polydat 0.3.2

Polydat — a variates construction engine
Documentation 
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// Copyright 2024-2026 Jonathan Shook
// SPDX-License-Identifier: Apache-2.0

//! Illustration: one two-dimensional comprehension dispensed under several
//! traversal strategies and a filter, as coordinate tuples.

use polydat::iteration::comprehension::ast::Comprehension;
use polydat::iteration::comprehension::ir::{compile, interpret};
use polydat::iteration::comprehension::optimize::optimize;
use polydat::iteration::comprehension::source::Source;
use polydat::iteration::comprehension::strategy::StrategyName;

fn show(label: &str, ast: &Comprehension) {
    let prog = compile(&optimize(ast.clone()));
    let mut stream = interpret(&prog);
    let mut out = Vec::new();
    while let Some(t) = stream.advance() {
        let cells: Vec<String> = t
            .bindings
            .iter()
            .map(|(_, v)| format!("{v:?}"))
            .map(|s| {
                s.trim_start_matches("I64(")
                    .trim_end_matches(')')
                    .to_string()
            })
            .collect();
        out.push(format!("({})", cells.join(",")));
    }
    println!("{label:<14} {:>2}  {}", out.len(), out.join(" "));
}

fn main() {
    let base = Comprehension::cartesian(vec![
        Comprehension::clause(
            "k",
            Source::IntRange {
                lo: 1,
                hi: 4,
                step: 1,
            },
        ),
        Comprehension::clause(
            "limit",
            Source::IntRange {
                lo: 10,
                hi: 40,
                step: 10,
            },
        ),
    ]);
    show("lex", &base);
    show(
        "reverse",
        &Comprehension::order(base.clone(), StrategyName::ReverseLex, None),
    );
    show(
        "diagonal",
        &Comprehension::order(base.clone(), StrategyName::Diagonal, None),
    );
    show(
        "shells",
        &Comprehension::order(base.clone(), StrategyName::Shells, None),
    );
    show(
        "extrema/1",
        &Comprehension::order(base.clone(), StrategyName::Extrema, Some(1)),
    );
    show(
        "halton/5",
        &Comprehension::order(base.clone(), StrategyName::Halton, Some(5)),
    );
    show(
        "where",
        &Comprehension::filter(base.clone(), "{k} >= 2 && {limit} != 20"),
    );
}