Enum MigrationStep 

pub enum MigrationStep {
    Rename {
        from: String,
        to: String,
    },
    Default {
        path: String,
        value: Value,
    },
    Drop {
        path: String,
    },
}

One step of a payload migration.

A closed set, not an expression language. Three steps covered every incompatible edit the Studio domain model produced in three days, and a closed set is what lets every path be a checked literal and every value a bound parameter.

Variants

Rename

Move a value to another path, if the source is present. An absent source is a no-op: a migration fills gaps, it does not invent values.

Fields

from: String

to: String

Default

Set path when nothing is there. A present value is left alone — otherwise a “default” would be an overwrite.

Fields

path: String

value: Value

Drop

Remove path if present.

Fields

path: String

Implementations

impl MigrationStep

pub fn paths(&self) -> Vec<&str>

The paths this step touches, for the overlap check.

Trait Implementations

impl Clone for MigrationStep

fn clone(&self) -> MigrationStep

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for MigrationStep

fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error>

Formats the value using the given formatter.

impl PartialEq for MigrationStep

fn eq(&self, other: &MigrationStep) -> bool

Equality operator ==.

fn ne(&self, other: &Rhs) -> bool

Inequality operator !=.

impl StructuralPartialEq for MigrationStep