add docs for inet

content/compatibility/sql_features.md

@@ -181,7 +181,7 @@ the [system table compatibility](../system_table) page.
 | circle                                  | No                |                                                                 |
 | date                                    | Yes               |           [Date Documentation](/docs/references/datatypes/date) |
 | double precision                        | Yes               |        [Double Documentation](/docs/references/datatypes/float) |
-| inet                                    | No                |                                                                 |
+| inet                                    | Partial           |           [Inet Documentation](/docs/references/datatypes/inet) |
 | integer                                 | Yes               |     [Integer Documentation](/docs/references/datatypes/integer) |
 | interval [ fields ] [ (p) ]             | Yes               |   [Interval Documentation](/docs/references/datatypes/interval) |
 | json                                    | Yes               |           [JSON Documentation](/docs/references/datatypes/json) |

content/references/datatypes/_index.md

@@ -24,6 +24,7 @@ The complete list of supported data types in CedarDB is as follows:
 * [`double precision`](float)
 * [`enum`](enums)
 * [`float`](float)
+* [`inet`](inet)
 * [`integer`](integer) (`int4`)
 * [`interval`](interval)
 * [`json`](json)

content/references/datatypes/inet.md

@@ -0,0 +1,118 @@
+---
+title: "Reference: Inet Type"
+linkTitle: "Inet"
+weight: 24
+---
+
+The `inet` type stores an IPv4 or IPv6 host address, optionally together with its subnet as a netmask length.
+For example, `192.168.1.5/24` describes the host `192.168.1.5` in the subnet `192.168.1.0/24`.
+
+{{< callout type="info" >}}
+CedarDB currently only supports basic `inet` functionality.
+PostgreSQL's network operators, functions (for example, `<<`, `host()`, or `masklen()`), the `cidr` type, and 
+non-standard prefix-only IPs (`10/24`) are not yet supported.
+{{< /callout >}}
+
+## Usage Example
+
+```sql
+create table connections (
+    client inet,
+    ts timestamp
+);
+insert into connections values
+    ('192.168.1.226/24', now()),
+    ('10.1.2.3', now()),
+    ('10:23::f1/64', now()),
+    ('::1', now());
+select client from connections order by client;
+```
+
+```text
+      client
+------------------
+ 10.1.2.3
+ 192.168.1.226/24
+ ::1
+ 10:23::f1/64
+(4 rows)
+```
+
+## Input
+
+`inet` values are written as `address/bits`, where `address` is an IPv4 or IPv6 address and `bits` is the netmask.
+Omitting the `/bits` specifies a single host with a full netmask.
+
+```sql
+-- IPv4
+select inet '192.168.1.226/24';
+select inet '192.168.1.226';
+-- IPv6
+select inet '10:23::f1/64';
+select inet '0000:0000:0000:0000:0000:0000:0000:0001';
+-- IPv6 with the last 32 bits in dotted IPv4 notation
+select inet '::4.3.2.1/24';
+```
+
+## Output
+
+CedarDB prints `inet` values in their normalized RFC 3493 form, and omits the netmask in the output for a single hosts.
+IPv6 addresses are printed in their shortest form, without leading zeros and with the longest run of zero groups
+replaced by `::`:
+
+```sql
+select inet '10.1.2.3/32', inet '0000:0000:0000:0000:0000:0000:0000:0001/128', inet '8000:0000:0000:0000:0000:0000:0000:0000/1';
+```
+
+```text
+   inet   | inet |  inet
+----------+------+---------
+ 10.1.2.3 | ::1  | 8000::/1
+(1 row)
+```
+
+## Comparison and Sorting
+
+`inet` values support the regular comparison operators:
+IPv4 addresses sort before IPv6 addresses.
+Within the same address family, values are first compared by their network part, then by their netmask length,
+and then by the full address.
+
+```sql
+select a from (values
+    ('192.168.1.0/24'::inet),
+    ('192.168.1.0/25'::inet),
+    ('192.168.1.1/23'::inet),
+    ('10:23::ffff'::inet),
+    ('10.1.2.3'::inet)
+) as i(a) order by a;
+```
+
+```text
+       a
+----------------
+ 10.1.2.3
+ 192.168.1.1/23
+ 192.168.1.0/24
+ 192.168.1.0/25
+ 10:23::ffff
+(5 rows)
+```
+
+## Functions
+
+### inet_client_addr
+
+`inet_client_addr()` returns the IP address of the client connected to the current session, `NULL` for connections via
+Unix domain socket.
+
+```sql
+select inet_client_addr();
+```
+
+```text
+ inet_client_addr
+------------------
+ 192.168.1.42
+(1 row)
+```