use crate::sym_db::{SymDB, SYM_DB};
use crate::nkgc::{ConsElem, ConsIter};
use crate::nk::NkAtom;
use std::fmt;
use fnv::FnvHashSet;
use std::slice::Iter;
pub type VisitSet = FnvHashSet<*const NkAtom>;
struct FmtWrap<'a, 'b, T> where T: ?Sized {
val: &'a T,
db: &'b dyn SymDB
}
impl<T> fmt::Display for FmtWrap<'_, '_, T> where T: LispFmt + ?Sized {
#[inline]
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
let mut visited = FnvHashSet::default();
self.val.lisp_fmt(self.db, &mut visited, f)
}
}
pub trait LispFmt {
fn lisp_fmt(&self,
db: &dyn SymDB,
visited: &mut VisitSet,
f: &mut fmt::Formatter<'_>) -> fmt::Result;
fn lisp_to_string(&self, db: &dyn SymDB) -> String {
format!("{}", FmtWrap { val: self, db })
}
}
impl fmt::Display for dyn LispFmt {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> Result<(), fmt::Error> {
write!(f, "{}", self.lisp_to_string(&SYM_DB))
}
}
impl<T> LispFmt for Vec<T>
where T: LispFmt
{
fn lisp_fmt(&self,
db: &dyn SymDB,
visited: &mut VisitSet,
f: &mut fmt::Formatter<'_>) -> fmt::Result {
write!(f, "(vec")?;
if self.is_empty() {
write!(f, ")")
} else {
write!(f, " ")?;
self.iter().lisp_fmt(db, visited, f)?;
write!(f, ")")
}
}
}
impl<T> LispFmt for Iter<'_, T>
where T: LispFmt
{
fn lisp_fmt(&self,
db: &dyn SymDB,
visited: &mut VisitSet,
f: &mut fmt::Formatter<'_>) -> fmt::Result {
let mut it = self.clone().peekable();
while let Some(item) = it.next() {
item.lisp_fmt(db, visited, f)?;
if it.peek().is_some() {
write!(f, " ")?;
}
}
Ok(())
}
}
impl LispFmt for ConsIter {
fn lisp_fmt(&self,
db: &dyn SymDB,
visited: &mut VisitSet,
f: &mut fmt::Formatter<'_>) -> fmt::Result {
let mut it = self.clone().peekable();
write!(f, "(")?;
while let Some(item) = it.next() {
if matches!(item, ConsElem::Tail(_)) {
write!(f, ". ")?;
}
item.get().lisp_fmt(db, visited, f)?;
if it.peek().is_some() {
write!(f, " ")?;
}
}
write!(f, ")")
}
}