Ergo Standard Library

The following libraries are provided with the Ergo compiler.

Stdlib

The following functions are in the org.accordproject.ergo.stdlib namespace and available by default.

Functions on Integer

Name	Signature	Description
integerAbs	(x:Integer) : Integer	Absolute value
integerLog2	(x:Integer) : Integer	Base 2 integer logarithm
integerSqrt	(x:Integer) : Integer	Integer square root
integerToDouble	(x:Integer) : Double	Cast to a Double
integerMod	(x:Integer, y:Integer) : Integer	Integer remainder
integerMin	(x:Integer, y:Integer) : Integer	Smallest of x and y
integerMax	(x:Integer, y:Integer) : Integer	Largest of x and y

Functions on Double

Name	Signature	Description
abs	(x:Double) : Double	Absolute value
sqrt	(x:Double) : Double	Square root
exp	(x:Double) : Double	Exponential
log	(x:Double) : Double	Natural logarithm
log10	(x:Double) : Double	Base 10 logarithm
ceil	(x:Double) : Double	Round to closest integer above
floor	(x:Double) : Double	Round to closest integer below
truncate	(x:Double) : Integer	Cast to an Integer
doubleToInteger	(x:Double) : Integer	Same as truncate
minPair	(x:Double, y:Double) : Double	Smallest of x and y
maxPair	(x:Double, y:Double) : Double	Largest of x and y

Functions on String

Name	Signature	Description
length	(x:String) : Integer	Prints length of a string
encode	(x:String) : String	Encode as URI component
decode	(x:String) : String	Decode as URI component

Functions on Arrays

Name	Signature	Description
count	(x:Any[]) : Integer	Number of elements
flatten	(x:Any[][]) : Any[]	Flattens a nested array
arrayAdd	(x:Any[],y:Any[]) : Any[]	Array concatenation
arraySubtract	(x:Any[],y:Any[]) : Any[]	Removes elements of y in x
inArray	(x:Any,y:Any[]) : Boolean	Whether x is in y
containsAll	(x:Any[],y:Any[]) : Boolean	Whether all elements of y are in x
distinct	(x:Any[]) : Any[]	Duplicates elimination

Note: For most of these functions, the type-checker infers more precise types than indicated here. For instance concat([1,2],[3,4]) will return [1,2,3,4] and have the type Integer[].

Aggregate functions

Name	Signature	Description
max	(x:Double[]) : Double	The largest element in x
min	(x:Double[]) : Double	The smallest element in x
sum	(x:Double[]) : Double	Sum of the elements in x
average	(x:Double[]) : Double	Arithmetic mean

Math functions

Name	Signature	Description
acos	(x:Double) : Double	The inverse cosine of x
asin	(x:Double) : Double	The inverse sine of x
atan	(x:Double) : Double	The inverse tangent of x
atan2	(x:Double, y:Double) : Double	The inverse tangent of x / y
cos	(x:Double) : Double	The cosine of x
cosh	(x:Double) : Double	The hyperbolic cosine of x
sin	(x:Double) : Double	The sine of x
sinh	(x:Double) : Double	The hyperbolic sine of x
tan	(x:Double) : Double	The tangent of x
tanh	(x:Double) : Double	The hyperbolic tangent of x

Other functions

Name	Signature	Description
failure	(x:String) : ErgoErrorResponse	Ergo error from a string
toString	(x:Any) : String	Prints any value to a string
toText	(x:Any) : String	Template variant of toString (internal)

Time

The following functions are in the org.accordproject.time namespace and are available by importing that namespace. They rely on the time.cto types from the Accord Project models.

Functions on DateTime

Name	Signature	Description
now	() : DateTime	Returns the time when execution started
dateTime	(x:String) : DateTime	Parse a date and time
getSecond	(x:DateTime) : Long	Second component of a DateTime
getMinute	(x:DateTime) : Long	Minute component of a DateTime
getHour	(x:DateTime) : Long	Hour component of a DateTime
getDay	(x:DateTime) : Long	Day of the month component of a DateTime
getWeek	(x:DateTime) : Long	Week of the year component of a DateTime
getMonth	(x:DateTime) : Long	Month component in a DateTime
getYear	(x:DateTime) : Long	Year component in a DateTime
isAfter	(x:DateTime, y:DateTime) : Boolean	Whether x if after y
isBefore	(x:DateTime, y:DateTime) : Boolean	Whether x is before y
isSame	(x:DateTime, y:DateTime) : Boolean	Whether x is the same DateTime as y
dateTimeMin	(x:DateTime[]) : DateTime	The earliest in an array of DateTime
dateTimeMax	(x:DateTime[]) : DateTime	The latest in an array of DateTime
format	(x:DateTime,f:String) : String	Prints date x according to format f

Functions on Duration

Name	Signature	Description
durationAs	(x:Duration, y:TemporalUnit) : Duration	Change the unit for duration x to y
diffDurationAs	(x:DateTime, y:DateTime, z:TemporalUnit) : Duration	Duration between x and y in unit z
diffDuration	(x:DateTime, y:DateTime) : Duration	Duration between x and y in seconds
addDuration	(x:DateTime, y:Duration) : DateTime	Add duration y to x
subtractDuration	(x:DateTime, y:Duration) : DateTime	Subtract duration y to x
divideDuration	(x:Duration, y:Duration) : Double	Ratio between durations x and y

Functions on Period

Name	Signature	Description
diffPeriodAs	(x:DateTime, y:DateTime, z:PeriodUnit) : Period	Time period between x and y in unit z
addPeriod	(x:DateTime, y:Period) : DateTime	Add time period y to x
subtractPeriod	(x:DateTime, y:Period) : DateTime	Subtract time period y to x
startOf	(x:DateTime, y:PeriodUnit) : DateTime	Start of period y nearest to DateTime x
endOf	(x:DateTime, y:PeriodUnit) : DateTime	End of period y nearest to DateTime x