File functions

These functions can be used to work with files.

Function	Description
`file::bucket()`	Returns the bucket path from a file pointer
`file::copy()`	Copies the contents of a file
`file::copy_if_not_exists()`	Copies the contents of a file to a new file if the name is available
`file::delete()`	Deletes a file
`file::exists()`	Checks if a file already exists
`file::get()`	Loads a file
`file::head()`	Returns the metadata of a file
`file::key()`	Returns the key (the portion following the bucket) from a file pointer
`file::list()`	Returns a list of files inside a bucket
`file::put()`	Writes bytes to a file
`file::put_if_not_exists()`	Attempts to write bytes to a file
`file::rename()`	Renames a file
`file::rename_if_not_exists()`	Renames a file if the new name is not already in use

`file::bucket`

API DEFINITION

file::bucket(file) -> string

The file::bucket function returns the name of the bucket in which a file is located.

file::bucket(f"my_bucket:/file_name");

DEFINE PARAM $SOME_DATABASE_FILE VALUE f"my_bucket:/file_name";
file::bucket($SOME_DATABASE_FILE);

Output

'my_bucket'

The counterpart to this function is file::key, which returns the latter part of a file pointer.

`file::copy`

The file::copy function copies the contents of a file to a new file, overwriting any existing file that has the same name as the new file.

API DEFINITION

file::copy(string)

Example of a file my_book.txt being copied to a new location lion_witch_wardrobe.txt:

f"my_bucket:/my_book.txt".copy("lion_witch_wardrobe.txt");

`file::copy_if_not_exists`

The file::copy_if_not_exists function copies the contents of a file to a new file, returning an error if a file already exists that has the same name as that of the intended copy.

API DEFINITION

file::copy_if_not_exists(string)

Example of a file my_book.txt attempting to copy to a new location lion_witch_wardrobe.txt:

DEFINE BUCKET my_bucket BACKEND "memory";

f"my_bucket:/lion_witch_wardrobe.txt".put("Once there were four children whose names were Peter, Susan...");
f"my_bucket:/other_book.txt".put("Um meine Geschichte zu erzählen, muß ich weit vorn anfangen.");
f"my_bucket:/other_book.txt".copy_if_not_exists("lion_witch_wardrobe.txt");

Output

'Operation for bucket `my_bucket` failed: Object at location lion_witch_wardrobe.txt already exists:
Object already exists at that location: lion_witch_wardrobe.txt'

`file::delete`

The file::delete function deletes a file.

API DEFINITION

file::delete(string)

Example of a file my_book.txt being deleted:

f"my_bucket:/my_book.txt".delete();

`file::exists`

The file::exists function checks to see if a file exists at the path and file name indicated.

API DEFINITION

file::exists(string) -> bool

Example of an IF else STATEMENT used to check if a file exists before writing content to the location:

IF f"my_bucket:/my_book.txt".exists() {
    THROW "Whoops, already there!"
} ELSE {
    f"my_bucket:/my_book.txt".put("Some content")
};

`file::get`

The file::get function retrieves a file for use.

API DEFINITION

file::get(string) -> bytes

A retrieved file will display as bytes. If valid text, these can be cast into a string.

f"my_bucket:/my_book.txt".get();
<string>f"my_bucket:/my_book.txt".get();

Output

-------- Query --------

b"536F6D6520636F6E74656E74"

-------- Query --------

'Once there were four children whose names were Peter, Susan...'

`file::head`

The file::head function returns the metadata for a file.

API DEFINITION

file::head() -> object

If a file is found, the metadata will be returned as an object with the following fields:

e_data (option<string>): the unique identifier for the file.
last_modified (datetime)
location (string)
size (int)
version (option<string>)

An example of this function and its output:

f"my_bucket:/my_book.txt".head();

Output

{
	e_tag: '1',
	key: 'my_book.txt',
	last_modified: d'2025-03-26T06:29:18.988Z',
	size: 78,
	version: NONE
}

`file::key`

API DEFINITION

file::key(file) -> string

The file::key function returns the key of a file: the part of a file pointer following the bucket name.

file::key(f"my_bucket:/file_name");

DEFINE PARAM $SOME_DATABASE_FILE VALUE f"my_bucket:/file_name";
file::key($SOME_DATABASE_FILE);

Output

'/file_name'

The counterpart to this function is file::bucket, which returns the bucket name of a file pointer.

`file::list`

API DEFINITION

file::list(string, $list_options: option<object>) -> array<object>

The file::list returns the metadata for the files inside a certain bucket. The output is an array of objects, each containing the following fields:

file: the pointer to the file.
size (int): the file size in bytes.
updated (datetime): the last time a change was made to the file.

