Crate frequenz_microgrid_formula_engine 

frequenz-formula-engine-rs

A library to create formulas over streamed data

Usage

A FormulaEngine instance can be created from a String formula with the try_new method. Such a formula can contain component placeholders, which are represented by # followed by a number. To calculate the formula, you need to provide an iterator of Option values, where

• None represents a missing value
• Some(value) represents a value.

The iterator must contain as many values as the formula has placeholders. The result of the calculation is an Option value.

use frequenz_microgrid_formula_engine::{FormulaEngine, FormulaError};
use std::collections::HashMap;

fn main() -> Result<(), FormulaError> {
    let fe = FormulaEngine::try_new("#0 + #1")?;
    let components = fe.components();
    assert_eq!(components, &[0, 1].into_iter().collect());
    assert_eq!(fe.calculate(&HashMap::from([(0, Some(1.)), (1, Some(2.))]))?, Some(3.0));
    Ok(())
}

Modules

traits

Traits used in the FormulaEngine.

Structs

FormulaEngine

FormulaEngine holds the parsed expression and can calculate the result based on the provided component values.

FormulaError