Enum ConstraintAtom 

pub enum ConstraintAtom {
    DefBeforeUse {
        def: NonTerminalRef,
        use_: NonTerminalRef,
    },
    EqualCount {
        left: NonTerminalRef,
        right: NonTerminalRef,
    },
    LengthField {
        field: NonTerminalRef,
        body: NonTerminalRef,
        unit: LengthUnit,
    },
    Unique {
        target: NonTerminalRef,
    },
    Ordered {
        target: NonTerminalRef,
    },
}

A grammar-aware atomic predicate over derivation-tree observations.

Variants

DefBeforeUse

Every use must match a previously seen definition.

Fields

def: NonTerminalRef

Non-terminal that contributes definitions.

use_: NonTerminalRef

Non-terminal that contributes uses.

EqualCount

The number of left and right matches must be equal.

Fields

left: NonTerminalRef

Left-hand non-terminal.

right: NonTerminalRef

Right-hand non-terminal.

LengthField

A numeric field must equal the measured length of a body.

Fields

field: NonTerminalRef

Numeric length field.

body: NonTerminalRef

Body whose length is measured.

unit: LengthUnit

Unit used for measuring the body.

Unique

Values matched at the target must be pairwise distinct.

Fields

target: NonTerminalRef

Non-terminal whose values must be distinct.

Ordered

Values matched at the target must be non-decreasing in document order.

Fields

target: NonTerminalRef

Non-terminal whose values must be ordered.

Trait Implementations

impl Clone for ConstraintAtom

fn clone(&self) -> ConstraintAtom

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for ConstraintAtom

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

Formats the value using the given formatter.

impl PartialEq for ConstraintAtom

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

Tests for self and other values to be equal, and is used by ==.

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

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl Eq for ConstraintAtom

impl StructuralPartialEq for ConstraintAtom