Truthy logic

Some functions use transformers to evaluate boolean conditions.

The following table will explain what is the default implicit behavior of resolved values from such transformers:

Value (JSON)	Boolean value	Comment
Boolean		Used as-is
`true`	`true`
`false`	`false`
Null
`null`	`false`
Number		True if not zero
`1`	`true`
`-1`	`true`
`0.1`	`true`
`0`	`false`
String		True if not empty (JavaScript style)
`""`	`false`
`"false"`	`true`	Notice: we don't use `parseBoolean`
Object		True if any key exists
`{}`	`false`
`{ "a": false }`	`true`
Array		True if length > 0
`[]`	`false`
`[false]`	`true`
`[null]`	`true`

note

Strings behave different when evaluated with $$boolean & $$not (unless specified with JS as style)