ADD creates an Expr that obtains its value by adding right and left.

AND tests whether left and right is true.

AssertFloatEquals does a fuzzy comparison of floats.

AssertFloatWithin checks whether a given float is within e error (decimal) of another float.

AVG creates an Expr that obtains its value as the arithmetic mean over the given value.

BOUNDED bounds the given expression to min <= val <= max.

CONST returns an Accumulator that always has a constant value.

COUNT creates an Expr that counts the number of values.

DIV creates an Expr that obtains its value by dividing left by right.

EQ tests whether left equals right.

FIELD creates an Expr that obtains its value from a named field.

courtesy of https://gist.github.com/cevaris/bc331cbe970b03816c6b.

GT tests whether left is greater than right.

GTE tests whether left is greater than or equal to right.

IsField checks whether the given expression is a field expression and if so, returns the name of the field.

IsPercentile indicates whether the given expression is a percentile expression.

LT tests whether left is less than right.

LTE tests whether left is less than or equal to the right.

MAX creates an Expr that keeps track of the maximum value of the wrapped expression or field.

MIN creates an Expr that keeps track of the minimum value of the wrapped expression or field.

MULT creates an Expr that obtains its value by multiplying right and left.

NEQ tests whether left is different from right.

OR tests whether left or right is true.

PERCENTILE tracks estimated percentile values for the given expression assuming the given min and max possible values, to the given precision (where precision is the number of decimal points).

PERCENTILEOPT returns an optimized PERCENTILE that wraps an existing PERCENTILE.

SUB creates an Expr that obtains its value by subtracting right from left.

SUM creates an Expr that obtains its value by summing the given expressions or fields.

WAVG creates an Expr that obtains its value as the weighted arithmetic mean over the given value weighted by the given weight.

An Expr is expression that stores its value in a byte array and that evaluates to a float64.

Params is an interface for data structures that can contain named values.

FloatParams is an implementation of Params that always returns the same float64 value.

Map is an implementation of the Params interface using a map.

SubMerge is a function that merges other into data for a given Expr, potentially taking into account the supplied metadata.