Macros are steps that can be automatically expanded to other steps.

['<^_^>', 'a', 'b', 'string^System.String', '^System.IO.Pipe', '^^i']

to

['< >', 'a', 'b', 'string', 'System.IO.Pipe', 'i'],
['<^>', 'string', 'System.String'],
['<^>', 'System.IO.Pipe'],
['<^>', 'i', ['i']],

['<:>.[]', 'u8', ['target'], 'byteField']

to

['<:>', 'u8', ['.[]', ['target'], 'byteField']]

Macro Name: 'function' Evaluates To: the callable function object

Parameters:

• (optional) scoped name:
  • if an existing scoped value name, the function also assigned to this
  • if a string literal, a new scope is created here that extends to the end of the current block, containing a new named value for this function object
• block or step: the function body definition

If the scoped name parameter is not given, this is effectively identical to a 'c():' step.

Macro Step Name: '<pop>'
Evaluates to: null

Parameters:

• The names of the popped values in the new scope.

Similar to '< >' except the values are pulled from the stack, with the rightmost value taken from the top.

For example, this:

[
  ['<pop>', 'a','b','c'],
]

...gets expanded to:

[
  ['< >', 'a','b','c'],
  ['set', 'c', ['pop']],
  ['set', 'b', ['pop']],
  ['set', 'a', ['pop']],
]

Scoped stack operations are useful if you want to do pretty much anything more complex than popping the top value.

For example, to duplicate the top value:

['<pop>','top'],
['push', ['top'], ['top']],
['</>'],

To re-insert the top value five places down:

['<pop>','-5','-4','-3','-2','-1'],
['push',['-1'],['-5'],['-4'],['-3'],['-2']],
['</>'],

Or simply to get the order of operands right in a non-commutative operation:

['<pop>', 'left', 'right'],
['push', ['/', ['left'], ['right']]],
['</>'],

As step parameters are always evaluated left-to-right, if the stack-pop is the right operand with the left operand below, ['/', ['pop'], ['pop']] would end up as (right / left).

In fact, this is such a useful use-case, there is a second macro just for this.

['...LR', ['/', ['left'], ['right']]]

to:

['...!', ['<pop>','left','right'], ['/', ['left'], ['right']]]

to:

['...!',
  ['< >', 'left', 'right'],
  ['set', ['right'], ['pop']],
  ['set', ['left'], ['pop']],

  ['/', ['left'], ['right']]
]

Parameter:

• step to run in context where ['left'] and ['right'] are defined

This macro is a specialization of the Scoped Pop Stack that pops the rightmost two values from the stack, calls them "left" and "right", and executes the given operation in this context.

['binop', '<SYMBOL>']

to

['push', ['...!', ['<pop>','L','R'], ['<SYMBOL>','L','R']]]

['unop', '<SYMBOL>']

to

['push', ['<SYMBOL>', ['pop']]]

['c(<pop>)', ['func'], 3]

to

['...!',
  ['<pop>', 'a1','a2','a3'],
  ['c()', ['func'], ['a1'],['a2'],['a3']]
]