kinds
The Nu kind taxonomy: the user-facing Term classes that declare each sort.
Module nu.lang.kinds.
The Nu kind taxonomy: the user-facing Term classes that declare each sort.
A taxonomy of Nu subclasses. The leaves (Ref, ScalarQuery,
StreamQuery, Reduction, Command, ScalarAction,
StreamAction, Strategy, Control, Bracket, Policy) carry
the sort and cardinality bindings concrete nodes use. The interiors
(Interaction, Query, Action, Flow, Span) are abstract
groupings for subsort queries and for the dispatch surface
Interaction._eval / _aeval.
"Kind" is the Python class of a Term (Ref, Interaction, ...); "sort" is the
attribute concern naming the structural category. This module sits on top
of nu.lang.nu (the base) and nu.lang.attributes (Sort and
Cardinality value spaces).
| Name | Sort | Call | Meaning |
|---|---|---|---|
| Action | Action() | Abstract: a dual-citizen Interaction. Mutates Context and yields a value. | |
| Bracket | bracket | Bracket() | A Span that governs a body's lifecycle. |
| Command | scalar_command | Command() | A mutating Interaction. Yields nothing; its only sub-shape is scalar. |
| Control | control | Control() | A Flow that composes Commands under Query parameters. |
| Flow | Flow() | Abstract: a Command-composing Interaction. Yields nothing. | |
| Interaction | Interaction() | Abstract: a node that interacts with the Context. Never instantiated. | |
| Policy | policy | Policy() | A Span that governs a body's execution on failure. |
| Query | Query() | Abstract: a value-producing Interaction. | |
| Reduction | reduction | Reduction() | A ScalarQuery that folds a stream child down to one value. |
| ScalarAction | scalar_action | ScalarAction() | An Action that mutates and yields exactly one value. |
| ScalarQuery | scalar_query | ScalarQuery() | A Query that yields exactly one value. |
| Span | Span() | Abstract: a transparent Interaction; yields what its body yields. | |
| Strategy | strategy | Strategy() | A Flow that composes Commands directly. |
| StreamAction | stream_action | StreamAction() | An Action that mutates and yields zero or more values. |
| StreamQuery | stream_query | StreamQuery() | A Query that yields zero or more values. |
Action
Abstract: a dual-citizen Interaction. Mutates Context and yields a value.
Action()Path nu.lang.Action. Kind Action. Abstract: a taxonomy base, not an atom you build.
Undocumented: yields, example.
Bracket
A Span that governs a body's lifecycle.
Bracket()Path nu.lang.Bracket. Kind Bracket, sort bracket, cardinality transparent. Abstract: a taxonomy base, not an atom you build.
Undocumented: yields, example.
Command
A mutating Interaction. Yields nothing; its only sub-shape is scalar.
Command()Path nu.lang.Command. Kind Command, sort scalar_command, cardinality void. Abstract: a taxonomy base, not an atom you build.
Undocumented: yields, example.
Control
A Flow that composes Commands under Query parameters.
Control()Path nu.lang.Control. Kind Control, sort control, cardinality void. Abstract: a taxonomy base, not an atom you build.
Undocumented: yields, example.
Flow
Abstract: a Command-composing Interaction. Yields nothing.
Flow()Path nu.lang.Flow. Kind Flow, cardinality void. Abstract: a taxonomy base, not an atom you build.
Undocumented: yields, example.
Interaction
Abstract: a node that interacts with the Context. Never instantiated.
Interaction()Path nu.lang.Interaction. Kind Interaction. Abstract: a taxonomy base, not an atom you build.
Concrete sub-kinds implement _eval / _aeval to drive execution.
Both receive the per-execution Runtime and the node's nid (its
integer position in the attributed program); they recurse via
rt.eval(child_nid) and reach for self._children / self._payload
directly. Attribute reads use rt.program.attrs[name][nid].
Undocumented: yields, example.
Policy
A Span that governs a body's execution on failure.
Policy()Path nu.lang.Policy. Kind Policy, sort policy, cardinality transparent. Abstract: a taxonomy base, not an atom you build.
Undocumented: yields, example.
Query
Abstract: a value-producing Interaction.
Query()Path nu.lang.Query. Kind Query. Abstract: a taxonomy base, not an atom you build.
Undocumented: yields, example.
Reduction
A ScalarQuery that folds a stream child down to one value.
Reduction()Path nu.lang.Reduction. Kind Reduction, sort reduction, cardinality scalar. Abstract: a taxonomy base, not an atom you build.
Undocumented: yields, example.
ScalarAction
An Action that mutates and yields exactly one value.
ScalarAction()Path nu.lang.ScalarAction. Kind ScalarAction, sort scalar_action, cardinality scalar. Abstract: a taxonomy base, not an atom you build.
Undocumented: yields, example.
ScalarQuery
A Query that yields exactly one value.
ScalarQuery()Path nu.lang.ScalarQuery. Kind ScalarQuery, sort scalar_query, cardinality scalar. Abstract: a taxonomy base, not an atom you build.
Undocumented: yields, example.
Span
Abstract: a transparent Interaction; yields what its body yields.
Span()Path nu.lang.Span. Kind Span, cardinality transparent. Abstract: a taxonomy base, not an atom you build.
Undocumented: yields, example.
Strategy
A Flow that composes Commands directly.
Strategy()Path nu.lang.Strategy. Kind Strategy, sort strategy, cardinality void. Abstract: a taxonomy base, not an atom you build.
Undocumented: yields, example.
StreamAction
An Action that mutates and yields zero or more values.
StreamAction()Path nu.lang.StreamAction. Kind StreamAction, sort stream_action, cardinality stream. Abstract: a taxonomy base, not an atom you build.
The stream-shaped twin of ScalarAction: one atomic mutate-and-yield-many
(drain a queue, DELETE ... RETURNING over a predicate). A scalar
consumer must reduce it like any StreamQuery; the cardinality law gates
that off cardinality alone, with no per-kind special case.
Undocumented: yields, example.
StreamQuery
A Query that yields zero or more values.
StreamQuery()Path nu.lang.StreamQuery. Kind StreamQuery, sort stream_query, cardinality stream. Abstract: a taxonomy base, not an atom you build.
Undocumented: yields, example.