Struct ConstPrattParser 

pub struct ConstPrattParser<R: RuleType + 'static, const N: usize> { /* private fields */ }

A Pratt parser that can be built in a const context and stored in static memory.

It is functionally equivalent to PrattParser, but it is constructed from a static array of Ops rather than the chained .op(...) builder.

Implementations

impl<R: RuleType + 'static, const N: usize> ConstPrattParser<R, N>

pub const fn new_const(ops: [(Op<R>, bool); N]) -> Self

Create a ConstPrattParser from a static array of ([Op], bool) pairs.

Just like PrattParser::op, but for use in a const context. The bool in each pair tells whether the operator starts a new precedence level (true) or shares the previous operator’s level (false). Levels are ordered from lowest to highest precedence; the first operator must start a new level (true).

Example

static PRATT: ConstPrattParser<Rule, 7> = ConstPrattParser::new_const([
    (Op::infix(Rule::add, Assoc::Left), true), // lowest precedence
    (Op::infix(Rule::sub, Assoc::Left), false), // same precedence as add
    (Op::infix(Rule::mul, Assoc::Left), true), // next precedence level
    (Op::infix(Rule::div, Assoc::Left), false), // same precedence as mul
    (Op::infix(Rule::pow, Assoc::Right), true),
    (Op::prefix(Rule::neg), true),
    (Op::postfix(Rule::fac), true), // highest precedence
]);

pub fn map_primary<'pratt, 'a, 'i, X, T>( &'pratt self, primary: X, ) -> PrattParserMap<'pratt, 'a, 'i, R, X, T, Self>

where X: FnMut(Pair<'i, R>) -> T, R: 'pratt,

Maps primary expressions with a closure primary.