Reorganise HUGR views (#386)

I have moved the file reorganisation out of #336. Please ignore the
slightly
messy history, this will get squashed away.

---------

Co-authored-by: Seyon Sivarajah <[email protected]>

src/algorithm/half_node.rs

@@ -1,7 +1,7 @@
 use std::hash::Hash;
 
 use super::nest_cfgs::CfgView;
-use crate::hugr::view::HugrView;
+use crate::hugr::views::HugrView;
 use crate::ops::OpTag;
 use crate::ops::OpTrait;
 use crate::{Direction, Node};

src/algorithm/nest_cfgs.rs

@@ -43,7 +43,7 @@ use std::hash::Hash;
 
 use itertools::Itertools;
 
-use crate::hugr::view::HugrView;
+use crate::hugr::views::HugrView;
 use crate::ops::OpTag;
 use crate::ops::OpTrait;
 use crate::{Direction, Node};
@@ -398,7 +398,7 @@ impl<T: Copy + Clone + PartialEq + Eq + Hash> EdgeClassifier<T> {
 pub(crate) mod test {
  use super::*;
  use crate::builder::{BuildError, CFGBuilder, Container, DataflowSubContainer, HugrBuilder};
- use crate::hugr::hierarchical_views::{HierarchyView, SiblingGraph};
+ use crate::hugr::views::{HierarchyView, SiblingGraph};
  use crate::ops::handle::{BasicBlockID, ConstID, NodeHandle};
  use crate::ops::Const;
  use crate::types::{ClassicType, SimpleType};

src/builder/build_traits.rs

@@ -1,5 +1,5 @@
 use crate::hugr::validate::InterGraphEdgeError;
-use crate::hugr::view::HugrView;
+use crate::hugr::views::HugrView;
 use crate::hugr::{Node, NodeMetadata, Port, ValidationError};
 use crate::ops::{self, LeafOp, OpTrait, OpType};
 

src/builder/cfg.rs

@@ -5,7 +5,7 @@ use super::{
  BasicBlockID, BuildError, CfgID, Container, Dataflow, HugrBuilder, Wire,
 };
 
-use crate::hugr::view::HugrView;
+use crate::hugr::views::HugrView;
 use crate::ops::handle::NodeHandle;
 use crate::ops::{self, BasicBlock, OpType};
 use crate::types::AbstractSignature;

src/builder/conditional.rs

@@ -1,4 +1,4 @@
-use crate::hugr::view::HugrView;
+use crate::hugr::views::HugrView;
 use crate::types::{AbstractSignature, ClassicRow, SimpleRow};
 
 use crate::ops;

src/builder/module.rs

@@ -5,7 +5,7 @@ use super::{
 };
 
 use crate::{
- hugr::{view::HugrView, ValidationError},
+ hugr::{views::HugrView, ValidationError},
  ops,
  types::{simple::TypeTag, PrimType, SimpleType},
 };

src/builder/tail_loop.rs

@@ -1,6 +1,6 @@
 use crate::ops::{self, OpType};
 
-use crate::hugr::{view::HugrView, NodeType};
+use crate::hugr::{views::HugrView, NodeType};
 use crate::types::{AbstractSignature, ClassicRow, SimpleRow};
 use crate::{Hugr, Node};
 

src/hugr.rs

@@ -2,11 +2,10 @@
 
 mod hugrmut;
 
-pub mod hierarchical_views;
 pub mod rewrite;
 pub mod serialize;
 pub mod validate;
-pub mod view;
+pub mod views;
 
 use std::collections::VecDeque;
 use std::iter;
@@ -24,7 +23,7 @@ use thiserror::Error;
 #[cfg(feature = "pyo3")]
 use pyo3::prelude::*;
 
-pub use self::view::HugrView;
+pub use self::views::HugrView;
 use crate::ops::{OpTag, OpTrait, OpType};
 use crate::resource::ResourceSet;
 use crate::types::{AbstractSignature, Signature};

src/hugr/rewrite/simple_replace.rs

@@ -209,7 +209,7 @@ mod test {
  BuildError, Container, DFGBuilder, Dataflow, DataflowHugr, DataflowSubContainer,
  HugrBuilder, ModuleBuilder,
  };
- use crate::hugr::view::HugrView;
+ use crate::hugr::views::HugrView;
  use crate::hugr::{Hugr, Node};
  use crate::ops::OpTag;
  use crate::ops::{LeafOp, OpTrait, OpType};

src/hugr/validate.rs

@@ -18,8 +18,7 @@ use crate::resource::ResourceSet;
 use crate::types::{ClassicType, EdgeKind, SimpleType};
 use crate::{Direction, Hugr, Node, Port};
 
