====== Sycl ======

[[https://git.syndicate-lang.org/ehmry/sycl|Sycl]] is the Tcl implementation of the [[.:syndicate|Syndicated Actor Model]].

Sycl is comprised of the ''preserves'' and ''syndicate'' libraries.

==== Preserves ====

A Tcl interpreter extension((https://git.syndicate-lang.org/ehmry/sycl/src/branch/trunk/preserves.md)) implemented in [[Nim]].
Preserves((https://preserves.dev/)) is the data language used by Syndicate.
Preserves can be written in text syntax, which the interpreter extension
can parse automatically from Tcl strings.
Preserves also has a binary syntax, which the Syndicate library uses for communicating over a network.

Preserves text syntax is a superset of JSON, so the library also acts as a JSON parser. The library can render to JSON as well, but some type conversions are made. 

<code tcl>
package require preserves

set pr [preserves parse {{foo: 0 bar: 1}}]
# {bar: 1 foo: 0}

preserves render $pr
# {bar: 1 foo: 0}

preserves render -json $pr
# {"bar":1,"foo":0}
</code>

==== Syndicate ====

The Syndicate library((https://git.syndicate-lang.org/ehmry/sycl/src/branch/trunk/syndicate.md)) is almost pure Tcl and makes heavy use of namespaces.

The library supports a SAM facet((https://synit.org/book/glossary.html#facet)) tree using nested namespaces. The ''during'' proc (equivalent to ''When'') executes its handle script in a new namespace on every match, and when the ''during'' statement expires the namespaces are destroyed automatically.

=== Relaying ===

The library does not implement [[.:syndicate#dataspaces|dataspaces]].
It can however communicate with external dataspaces provided by ''syndicate-server'' from the Rust implementation((https://git.syndicate-lang.org/syndicate-lang/syndicate-rs)).

<code tcl>
package require syndicate

set route {<route [<tcp "localhost" 4567>]>}

syndicate::spawn exampleActor {

    connect $route remoteDataspace {
        setDefaultTarget $remoteDataspace
        
        assert [list hello world]
        
        during "[weather is @weather #?]" {
            puts "Weather at $::route is $weather."
        } 
    }
}

vwait ${exampleActor}::stopped
</code>

=== Patterns ===

Patterns for matching SAM assertions are written as strings.
The pattern ''@z #([@x #? #_ @y #?])'' would match against ''[foo baz bar]'' and could trigger a handler bindings equivalent to:
<code tcl>
set x foo
set y bar
set z [list foo bar baz]
</code>

===== Availability =====

Sycl is only known to have been built with the [[Nix]] package manager, but Nix can work on practically any Linux distro.
Sycl is compatible with Tcl 8 & 9.

===== Example programs =====

  * [[.:synit|Synit]] service utility: https://git.syndicate-lang.org/synit/synit-service
  * [[.:synit|Synit]] network-configurator: https://git.syndicate-lang.org/synit/synit-network-utils/src/branch/trunk/network-configurator.tcl