The Go runtime module

Generated Go is not self-contained. The support types it leans on live in one module, gitlab.com/terryp/model/go-runtime, and every generated file imports it. Add it to the module that holds the generated file:

go get gitlab.com/terryp/model/go-runtime

Generation itself needs the dependency in place: a model with routes type-checks the target package between passes, and that fails if the import cannot be resolved.

Why a module rather than a copy

The support types used to be copied into each generated file. That made a small output mostly scaffolding, and it made two generated packages in one program unable to talk to each other — each had its own Optional[T] and its own ValidationError, distinct types as far as Go was concerned. Sharing one module fixes both.

What you use

The generator imports each package under a fixed alias, so generated declarations read the way this table spells them.

Import path	Alias	What it holds
…/go-runtime	mdl	Optional[T], ValidationError, TimeOfDay, Path, FromError, StatusCoder
…/go-runtime/pg	mdlpg	DB, DBMiddleware, WithTx, UseTx — the transaction plumbing the postgres feature runs in
…/go-runtime/fyne	mdlfyne	TimeEntry and HelpButton, what the fyne feature’s New<Field>Entry and New<Field>Help return

An optional field is mdl.Optional[T]; read it with IsSome, Get, or GetOrZero, and build one with mdl.Some or mdl.None[T](). A Validate method reports *mdl.ValidationError. A route’s error response type implements mdl.FromError, and either it or the error implements mdl.StatusCoder.

What you do not

Everything under …/go-runtime/gen is a generator implementation detail: the validation walk, the yaml and etree helpers, the pgx converters, the REST handlers. Those identifiers are exported only because generated code sits in your package and cannot reach unexported ones. They carry no compatibility promise and may change in any release. Nothing outside generated code should name them.

Dependencies

Only the root package is unconditional, and it pulls in nothing third-party. The feature packages are separate so a consumer who enables no features never compiles fyne or pgx: yamlx needs gopkg.in/yaml.v3, xmlx needs github.com/beevik/etree, fyne needs fyne.io/fyne/v2, and pg, pgconv and rest need github.com/jackc/pgx/v5. Go only builds the ones your generated file actually imports.