commit 85bac6b12be776274de0d6f6d63242278740bfa3
Author: Branden J Brown <zephyrtronium@gmail.com>
Date:   Wed Aug 27 08:48:19 2025 -0400

    initial commit

diff --git a/boolean/boolean.go b/boolean/boolean.go
new file mode 100644
index 0000000..ceb83f0
--- /dev/null
+++ b/boolean/boolean.go
@@ -0,0 +1,14 @@
+// boolean.go
+package bocchi
+
+import "git.sunturtle.xyz/zephyr/errors-my-beloved/boolean/secret"
+
+var _ = map[bool]struct{}{
+	false:                     {},
+	secret.Secret == "gc25{}": {}, // ERROR: ./boolean.go:7:2: duplicate key false in map literal
+}
+
+var _ = map[bool]struct{}{
+	false:                        {},
+	secret.Secret[:5] != "gc25{": {}, // silently succeeds, even though it evaluates to false
+}
diff --git a/boolean/go.mod b/boolean/go.mod
new file mode 100644
index 0000000..f6bfeae
--- /dev/null
+++ b/boolean/go.mod
@@ -0,0 +1,3 @@
+module git.sunturtle.xyz/zephyr/errors-my-beloved/boolean
+
+go 1.25.0
diff --git a/boolean/secret/secret.go b/boolean/secret/secret.go
new file mode 100644
index 0000000..a8e8e1e
--- /dev/null
+++ b/boolean/secret/secret.go
@@ -0,0 +1,3 @@
+package secret
+
+const Secret = "gc25{afR7yRQVCRDy}"
diff --git a/distant/brain/brain.go b/distant/brain/brain.go
new file mode 100644
index 0000000..ed47b66
--- /dev/null
+++ b/distant/brain/brain.go
@@ -0,0 +1,7 @@
+package brain
+
+type Interface interface {
+	Think(prefix []string) (string, error)
+}
+
+func Think(s Interface, prompt string) (string, error) { panic("TODO") }
diff --git a/distant/brain/sqlbrain/brain.go b/distant/brain/sqlbrain/brain.go
new file mode 100644
index 0000000..d0ec8da
--- /dev/null
+++ b/distant/brain/sqlbrain/brain.go
@@ -0,0 +1,3 @@
+package sqlbrain
+
+type Brain struct{} // SQL db
diff --git a/distant/brain/types.go b/distant/brain/types.go
new file mode 100644
index 0000000..3f4b66a
--- /dev/null
+++ b/distant/brain/types.go
@@ -0,0 +1,6 @@
+package brain
+
+type (
+	Message struct{}
+	Tuple   struct{}
+)
diff --git a/distant/go.mod b/distant/go.mod
new file mode 100644
index 0000000..f3001d6
--- /dev/null
+++ b/distant/go.mod
@@ -0,0 +1,3 @@
+module git.sunturtle.xyz/zephyr/errors-my-beloved/distant
+
+go 1.24.2
diff --git a/distant/go.sum b/distant/go.sum
new file mode 100644
index 0000000..e69de29
diff --git a/distant/main.go b/distant/main.go
new file mode 100644
index 0000000..341f1ea
--- /dev/null
+++ b/distant/main.go
@@ -0,0 +1,10 @@
+package main
+
+import (
+	"git.sunturtle.xyz/zephyr/errors-my-beloved/distant/brain"
+	"git.sunturtle.xyz/zephyr/errors-my-beloved/distant/brain/sqlbrain"
+)
+
+func main() {
+	brain.Think(new(sqlbrain.Brain), "")
+}
diff --git a/generated/bocchi.sqlite3 b/generated/bocchi.sqlite3
new file mode 100644
index 0000000..874c5a4
Binary files /dev/null and b/generated/bocchi.sqlite3 differ
diff --git a/generated/bocchi_test.go b/generated/bocchi_test.go
new file mode 100644
index 0000000..8f74d9d
--- /dev/null
+++ b/generated/bocchi_test.go
@@ -0,0 +1,11 @@
+package bocchi_test
+
+import (
+	"unsafe"
+
+	"git.sunturtle.xyz/zephyr/errors-my-beloved/generated/models"
+)
+
+// If a compiler error happens here, then the database schema has changed,
+// so you need to update unit tests.
