Struct GitAdapter 

pub struct GitAdapter { /* private fields */ }

A git repository, exposed as an arbor.

Implementations

impl GitAdapter

pub fn open(path: &Path) -> Result<Self, GitError>

Open the repository at path (any directory inside it).

pub fn open_with_decoding( path: &Path, decoding: SourceDecoding, ) -> Result<Self, GitError>

open under a mount’s source-boundary rule: blobs decode by ?encoding=, a byte-order mark, else strict UTF-8 (a blob that decodes under none has no text).

pub fn locator(&self, node: NodeId) -> String

A human-readable locator: /commits/<short>/path, /branches/<name>/path, …

Trait Implementations

impl AstAdapter for GitAdapter

fn children_named(&self, node: NodeId, name: &str) -> Vec<NodeId>

Literal names under /commits go straight through rev-parse — unique prefixes, HEAD~2, v1.0^{} — with no enumeration.

fn traits(&self, node: NodeId) -> Vec<String>

<commit>, <branch>, <tag>, <tree>, <blob>.

fn property(&self, node: NodeId, name: &str) -> Option<Value>

Commit header fields (ref aliases answer for their commit).

fn provenance(&self, node: NodeId) -> Provenance

Data provenance: the repository path as the source; the nearest commit-backed ancestor’s author date as the instant (a tree entry answers “this repo, as of that commit” — the same instant ::date mints). The structural dirs and the root have no commit ancestor and answer source only. No dpid — the commit hash stays on ::hash / ::::short.

fn default_value(&self, node: NodeId) -> Option<Value>

A blob’s content (text, lossily decoded).

fn aliased_metadata(&self, _node: NodeId) -> &'static [&'static str]

Commits: ;;;short, ;;;n-parents, ;;;tags, ;;;n-tags. Entries: ;;;type, ;;;mode, ;;;size, ;;;hash. Ruling #29: this adapter’s property surface is closed — a commit object cannot grow fields — so its annotations answer at :: too. hash is in the list on purpose: commits expose the oid as a property and tree entries as metadata, but it is one concept — this node’s object id — and aliasing is what makes ::hash answer everywhere in the arbor instead of falling silently null on entries.

fn resolve( &self, node: NodeId, property: &str, _hint: Option<&str>, ) -> Option<NodeId>

::parent--> — the first parent (the hint is unused: the target is inherently a commit).

fn links(&self, node: NodeId) -> Vec<(String, NodeId)>

Every parent is an outgoing parent edge (merges fan out).

fn ref_property(&self, node: NodeId) -> Option<String>

A commit’s reference is its parent: the bare arrows (/HEAD-->, /HEAD<--) read it.

fn reverse_resolve( &self, node: NodeId, property: Option<&str>, _hint: Option<&str>, ) -> Option<Vec<NodeId>>

<--(::parent) from the enumeration, with no walk: the commits whose parent resolves here — ::parent--> follows the FIRST parent, so a merge counts under its first parent only. Any other property has no referrers; with no property named the question stays the engine’s.

fn backlinks(&self, node: NodeId) -> Vec<(String, NodeId)>

The commits whose parent is here (the children — served from the enumeration, so this loads the commit list).

fn root(&self) -> NodeId

The root node — the initial navigation context.

fn children(&self, node: NodeId) -> Vec<NodeId>

The tree children of node, in document order.

fn name(&self, node: NodeId) -> Option<String>

The name of node — the label of its incoming tree edge.

fn parent(&self, node: NodeId) -> Option<NodeId>

The parent of node, or None for the root.

fn metadata(&self, node: NodeId, key: &str) -> Option<Value>

Adapter-defined metadata — ::::key (a filesystem adapter’s size, modified, permissions, …). None if absent.

fn properties(&self, _node: NodeId) -> Vec<(String, Value)>

The node’s own properties, enumerated — name and value, in the source’s order — for readings that keep values off the tree (the JSON property reading, where an object’s scalar fields are no nodes). The serializers (| json, | xml, | kaiv) merge them with the children, a child winning a shared name. The default is none: for a reading whose values are all nodes, the children already say everything.

fn walks_for_references(&self) -> bool

Whether a reverse resolution or a value match with no scope may walk the whole arbor to find its referrers. An adapter over a small, in-memory source opens to the walk; a store or a service does not, and such a query is refused with a message asking for a scope — an empty answer could not be told from an absence of referrers. A declared reference (a foreign key, a model ref) answers through reverse_resolve and needs no walk.

