Function wat::parse_bytes
source · [−]Expand description
Parses in-memory bytes as either the WebAssembly Text format, or a binary WebAssembly module.
This function will attempt to interpret the given bytes as one of two options:
- A utf-8 string which is a
*.wat
file to be parsed. - A binary WebAssembly file starting with
b"\0asm"
If the input is a string then it will be parsed as *.wat
, and then after
parsing it will be encoded back into a WebAssembly binary module. If the
input is a binary that starts with b"\0asm"
it will be returned verbatim.
Everything that doesn’t start with b"\0asm"
will be parsed as a utf-8
*.wat
file, returning errors as appropriate.
For more information about parsing wat files, see parse_str
.
Errors
In addition to all of the errors that can be returned from parse_str
,
this function will also return an error if the input does not start with
b"\0asm"
and is invalid utf-8. (failed to even try to call parse_str
).
Examples
// Parsing bytes that are actually `*.wat` files
assert_eq!(&*wat::parse_bytes(b"(module)")?, b"\0asm\x01\0\0\0");
assert!(wat::parse_bytes(b"module").is_err());
assert!(wat::parse_bytes(b"binary\0file\0\that\0is\0not\0wat").is_err());
// Pass through binaries that look like real wasm files
assert_eq!(&*wat::parse_bytes(b"\0asm\x01\0\0\0")?, b"\0asm\x01\0\0\0");