Enum Transform 

pub enum Transform {
    Filter {
        field: String,
        value: String,
    },
    Select {
        fields: Vec<String>,
    },
    Sort {
        field: String,
        desc: bool,
    },
    Limit {
        n: usize,
    },
    Count,
    Sum {
        field: String,
    },
    Mean {
        field: String,
    },
    Rate {
        window: String,
    },
    Percentage,
    Join {
        other: String,
        on: String,
    },
    Sample {
        n: usize,
    },
    GroupBy {
        field: String,
    },
    Distinct {
        field: Option<String>,
    },
    Where {
        field: String,
        op: String,
        value: String,
    },
    Offset {
        n: usize,
    },
    Min {
        field: String,
    },
    Max {
        field: String,
    },
    First {
        n: usize,
    },
    Last {
        n: usize,
    },
    Flatten,
    Reverse,
    Map {
        expr: String,
    },
    Reduce {
        initial: String,
        expr: String,
    },
    Aggregate {
        field: String,
        op: AggregateOp,
    },
    Pivot {
        row_field: String,
        col_field: String,
        value_field: String,
    },
    CumulativeSum {
        field: String,
    },
    Rank {
        field: String,
        method: RankMethod,
    },
    MovingAverage {
        field: String,
        window: usize,
    },
    PercentChange {
        field: String,
    },
    Suggest {
        prefix: String,
        count: usize,
    },
}

A transform operation in the expression pipeline.

Variants

Filter

Filter rows: filter(field=value)

Fields

field: String

Field to filter on

value: String

Value to match

Select

Select columns: select(field1, field2)

Fields

fields: Vec<String>

Fields to select

Sort

Sort rows: sort(field, desc=true)

Fields

field: String

Field to sort by

desc: bool

Sort descending

Limit

Limit rows: limit(n)

Fields

n: usize

Maximum number of rows

Count

Count rows

Sum

Sum a field: sum(field)

Fields

field: String

Field to sum

Mean

Average a field: mean(field)

Fields

field: String

Field to average

Rate

Rate over window: rate(window)

Fields

window: String

Time window (e.g., “1m”, “5m”)

Percentage

Convert to percentage

Join

Join with another dataset: join(other, on=field)

Fields

other: String

Other dataset

on: String

Join field

Sample

Sample rows: sample(n)

Fields

n: usize

Number of rows to sample

GroupBy

Group by field: group_by(field)

Fields

field: String

Field to group by

Distinct

Get distinct values: distinct(field)

Fields

field: Option<String>

Field to get distinct values from (optional)

Where

Advanced filter with operators: where(field, op, value)

Fields

field: String

Field to filter on

op: String

Comparison operator (eq, ne, gt, lt, gte, lte, contains)

value: String

Value to compare

Offset

Offset/skip rows: offset(n)

Fields

n: usize

Number of rows to skip

Min

Minimum value: min(field)

Fields

field: String

Field to find minimum

Max

Maximum value: max(field)

Fields

field: String

Field to find maximum

First

First n rows: first(n)

Fields

n: usize

Number of rows

Last

Last n rows: last(n)

Fields

n: usize

Number of rows

Flatten

Flatten nested arrays: flatten

Reverse

Reverse order: reverse

Map

Map/transform each element: map(expr)

Fields

expr: String

Expression to apply to each element

Reduce

Reduce/fold elements: reduce(initial, accumulator_expr)

Fields

initial: String

Initial value

expr: String

Accumulator expression (uses acc and item variables)

Aggregate

Aggregate after group_by: agg(field, op)

Fields

field: String

Field to aggregate

op: AggregateOp

Aggregation operation (sum, count, mean, min, max)

Pivot

Pivot table: pivot(row_field, col_field, value_field)

Fields

row_field: String

Field for row labels

col_field: String

Field for column headers

value_field: String

Field for values

CumulativeSum

Running total: cumsum(field)

Fields

field: String

Field to sum

Rank

Rank within group: rank(field, method)

Fields

field: String

Field to rank by

method: RankMethod

Ranking method (dense, ordinal, average)

MovingAverage

Moving average: moving_avg(field, window)

Fields

field: String

Field to average

window: usize

Window size

PercentChange

Percent change: pct_change(field)

Fields

field: String

Field to calculate percent change

Suggest

Model suggestion: suggest(prefix, count) - for N-gram/autocomplete models

Fields

prefix: String

Input prefix to get suggestions for

count: usize

Maximum number of suggestions to return

Trait Implementations

impl Clone for Transform

fn clone(&self) -> Transform

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for Transform

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl<'de> Deserialize<'de> for Transform

fn deserialize<__D>(__deserializer: __D) -> Result<Self, __D::Error>

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl PartialEq for Transform

fn eq(&self, other: &Transform) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl Serialize for Transform

fn serialize<__S>(&self, __serializer: __S) -> Result<__S::Ok, __S::Error>

where __S: Serializer,

Serialize this value into the given Serde serializer.

impl Eq for Transform

impl StructuralPartialEq for Transform