🚀 go-pugleaf

[apologies if this is a re-post --- problems first time around]

Hello.  I am looking for a small language to use and modify for teaching
purposes.  Features I want include:

* small, simple implementation in C (at most one week for a senior
  student with a C/Unix background to read and understand source).

* very simple syntax --- preferably only a single syntactic form,
  like Scheme, Logo, and Forth.

* textual scoping of variables (which (sigh) rules out Logo itself)

* logical, integer, floating-point, and string data types (I'm
  happy to have single characters treated as 1-length strings)

Other features that would be nice include

* objects (something simple, like Object Logo, would do --- I
  regularly lambast physicists for using "old" languages like Fortran,
  so I feel I should set a good example for students by using some
  modern ideas myself)

* a source-language debugger

* the ability to cross-call C

Note that a compiler is not needed; performance is not a primary
concern, so interpretation would be fine. 

Any help would be much appreciated.

Thanks in advance,

 ========================================================================
  Gregory V. Wilson                    ||  For in much wisdom is much
  Technical Coordinator                ||  grief; and he that increaseth
  Edinburgh Parallel Computing Centre  ||  knowledge, increaseth sorrow.
  gvw@epcc.edinburgh.ac.uk             ||               - Ecclesiastes
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