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Chandler Carruth
7612b3d821
Document the phase of associated constants, which the discussions of
contextual phase defaults never covered: an associated constant is
always a checked generic binding. This is deliberately not presented as
a contextual default, because no other phase is possible for the
construct; correspondingly, no phase keyword (including `template`) is
allowed on one. Also rework the associated constants section of the
design README where the migration left a non-sequitur ("set to
compile-time values ... and so are defined using a `let` declaration"):
describe the `let` syntax and the binding's contextual phase separately.
Use consistent terminology for bindings versus constants. Bindings are
"checked" or "template" (generic) bindings, replacing the "symbolic
binding" and bare "generic binding" terms, so "symbolic" now only
describes constants and values. The "Symbolic facet bindings" section of
the generics details becomes "Checked facet bindings". The
expression-phase terms "symbolic constant" and "template constant" are
unchanged, and the binding-pattern definitions now name the constant
each kind binds. Template bindings are additionally described as
dependent and late checked, with each instantiation providing the
binding's value.
Also normalize the remaining "regular parameter" mentions to "runtime
parameter" to match the binding terminology, and describe the
compile-time "let template" as introducing a template generic binding
"T: C" whose uses are template constants.
Assisted-by: Claude Code
Generics
This directory contains the collection of documents describing the generics feature of Carbon:
- Overview - A high-level description of the generics design, with pointers to other design documents that dive deeper into individual topics
- Goals - The motivation and principles guiding the design direction
- Terminology - A glossary establishing common terminology for describing the design
- Detailed design - In-depth description
- Appendix: Coherence - Describes the rationale for Carbon's choice to have coherent generics, and the alternatives.
- Appendix: Rewrite constraints - Describes the detailed rules governing rewrite constraints, and why resolving them terminates.
- Appendix: Witness tables - Describes an implementation strategy for checked generics, and Carbon's rationale for only using it for dynamic dispatch.