Macro trace 

macro_rules! trace {
    (
        { $($key:expr => $value:expr),* $(,)? };
        $(
            $activity:expr $(; { $($keys:expr => $values:expr),* $(,)?})?
        ),*
    ) => { ... };
    ($($content:tt)*) => { ... };
}

Create a Trace.

A trace is a sequence of events, using the syntax of the event macro. If an event has no timestamp, it is set 1 hour after the previous event. The first event uses the unix epoch as the default timestamp.

Trace-level attributes can optionally be provided as the first component of the macro invocation, using a {key => value, ...} syntax, and separated from the events with a semicolon.

Examples

use process_mining::{
    core::chrono::{DateTime, Utc},
    trace
};

let trace_1 = trace!("a", "b", "c", "d");
// Add trace-level attributes
let trace_2 = trace!({"org:resource" => "John"}; "a", "b", "c", "d");
// Add trace and event-level attributes
let trace_3 = trace!(
    {"outcome" => "approved"};
    "a"; {"time:timestamp" => DateTime::UNIX_EPOCH},
    "b"; {"time:timestamp" => Utc::now()},
    "c",
    "d"; {"approved" => true, "cost" => 2500.00}
);