= SPSS Macro Arguments =

'''Arguments''' to SPSS macros need to be explicitly parsed on the macro definition.

<<TableOfContents>>

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== Declaration ==

{{{
define !foo(variables=!cmdend)
  compute foo=!variables.
enddefine.

!foo variables=bar baz.
}}}

The available functions are:

||'''Function'''     ||'''Behavior'''                                 ||
||`!CHAREND('C')`    ||Consume all tokens until `C`                   ||
||`!CMDEND`          ||Consume all tokens until the end of the command||
||`!ECNLOSE('S','E')`||Consume all tokens starting from `S` until `E` ||
||`!TOKENS(N)`       ||Consume `N` tokens                             ||
||`!POSITIONAL`      ||Used with one of the above functions           ||

Note that arguments are tokenized ''before'' being exposed to the macro expansion.

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== Usage ==

If an argument is bound to a name, it becomes a '''named argument'''. If the `!POSITIONAL` function is used, it becomes a '''positional argument'''.

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=== Named Arguments ===

Named arguments are accessed by their name prefixed with an exclamation mark (`!`).

{{{
define !foo(bar=!tokens(1)
           /baz=!tokens(1))
  compute !bar=0.
  compute !baz=0.
!enddefine.

!foo bar=x baz=y.
}}}

In this example, the variables `x` and `y` will be created.

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=== Positional Arguments ===

Positional arguments are set into sequential integer names prefixed with an exclamation mark (`!`) (i.e. `!1`, `!2`, and so on).

{{{
define !foo(!positional !tokens(1)
           /!positional !tokens(1))
  compute !1=0.
  compute !2=0.
!enddefine.

!foo x y.
}}}

In this example also, the variables `x` and `y` will be created.

The entire series of positional arguments as a space-delimited string can be accessed as `!*`.

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=== Default Values ===



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