ErrSeriesDoesNotExist = ParseError("no timeseries with that name")
	// ErrUnknownTimeUnits is an eval error returned when a time unit is unknown to system
	ErrUnknownTimeUnits = ParseError("unknown time units")
	// ErrDifferentCountMetrics is an eval error returned when a function that works on pairs of metrics receives arguments having different number of metrics.
	ErrDifferentCountMetrics = ParseError("both arguments must have the same number of metrics")
	// ErrInvalidArgumentValue is an eval error returned when a function received an argument that has the right type but invalid value
	ErrInvalidArgumentValue = ParseError("invalid function argument value")
)

var RangeTables []*unicode.RangeTable

RangeTables is an array of *unicode.RangeTable

Functions

func IntervalString

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

IntervalString converts a sign and string into a number of seconds

func IsNameChar

func IsNameChar(r byte) bool

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

func TruthyBool

func TruthyBool(s string) bool

TruthyBool evaluates a string into a boolean

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
	// 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

	// Args returns slice of arguments (parsed, as Expr interface as well)
	Args() []Expr
	// NamedArgs returns map of named arguments. E.x. for nonNegativeDerivative(metric1,maxValue=32) it will return map{"maxValue": constExpr(32)}
	NamedArgs() map[string]Expr
	// 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() []MetricRequest

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

	// GetIntervalArg returns n-th argument as string.
	GetStringArg(n int) (string, error)
	// GetIntervalArg 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)
	// GetIntNamedOrPosArgDefault returns specific positioned int-typed argument or replace it with default if none found.
	GetIntNamedOrPosArgDefault(k string, n int, d int) (int, 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)
	// 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 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
)

type MetricRequest

type MetricRequest struct {
	Metric string
	From   int32
	Until  int32
}

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 ParseError

type ParseError string

ParseError is a type of errors returned from the parser

func (ParseError) Error

func (p ParseError) Error() string