From a7e38bd0e8a7b25f8d6ae8f5069e931026a7d8e7 Mon Sep 17 00:00:00 2001 From: Marshall Lochbaum Date: Sat, 9 Apr 2022 15:59:45 -0400 Subject: =?UTF-8?q?=E2=80=A2file.MapBytes=20specification?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit --- spec/system.md | 5 +++++ 1 file changed, 5 insertions(+) (limited to 'spec') diff --git a/spec/system.md b/spec/system.md index 395464a7..c9c6d11d 100644 --- a/spec/system.md +++ b/spec/system.md @@ -118,6 +118,7 @@ File access functions read or write files, either by manipulating files as a who | `Chars` | Read from or write to entire file, as characters | `Lines` | Read from or write to entire file, as lines | `Bytes` | Read from or write to entire file, as bytes +| `MapBytes` | Create a memory-mapped array aliasing the file `Rename`, `Copy`, and `CreateDir` return the path of the new file. `Remove` and `RemoveDir` return `1` to indicate successful removal (and error otherwise). @@ -129,6 +130,8 @@ Functions `Chars`, `Lines`, and `Bytes` are all ambivalent. If only `š¯•©` is gi - Lines: BQN strings. The file is decoded as with chars, then split into lines by CR, LR, or CRLF line endings. - Bytes: Single-byte values, stored as BQN characters from `@` to `@+255`. +The `MapBytes` function only takes one argument, a filename, and returns an array matching the result of `Bytes`. However, the array data should be [memory-mapped](https://en.wikipedia.org/wiki/Memory-mapped_file) allowing it to be loaded into memory on use. The array and arrays derived from it (such as slices) may change in value if the underlying file is modified after `MapBytes` is called. + The following short names can also be provided for file access. They can be provided, and use the definitions from above even if `ā€¢file` is not provided. | Name | Equivalent @@ -139,6 +142,8 @@ The following short names can also be provided for file access. They can be prov ### Open file object +Not yet specified. + ## Input and output | Name | Summary -- cgit v1.2.3