reorganize code

1 files changed, 55 insertions, 0 deletions

diff --git a/info/info.go b/info/info.go
new file mode 100644
index 0000000..7ca35ba
--- /dev/null
+++ b/info/info.go
@@ -0,0 +1,55 @@
+// SPDX-FileCopyrightText: 2026 Stefan Majewsky <majewsky@gmx.net>
+// SPDX-License-Identifier: Apache-2.0
+
+// Package info contains marker types that can be placed in user-defined struct types.
+// Doing so enables certain operations within Oblast that rely on the metadata attached to these markers.
+package info // import "go.xyrillian.de/oblast/info"
+
+// seal is a private type that appears in interface definitions below,
+// to ensure that only types from this package can implement these interfaces.
+type seal struct{}
+
+// TableNameIs is a zero-sized marker for struct types that correspond to tables.
+// Put this as an embedded field on your struct type and put the table name in the field's `db` tag.
+//
+//	// For example, this struct type...
+//	type LogEntry struct {
+//		info.TableNameIs  `db:"log_entries"`
+//		info.PrimaryKeyIs `db:"id"`
+//		ID                int64     `db:"id,auto"`
+//		CreatedAt         time.Time `db:"created_at"`
+//		Message           string    `db:"message"`
+//	}
+//	// ...corresponds to this table schema (shown here in PostgreSQL syntax):
+//	CREATE TABLE log_entries (
+//		id          BIGSERIAL    NOT NULL PRIMARY KEY,
+//		created_at  TIMESTAMPTZ  NOT NULL,
+//		message     TEXT         NOT NULL
+//	);
+//
+// This marker is required for all operations that use autogenerated SQL statements.
+type TableNameIs struct{}
+
+// hasTableMarker implements the IsTable interface.
+func (TableNameIs) hasTableMarker(seal) {}
+
+// IsTable is implemented by all types that have an embedded field of type [TableNameIs].
+type IsTable interface {
+	hasTableMarker(seal)
+}
+
+// PrimaryKeyIs is a zero-sized marker for struct types that correspond to tables with a primary key.
+// Put this as an embedded field on your struct type and list the columns of the primary key in the field's `db` tag,
+// as shown on the example for type [TableNameIs].
+//
+// This marker is required for all UPDATE and DELETE operations that use autogenerated SQL statements.
+type PrimaryKeyIs struct{}
+
+// hasPrimaryKeyMarker implements the IsTableWithPrimaryKey interface.
+func (PrimaryKeyIs) hasPrimaryKeyMarker(seal) {} //nolint:unused // TODO
+
+// IsTableWithPrimaryKey is implemented by all types that have embedded fields of type [TableNameIs] and [PrimaryKeyIs].
+type IsTableWithPrimaryKey interface {
+	hasTableMarker(seal)
+	hasPrimaryKeyMarker(seal)
+}