Reserved Keywords

Declarations

Keyword	Description
stream	Declares a stream
event	Declares an event type
type	Declares a type alias
let	Declares an immutable variable
var	Declares a mutable variable
const	Declares a global constant
fn	Declares a function
context	Declares an execution context for multi-threaded parallelism
config	Configuration block

Control Flow

Keyword	Description
if	Condition
else	Alternative branch
elif	Alternative condition (else if)
match	Pattern matching
for	Loop over iterable
while	Conditional loop
break	Exit loop
continue	Skip to next iteration
return	Return a value

Stream Operators

Keyword	Description
from	Connector source binding (.from())
where	Filtering
select	Projection
join	Inner stream join
left_join	Left outer join (all left events, null-fill right)
right_join	Right outer join (null-fill left, all right events)
full_join	Full outer join (all events from both sides)
merge	Stream merge
window	Time window
aggregate	Aggregation
partition_by	Partitioning
order_by	Sorting
limit	Limitation
distinct	Deduplication
emit	Emit output events
forecast	PST-based pattern forecasting

Forecast Built-in Variables

Variable	Description
forecast_probability	Pattern completion probability (0.0–1.0)
forecast_time	Expected time to completion (nanoseconds)
forecast_state	Current NFA state label
forecast_context_depth	PST context depth used for prediction

Patterns

Keyword	Description
pattern	Defines a detection pattern

Types and Values

Keyword	Description
true	Boolean true
false	Boolean false
null	Absence of value
int	Integer type
float	Floating point type
bool	Boolean type
str	String type
timestamp	Timestamp type
duration	Duration type

Logical Operators

Keyword	Description
and	Logical AND
or	Logical OR
not	Logical NOT
in	Membership
is	Type/identity test

Error Handling

Keyword	Description
try	Try block
catch	Exception capture
finally	Final block
raise	Raise an exception

Other

Keyword	Description
as	Alias/cast
extends	Event inheritance
import	Module import
export	Symbol export

Keywords Reserved for Future Use

The following words are reserved for potential extensions:

• async, await
• class, trait, impl
• pub, priv
• mod, use
• yield
• defer
• go, spawn