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Alphabetic catalog of Language elements V

vector

vector creates a vector from its arguments.

Category Primitive procedure
Format (vector obj₁ ...)
Parameters

obj_i any object

Description vector gathers its arguments into a vector and returns it.
R⁴RS Compliance Full
Examples

(vector 'a -3 "hello") => #(a -3 "hello")
(vector '()) => #(())
(vector) => #()

vector->list

vector->list converts a vector to a list.

Category Native procedure
Format (vector->list vec)
Parameters

vec a vector

Description vector->list returns a newly allocated list of the elements of the vector vec.
R⁴RS Compliance Full
Examples

(vector->list #(foo bar)) => (foo bar)
(vector->list (make-vector 10 42)) => (42 42 42 42 42 42 42 42 42 42)

vector-length

vector-length counts the elements in a vector.

Category Primitive procedure
Format (vector-length vec)
Parameters

vec a vector

Description vector-length returns the number of elements in vec.
R⁴RS Compliance Full
Examples

(vector-length #(foo bar)) => 2
(vector-length (make-vector 97 #n)) => 97
(vector-length (vector)) => 0

vector-ref

vector-ref returns an element of a vector by index.

Category Primitive procedure
Format (vector-ref vec index)
Parameters

vec a vector
index an integer

Description vector-ref returns the indexth element of vec. The index of the first element is 0, and the index of the last element is the length of vec minus one.
R⁴RS Compliance Full
Examples

(vector-ref #(foo bar) 1) => bar
(vector-ref #(0 1 2 3) 5) => error

vector-set!

vector-set! modifies an element in a vector.

Category Primitive procedure
Format (vector-set! vec index obj)
Parameters

vec a vector
index an integer
obj any object

Description vector-set! replaces the indexth element of vec by obj. The modified vector is returned. The index of the first element is 0, and the index of the last element is the length of vec minus one. It's no error to modify a constant vector in LispMe, as all values are heap-allocated and constant vectors are never shared, so the examples are valid.
R⁴RS Compliance Full
Examples

(vector-set! #(1 2 3) 2 #\r) => #(1 2 #\r)
(vector-set! (make-vector 10 'jamaica) -4 'rum) => error

vector?

vector? recognizes vectors.

Category Primitive procedure
Format (vector? obj)
Parameters

obj any object

Description vector? returns #t for a vector and #f for any other object.
R⁴RS Compliance Full
Examples

(vector? '(1 2 3)) => #f
(vector? '#(1 2 3)) => #t
(vector? 'x) => #f

vfs-close

vfs-close closes an open file.

Category Native procedure
Format (vfs-close fileref)
Parameters

fileref a reference to an open file

Description vfs-close closes an open file or directory specified by fileref, which must be a file reference created by vfs-open.
If the file has been closed successfully, #t is returned, otherwise #f.

R⁴RS Compliance LispMe extension
Examples

(vfs-close fref) => #t
Assuming fref is a valid file reference.

vfs-create-dir

vfs-create-dir creates a new directory.

Category Native procedure
Format (vfs-create-dir volref pathname)
Parameters

volref a small integer
pathname a string

Description vfs-create-dir creates a new empty directory named pathname in the VFS volume volref. All parts of the path except the last component must already exist before.
If the directory has been created successfully, #t is returned, otherwise #f.

R⁴RS Compliance LispMe extension
Examples

(vfs-create-dir 4 "palm/MyToyDir") => #t

vfs-delete

vfs-delete deletes a file or directory.

Category Native procedure
Format (vfs-delete volref pathname)
Parameters

volref a small integer
pathname a string

Description vfs-delete deletes the file or directory specified by pathname from the VFS volume volref. The full pathname must be given, since VFS doesn't support the concept of a current directory.
A file must be closed to be deleted. When deleting a directory, it must be empty. If the file has been deleted successfully, #t is returned, otherwise #f.

R⁴RS Compliance LispMe extension
Examples

(vfs-delete 4 "palm/programs") => #f since directory is not empty

vfs-dir

vfs-dir reads the directory of a VFS volume.

Category Native procedure
Format (vfs-dir volref directory)
Parameters

volref a small integer
directory a string

Description vfs-dir retrieves the files in directory of the VFS volume volref as a list of file names (strings). The root directory of a volume is specified by an empty directory name, paths are separated by forward slashes. All file names in the returned list omit the path component.
If any error occurred, #f is returned.

