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Thu Mar 13 12:27:21 EDT 2008

defining names from macro

#lang scheme/base
(require
 (for-syntax scheme/base))

(define-syntax (foo stx)
  #`(define bar 123))

(define-syntax (broem stx)
  (syntax-case stx ()
    ((_ name)
     (printf "expanding (broem)\n")
     #`(define name 123))))

(broem lalala)
(foo)

;;---

this defines 'lalala' as a symbol, but 'bar' is not accessible. looks
like a hygiene issue where hygiene has to be broken explicitly?

a better approach is maybe to expand to a 'module' form, so all
symbols are introduces in the same place, and no capturing is
necessary?

something like:

(module state-snarfs "snarfer-lang.ss"
   (snarf-from "../base/base.ss" (state) (base) lift-state))

where 'snarf-from' is a macro provided by snarfer-lang.ss which
expands to a #%plain-module-begin form.

rationale: what is a module? it is a finite map (name -> stx/value)
in that sense, a snarf is maybe indeed better exposed as a module
transformer, mapping modules -> module instead of modules -> expressions

again: the alternatives are:
  * variable capture for define forms (non-hygienic)
  * whole module expression generation



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