Files
sx/examples/1213-ffi-05-string-args.sx
agra d8076b9333 lang: rename signed integer types sN -> iN
Surface rename of the signed integer family: s1..s64 become i1..i64
(u1..u64, usize, isize unchanged). 'string' keeps the s-prefix arm in
name classification; width parsing moves to the i-prefix arm next to
isize.

Internal TypeId tags follow the surface (.s8/.s16/.s32/.s64 ->
.i8/.i16/.i32/.i64), as do mono-key mangle fragments (ptr_i64,
tu_i64_bool) and all display/diagnostic formatting (i{d}).

Migrated in the same sweep: stdlib + examples + issue repros + FFI C
companions (shared symbol names like ffi_id_i64), expected
stdout/stderr/ir snapshots, specs.md, readme.md, CLAUDE.md/AGENTS.md,
implementation_plan.md, docs/, issue writeups. Vendored stb_image and
historical flow state left untouched.

zig build test: 426/426; examples suite: 595/595.
2026-06-12 09:31:53 +03:00

50 lines
2.2 KiB
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// Phase 0 baseline (PLAN-FFI.md step 0.5): the three shapes that
// actually appear at the sx ↔ C boundary today:
//
// 1. Null-terminated `[:0]u8` — passed by `.ptr` to a `const char *`.
// 2. Raw byte buffer `[*]u8` — pointer + explicit length.
// 3. sx `string` value — coerceArg's "fat-pointer decay" branch
// pulls `.ptr` automatically for `*u8`/
// `[:0]u8` params (string is `{ptr, len}`).
// 4. Pointer return from C — round-trips back as `[*]u8` / `*u8`.
#import "modules/std.sx";
#import c {
#source "1213-ffi-05-string-args.c";
};
ffi_strlen :: (s: [:0]u8) -> i32 #foreign;
ffi_first_byte :: (s: [:0]u8) -> i32 #foreign;
ffi_sum_bytes :: (buf: [*]u8, len: i32) -> i32 #foreign;
ffi_write_byte :: (buf: [*]u8, idx: i32, v: u8) -> void #foreign;
ffi_static_greeting :: () -> [*]u8 #foreign;
main :: () -> i32 {
// ── [:0]u8 null-terminated literal ─────────────────────────────
msg : [:0]u8 = "hello";
print("strlen(\"hello\") = {}\n", ffi_strlen(msg));
print("first_byte = {}\n", ffi_first_byte(msg));
// ── sx `string` → C `const char *` (slice-decay through coerceArg) ─
s : string = "sx string here";
print("strlen(sx string) = {}\n", ffi_strlen(xx s.ptr));
// ── [*]u8 raw buffer + length ──────────────────────────────────
bytes : [4]u8 = .[10, 20, 30, 40];
bp : [*]u8 = xx @bytes[0];
print("sum_bytes([10,20,30,40]) = {}\n", ffi_sum_bytes(bp, 4));
// ── Mutate buffer via C, read back from sx ─────────────────────
ffi_write_byte(bp, 1, 99);
print("bytes[1] after write = {}\n", bytes[1]);
// ── C returns a static string pointer; read it byte-by-byte ────
g := ffi_static_greeting();
n := ffi_strlen(xx g);
print("static greeting len = {}\n", n);
print("static greeting [0] = {}\n", g[0]);
0
}