tame/tamer/src/asg/graph/object/root.rs

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// Root of the ASG.
//
// Copyright (C) 2014-2023 Ryan Specialty, LLC.
//
// This file is part of TAME.
//
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program. If not, see <http://www.gnu.org/licenses/>.
//! Root node of the ASG.
use std::fmt::Display;
use super::{
Ident, Object, ObjectIndex, ObjectRel, ObjectRelFrom, ObjectRelTy,
ObjectRelatable, Pkg,
};
#[cfg(doc)]
use super::ObjectKind;
/// A unit [`Object`] type representing the root node.
///
/// This exists for consistency with the rest of the object API,
/// and for use with [`ObjectIndex`].
#[derive(Debug, PartialEq)]
pub struct Root;
impl Display for Root {
fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
write!(f, "ASG root")
}
}
/// Subset of [`ObjectKind`]s that are valid targets for edges from
/// [`Ident`].
///
/// See [`ObjectRel`] for more information.
#[derive(Debug, PartialEq, Eq)]
pub enum RootRel {
Pkg(ObjectIndex<Pkg>),
Ident(ObjectIndex<Ident>),
}
impl ObjectRel<Root> for RootRel {
fn narrow<OB: ObjectRelFrom<Root> + ObjectRelatable>(
self,
) -> Option<ObjectIndex<OB>> {
match self {
Self::Ident(oi) => oi.filter_rel(),
Self::Pkg(oi) => oi.filter_rel(),
}
}
/// The root of the graph by definition has no cross edges.
fn is_cross_edge(&self) -> bool {
false
}
}
impl ObjectRelatable for Root {
type Rel = RootRel;
fn rel_ty() -> ObjectRelTy {
ObjectRelTy::Root
}
fn new_rel_dyn(
ty: ObjectRelTy,
oi: ObjectIndex<Object>,
) -> Option<RootRel> {
match ty {
ObjectRelTy::Root => None,
ObjectRelTy::Pkg => Some(RootRel::Pkg(oi.must_narrow_into())),
ObjectRelTy::Ident => Some(RootRel::Ident(oi.must_narrow_into())),
ObjectRelTy::Expr => None,
ObjectRelTy::Tpl => None,
}
}
}
impl From<ObjectIndex<Pkg>> for RootRel {
fn from(value: ObjectIndex<Pkg>) -> Self {
Self::Pkg(value)
}
}
impl From<ObjectIndex<Ident>> for RootRel {
fn from(value: ObjectIndex<Ident>) -> Self {
Self::Ident(value)
}
}