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

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// Packages represented on 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/>.
//! Package object on the ASG.
use super::{prelude::*, Doc, Ident, Tpl};
use crate::{
f::Functor,
fmt::{DisplayWrapper, TtQuote},
parse::{util::SPair, Token},
span::Span,
};
use std::fmt::Display;
#[cfg(doc)]
use super::ObjectKind;
tamer: src::asg::graph::object::pkg::name: New module This introduces, but does not yet integrate, `CanonicalName`, which not only represents canonicalized package names, but handles namespec resolution. The term "namespec" is motivated by Git's use of *spec (e.g. refspec) referring to various ways of specifying a particular object. Names look like paths, and are derived from them, but they _are not paths_. Their resolution is a purely lexical operation, and they include a number of restrictions to simplify their clarity and handling. I expect them to evolve more in the future, and I've had ideas to do so for quite some time. In particular, resolving packages in this way and then loading the from the filesystem relative to the project root will ensure that traversing (conceptually) to a parent directory will not operate unintuitively with symlinks. The path will always resolve unambigiously. (With that said, if the symlink is to a shared directory with different directory structures, that doesn't solve the compilation problem---we'll have to move object files into a project-specific build directory to handle that.) Span Slicing ------------ Okay, it's worth commenting on the horridity of the path name slicing that goes on here. Care has been taken to ensure that spans will be able to be properly sliced in all relevant contexts, and there are plenty of words devoted to that in the documentation committed here. But there is a more fundamental problem here that I regret not having solved earlier, because I don't have the time for it right now: while we do have SPair, it makes no guarantees that the span associated with the corresponding SymbolId is actually the span that matches the original source lexeme. In fact, it's often not. This is a problem when we want to slice up a symbol in an SPair and produce a sensible span. If it _is_ a source lexeme with its original span, that's no problem. But if it's _not_, then the two are not in sync, and slicing up the span won't produce something that actually makes sense to the user. Or, worse (or maybe it's not worse?), it may cause a panic if the slicing is out of bounds. The solution in the future might be to store explicitly the state of an SPair, or call it Lexeme, or something, so that we know the conditions under which slicing is safe. If I ever have time for that in this project. But the result of the lack of a proper abstraction really shows here: this is some of the most confusing code in TAMER, and it's really not doing anything all that complicated. It is disproportionately confusing. DEV-13162
2023-05-04 12:28:08 -04:00
mod name;
pub use name::{CanonicalName, CanonicalNameError};
#[derive(Debug, PartialEq, Eq)]
pub struct Pkg(Span, CanonicalName);
impl Pkg {
/// Create a new package with a canonicalized name.
///
/// A canonical package name is a path relative to the project root.
pub(super) fn new_canonical<S: Into<Span>>(
start: S,
name: SPair,
) -> Result<Self, AsgError> {
Ok(Self(start.into(), CanonicalName::from_canonical(name)?))
}
/// Import a package with a namespec canonicalized against a reference
/// parent package.
///
/// The parent package should be the package containing the namespec.
pub fn new_imported(
Pkg(_, parent_name): &Pkg,
namespec: SPair,
) -> Result<Self, AsgError> {
Ok(Self(
namespec.span(),
CanonicalName::resolve_namespec_rel(parent_name, namespec)?,
))
}
pub fn span(&self) -> Span {
match self {
Self(span, _) => *span,
}
}
/// The canonical name for this package assigned by
/// [`Self::new_canonical`],
/// if any.
pub fn canonical_name(&self) -> SPair {
match self {
Self(_, name) => (*name).into(),
}
}
}
impl Display for Pkg {
fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
match self {
Self(_, name) => write!(f, "package {}", TtQuote::wrap(name)),
}
}
}
impl Functor<Span> for Pkg {
fn map(self, f: impl FnOnce(Span) -> Span) -> Self::Target {
match self {
Self(span, path) => Self(f(span), path),
}
}
}
object_rel! {
/// Packages serve as a root for all identifiers defined therein,
/// and so an edge to [`Ident`] will never be a cross edge.
///
/// Imported [`Ident`]s do not have edges from this package.
Pkg -> {
// Package import
cross Pkg,
// Identified objects owned by this package.
tree Ident,
// Anonymous templates are used for expansion.
tree Tpl,
// Arbitrary blocks of text serving as documentation.
tree Doc,
}
}
impl ObjectIndex<Pkg> {
/// Complete the definition of a package.
pub fn close(self, asg: &mut Asg, span: Span) -> Self {
self.map_obj(asg, Pkg::fmap(|open| open.merge(span).unwrap_or(open)))
}
/// Indicate that a package should be imported at the provided
/// pathspec.
///
/// This simply adds the import to the graph;
/// package loading must be performed by another subsystem.
pub fn import(
self,
asg: &mut Asg,
namespec: SPair,
) -> Result<Self, AsgError> {
let parent = self.resolve(asg);
let oi_import = asg.create(Pkg::new_imported(parent, namespec)?);
Ok(self.add_edge_to(asg, oi_import, Some(namespec.span())))
}
/// Arbitrary text serving as documentation in a literate style.
pub fn append_doc_text(&self, asg: &mut Asg, text: SPair) -> Self {
let oi_doc = asg.create(Doc::new_text(text));
self.add_edge_to(asg, oi_doc, None)
}
}