嵌入

Embeds a package file into a module constant at build time.

Syntax: const <type> <name> = embed \"<path>\"

Category#

comptime

Related#

• 静态
• 文本
• 字节
• 前缀

Examples#

radix/corpus/insere/insere.fab (canonical · keyword)#

Embeds a package file into a module constant at build time.

# =============================================================================
# 嵌入 — Embeds a package file into a module constant at build time.
# =============================================================================
#
# What this teaches:
#   • Build-time embed — `const T X = embed "path"` reads a file while compiling; the program carries its contents as a literal.
#   • One keyword, two results — the declared type decides: `string` requires valid UTF-8, `bytes` takes the raw bytes.
#   • Package-relative paths — resolved against the package root (the nearest `faber.toml`), or this file's directory when there is none.
#
# Common mistakes:
#   • Using an absolute path or `..` to reach outside the package — both are compile errors (SEM061).
#   • Declaring `string` for a binary file — invalid UTF-8 is a compile error; declare `bytes`.
#   • Expecting a runtime read — changing the file needs a rebuild; for run-time I/O use a `call` route.
#
# See also: 静态, 文本, 字节, 前缀
# =============================================================================

# 嵌入 — build-time file embed (en `embed`)
#
# const <type> <name> = embed "<path>"
#
# GRAMMAR:
#   fixum_decl  :← '常量' type_annotation IDENTIFIER '=' const_init
#   const_init  :← insere_expr | expression
#   insere_expr :← '嵌入' STRING
#
# EXPECTED OUTPUT:
#   insere.expected — the embedded text, its length, and the byte count.

const string NUNTIUS = embed "nuntius.txt"

const bytes SIGNUM = embed "signum.bin"

class Tabula {
    static string TITULUS = embed "nuntius.txt"
}

# `embed` is contextual: directly before a string literal it is the embed; any
# other use of the name, like this call, is an ordinary identifier.
fn embed(int n) → int {
    return n * 2
}

main {
    print NUNTIUS
    print NUNTIUS.length()
    print SIGNUM.length()
    print embed(21)
}

Expected output:

salve ex tabula
15
6
42