Macro filter 

macro_rules! filter {
    ($field:ident == $value:expr) => { ... };
    ($field:ident != $value:expr) => { ... };
    ($field:ident > $value:expr) => { ... };
    ($field:ident >= $value:expr) => { ... };
    ($field:ident < $value:expr) => { ... };
    ($field:ident <= $value:expr) => { ... };
    ($field:ident is null) => { ... };
    ($field:ident is not null) => { ... };
    ($field:ident contains $value:expr) => { ... };
    ($field:ident starts_with $value:expr) => { ... };
    ($field:ident ends_with $value:expr) => { ... };
    ($field:ident in [$($value:expr),* $(,)?]) => { ... };
    ($field:ident not in [$($value:expr),* $(,)?]) => { ... };
}

Create a filter expression with minimal allocations.

Syntax

• filter!(field == value) - Equality
• filter!(field != value) - Not equals
• filter!(field > value) - Greater than
• filter!(field >= value) - Greater than or equal
• filter!(field < value) - Less than
• filter!(field <= value) - Less than or equal
• filter!(field is null) - IS NULL
• filter!(field is not null) - IS NOT NULL
• filter!(field contains value) - LIKE %value%
• filter!(field starts_with value) - LIKE value%
• filter!(field ends_with value) - LIKE %value
• filter!(field in [v1, v2, ...]) - IN clause
• filter!(field not in [v1, v2, ...]) - NOT IN clause

Examples

use prax_query::filter;
use prax_query::filter::Filter;

// Basic comparisons
let f = filter!(id == 42);
let f = filter!(age > 18);
let f = filter!(score >= 100);

// String comparisons
let f = filter!(name == "Alice");
let f = filter!(email contains "@example.com");

// Null checks
let f = filter!(deleted_at is null);
let f = filter!(verified_at is not null);

// IN clauses
let f = filter!(status in ["active", "pending"]);