class Tag

Identity provider for Cells and Builtins.

Tags are one of:

• 'blank' ([?], to be auto-assigned by the Copilot)
• literal ([1])
• cloned ([X.Y], obtained by cloning Y with parent X)

index

members

• tag\last()  – obtain the registered value of the last eval-cycle.
• tag\register(expr)  – register expr for this tag for the current eval cycle.
• tag\clone(parent)  – create a copy of this tag scoped to a parent tag.

static functions

• Tag.blank()  – create a blank Tag.
• Tag.parse(num)  – parse a Tag (for Lpeg parsing).

internals for `registry`

• tag\index()  – get a unique index value for this Tag.
• tag\set(value)  – callback to set value for blank tags.

details

members

• tag\last()  – obtain the registered value of the last eval-cycle.
  Obtain the value that was previously registered for this tag on the last eval-cylce.

  returns:

  1. (optional any)
• tag\register(expr)  – register expr for this tag for the current eval cycle.
  Will mark blank tags for auto-assignment at the end of the eval cycle.

  parameters:

  • expr (any): the value to register
• tag\clone(parent)  – create a copy of this tag scoped to a parent tag.
  Will mark blank tags for auto-assignment at the end of the eval cycle.

  parameters:

  • parent (Tag): the parent tag

  returns:

  1. (Tag): the cloned tag

static functions

• Tag.blank()  – create a blank Tag.

  returns:

  1. (Tag)
• Tag.parse(num)  – parse a Tag (for Lpeg parsing).

  parameters:

  • num (string): the number-string

  returns:

  1. (Tag)

internals for `registry`

• tag\index()  – get a unique index value for this Tag.
  The index is equal to value for simple tags and a path-like string for cloned tags.

  returns:

  1. (number or string)
• tag\set(value)  – callback to set value for blank tags.
  value may be blank to reassign duplicate tags.

  parameters:

  • value (optional number)