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DSL Quick Reference

One-line syntax for every construct. For full semantics, see the DSL Reference.

Patterns​

pattern <name> {
  ...
}
pattern betrayal {
  stage e1 {
    e1.type = "betray"
  }
}

Stages​

A stage is an event slot. The anchor name (e1) becomes the source for clauses inside the block.

stage <anchor> {
  <clauses>
}
stage e1 {
  e1.type = "greet"
  e1.actor -> ?who
}

Clauses​

String match​

source.label = "value"
e1.location = "throne_room"

Numeric match​

source.label = <number>
e1.points = 100

Boolean match​

source.label = true | false
e1.active = true

Variable binding​

Bind a target node to a variable with ->. The same ?var in a later stage creates a join.

source.label -> ?var
e1.actor -> ?char

Node reference​

Match a specific named node (no ? prefix).

source.label -> node_name
e1.actor -> alice

Cross-stage comparison​

Compare a value against a previously bound variable. Operators: >, <, >=, <=, =.

source.label > ?var
source.label < ?var
source.label >= ?var
source.label <= ?var
source.label = ?var
e2.severity > ?level

Note: = ?var compares values. -> ?var binds/joins node references. They are not interchangeable.

Negated clause​

Prefix with !. Works with literal values and node references only.

! source.label = "value"
! e1.status = "invited"

Negation Windows​

Unless between​

No matching event between two stages.

unless between <start> <end> {
  <clauses>
}
unless between e1 e2 {
  mid.type = "fulfill"
  mid.actor -> ?char
}

Unless after​

No matching event after a stage (open-ended).

unless after <start> {
  <clauses>
}
unless after e2 {
  end.type = "resolve"
  end.actor -> ?char
}

Unless global​

No matching event across the entire pattern span.

unless {
  <clauses>
}
unless {
  mid.type = "reconcile"
  mid.actor -> ?char
}

Temporal Constraints​

Allen relation (qualitative)​

All 13 Allen relations: before, after, meets, met_by, overlaps, overlapped_by, during, contains, starts, started_by, finishes, finished_by, equals.

temporal <left> <relation> <right>
temporal e1 before e2

Metric gap​

Add a bounded distance constraint to any Allen relation.

temporal <left> <relation> <right> gap <min>..<max>
temporal e1 before e2 gap 0..100

Other gap forms: ..10 (no min), 3.. (no max), 5 (exact).

Concurrent Groups​

Stages inside concurrent { } can match in any order. All must match before the pattern advances past the group.

concurrent {
  stage <a> { ... }
  stage <b> { ... }
}
concurrent {
  stage e2 {
    e2.type = "temp_spike"
    e2.sensor -> ?s
  }
  stage e3 {
    e3.type = "pressure_drop"
    e3.sensor -> ?s
  }
}

Composition​

Sequence​

Concatenate two patterns. sharing(...) joins variables across them.

compose <name> = <a> >> <b> sharing(<var>, ...)
compose promise_kept = setup >> payoff sharing(char)

Choice​

Exclusive choice -- when one alternative completes, siblings are killed.

compose <name> = <a> | <b> | <c>
compose crisis = war | famine | plague

Exact repeat​

compose <name> = <pattern> * <count> sharing(<var>, ...)
compose three_strikes = offense * 3 sharing(offender)

Range repeat​

Match N to M times. Also supports unbounded: * 3.. (3 or more).

compose <name> = <pattern> * <min>..<max> sharing(<var>, ...)
compose brute_force = login_fail * 5..10 sharing(acct)

Metadata​

Attach key-value pairs to a pattern. Propagated to matches and events.

meta("<key>", "<value>")
meta("thread_type", "conflict")
meta("priority", "high")

Deadline​

Expire partial matches after N ticks without completion.

deadline <ticks>
deadline 30

Graph (testing / playground)​

Define a test graph with timestamped edges.

graph {
  @<time> source.label = <value>
  @<time> source.label -> <node>
  @<start>..<end> source.label = <value>
  now = <number>
}
graph {
  @1 e1.type = "enter"
  @1 e1.actor -> alice
  @5..10 e2.type = "siege"
  now = 15
}

Comments​

// Line comments start with //
e1.type = "enter" // end-of-line comments too