Re: putting symbols into Environment

[Per Bothner <per@bothner.com>]

On 09/15/2017 05:48 AM, Sonny To wrote:
> How close does kawa stick to standard scheme? I'm trying these
> functions described here
> https://www.gnu.org/software/mit-scheme/documentation/mit-scheme-ref/Environment-Operations.html
> and none of work

That page is for MIT Scheme - a specific Scheme implementation/dialect,
not "standard Scheme".

> #|kawa:5|# (define e (environment))
> #|kawa:6|# (environment-bindings e)
> /dev/stdin:6:2: unbound location: environment-bindings

The Git version of Kawa (and soon Kawa 3.0) includes environment-fold

-- Procedure: (environment-fold environment proc init)
      Call PROC for each key in the ENVIRONMENT, which may be any
      argument to ‘eval’, such as ‘(interaction-environment)’ or a call
      to the ‘environment’ procedure.  The PROC is called with two
      arguments: The binding’s key, and an accumulator value.  The INIT
      is the initial accumulator value; the result returned by PROC is
      used for subsequent accumulator values.  The value returned by
      ‘environment-fold’ is the final acumulator value.

      A key is normally a symbol, but can also be a ‘KeyPair’ object (a
      pair of a symbol and a property symbol used to implement Common
      Lisp-style property lists).
           (environment-fold (environment '(scheme write)) cons '())
             ⇒ (display write-shared write write-simple)
      To get all the predefined bindings use
          (environment '(kawa base))


-- 
	--Per Bothner
per@bothner.com   http://per.bothner.com/