-use super::hierarchical_views::{HierarchyView, SiblingGraph};
-use super::view::HugrView;
+use super::views::{HierarchyView, HugrView, SiblingGraph};
 
 /// Structure keeping track of pre-computed information used in the validation
 /// process.

src/hugr/view.rs → src/hugr/views.rs

@@ -1,10 +1,10 @@
-#![allow(unused)]
-//! A Trait for "read-only" HUGRs.
+//! Read-only access into HUGR graphs and subgraphs.
 
-use std::iter::FusedIterator;
-use std::ops::Deref;
+pub mod hierarchy;
 
-use context_iterators::{ContextIterator, IntoContextIterator, MapCtx, MapWithCtx, WithCtx};
+pub use hierarchy::{DescendantsGraph, HierarchyView, SiblingGraph};
+
+use context_iterators::{ContextIterator, IntoContextIterator, MapWithCtx};
 use itertools::{Itertools, MapInto};
 use portgraph::dot::{DotFormat, EdgeStyle, NodeStyle, PortStyle};
 use portgraph::{multiportgraph, LinkView, MultiPortGraph, PortView};
@@ -299,7 +299,6 @@ where
  #[inline]
  fn get_io(&self, node: Node) -> Option<[Node; 2]> {
  let op = self.get_nodetype(node);
- let dfp = OpTag::DataflowParent;
  if op.tag().is_superset(OpTag::DataflowParent) {
  self.children(node).take(2).collect_vec().try_into().ok()
  } else {

src/hugr/hierarchical_views.rs → src/hugr/views/hierarchy.rs

@@ -25,8 +25,7 @@ use portgraph::{LinkView, PortIndex, PortView};
 
 use crate::{hugr::NodeType, hugr::OpType, Direction, Hugr, Node, Port};
 
-use super::view::sealed::HugrInternals;
-use super::{HugrView, NodeMetadata};
+use super::{sealed::HugrInternals, HugrView, NodeMetadata};
 
 type FlatRegionGraph<'g, Base> =
  portgraph::view::FlatRegion<'g, <Base as HugrInternals>::Portgraph>;
@@ -345,7 +344,7 @@ where
  }
 }
 
-/// A common trait for views of a hugr region.
+/// A common trait for views of a HUGR hierarchical subgraph.
 pub trait HierarchyView<'a>:
  HugrView
  + pv::GraphBase<NodeId = Node>
@@ -359,10 +358,10 @@ pub trait HierarchyView<'a>:
 where
  for<'g> &'g Self: pv::IntoNeighborsDirected + pv::IntoNodeIdentifiers,
 {
- /// The base from which the region is derived.
+ /// The base from which the subgraph is derived.
  type Base;
 
- /// Create a region view of a HUGR given a root node.
+ /// Create a hierarchical view of a HUGR given a root node.
  fn new(hugr: &'a Self::Base, root: Node) -> Self;
 }
 
@@ -404,7 +403,7 @@ where
  }
 }
 
-impl<'g, Base> super::view::sealed::HugrInternals for SiblingGraph<'g, Base>
+impl<'g, Base> super::sealed::HugrInternals for SiblingGraph<'g, Base>
 where
  Base: HugrInternals,
 {
@@ -421,7 +420,7 @@ where
  }
 }
 
-impl<'g, Base> super::view::sealed::HugrInternals for DescendantsGraph<'g, Base>
+impl<'g, Base> super::sealed::HugrInternals for DescendantsGraph<'g, Base>
 where
  Base: HugrInternals,
 {

src/hugr/hierarchical_views/petgraph.rs → src/hugr/views/hierarchy/petgraph.rs

@@ -1,7 +1,7 @@
 //! Implementations of petgraph's traits for Hugr Region views.
 
 use super::{DescendantsGraph, SiblingGraph};
-use crate::hugr::view::sealed::HugrInternals;
+use crate::hugr::views::sealed::HugrInternals;
 use crate::hugr::HugrView;
 use crate::ops::OpType;
 use crate::types::EdgeKind;