+var _ [0]struct{} = [unsafe.Sizeof(models.Bocchi{}) - 56]struct{}{}
diff --git a/generated/go.mod b/generated/go.mod
new file mode 100644
index 0000000..ab02eae
--- /dev/null
+++ b/generated/go.mod
@@ -0,0 +1,3 @@
+module git.sunturtle.xyz/zephyr/errors-my-beloved/generated
+
+go 1.25.0
diff --git a/generated/models/bocchi.xo.go b/generated/models/bocchi.xo.go
new file mode 100644
index 0000000..3fc3434
--- /dev/null
+++ b/generated/models/bocchi.xo.go
@@ -0,0 +1,147 @@
+// Package models contains generated code for schema 'bocchi.sqlite3'.
+package models
+
+// Code generated by xo. DO NOT EDIT.
+
+import (
+	"context"
+	"database/sql"
+)
+
+// Bocchi represents a row from 'bocchi'.
+type Bocchi struct {
+	ID           sql.NullString `json:"id"`           // id
+	Name         sql.NullString `json:"name"`         // name
+	Performances sql.NullInt64  `json:"performances"` // performances
+	// xo fields
+	_exists, _deleted bool
+}
+
+// Exists returns true when the [Bocchi] exists in the database.
+func (b *Bocchi) Exists() bool {
+	return b._exists
+}
+
+// Deleted returns true when the [Bocchi] has been marked for deletion
+// from the database.
+func (b *Bocchi) Deleted() bool {
+	return b._deleted
+}
+
+// Insert inserts the [Bocchi] to the database.
+func (b *Bocchi) Insert(ctx context.Context, db DB) error {
+	switch {
+	case b._exists: // already exists
+		return logerror(&ErrInsertFailed{ErrAlreadyExists})
+	case b._deleted: // deleted
+		return logerror(&ErrInsertFailed{ErrMarkedForDeletion})
+	}
+	// insert (manual)
+	const sqlstr = `INSERT INTO bocchi (` +
+		`id, name, performances` +
+		`) VALUES (` +
+		`$1, $2, $3` +
+		`)`
+	// run
+	logf(sqlstr, b.ID, b.Name, b.Performances)
+	if _, err := db.ExecContext(ctx, sqlstr, b.ID, b.Name, b.Performances); err != nil {
+		return logerror(err)
+	}
+	// set exists
+	b._exists = true
+	return nil
+}
+
+// Update updates a [Bocchi] in the database.
+func (b *Bocchi) Update(ctx context.Context, db DB) error {
+	switch {
+	case !b._exists: // doesn't exist
+		return logerror(&ErrUpdateFailed{ErrDoesNotExist})
+	case b._deleted: // deleted
+		return logerror(&ErrUpdateFailed{ErrMarkedForDeletion})
+	}
+	// update with primary key
+	const sqlstr = `UPDATE bocchi SET ` +
+		`name = $1, performances = $2 ` +
+		`WHERE id = $3`
+	// run
+	logf(sqlstr, b.Name, b.Performances, b.ID)
+	if _, err := db.ExecContext(ctx, sqlstr, b.Name, b.Performances, b.ID); err != nil {
+		return logerror(err)
+	}
+	return nil
+}
+
+// Save saves the [Bocchi] to the database.
+func (b *Bocchi) Save(ctx context.Context, db DB) error {
+	if b.Exists() {
+		return b.Update(ctx, db)
+	}
+	return b.Insert(ctx, db)
+}
+
+// Upsert performs an upsert for [Bocchi].