fn can_refer_to(&self, source: NodeId, _target: NodeId) -> Option<bool>

Whether a reference declared on source — a catalog key, a model ref, a reference property the format defines — can land in target’s container. A question of the schema, never of the data; None where nothing is declared at the node. The default: a node with a reference property of its own can refer anywhere (an href may point at any element).

fn reference_properties(&self, source: NodeId, _target: NodeId) -> Vec<String>

The reference properties declared on source that can land in target’s container: a catalog’s key columns into the target’s table, the fields of a model’s refs, the node’s own reference property. What t<-- and t<--(SCOPE) read when the query names no property; empty where none is declared.

fn resolve_needs_label(&self, _node: NodeId, _property: &str) -> bool

Whether resolving property of node needs a reference label, because the property itself declares no target: a column with no key, or any property of a property graph, where a value names a node only under a node label. A label-less ::p--> over such a property is refused with the remedy, since an empty answer would read as “points nowhere”.

fn reverse_label(&self, _target: NodeId) -> Option<String>

The reference label under which a referrer’s property is also resolved when a reverse arrow asks about target and the query writes no label. None (the default): only the label-less resolution counts. An adapter whose label names a container (a table, a collection, a node label) returns the one target stands in, so /authors/1<--(/books/*::author_id) reads author_id as a key into authors without the query saying so. The engine derives no label of its own.

fn tree_identities(&self) -> Vec<(String, NodeId)>

The trees of this arbor other trees refer to by name: each identity (a URL, a path, any string a reference may hold) with the node that stands for the tree. An identity ending in a separator is a base: every identity beneath it names the node reached beneath the base’s node by the remainder’s segments. Declared in a model (tree IDENTITY: PATH;) and automatic for a mount’s own target; the engine reads nothing inside an identity beyond prefix and separator.

fn property_names(&self, node: NodeId) -> Vec<String>

The names of the properties a node has — what “any property” means for <--(SCOPE::*). By default its off-tree properties, its reference property, and its children’s names (a row’s columns, an object’s keys are properties under the same names); an adapter whose properties are not children (an element’s attributes) lists them.

fn resolves_references(&self) -> bool

Whether this source resolves references at all. An adapter with no notion of a reference (a CSV file, a directory, a log stream) says no, and a reverse arrow over it is refused with the value match as the remedy, rather than answered with an empty set that would read as “nothing points here”.

fn index_lookup( &self, _scope: &str, _property: &str, _value: &Value, ) -> Option<Vec<NodeId>>

index SCOPE::prop; — the nodes of the declared scope whose property holds value, from an index the model keeps; None when no declaration covers the pair (the walk answers). An index changes cost, never the answer: the caller still tests each node it names.

fn index_referrers( &self, _scope: &str, _property: &str, _label: Option<&str>, _target: NodeId, ) -> Option<Vec<NodeId>>

The declared-scope nodes whose property resolves (under the relation label, when given) to target, from the same index; None when no declaration covers the pair.

fn non_tree_nodes(&self) -> Vec<NodeId>

The nodes of the arbor that are not in the tree — joined to it by crosslinks alone, with no parent and no path. The universal search *// reaches them after the tree, in this order; :::is-non-tree is true on them. The default is none: every shipped adapter puts every node in the tree.

fn child_host(&self, node: NodeId) -> NodeId

The node whose children an explicit child step from node reads. The default is node itself. An adapter whose tree holds transparent links (a filesystem’s symlink to a directory) answers the link’s target, so /link/name lands on the target’s own child — the same node /target/name reaches. The descendant walk never consults this: it reads children alone, so a linked subtree is walked once, under its own parent, and a cycle of links cannot trap it.

fn answers_to(&self, node: NodeId, name: &str) -> bool

Whether node answers to name as a literal spelling . The default is canonical equality. An adapter may declare per-node aliases — a social feed spelling a handle @alice while the stripped alice is the hop name — and the engine consults this wherever a literal name is matched, on every axis, so one override keeps /@alice and //@alice in agreement. :::name stays canonical (locators and reflection print it; an alias is a way in, never a way out), and name patterns (~(...), *) test the canonical name only.

fn has_trait(&self, node: NodeId, name: &str) -> bool

Whether node bears name as a trait, as written in a <...> clause. The default is membership in traits; an adapter may declare aliases the way answers_to does for names — a model file’s alias <chunk> <block>; or alias <s/^tag://i>; — and the engine consults this wherever a written trait is matched. Reflection and serialization print the canonical traits only.

fn external_ref( &self, _node: NodeId, _property: &str, _hint: Option<&str>, ) -> Option<ExternalRef>

