Trait HumanizerMode

pub trait HumanizerMode: Sized + Clone {
    // Required methods
    fn new(redacted: bool) -> Self;
    fn redacted(&self) -> bool;
    fn humanize_ident(col: usize, ident: Ident, f: &mut Formatter<'_>) -> Result;

    // Provided methods
    fn default() -> Self { ... }
    fn expr<'a, T>(
        &self,
        expr: &'a T,
        cols: Option<&'a Vec<String>>,
    ) -> HumanizedExpr<'a, T, Self> { ... }
    fn humanize_datum(&self, datum: Datum<'_>, f: &mut Formatter<'_>) -> Result { ... }
    fn seq<'i, T>(
        &self,
        exprs: &'i [T],
        cols: Option<&'i Vec<String>>,
    ) -> impl Iterator<Item = HumanizedExpr<'i, T, Self>> + Clone { ... }
}

A trait that abstracts the various ways in which we can humanize expressions.

Currently, the degrees of freedom are:

• Humanizing for an EXPLAIN output vs humanizing for a notice output. This is currently handled by the two different implementations of this trait - HumanizedExplain vs HumanizedNotice.
• Humanizing with redacted or non-redacted literals. This is currently covered by the HumanizerMode::redacted method which is used by the default implementation of HumanizerMode::humanize_datum.

Required Methods

fn new(redacted: bool) -> Self

Create a new instance of the optimizer mode with literal redaction determined by the redacted parameter value.

fn redacted(&self) -> bool

Return true iff literal redaction is enabled for this mode.

fn humanize_ident(col: usize, ident: Ident, f: &mut Formatter<'_>) -> Result

Render reference to column col which resolves to the given ident.

Provided Methods

fn default() -> Self

Default implementation of a default constructor.

This will produce a HumanizerMode instance that redacts output in production deployments, but not in debug builds and in CI.

fn expr<'a, T>( &self, expr: &'a T, cols: Option<&'a Vec<String>>, ) -> HumanizedExpr<'a, T, Self>

Factory method that wraps the given expr and cols into a HumanizedExpr with the current mode.

fn humanize_datum(&self, datum: Datum<'_>, f: &mut Formatter<'_>) -> Result

Render a literal datum.

The default implementation prints a redacted symbol (█) if redaction is enabled.

fn seq<'i, T>( &self, exprs: &'i [T], cols: Option<&'i Vec<String>>, ) -> impl Iterator<Item = HumanizedExpr<'i, T, Self>> + Clone

Wrap the given exprs (with cols) into HumanizedExpr with the current mode.

Dyn Compatibility

This trait is not dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety", so this trait is not object safe.

Implementors

impl HumanizerMode for HumanizedExplain

impl HumanizerMode for HumanizedNotice