DEFINE BUCKET my_bucket BACKEND "memory";

f"my_bucket:/some_book".put("Once upon a time...");
f"my_bucket:/some_book".rename("awesome_book");
f"my_bucket:/some_book".put("In a hole in the ground lived a Hobbit.");
file::list("my_bucket");

Output

[
	{
		file: f"my_bucket:/awesome_book",
		size: 19,
		updated: d'2025-04-08T03:28:20.530511Z'
	},
	{
		file: f"my_bucket:/some_book",
		size: 39,
		updated: d'2025-04-08T03:28:20.530704Z'
	}
]

To modify the output, a second argument can be passed in that contains a single object with up to three fields:

limit (int): the maximum number of files to display.
start (string): displays files ordered after start.
prefix (string): displays files whose names begin with prefix.

Some examples of the function containing the second object and their responses:

file::list("my_bucket", { limit: 1 });
file::list("my_bucket", { limit: 0 });

Output

-------- Query --------
[
	{
		file: f"my_bucket:/awesome_book",
		size: 19,
		updated: d'2025-04-15T05:35:40.913221Z'
	}
]

-------- Query --------
[]

file::list("my_bucket", { prefix: "some" });
file::list("my_bucket", { prefix: "someBOOOEOEOK" });

Output

-------- Query --------
[
	{
		file: f"my_bucket:/some_book",
		size: 39,
		updated: d'2025-04-15T05:35:40.913554Z'
	}
]

-------- Query --------
[]

file::list("my_bucket", { start: "a" });
file::list("my_bucket", { start: "m" });

Output

-------- Query --------
[
	{
		file: f"my_bucket:/awesome_book",
		size: 19,
		updated: d'2025-04-15T05:55:41.973869Z'
	},
	{
		file: f"my_bucket:/some_book",
		size: 39,
		updated: d'2025-04-15T05:55:41.974370Z'
	}
]

-------- Query --------
[
	{
		file: f"my_bucket:/some_book",
		size: 39,
		updated: d'2025-04-15T05:55:41.974370Z'
	}
]

file::list("my_bucket", { prefix: "some", start: "a", limit: 1 });

Output

[
	{
		file: f"my_bucket:/some_book",
		size: 39,
		updated: d'2025-04-15T05:35:40.913554Z'
	}
]

`file::put`

The file::put function adds data into a file, overwriting any existing data.

API DEFINITION

file::put()

An example of this function followed by file::get() to display the contents:

DEFINE BUCKET my_bucket BACKEND "memory";

f"my_bucket:/my_book.txt".put("Once there were four children whose names were Peter, Susan...");
f"my_bucket:/my_book.txt".put("Or were there? I don't quite remember.");
<string>f"my_bucket:/my_book.txt".get();

Output

"Or were there? I don't quite remember."

`file::put_if_not_exists`

The file::put function adds data into a file, unless a file of the same name already exists.

API DEFINITION

file::put_if_not_exists()

An example of this function followed by file::get() to display the contents:

DEFINE BUCKET my_bucket BACKEND "memory";

-- Creates file and adds data
f"my_bucket:/my_book.txt".put_if_not_exists("Once there were four children whose names were Peter, Susan...");
-- Does nothing
f"my_bucket:/my_book.txt".put_if_not_exists("Or were there? I don't quite remember.");
<string>f"my_bucket:/my_book.txt".get();

Output

'Once there were four children whose names were Peter, Susan...'

`file::rename`

The file::rename function renames a file, overwriting any existing file that has the same name as the target name.

API DEFINITION

file::rename()

An example of a file being renamed over an existing file:

DEFINE BUCKET my_bucket BACKEND "memory";

f"my_bucket:/my_book.txt".put("Once there were four children whose names were Peter, Susan...");
f"my_bucket:/other_book.txt".put("Or were there? I don't quite remember.");
-- Rename to my_book.txt, overwriting existing file of the same name
f"my_bucket:/other_book.txt".rename("my_book.txt");
<string>f"my_bucket:/my_book.txt".get();

Output

"Or were there? I don't quite remember."

`file::rename_if_not_exists`

The file::rename_if_not_exists function renames a file, returning an error if a file already exists that has the same name as the target name.

API DEFINITION

file::rename_if_not_exists()

Output

-------- Query --------

'Operation for bucket `my_bucket` failed: Object at location my_book.txt already exists:
Object already exists at that location: my_book.txt'

-------- Query --------

'Once there were four children whose names were Peter, Susan...