AS Functional Keyword

Feature	Since Version	Notes
`AS`	>v1.4.4	Data type conversion
`AS STRING`, `AS INT`, `AS DOUBLE`	???	Type casting

Overview

Description: Used to explicitly convert a value to a specific data type. This is often necessary when performing operations that require a certain type or when publishing data in a specific format.

Signature

Syntax:
```
<value> AS <DataType>
```

Parameters

<value>: The value or expression to be converted.
<DataType>: The target data type. Common types include:
- STRING
- INT
- DOUBLE
- BOOL (Conversion rules apply, e.g., non-empty strings/non-zero numbers might be true)

Usage Examples

Basic Example: String to Integer

Convert a payload received as a string to an integer for calculation.

DEFINE ACTION CalculateWithConversion
ON TOPIC "input/numeric_string" DO
    // Payload might be "25"
    SET "intValue" = PAYLOAD AS INT
    PUBLISH TOPIC "output/calculated" WITH ({intValue} + 10)

Intermediate Example: Publishing as String

Ensure a calculated numeric value is published as a string.

DEFINE ACTION PublishStringValue
ON TOPIC "input/calculate" DO
    SET "result" = (PAYLOAD * 5)
    PUBLISH TOPIC "output/string_result" WITH ({result} AS STRING)

Advanced Example: Boolean Conversion in Condition

Explicitly convert a topic value (e.g., "1", "0", "true", "false") to boolean for an IF condition.

DEFINE ACTION CheckBooleanString
ON TOPIC "config/enable_feature" DO
    // Payload could be "true", "1", "false", "0"
    IF (PAYLOAD AS BOOL) THEN
        PUBLISH TOPIC "feature/status" WITH "Enabled"
    ELSE
        PUBLISH TOPIC "feature/status" WITH "Disabled"
    ENDIF

Notes & Additional Information

LOT performs some automatic type conversions, but AS provides explicit control when needed.
Conversion rules (e.g., how strings are converted to BOOL) depend on the broker implementation.
Invalid conversions might result in errors or default values (like 0 for failed string-to-int).