R⁴RS Compliance LispMe extension
Examples

(vfs-dir 4 "") => ("PALM" "AUDIO" "WebPro" "DCIM")
(vfs-dir 4 "palm/programs") => ("VFSMark" "DXTG")

vfs-eof?

vfs-eof? gets the end-of-file status of an open file.

Category Native procedure
Format (vfs-eof? fileref)
Parameters

fileref a reference to an open file

Description vfs-eof? gets the end-of-file status of the file specified by fileref, which must be a file reference created by vfs-open.
If the file is valid and is the file pointer is at the end, #t is returned, #f otherwise.

R⁴RS Compliance LispMe extension
Examples

(vfs-eof? fref) => #f
Assuming fref is a valid file reference.

vfs-get-attr

vfs-get-attr reads the attributes of an open file.

Category Native procedure
Format (vfs-get-attr fileref)
Parameters

fileref a reference to an open file

Description vfs-get-attr reads the attributes of an open file or directory specified by fileref, which must be a file reference created by vfs-open. The attributes are returned as an integer, which is in fact a disjunction of the following bit flags:

Constant Value Description

vfsFileAttrReadOnly #x01 Read-only file or dir

vfsFileAttrHidden #x02 Hidden file or dir

vfsFileAttrSystem #x04 System file or dir

vfsFileAttrVolumeLabel #x08 Volume label

vfsFileAttrDirectory #x10 This is a directory

vfsFileAttrArchive #x20 Archived file or dir

vfsFileAttrLink #x40 Link to another file or dir

Please note that not all attributes may be supported on a specific file system.
If any error occurred, #f is returned.

R⁴RS Compliance LispMe extension
Examples

(vfs-get-attr fref) => 33 (read-only and archived)
Assuming fref is a valid file reference.

vfs-get-ts

vfs-get-ts reads the timestamps of an open file.

Category Native procedure
Format (vfs-get-ts fileref which)
Parameters

fileref a reference to an open file
which a small integer

Description vfs-get-ts reads a timestamp of an open file or directory specified by fileref, which must be a file reference created by vfs-open. Which timestamp is returned is determined by which according to the following table:

Constant Value Description

vfsFileDateCreated 1 File creation timestamp

vfsFileDateModified 2 File last modified timestamp

vfsFileDateAccessed 3 File last access timestamp

Please note that not all timestamps may be supported on a specific file system.
If any error occurred, #f is returned.

R⁴RS Compliance LispMe extension
Examples

(vfs-get-ts fref 2) => [ts 2003-12-05-01-09-02]
Assuming fref is a valid file reference.

vfs-open

vfs-open opens a (raw) file or directory.

Category Native procedure
Format (vfs-open volref pathname mode)
Parameters

volref a small integer
pathname a string
mode a small integer

Description vfs-open opens the file or directory named pathname in the VFS volume volref using the open mode mode. The open mode is a bit flag array assembled of these constants

Constant Value Description

vfsModeExclusive #x01 Don't let others open this file

vfsModeRead #x02 Open for read access

vfsModeWrite #x05 Open for write access. Note that vfsModeExclusive must be set, too.

vfsModeReadWrite #x07 Open for read/write access. Note that vfsModeExclusive must be set, too.

vfsModeCreate #x08 Create the file if it doesn't exist yet.

vfsModeTruncate #x10 Truncate the file to 0 bytes after opening.

vfsModeLeaveOpen #x20 Leave the file open after quitting. Not supported by LispMe, files are always closed and re-opened automatically

The open mode is ignored when opening a directory. If the file has been opened successfully, a file reference (foreign type) is returned, otherwise #f.
If you want to open a file to be used with Scheme's port mechanism, use vfs-open-input or vfs-open-output instead.

R⁴RS Compliance LispMe extension
Examples

(vfs-open 4 "palm/test" #x1f) => [file "palm/test"]

The file has been created or truncated and been opened for both read and write access.

vfs-open-input

vfs-open-input opens a file for input.

Category Native procedure
Format (vfs-open-input volref pathname)
Parameters

volref a small integer
pathname a string

Description vfs-open-input opens the file named pathname in the VFS volume volref for input and creates a buffered Scheme input port on top of it.
If any error occurred, #f is returned. See also vfs-open for opening raw files.

