What is the syntax of IF plugin condition

Here are some examples of IF action plugin conditions.

Simple condition with equals operator:

payload@field == "value"

Complex condition with AND:

(payload@field1 == "value1" AND payload@field2 != "value2")

Complex condition with OR:

(payload@field1 > 10 OR payload@field2 <= 5)

BETWEEN condition:

payload@age BETWEEN 18 AND 30

IS NULL condition:

session@user_id IS NULL

EXISTS condition:

profile@email EXISTS

NOT EXISTS condition:

memory@key NOT EXISTS

Compound value in a function:

event@timestamp > datetime(2023-01-01T00:00:00)

Empty condition:

flow@details EMPTY

Complex condition with nested parentheses:

(payload@field1 == "value1" AND (payload@field2 != "value2" OR payload@field3 > 0))

Complex condition that uses data functions.

(
    payload@age > 18 AND 
    (
        event@event_type == "click" OR 
        event@properties.action == "add_to_cart"
    ) AND 
    (
        profile@data.pii.age > 25 AND 
        (
            event@action == "purchase" OR 
            event@properties.action == "add_to_cart"
        )
    )
) OR (
    (
        payload@quantity BETWEEN 10 AND 50 OR 
        payload@timestamp BETWEEN 1631233200 AND 1631319600
    ) AND 
    (
        payload@description IS NULL OR 
        event@type IS NOT NULL
    ) AND 
    (
        event@properties.location EXISTS AND 
        profile@address NOT EXISTS
    )
) AND (
    (
        memory@notes EMPTY OR 
        payload@items NOT EMPTY
    ) AND 
    (
        payload@keywords CONTAINS "technology" OR 
        event@tags CONTAINS "important"
    )
) AND (
    (
        payload@name STARTS WITH "John" OR 
        event@description ENDS WITH "exciting event"
    ) AND 
    (
        event@participants[0] == "Alice" OR 
        event@ratings[2] >= 4.5
    )
) AND (
    now("europe/warsaw") > datetime("2021-01-01 00:00:00") AND 
    now("europe/london") < now.offset(payload@time, "+700 days")
)

CONTAINS Condition (contains string):
Check if keywords in payload contain "technology":
```
  payload@keywords CONTAINS "technology"
```
Check if event tags contain the word "important":
```
  event@tags CONTAINS "important"
```
STARTS WITH/ENDS WITH String Conditions:
Check if payload name starts with "John":
```
  payload@name STARTS WITH "John"
```
Check if event description ends with "exciting event":
```
  event@description ENDS WITH "exciting event"
```

Remember, these examples follow the syntax you provided and assume that the specified fields like payload@keywords , event@tags, payload@name, and event@participants[0], etc. exist in the data structure you're working with.