Enum SkipPolicy 

pub enum SkipPolicy {
    None,
    Whitespace,
    Newlines,
}

How chars(P, skip:) trims between matches (§7.5).

Read the two non-None variants as an inclusion, because the names do not say so. Whitespace is horizontal whitespace; Newlines is horizontal whitespace and line endings. So Newlines skips strictly more than Whitespace — whitespace is the narrower policy despite being the broader English word, and skip: newlines means “newlines as well”, not “newlines only”.

That inversion is not academic: chars(one_of("^v<>"), skip: whitespace) — §7.5’s own example — looks like it should absorb an input file’s trailing \n. It does not, and it does not have to: the terminator is inside the root region — the root region is the whole buffer, and nothing is trimmed off it — and it is forgiven because it is whitespace the character parser declined (walk_characters asks the child first and accepts a whitespace-only leftover through ByteRegion::is_all_whitespace, the bound half of ADR-078’s rule). No skip policy has to account for it. The sets are the ones §7.5’s example needs, and swapping them would silently change what every existing skip: newlines program accepts. walk_characters / skip_chars in praxis-runtime is the implementation, and SkipPolicy::skips below is the single description both the runtime comment and the skip: diagnostic quote.

Variants

None

No trimming between matches: every byte of the region is the child’s.

Whitespace

Skip horizontal whitespace — spaces and tabs — between matches. Not line endings: see the type’s own documentation.

Newlines

Skip horizontal whitespace and line endings between matches. The broader of the two policies.

Implementations

impl SkipPolicy

pub const ALL: &'static [SkipPolicy]

Every policy, in §7.5’s order. The list is closed: a test sweeps it.

pub fn from_keyword(name: &str) -> Option<Self>

Parse a skip: keyword value, or None if unknown.

pub fn skips(self) -> &'static str

What this policy skips, in the words the skip: diagnostic uses.

One description, quoted by the diagnostic and by the runtime, so a reader who reaches either one is told that newlines is the broader policy rather than left to infer it from the names.

Trait Implementations

impl Clone for SkipPolicy

fn clone(&self) -> SkipPolicy

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Copy for SkipPolicy

impl Debug for SkipPolicy

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

Formats the value using the given formatter.

impl Eq for SkipPolicy

impl PartialEq for SkipPolicy

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

Equality operator ==.

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

Inequality operator !=.

impl StructuralPartialEq for SkipPolicy