+func (b *Bocchi) Upsert(ctx context.Context, db DB) error {
+	switch {
+	case b._deleted: // deleted
+		return logerror(&ErrUpsertFailed{ErrMarkedForDeletion})
+	}
+	// upsert
+	const sqlstr = `INSERT INTO bocchi (` +
+		`id, name, performances` +
+		`) VALUES (` +
+		`$1, $2, $3` +
+		`)` +
+		` ON CONFLICT (id) DO ` +
+		`UPDATE SET ` +
+		`name = EXCLUDED.name, performances = EXCLUDED.performances `
+	// run
+	logf(sqlstr, b.ID, b.Name, b.Performances)
+	if _, err := db.ExecContext(ctx, sqlstr, b.ID, b.Name, b.Performances); err != nil {
+		return logerror(err)
+	}
+	// set exists
+	b._exists = true
+	return nil
+}
+
+// Delete deletes the [Bocchi] from the database.
+func (b *Bocchi) Delete(ctx context.Context, db DB) error {
+	switch {
+	case !b._exists: // doesn't exist
+		return nil
+	case b._deleted: // deleted
+		return nil
+	}
+	// delete with single primary key
+	const sqlstr = `DELETE FROM bocchi ` +
+		`WHERE id = $1`
+	// run
+	logf(sqlstr, b.ID)
+	if _, err := db.ExecContext(ctx, sqlstr, b.ID); err != nil {
+		return logerror(err)
+	}
+	// set deleted
+	b._deleted = true
+	return nil
+}
+
+// BocchiByID retrieves a row from 'bocchi' as a [Bocchi].
+//
+// Generated from index 'sqlite_autoindex_bocchi_1'.
+func BocchiByID(ctx context.Context, db DB, id sql.NullString) (*Bocchi, error) {
+	// query
+	const sqlstr = `SELECT ` +
+		`id, name, performances ` +
+		`FROM bocchi ` +
+		`WHERE id = $1`
+	// run
+	logf(sqlstr, id)
+	b := Bocchi{
+		_exists: true,
+	}
+	if err := db.QueryRowContext(ctx, sqlstr, id).Scan(&b.ID, &b.Name, &b.Performances); err != nil {
+		return nil, logerror(err)
+	}
+	return &b, nil
+}
diff --git a/generated/models/db.xo.go b/generated/models/db.xo.go
new file mode 100644
index 0000000..7867dc0
--- /dev/null
+++ b/generated/models/db.xo.go
@@ -0,0 +1,240 @@
+package models
+
+// Code generated by xo. DO NOT EDIT.
+
+import (
+	"context"
+	"database/sql"
+	"database/sql/driver"
+	"fmt"
+	"io"
+	"time"
+)
+
+var (
+	// logf is used by generated code to log SQL queries.
+	logf = func(string, ...interface{}) {}
+	// errf is used by generated code to log SQL errors.
+	errf = func(string, ...interface{}) {}
+)
+
+// logerror logs the error and returns it.
+func logerror(err error) error {
+	errf("ERROR: %v", err)
+	return err
+}
+
+// Logf logs a message using the package logger.
+func Logf(s string, v ...interface{}) {
+	logf(s, v...)
+}
+
+// SetLogger sets the package logger. Valid logger types:
+//
+//	io.Writer
+//	func(string, ...interface{}) (int, error) // fmt.Printf
+//	func(string, ...interface{}) // log.Printf
+func SetLogger(logger interface{}) {
+	logf = convLogger(logger)
+}
+
+// Errorf logs an error message using the package error logger.
+func Errorf(s string, v ...interface{}) {
+	errf(s, v...)
+}
+
+// SetErrorLogger sets the package error logger. Valid logger types:
+//
+//	io.Writer
+//	func(string, ...interface{}) (int, error) // fmt.Printf
+//	func(string, ...interface{}) // log.Printf
+func SetErrorLogger(logger interface{}) {
+	errf = convLogger(logger)
+}
+
+// convLogger converts logger to the standard logger interface.
