## 1.2 `Macro` Module

`macroExpand`

  > > `{Macro.macroExpand` `+X``` `+Env``` `?Y``}`

  `X` is a term representing Oz code using Syntax Tree Format. This performs full macro expansion on `X` with respect to macro environment `Env` and returns `Y` which is guaranteed to no longer contain any macro invocation. A macro environment maps macro names to expanders. `Env` may also be `unit` in which case the global macro environment is used which contains all the macros registered using `Macro.defmacro`.

`defmacro`

  > > `{Macro.defmacro` `+A``` `+F``}`

  `A` should be an atom. A new global macro is defined which is invoked using atom `A` and implemented using macro expander `F`.

`makeVar`
`makeNamedVar`

  > > `{Macro.makeVar` `?X``}`

  > > `{Macro.makeNamedVar` `+A``` `?X``}`

  This is very useful to create on the fly new representations of variables that are guaranteed not to conflict with those in user code. With `Macro.makeNamedVar`, you supply an atom that provides the variable with a more meaningful name. This can be helpful for debugging. For example:

  > `X = {Macro.makeNamedVar 'Tail'}`

  creates a new variable representation, guaranteed to be distinct from any other variable representation, and whose print name is `Tail`.

`sequenceToList`

  > > `{Macro.sequenceToList` `+X``` `?L``}`

  Converts the syntactic representation of a sequence to a list

`listToSequence`

  > > `{Macro.listToSequence` `+L``` `?X``}`

  Converts a list to the syntactic representation of a sequence