The external reference node’s property holds, if any: the identity of a document outside this arbor and, where the reference says so, the location within it — both as the adapter reads them out of its own reference syntax (for html, the anchor’s absolute URL and its fragment). The engine does not look inside either string: it asks for the document among the mounts (the host’s registration, then document_by_ref), and hands the location to resolve_fragment on the document it found. Consulted by ::property--> when in-document resolution misses; an unmounted document lands among the run’s unresolved external references for the host’s acquisition loop. The engine itself never fetches.

fn resolve_fragment(&self, _node: NodeId, _fragment: &str) -> Option<NodeId>

The element fragment names inside the document node belongs to — html’s id lookup. The landing rung of a fragment-carrying external reference, once its document is mounted.

fn ref_label(&self, _node: NodeId, _property: &str) -> Option<String>

The relation name a resolution edge from node via property carries — html’s rel attribute. None falls back to the property name as the edge label.

fn link_property( &self, _source: NodeId, _label: &str, _target: NodeId, _name: &str, ) -> Option<Value>

A property of the crosslink source --label--> target — the $-::prop read. Adapters whose edges carry data (a property graph’s relationship properties) override this; None if the edge is bare or unknown. Where parallel edges share source, label, and target, the adapter answers for one of them, consistently.

fn document_by_ref(&self, _id: &str) -> Option<NodeId>

The document this arbor holds under an external-reference identifier (a URL, fragment-stripped), when it can answer without the host’s registration: the landing rung of --> after the mounted-document table misses. An adapter over a store of pages answers by URL lookup; the engine performs no IO either way.

fn descendants_named( &self, _node: NodeId, _name: &str, ) -> Option<Vec<(NodeId, usize)>>

The descendants of node that answer to name, each with its depth (children are depth 1), in document order — the fast path behind //name for an adapter whose substrate indexes names. None keeps the engine’s walk; Some must be exactly what the walk would find.

fn descendants_where( &self, _node: NodeId, _name: &str, _property: &str, _value: &Value, ) -> Option<Vec<(NodeId, usize)>>

The descendants of node named name whose property property equals value, each with its depth, in document order — the fast path behind //name[::property = "value"] for an adapter that indexes a property (the corpus reading’s positional index answers //token[::lower = "tom"] from it). None keeps the engine’s walk and its comparison; Some must be exactly what the walk would find under the standard equality, so an adapter answers only the values it can compare as the engine does (text against text).

fn prefetch_links(&self, _nodes: &[NodeId], _dir: LinkDir)

A batching hint: the engine is about to follow dir crosslinks from every node in nodes. An adapter backed by a store may fetch them in one statement; semantics are unchanged either way.

fn quantifier_bound(&self) -> usize

The quantifier bound N_max: the depth to which open-ended path quantifiers (+, *, {m,}) expand, and the ceiling of any explicit {m,n} (the effective upper bound is min(n, N_max)). An adapter whose natural structures run deep may raise it; the CLI overrides it per run (qua --quantifier-bound).

fn allow_shell(&self) -> bool

Whether the sh(...) pipeline stage may run external commands. False by default — query text stays inert data — and enabled per run by the CLI (qua --allow-shell) through the AllowShell wrapper.

fn invocation_instant(&self) -> Option<(i64, u32)>

The invocation instant now() denotes (spec: The Temporal Fragment, Determinism): one UTC timeline point bound by the runner BEFORE evaluation begins — evaluation itself never reads a clock. None by default (a library run is fully deterministic; now() reads as null); the CLI binds it at startup — pinnable with qua --now — through the WithNow wrapper.

fn has_node(&self, node: NodeId) -> bool

Whether node is an id this adapter minted — the guard behind the node-id anchor ((!N)), which may name an id from an earlier run (ids are minted deterministically: the same source, the same ids). The default probes the id through parent and name and treats a panic as absence, so an adapter that indexes by id needs no override; one that can answer cheaply should.

fn provenance_list(&self, node: NodeId) -> ProvenanceList

The data provenance of node as a list — every source the substrate records for the datum, and how many it elides. The default is the singular answer as a one-entry list; an adapter whose substrate records several (kaiv’s ?a;b;+N) overrides it, and a wrapper layers each entry.

fn unit_scale(&self, expr: &str) -> Option<(f64, String)>

The scale of a unit expression — (factor, canonical SI-base expansion) — for the unital reading’s criterion text (spec: The Quantital Fragment). The default answers from the engine’s frozen built-in table; a unit-aware adapter (kaiv) overrides it to include the mounted document’s own custom units, so [::range < '50kellicam'] resolves through the document’s .!units imports.