Build-in Operators

Aggregating Functions

Aggregating function	What it does
`Sum= x`, `+= x`	Summation of all x
`Min= x`	Minimum of all x
`Max= x`	Maximum of all x
`StringAgg= x`	A comma-separated concatenation of all x's. Also can be used to define concatenations via other symbol: `JoinWithDash(x) = StringAgg(x "-")`; JoinWithDash will join the x's with a dash.
`ArgMin= x -> y`	One of x's corresponding to the smallest y
`ArgMax= x -> y`	One of x's corresponding to the largest y
`Count= x`	Approximate count of the number of distinct x.
`List= x`	An array of all x's.
`Set= x`	An array of all distinct x's.
`ArgMaxK(x -> y, k)`	A list of length k containing x's corresponding to largest y's. To be used via defining an auxiliary aggregating function like: `ArgMax5(a) = ArgMaxK(a, 5)`; And then use `ArgMax5= x -> y`.
`ArgMinK(x -> y, k)`	A list of length k containing x's corresponding to smallest y's.
`Array= x -> y`	An array of all y's sorted by corresponding x.
`Avg= x`	Average over values of x.
`1= x`	One (arbitrary) value from what x runs over. This is useful for left joins.

String Manipulation Functions

Function	What it does
`x ++ y`	Concatenation of x and y
`Substr(s, i, l)`	Substring of s starting at position i of length l. Position starts from 1.
`Length(s)`	Length of string s.
`Join(l, c)`	String join of elements of l interleaved with c. E.g., `Join(["a", "b", "c"], "-") == "a-b-c"`
`Split(s, c)`	Splits the string s on separator c into an array of string components. E.g., `Split("a-b-c", "-") = ["a", "b", "c"]`
`Like(s, p)`	Boolean answering whether string s matches pattern p. Corresponds to SQL’s `s LIKE p`. Pattern p allows `%` wildcard matching any string.
`Upper(s)`	Turns s into upper case.

Array Manipulation Functions

Function	What it does
`Size(a)`	Length of the array a.
`Element(a, i)`	Element of a at index i. Indices start with 0.
`ArrayConcat(a, b)`	Concatenation of arrays a and b.

Type Casting Functions

Function	What it does
`ToInt64(x)`	Casts x to an integer number.
`ToFloat64(x)`	Casts x to a float number.
`ToString(x)`	Casts x to a string.

Mathematical Functions

Function	What it does
`Exp(x)`	Exponent of x.
`Sin(x)`	Sin of x.
`Cos(x)`	Cos of x.
`Log(x)`	Natural logarithm of x.

Some Other Functions

Function	What it does
`IsNull(x)`	Boolean answering whether x is null.
`Constraint(x)`	A proposition that x is a boolean which is true. Use it in the body of the predicate to filter on a boolean variable or boolean function value. E.g., `Q(x, y) :- T(x, y, z), Constraint(z), Constraint(F(x));` Here z is a boolean column and F is a boolean function.
`Constraint(x in l)`	Boolean value that checks that x is an element of a list l.
`Range(n)`	An array of natural numbers from 0 to n - 1.
`SqlExpr(s, r)`	Compiles to an SQL expression equal to Python’s s.format(r) where record r is interpreted as a dictionary.