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mod combined_expr;
mod field_expr;
mod simple_expr;
use self::combined_expr::CombinedExpr;
use filter::{CompiledExpr, Filter};
use lex::{LexResult, LexWith};
use scheme::{Field, Scheme, UnknownFieldError};
use serde::Serialize;
use std::fmt::{self, Debug};
trait Expr<'s>: Sized + Eq + Debug + for<'i> LexWith<'i, &'s Scheme> + Serialize {
fn uses(&self, field: Field<'s>) -> bool;
fn compile(self) -> CompiledExpr<'s>;
}
#[derive(PartialEq, Eq, Serialize, Clone)]
#[serde(transparent)]
pub struct FilterAst<'s> {
#[serde(skip)]
scheme: &'s Scheme,
op: CombinedExpr<'s>,
}
impl<'s> Debug for FilterAst<'s> {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
self.op.fmt(f)
}
}
impl<'i, 's> LexWith<'i, &'s Scheme> for FilterAst<'s> {
fn lex_with(input: &'i str, scheme: &'s Scheme) -> LexResult<'i, Self> {
let (op, input) = CombinedExpr::lex_with(input, scheme)?;
Ok((FilterAst { scheme, op }, input))
}
}
impl<'s> FilterAst<'s> {
pub fn uses(&self, field_name: &str) -> Result<bool, UnknownFieldError> {
self.scheme
.get_field_index(field_name)
.map(|field| self.op.uses(field))
}
pub fn compile(self) -> Filter<'s> {
Filter::new(self.op.compile(), self.scheme)
}
}