R⁴RS Compliance LispMe extension
Examples

(vfs-open-input 4 "palm/test") => [inport 10 @0 [file "palm/test"]]

vfs-open-output

vfs-open-output opens a file for output.

Category Native procedure
Format (vfs-open-output volref pathname)
Parameters

volref a small integer
pathname a string

Description vfs-open-input opens the file named pathname in the VFS volume volref for output and creates a buffered Scheme output port on top of it. An existing file with the same name is overwritten.
If any error occurred, #f is returned. See also vfs-open for opening raw files.

R⁴RS Compliance LispMe extension
Examples

(vfs-open-output 4 "palm/test") => [outport 10 @0 [file "palm/test"]]

vfs-read

vfs-read reads from an open file.

Category Native procedure
Format (vfs-read fileref len)
Parameters

fileref a reference to an open file
len an integer

Description vfs-read reads a block of data from an open file specified by fileref, which must be a file reference created by vfs-open. A maximum of len bytes is read (or fewer, if EOF is reached) and returned as a string. Thus the block size is limited by the max. string size, which is about 64k.
If any error occurred, #f is returned.

R⁴RS Compliance LispMe extension
Examples

(vfs-read fref 10) => "This is an"
Assuming fref is a valid file reference.

vfs-ref?

vfs-ref? recognizes file references.

Category Primitive procedure
Format (vfs-ref? obj)
Parameters

obj any object

Description vfs-ref? returns #t for a file reference created by vfs-open and #f for any other object.
R⁴RS Compliance LispMe extension
Examples

(vfs-ref? "foo") => #f
(vfs-ref? (vfs-open 4 "foo" #x02)) => #t

vfs-rename

vfs-rename renames a file or directory.

Category Native procedure
Format (vfs-rename volref pathname newname)
Parameters

volref a small integer
pathname a string
newname a string

Description vfs-rename renames the file or directory specified by pathname in the VFS volume volref to newname. The full pathname must be given, since VFS doesn't support the concept of a current directory.
A file must be closed to be renamed. The new name must be the name component only and may not contain a path. Therefore it's not possible to move a file with this procedure.
If the file has been renamed successfully, #t is returned, otherwise #f.

R⁴RS Compliance LispMe extension
Examples

(vfs-rename 4 "audio/a_song.mp3" "other.mp3") => #t

vfs-seek

vfs-seek repositions the file pointer.

Category Native procedure
Format (vfs-seek fileref origin offset)
Parameters

fileref a reference to an open file
origin a small integer
offset an integer

Description vfs-seek sets the position of the file pointer within an open filespecified by fileref, which must be a file reference created by vfs-open. Origin determines the origin from which the offset (in bytes) is counted:

Constant Value Description

vfsOriginBeginning 0 The beginning of the file, only non-negative offsets allowed

vfsOriginCurrent 1 The current file pointer position

vfsOriginEnd 2 The end of the file, only negative offsets allowed

If any error occurred, #f is returned, #t otherwise.

R⁴RS Compliance LispMe extension
Examples

(vfs-seek fref 2 -1) => #t (positioned at the last byte)
Assuming fref is a valid file reference.

vfs-set-attr

vfs-set-attr sets the attributes of an open file.

Category Native procedure
Format (vfs-set-attr fileref attr)
Parameters

fileref a reference to an open file
attr a small integer

Description vfs-set-attr sets the attributes of an open file or directory specified by fileref, which must be a file reference created by vfs-open. The attributes attr are described here, but please note that vfsFileAttrVolumeLabel and vfsFileAttrDirectory may not be changed by this procedure. Also note that the file must have been opened for writing to be able to change attributes.
If the attributes have been set successfully, #t is returned, otherwise #f.

R⁴RS Compliance LispMe extension
Examples

(vfs-set-attr fref 32) => #t (read-only flag reset, see here)
Assuming fref is a valid file reference.

vfs-set-ts

vfs-set-ts sets the timestamps of an open file.

Category Native procedure
Format (vfs-set-ts fileref which ts)
Parameters

fileref a reference to an open file
which a small integer
ts a timestamp

Description vfs-set-ts sets a timestamp of an open file or directory specified by fileref, which must be a file reference created by vfs-open. The timestamp to be set is specified by which (see here for allowed values).
If the attributes have been set successfully, #t is returned, otherwise #f. Please note that the file must have been opened for writing to be able to change timestamps.
If the timestamp has been set successfully, #t is returned, otherwise #f.

