- Documentation
- Reference manual
- Packages
- Redis -- a SWI-Prolog client for redis
- library(redis): Redis client
- redis_server/3
- redis_connect/1
- redis_connect/3
- tls_verify/5
- sentinel_slave/4
- redis_disconnect/1
- redis_disconnect/2
- redis/2
- redis/3
- redis/1
- redis_write/2
- redis_read/2
- redis_get_list/3
- redis_get_list/4
- redis_set_list/3
- redis_get_hash/3
- redis_set_hash/3
- redis_array_dict/3
- redis_scan/3
- redis_sscan/4
- redis_hscan/4
- redis_zscan/4
- redis_current_command/2
- redis_current_command/3
- redis_property/2
- redis_subscribe/4
- redis_subscribe/2
- redis_unsubscribe/2
- redis_current_subscription/2
- library(redis): Redis client
- Redis -- a SWI-Prolog client for redis
- Atomic values are emitted verbatim
- A term A:B:... where all arguments are either atoms, strings or
integers (no floats) is translated into a string
"A:B:..."
. This is a common shorthand for representing Redis keys. - A term Term as prolog is emitted as "
\
u0000T\
u0000" followed by Term in canonical form. - Any other term is emitted as write/1.
Reply is either a plain term (often a variable) or a term Value as Type
.
In the latter form, Type dictates how the Redis bulk
reply is translated to Prolog. The default equals to auto
,
i.e., as a number of the content satisfies the Prolog number syntax and
as an atom otherwise.
status(Atom)
Returned if the server replies with+ Status
. Atom is the textual value of Status converted to lower case, e.g.,status(ok)
orstatus(pong)
.nil
This atom is returned for a NIL/NULL value. Note that if the reply is onlynil
, redis/3 fails. Thenil
value may be embedded inside lists or maps.- A number Returned if the server replies an integer (":Int"), double (",Num") or big integer ("(Num")
- A string Returned on a bulk reply. Bulk replies are supposed
to be in UTF-8 encoding. The the bulk reply starts with "
\
u0000T\
u0000" it is supposed to be a Prolog term. Note that this intepretation means it is not possible to read arbitrary binary blobs. - A list of replies. A list may also contain
nil
. If Reply as a whole would benil
the call fails. - A list of pairs. This is returned for the redis version 3 protocol "%Map". Both the key and value respect the same rules as above.
Redis bulk replies are translated depending on the as
Type
as explained above.
- string
- string(Encoding)
- Create a SWI-Prolog string object interpreting the blob as following Encoding. Encoding
is a restricted set of SWI-Prolog's encodings:
bytes
(iso_latin_1
),utf8
andtext
(the current locale translation). - atom
- atom(Encoding)
- As above, producing an atom.
- codes
- codes(Encoding)
- As above, producing a list of integers (Unicode code points)
- chars
- chars(Encoding)
- As above, producing a list of one-character atoms.
- integer
- float
- rational
- number
- Interpret the bytes as a string representing a number. If the string
does not represent a number of the requested type a
type_error(Type, String)
is raised. - tagged_integer
- Same as integer, but demands the value to be between the Prolog flags
min_tagged_integer
andmax_tagged_integer
, allowing the value to be used as a dict key. - auto
- Same as
auto(atom, number)
- auto(AsText, AsNumber)
- If the bulk string confirms the syntax of AsNumber, convert the value to the requested numberical type. Else convert the value to text according to AsText. This is similar to the Prolog predicate name/2.
- dict_key
- Alias for
auto(atom,tagged_integer)
. This allows the value to be used as a key for a SWI-Prolog dict. - pairs(AsKey, AsValue)
- Convert a map or array of even length into pairs for which the key
satisfies AsKey and the value AsValue. The
pairs
type can also be applied to a Redis array. In this case the array length must be even. This notably allows fetching a Redis hash as pairs usingHGETALL
using version 2 of the Redis protocol. - dict(AsKey, AsValue)
- Similar to
pairs(AsKey, AsValue)
, but convert the resulting pair list into a SWI-Prolog dict. AsKey must convert to a valid dict key, i.e., an atom or tagged integer. Seedict_key
. - dict(AsValue)
- Shorthand for
dict(dict_key, AsValue)
.
Here are some simple examples
?- redis(default, set(a, 42), X). X = status("OK"). ?- redis(default, get(a), X). X = "42". ?- redis(default, get(a), X as integer). X = 42. ?- redis(default, get(a), X as float). X = 42.0. ?- redis(default, set(swipl:version, 8)). true. ?- redis(default, incr(swipl:version), X). X = 9.
- Errors
redis_error(Code, String)