`Joe` type (`joe`)

The Joe singleton collects a variety of useful functions related to the interpreter itself and to the installed Joe types.

Static Methods

Static Methods

Joe.compare()

Joe.compare(a, b) → Number

Given two strings or two numbers a and b, returns -1, 0, or 1 as a < b, a == b, or a > b. This function is useful when sorting collections.

Joe.currentTimeMillis()

Joe.currentTimeMillis() → Number

Returns Java's System.currentTimeMillis(), the current time in milliseconds since the epoch.

Joe.getFieldNames()

Joe.getFieldNames(value) → List

Returns a read-only list of the names of the fields defined on the value.

If the value has no fields, this method returns the empty list.

If the value is a Joe type, this method returns the names of the type's static fields.

Note: There is no way to know the names of an instance's fields just by looking at its type, generally speaking. Distinct instances of the same Joe class might have different fields.

Joe.isFact()

Joe.isFact(value) → Boolean

Returns true if the value can be used as a Nero Fact, and false otherwise.

Joe.isOpaque()

Joe.isOpaque(value) → Boolean

Returns true if the value is of an opaque type, and false otherwise. An opaque type is a Java type with no defined Joe binding.

Joe.isType()

Joe.isType(value) → Boolean

Returns true if the value represents a Joe type, e.g., the String type or a Joe class, and false otherwise.

Joe.stringify()

Joe.stringify(value) → String

Converts its value to a string for output. This function is functionally equivalent to String(), or to value.toString() (if the type defines a toString() method).

It is rare to need to call this function directly, but it is available if needed.

Joe v0.7.0 User's Guide