+func convLogger(logger interface{}) func(string, ...interface{}) {
+	switch z := logger.(type) {
+	case io.Writer:
+		return func(s string, v ...interface{}) {
+			fmt.Fprintf(z, s, v...)
+		}
+	case func(string, ...interface{}) (int, error): // fmt.Printf
+		return func(s string, v ...interface{}) {
+			_, _ = z(s, v...)
+		}
+	case func(string, ...interface{}): // log.Printf
+		return z
+	}
+	panic(fmt.Sprintf("unsupported logger type %T", logger))
+}
+
+// DB is the common interface for database operations that can be used with
+// types from schema 'bocchi.sqlite3'.
+//
+// This works with both [database/sql.DB] and [database/sql.Tx].
+type DB interface {
+	ExecContext(context.Context, string, ...interface{}) (sql.Result, error)
+	QueryContext(context.Context, string, ...interface{}) (*sql.Rows, error)
+	QueryRowContext(context.Context, string, ...interface{}) *sql.Row
+}
+
+// Error is an error.
+type Error string
+
+// Error satisfies the error interface.
+func (err Error) Error() string {
+	return string(err)
+}
+
+// Error values.
+const (
+	// ErrAlreadyExists is the already exists error.
+	ErrAlreadyExists Error = "already exists"
+	// ErrDoesNotExist is the does not exist error.
+	ErrDoesNotExist Error = "does not exist"
+	// ErrMarkedForDeletion is the marked for deletion error.
+	ErrMarkedForDeletion Error = "marked for deletion"
+)
+
+// ErrInsertFailed is the insert failed error.
+type ErrInsertFailed struct {
+	Err error
+}
+
+// Error satisfies the error interface.
+func (err *ErrInsertFailed) Error() string {
+	return fmt.Sprintf("insert failed: %v", err.Err)
+}
+
+// Unwrap satisfies the unwrap interface.
+func (err *ErrInsertFailed) Unwrap() error {
+	return err.Err
+}
+
+// ErrUpdateFailed is the update failed error.
+type ErrUpdateFailed struct {
+	Err error
+}
+
+// Error satisfies the error interface.
+func (err *ErrUpdateFailed) Error() string {
+	return fmt.Sprintf("update failed: %v", err.Err)
+}
+
+// Unwrap satisfies the unwrap interface.
+func (err *ErrUpdateFailed) Unwrap() error {
+	return err.Err
+}
+
+// ErrUpsertFailed is the upsert failed error.
+type ErrUpsertFailed struct {
+	Err error
+}
+
+// Error satisfies the error interface.
+func (err *ErrUpsertFailed) Error() string {
+	return fmt.Sprintf("upsert failed: %v", err.Err)
+}
+
+// Unwrap satisfies the unwrap interface.
+func (err *ErrUpsertFailed) Unwrap() error {
+	return err.Err
+}
+
+// ErrInvalidTime is the invalid Time error.
+type ErrInvalidTime string
+
+// Error satisfies the error interface.
+func (err ErrInvalidTime) Error() string {
+	return fmt.Sprintf("invalid Time (%s)", string(err))
+}
+
+// Time is a SQLite3 Time that scans for the various timestamps values used by
+// SQLite3 database drivers to store time.Time values.
+type Time struct {
+	time time.Time
+}
+
+// NewTime creates a time.
+func NewTime(t time.Time) Time {
+	return Time{time: t}
+}
+
+// String satisfies the fmt.Stringer interface.
+func (t Time) String() string {
+	return t.time.String()
+}
+
+// Format formats the time.
+func (t Time) Format(layout string) string {
+	return t.time.Format(layout)
+}
+
+// Time returns a time.Time.
+func (t Time) Time() time.Time {
+	return t.time
+}
+
+// Value satisfies the sql/driver.Valuer interface.
+func (t Time) Value() (driver.Value, error) {
+	return t.time, nil
+}
+
+// Scan satisfies the sql.Scanner interface.
