net

a channel encapsulates an open network resource
that can be read from and written to.
channels are usually installed by a successfully connected client
or a by a newly accepted server connection.

Note that even though UDP is a connection-less protocol its
usage in fuzion does not differ from TCP except for the following
caveats.
1) Reading a Datagram with a buffer not large enough to hold
all data will lead to the rest of the datagram being dropped.
2) writing to a channel installed by `server.accept` will result in an error.
3) reading from a channel installed by `client ...` will block indefinitely.

effect to hold active connections

defines constants for protocol families which
can be used for network communication.

defines constants for network protocols that
can be used for network communication.
usually there is only one possible protocol
for each pair of family and socket type.

server -- effect for storing a bound - and in the
case of TCP, listening - socket descriptor.

Basic usage description:
1) Initialize the server, e.g. like this:
`server family.ipv4 protocol.tcp 8080`
2) accept a new connection:

defines constants for socket types which
specify the communication semantics to
used in a socket.

create a String from this instance. Unless redefined, `a.as_string` will
create `"instance[T]"` where `T` is the dynamic type of `a`

This tries establishing a connection to `host`
on success returns an active connection.

Minimal example:


Blocks until connection is establised.
NYI blocking / none blocking

short-hand to get connections effect

Get the dynamic type of this instance. For value instances `x`, this is
equal to `type_of x`, but for `x` with a `ref` type `x.dynamic_type` gives
the actual runtime type, while `type_of x` results in the static
compile-time type.

There is no dynamic type of a type instance since this would result in an
endless hierarchy of types. So for Type values, dynamic_type is redefined
to just return Type.type.

convenience prefix operator to create a string from a value.

This permits usage of `$` as a prefix operator in a similar way both
inside and outside of constant strings: $x and "$x" will produce the
same string.

get currently installed server from env

string representation of this type to be used for debugging.

result has the form "Type of '<name>'", but this might change in the future

There is no dynamic type of a type instance since this would result in an
endless hierarchy of types, so dynamic_type is redefined to just return
Type.type here.

Is this type assignable to a type parameter with constraint `T`?

The result of this is a compile-time constant that can be used to specialize
code for a particular type.

is_of_integer_type(n T : numeric) => T : integer
say (is_of_integer_type 1234) # true
say (is_of_integer_type 3.14) # false

it is most useful in conjunction preconditions or `if` statements as in

pair(a,b T) is

=>

or

val(n T) is

name of this type, including type parameters, e.g. 'option (list i32)'.

convenience prefix operator to create a string from a value.

This permits usage of `$` as a prefix operator in a similar way both
inside and outside of constant strings: $x and "$x" will produce the
same string.

NYI: Redefinition allows the type feature to be distinguished from its normal counterpart, see #3913

Get a type as a value.

This is a feature with the effect equivalent to Fuzion's `expr.type` call tail.
It is recommended to use `expr.type` and not `expr.type_value`.

`type_value` is here to show how this can be implemented and to illustrate the
difference to `dynamic_type`.