R⁴RS Compliance LispMe extension
Examples

(vfs-set-ts fref 3 (current-ts)) => #t
Assuming fref is a valid file reference.

vfs-size

vfs-size gets the size of an open file.

Category Native procedure
Format (vfs-size fileref)
Parameters

fileref a reference to an open file

Description vfs-size gets the current size of the file specified by fileref, which must be a file reference created by vfs-open.
If any error occurred, #f is returned.

R⁴RS Compliance LispMe extension
Examples

(vfs-size fref) => 12030
Assuming fref is a valid file reference.

vfs-supported?

vfs-supported? indicates, if VFS is supported.

Category Native procedure
Format (vfs-supported?)
Parameters none
Description vfs-supported? returns #t if the Palm Virtual File System API is supported on this device (requires at least PalmOS4) and #f otherwise.
R⁴RS Compliance LispMe extension
Examples

(vfs-supported?) => #t on a modern Palm :-)

vfs-tell

vfs-tell tells the position in an open file.

Category Native procedure
Format (vfs-tell fileref)
Parameters

fileref a reference to an open file

Description vfs-tell gets the current position of the file pointer within an open file specified by fileref, which must be a file reference created by vfs-open.
If any error occurred, #f is returned.

R⁴RS Compliance LispMe extension
Examples

(vfs-tell fref) => 4711
Assuming fref is a valid file reference.

vfs-vol-get-label

vfs-vol-get-label returns the label of a VFS volume.

Category Native procedure
Format (vfs-vol-get-label volref)
Parameters

volref a small integer

Description vfs-vol-get-label searches for the VFS volume volref and returns its label (name) as a string. If no VFS volume exists, #f is returned.
R⁴RS Compliance LispMe extension
Examples

(vfs-vol-get-label 4) => "My new SD256 card"

vfs-vol-info

vfs-vol-info retrieves general information of a VFS volume.

Category Native procedure
Format (vfs-vol-info volref)
Parameters

volref a small integer

Description vfs-vol-info searches for the VFS volume volref and returns general information about it as a list of 7 elements:

Attributes
File system type
File system creator
Mount class
Slot library reference
Slot library
Media type
If no VFS volume exists, #f is returned.
R⁴RS Compliance LispMe extension
Examples

(vfs-vol-info 4) => (1 "vfat" "fatf" "libs" 2 1 "sdig")

vfs-vol-set-label

vfs-vol-set-label sets the label of a VFS volume.

Category Native procedure
Format (vfs-vol-set-label volref label)
Parameters

volref a small integer
label a string

Description vfs-vol-set-label searches for the VFS volume volref and sets its label (name) to label. If no VFS volume exists, #f is returned.
R⁴RS Compliance LispMe extension
Examples

(vfs-vol-set-label 4 "Backup") => #t

vfs-vol-size

vfs-vol-size returns the size of a VFS volume.

Category Native procedure
Format (vfs-vol-size volref)
Parameters

volref a small integer

Description vfs-vol-size searches for the VFS volume volref and returns the number of bytes used and the total capacity in bytes as a two-element list. If no VFS volume exists, #f is returned.
R⁴RS Compliance LispMe extension
Examples

(vfs-vol-size 4) => (203259904 258867200) on a typical 256MB SD-card

vfs-volumes

vfs-volumes returns a list of all VFS volumes.

Category Native procedure
Format (vfs-volumes)
Parameters none
Description vfs-volumes retrieves all currently mounted VFS volumes and returns them as a list of integer reference numbers. You have to use those reference numbers in other VFS calls. Current devices have only one card slot and thus only one volume available. If no card is mounted, the list is empty. Please note that reference numbers change when a card is removed and re-inserted!
R⁴RS Compliance LispMe extension
Examples

(vfs-volumes) => (4)

vfs-write

vfs-write writes data to an open file.

Category Native procedure
Format (vfs-write fileref data)
Parameters

fileref a reference to an open file
data a string

Description vfs-write writes the data block data to an open file specified by fileref, which must be a file reference created by vfs-open. The entire string is written at the current file position.
The number of bytes written is returned, or #f, if an error occurred.

R⁴RS Compliance LispMe extension
Examples

(vfs-write fref "nonsense") => 8
Assuming fref is a valid file reference.

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