+func (t *Time) Scan(v interface{}) error {
+	switch x := v.(type) {
+	case time.Time:
+		t.time = x
+		return nil
+	case []byte:
+		return t.Parse(string(x))
+	case string:
+		return t.Parse(x)
+	}
+	return ErrInvalidTime(fmt.Sprintf("%T", v))
+}
+
+// Parse attempts to Parse string s to t.
+func (t *Time) Parse(s string) error {
+	if s == "" {
+		return nil
+	}
+	for _, f := range TimestampFormats {
+		if z, err := time.Parse(f, s); err == nil {
+			t.time = z
+			return nil
+		}
+	}
+	return ErrInvalidTime(s)
+}
+
+// MarshalJSON satisfies the [json.Marshaler] interface.
+func (t Time) MarshalJSON() ([]byte, error) {
+	return t.time.MarshalJSON()
+}
+
+// UnmarshalJSON satisfies the [json.Unmarshaler] interface.
+func (t *Time) UnmarshalJSON(data []byte) error {
+	return t.time.UnmarshalJSON(data)
+}
+
+// TimestampFormats are the timestamp formats used by SQLite3 database drivers
+// to store a time.Time in SQLite3.
+//
+// The first format in the slice will be used when saving time values into the
+// database.  When parsing a string from a timestamp or datetime column, the
+// formats are tried in order.
+var TimestampFormats = []string{
+	// By default, use timestamps with the timezone they have. When parsed,
+	// they will be returned with the same timezone.
+	"2006-01-02 15:04:05.999999999-07:00",
+	"2006-01-02T15:04:05.999999999-07:00",
+	"2006-01-02 15:04:05.999999999",
+	"2006-01-02T15:04:05.999999999",
+	"2006-01-02 15:04:05",
+	"2006-01-02T15:04:05",
+	"2006-01-02 15:04",
+	"2006-01-02T15:04",
+	"2006-01-02",
+}
diff --git a/generated/schema.sql b/generated/schema.sql
new file mode 100644
index 0000000..7f64b7c
--- /dev/null
+++ b/generated/schema.sql
@@ -0,0 +1,5 @@
+CREATE TABLE bocchi (
+    id TEXT PRIMARY KEY,
+    name TEXT,
+    performances INTEGER
+);
\ No newline at end of file
diff --git a/go.work b/go.work
new file mode 100644
index 0000000..ec057f8
--- /dev/null
+++ b/go.work
@@ -0,0 +1,10 @@
+go 1.25.0
+
+use (
+	./boolean
+	./distant
+	./generated
+	./iface
+	./sizeofstring
+	./stringer
+)
diff --git a/iface/01-iface.go b/iface/01-iface.go
new file mode 100644
index 0000000..4bb327b
--- /dev/null
+++ b/iface/01-iface.go
@@ -0,0 +1,11 @@
+package main
+
+type Strummer interface {
+	Strum()
+}
+
+type Bocchi struct {
+	Guitar string
+}
+
+var _ Strummer = (*Bocchi)(nil)
diff --git a/iface/go.mod b/iface/go.mod
new file mode 100644
index 0000000..28ddb23
--- /dev/null
+++ b/iface/go.mod
@@ -0,0 +1,3 @@
+module git.sunturtle.xyz/zephyr/errors-my-beloved/iface
+
+go 1.24.2
diff --git a/sizeofstring/go.mod b/sizeofstring/go.mod
new file mode 100644
index 0000000..8a0657c
--- /dev/null
+++ b/sizeofstring/go.mod
@@ -0,0 +1,3 @@
+module git.sunturtle.xyz/zephyr/errors-my-beloved/sizeofstring
+
+go 1.25.0
diff --git a/sizeofstring/step1.go b/sizeofstring/step1.go
