code wiki / _hdl_build / nx_html_head_fd.nx
`nx_html_head_fd.nx` source

1// nx_html_head_fd.nx -- the fd-STREAMING half of the canonical accessible head (seq702/seq703).
2//
3// WHY A SECOND FILE: emitters come in TWO shapes, discovered while migrating them.
4//   (a) BUFFER-ACCUMULATING -- pd_cat / shf_cat / fb_puts / wc_cat build into (out, offset)
5//       and write once at the end. Those use nx_html_head.nx, which stays deliberately
6//       DEPENDENCY-FREE (no imports at all) so anything can adopt it.
7//   (b) fd-STREAMING -- hw(fd, s) writes each literal straight out via sys_write. The 16
8//       nx_wasm_*_html.nx GAME packagers are all this shape.
9// Writing to an fd needs sys_write, so the fd half lives here rather than contaminating the
10// dependency-free core. Every emitter already imports nx_syscalls, so this costs adopters nothing.
11//
12// USAGE -- mirrors the buffer API exactly:
13//     nxh_fd_head_open(fd, "My Title" as *u8)   // doctype+lang+charset+viewport+title
14//     hw(fd, "<style>...</style>" as *u8)        // emitter keeps its own CSS, unchanged
15//     nxh_fd_body_open(fd)                       // </head><body><main>
16//     ... page content ...
17//     nxh_fd_close(fd)                           // </main></body></html>
18//
19// Guarantees the three checks no stylesheet can supply: lang= on <html>, meta viewport,
20// and a <main> landmark. For the games the viewport line is the load-bearing one -- they
21// pair a fixed-px canvas with no viewport, which is why they do not scale on a phone.
22
23import "nx_syscalls.nx"
24
25// write one NUL-terminated literal to fd (same contract as the hw() every emitter defines)
26func nxh_fd_lit(fd: i64, s: *u8) -> i64 {
27    var n: i64 = 0
28    while s[n] != (0 as u8) { n = n + 1 }
29    sys_write(fd, s, n)
30    return 0
31}
32
33func nxh_fd_head_open(fd: i64, title: *u8) -> i64 {
34    nxh_fd_lit(fd, "<!doctype html><html lang=\"en\"><head><meta charset=\"utf-8\"><meta name=\"viewport\" content=\"width=device-width,initial-scale=1\"><title>" as *u8)
35    nxh_fd_lit(fd, title)
36    nxh_fd_lit(fd, "</title>" as *u8)
37    return 0
38}
39
40func nxh_fd_body_open(fd: i64) -> i64 {
41    return nxh_fd_lit(fd, "</head><body><main>" as *u8)
42}
43
44func nxh_fd_close(fd: i64) -> i64 {
45    return nxh_fd_lit(fd, "</main></body></html>" as *u8)
46}
nx_html_head_fd.nx source

`nx_html_head_fd.nx` source
