M2compiler-V3/bindings/sqlite3

SQLite binding (scalar slice)

This is a small, hand-written V3 binding for the scalar SQLite API. It is not a replacement for the full m2SQLITE definition.

Current surface

(* connection *)
sqlite3_open
sqlite3_exec
sqlite3_close

(* prepared statements *)
sqlite3_prepare_v2
sqlite3_bind_int
sqlite3_bind_int64
sqlite3_bind_double
sqlite3_bind_null
sqlite3_bind_text
sqlite3_step
sqlite3_reset
sqlite3_clear_bindings
sqlite3_finalize

(* column metadata and scalar results *)
sqlite3_column_count
sqlite3_data_count
sqlite3_column_type
sqlite3_column_bytes
sqlite3_column_int
sqlite3_column_int64
sqlite3_column_double
sqlite3_column_text
sqlite3_column_name
sqlite3_column_decltype

(* errors and ownership *)
sqlite3_errmsg
sqlite3_errstr
sqlite3_errcode
sqlite3_extended_errcode
sqlite3_extended_result_codes
sqlite3_free

(* binding helper *)
SQLiteTransient

The matching constants include the primary result codes (SQLiteOk, SQLiteConstraint, ...), SQLiteRow, SQLiteDone, storage classes (SQLiteInteger, SQLiteFloat, SQLiteText, SQLiteBlob, SQLiteNull) and a few extended constraints.

Tests and showcase

run.sh builds and runs:

• SQLiteSmoke.mod - open / exec / close
• SQLitePrepared.mod - prepared insert and select
• SQLiteScalar.mod - int, int64, double, text, NULL and column metadata
• SQLiteErrors.mod - error codes, errmsg/errstr and sqlite3_free
• showcase/SQLiteShowcase.mod - prepared-statement walkthrough

The showcase prints:

1: Ada
2: Grace

Build/run

./run.sh

The script uses pkg-config --libs sqlite3 when available; otherwise it links the versioned runtime library directly:

/usr/lib/x86_64-linux-gnu/libsqlite3.so.0

That fallback matters on systems with the SQLite runtime installed but without libsqlite3-dev.

Ownership notes

• sqlite3_exec now takes VAR errmsg : ADDRESS. A non-NIL message is allocated by SQLite and must be released with sqlite3_free.
• sqlite3_errmsg and sqlite3_errstr return borrowed C strings. Copy them with CStr.Copy if they need to outlive the next SQLite call.
• sqlite3_column_text is valid only until the next step, reset or finalize; copy it immediately.
• SQLiteTransient() supplies the SQLITE_TRANSIENT sentinel so SQLite copies bound text. Passing NIL means SQLITE_STATIC; the caller's buffer must then stay alive until the statement is reset or finalized.
• When extended result codes are enabled, sqlite3_exec and sqlite3_errcode can report an extended code such as SQLiteConstraintPrimaryKey (1555) rather than only SQLiteConstraint (19).

Still to add

BLOB binding/column access, open_v2 flags, close_v2, changes/rowid helpers, callbacks, BLOB I/O, backup and extension loading.