Enum Index 

pub enum Index<'a> {
    Create(&'a Index),
    Drop(&'a Index),
    Alter {
        previous: &'a Index,
        next: &'a Index,
    },
}

A single index-level change between two table versions.

Computed by Index::diff.

Variants

Create(&'a Index)

A new index was created.

Drop(&'a Index)

An existing index was dropped.

Alter

An index was modified (name, columns, uniqueness, or other property changed).

Fields

previous: &'a Index

The index definition before the change.

next: &'a Index

The index definition after the change.

Implementations

impl<'a> Index<'a>

pub fn diff( cx: &Context<'a>, previous: &'a [Index], next: &'a [Index], ) -> Vec<Self>

Computes the diff between two index slices.

Uses Context to resolve rename hints for both indices and columns. Indices matched by name (or by rename hint) are compared; unmatched indices in previous become drops, and unmatched indices in next become creates.

Examples

use toasty_core::schema::{db, diff};

let previous = db::Schema::default();
let next = db::Schema::default();
let hints = diff::RenameHints::new();
let cx = diff::Context::new(&previous, &next, &hints);
assert!(diff::Index::diff(&cx, &[], &[]).is_empty());