Module hyper_ast::position

Positioning elements in HyperAST

Because the HyperAST is a Direct Acyclic Graph (DAG), any given sub-tree possibly has multiple global positions. The global position, path, or offset of a subtree is global/contextual information, thus it cannot be stored efficiently on subtrees of a DAG.

You can look at this module as an example of computing global metrics out of local ones.

This module specifically helps with tasks related to positioning nodes globally,

• it helps maintain positional states during traversals
• it helps convert between positional representations
  • topological
  • path (list of offsets)
  • a file path, an offset and a length
  • with/out hidden nodes

Incremental position storing

[structural_pos]

topological index

[topological_offset] - post-order

path

offsets_and_nodes - list of offsets

collection of path

Optimisation related, sometimes necessary to have acceptable perfs.
- list of paths
- it of paths
- topo ordered list of paths
  incremental compute
- reversed dag of paths
  mem optimization,

with hidden nodes (spaces, abtract nodes,….)

Re-exports

• pub use building::CompoundPositionPreparer;
• pub use offsets_and_nodes::*;

Modules

• building
  Declares interfaces for position builders, while offering statemachine traits to orchestrate them statisticaly.
• file_and_offset
• offsets
• offsets_and_nodes
• position_accessors
• tags

Structs

• ExploreStructuralPositions
• PositionConverter
• Scout
• SpHandle
• StructuralPositionStore
• TypedScout
• WithHyperAstPositionConverter

Traits

• PrimInt
• TreePath
• TreePathMut
• TypedTreePath

Functions

• compute_position
• compute_position_and_nodes
• compute_position_and_nodes_with_no_spaces
• compute_position_with_no_spaces
• compute_range
  precondition: root node do not contain a File node TODO make whole thing more specific to a path in a tree
• global_pos_with_spaces
• path_with_spaces
• resolve_range
  must be in a file

Type Definitions

• Position
• StructuralPosition