nodejs-polars/bin/lazy/whenthen.js

Polars: Blazingly fast DataFrames in Rust, Python, Node.js, R and SQL

"use strict";
var __importDefault = (this && this.__importDefault) || function (mod) {
    return (mod && mod.__esModule) ? mod : { "default": mod };
};
Object.defineProperty(exports, "__esModule", { value: true });
exports.when = when;
const polars_internal_1 = __importDefault(require("../internals/polars_internal"));
const expr_1 = require("./expr");
function ChainedWhen(_chainedwhen) {
    return {
        then: ({ _expr }) => ChainedThen(_chainedwhen.then(_expr)),
    };
}
function ChainedThen(_chainedthen) {
    return {
        when: ({ _expr }) => ChainedWhen(_chainedthen.when(_expr)),
        then: ({ _expr }) => ChainedThen(_chainedthen.then(_expr)),
        otherwise: ({ _expr }) => expr_1.Expr(_chainedthen.otherwise(_expr)),
    };
}
function Then(_then) {
    return {
        when: ({ _expr }) => ChainedWhen(_then.when(_expr)),
        otherwise: ({ _expr }) => expr_1.Expr(_then.otherwise(_expr)),
    };
}
/**
 * Utility function.
 * @see {@link when}
 */
function When(_when) {
    return {
        then: ({ _expr }) => Then(_when.then(_expr)),
    };
}
/**
 * Start a when, then, otherwise expression.
 *
 * @example
 * ```
 * // Below we add a column with the value 1, where column "foo" > 2 and the value -1 where it isn't.
 * > df = pl.DataFrame({"foo": [1, 3, 4], "bar": [3, 4, 0]})
 * > df.withColumn(pl.when(pl.col("foo").gt(2)).then(pl.lit(1)).otherwise(pl.lit(-1)))
 * shape: (3, 3)
 * ┌─────┬─────┬─────────┐
 * │ foo ┆ bar ┆ literal │
 * │ --- ┆ --- ┆ ---     │
 * │ i64 ┆ i64 ┆ i32     │
 * ╞═════╪═════╪═════════╡
 * │ 1   ┆ 3   ┆ -1      │
 * ├╌╌╌╌╌┼╌╌╌╌╌┼╌╌╌╌╌╌╌╌╌┤
 * │ 3   ┆ 4   ┆ 1       │
 * ├╌╌╌╌╌┼╌╌╌╌╌┼╌╌╌╌╌╌╌╌╌┤
 * │ 4   ┆ 0   ┆ 1       │
 * └─────┴─────┴─────────┘
 *
 * // Or with multiple `when, thens` chained:
 * > df.with_column(
 * ...     pl.when(pl.col("foo").gt(2))
 * ...     .then(1)
 * ...     .when(pl.col("bar").gt(2))
 * ...     .then(4)
 * ...     .otherwise(-1)
 * ... )
 * shape: (3, 3)
 * ┌─────┬─────┬─────────┐
 * │ foo ┆ bar ┆ literal │
 * │ --- ┆ --- ┆ ---     │
 * │ i64 ┆ i64 ┆ i32     │
 * ╞═════╪═════╪═════════╡
 * │ 1   ┆ 3   ┆ 4       │
 * ├╌╌╌╌╌┼╌╌╌╌╌┼╌╌╌╌╌╌╌╌╌┤
 * │ 3   ┆ 4   ┆ 1       │
 * ├╌╌╌╌╌┼╌╌╌╌╌┼╌╌╌╌╌╌╌╌╌┤
 * │ 4   ┆ 0   ┆ 1       │
 * └─────┴─────┴─────────┘
 * ```
 */
function when(expr) {
    return When(polars_internal_1.default.when(expr._expr));
}