new file mode 100644
index 0000000..efbb4c6
--- /dev/null
+++ b/sizeofstring/step1.go
@@ -0,0 +1,13 @@
+//go:build ignore
+
+// step1.go
+package bocchi
+
+import "unsafe"
+
+type Bocchi struct {
+	x uint32
+	y uint64
+}
+
+var _ [0]struct{} = [unsafe.Sizeof(Bocchi{}) - 0]struct{}{}
diff --git a/sizeofstring/step2.go b/sizeofstring/step2.go
new file mode 100644
index 0000000..c78caaa
--- /dev/null
+++ b/sizeofstring/step2.go
@@ -0,0 +1,13 @@
+//go:build ignore
+
+// step2.go
+package bocchi
+
+import "unsafe"
+
+type Bocchi struct {
+	x uint32
+	y uint64
+}
+
+var _ [0]struct{} = [unsafe.Sizeof(Bocchi{}) - 16]struct{}{}
diff --git a/sizeofstring/step3.go b/sizeofstring/step3.go
new file mode 100644
index 0000000..caefc5b
--- /dev/null
+++ b/sizeofstring/step3.go
@@ -0,0 +1,18 @@
+package bocchi
+
+import "unsafe"
+
+type Bocchi struct {
+	x uint32
+	y uint64
+}
+
+// step3.go
+var (
+	// assert Bocchi.x doesn't move
+	_ [0]struct{} = [unsafe.Offsetof(Bocchi{}.x) - 0]struct{}{}
+	// assert Bocchi.y comes next after Bocchi.x
+	_ [0]struct{} = [unsafe.Offsetof(Bocchi{}.y) - (unsafe.Alignof(Bocchi{}.y))]struct{}{}
+	// assert y is the last field in Bocchi
+	_ [0]struct{} = [unsafe.Sizeof(Bocchi{}) - (unsafe.Alignof(Bocchi{}.y) + unsafe.Sizeof(Bocchi{}.y))]struct{}{}
+)
diff --git a/stringer/go.mod b/stringer/go.mod
new file mode 100644
index 0000000..7f4e44b
--- /dev/null
+++ b/stringer/go.mod
@@ -0,0 +1,3 @@
+module git.sunturtle.xyz/zephyr/errors-my-beloved/stringer
+
+go 1.24.2
diff --git a/stringer/kessoku/band.go b/stringer/kessoku/band.go
new file mode 100644
index 0000000..78e372e
--- /dev/null
+++ b/stringer/kessoku/band.go
@@ -0,0 +1,14 @@
+package kessoku
+
+type BandMember int
+
+const (
+	Bocchi BandMember = iota
+	Ryo
+	Nijika
+	Kita
+
+	maxBand
+)
+
+var _ [0]struct{} = [maxBand - 4]struct{}{}
diff --git a/stringer/kessoku/bandmember_string.go b/stringer/kessoku/bandmember_string.go
new file mode 100644
index 0000000..5c04007
--- /dev/null
+++ b/stringer/kessoku/bandmember_string.go
@@ -0,0 +1,27 @@
+// Code generated by "stringer -type BandMember ./03-stringer/kessoku/"; DO NOT EDIT.
+
+package kessoku
+
+import "strconv"
+
+func _() {
+	// An "invalid array index" compiler error signifies that the constant values have changed.
+	// Re-run the stringer command to generate them again.
+	var x [1]struct{}
+	_ = x[Bocchi-0]
+	_ = x[Ryo-1]
+	_ = x[Nijika-2]
+	_ = x[Kita-3]
+	_ = x[maxBand-4]
+}
+
+const _BandMember_name = "BocchiRyoNijikaKitamaxBand"
+
+var _BandMember_index = [...]uint8{0, 6, 9, 15, 19, 26}
+
+func (i BandMember) String() string {
+	if i < 0 || i >= BandMember(len(_BandMember_index)-1) {
+		return "BandMember(" + strconv.FormatInt(int64(i), 10) + ")"
+	}
+	return _BandMember_name[_BandMember_index[i]:_BandMember_index[i+1]]
+}