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C00002 00002	∂20-Jan-79  1754	RZ at MIT-MC (Richard E. Zippel)   
C00004 00003	∂22-Jan-79  0637	RLB,RWK,RZ,HIC at MIT-MC 	BYTE paper on LIL  
C00005 00004	∂04-Feb-79  1226	RWK at MIT-MC (Robert W. Kerns)    
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∂20-Jan-79  1754	RZ at MIT-MC (Richard E. Zippel)   
Date: 20 JAN 1979 2056-EST
From: RZ at MIT-MC (Richard E. Zippel)
Sent-by: RLB at MIT-MC
To: JRA at SU-AI, carl at MIT-AI
CC: RWK at MIT-MC, RLB at MIT-MC, HIC at MIT-MC, RZ at MIT-MC


This is to inform you that some subset of us will be submitting a
paper for the August issue of BYTE.  The title will probably be
something like "LIL - A Lisp Implementation Language". We will
present a Lisp based compiler for implementing system software.
With the language (compiler and perhaps interpreter) embedded in
a Lisp-like environment, the user will have access to the Lisp
debugging tools.  We feel that the ability to manipulate programs
via macros coded in Lisp will speed the code writing phase.  This
language should be usable on micro-processors without difficulty.

∂22-Jan-79  0637	RLB,RWK,RZ,HIC at MIT-MC 	BYTE paper on LIL  
Date: 22 JAN 1979 0939-EST
From: RLB,RWK,RZ,HIC at MIT-MC
Sent-by: RLB at MIT-MC
Subject: BYTE paper on LIL
To: JRA at SU-AI
CC: RLB at MIT-MC, RWK at MIT-MC, RZ at MIT-MC, HIC at MIT-MC

We need some idea about how long this should be - of course, it might
depend on how winning the outline is ...

∂04-Feb-79  1226	RWK at MIT-MC (Robert W. Kerns)    
Date: 4 FEB 1979 1526-EST
From: RWK at MIT-MC (Robert W. Kerns)
To: jra at SU-AI
CC: RZ at MIT-MC, RLB at MIT-MC, HIC at MIT-MC, RWK at MIT-MC
CC: CARL at MIT-MC


Here is a preliminary outline of our proposed LIL paper.  It would help us
a lot if you could give us some idea of how much space we can expect for
this paper, and how many diagrams it would be good to include, and of course
the deadlines.

Preliminary LIL paper outline

1. WHY MESS WITH LIL?
   a. Motivation - what is an implementation language?  Why do we need one?
   b. LIL is not X for X in {LISP, BLISS, C, Pascal, PL/I, assembler, etc.}
   c. Post parse-time macros (as opposed to textual substitution pre-parse-time
      macros)
      i.   Used for user-extentions to the control structure of the language
      ii.  Used to extend the semantics of the language
      iii. Used to extend the data structures which the language can handle.
   d. Debugging aids via interpretation in LISP.
   e. Stand alone debugging aids.
   f. Extra control structures not found in other languages.

2. WHAT IS LIL?
   a. Overture - What LIL offers, generally - functions, variables, pointers,
      special forms (control-sturcture contstructs)
   b. Syntax - what there is of it
      i.   lexical scan is easy, (), prefix characters ".'  - symbols/number
      ii.  parse is trivial, explicit list notation
      iii. all built into LISP's READ function.
   c. Basic semantics
      i.   Function calling
      ii.  Variables
      iii. . and ' (pointer-follower and address prefix)
   d. Special forms (case, select, do, cond, and, or, etc.)
   e. Macros - written in LISP, not LIL!
      i.   LISP is a good language for manipulating LIL code.  (Or other code)
      ii.  Full interpreter available in the compiler.
   f. Micros down to machine code level.
      i.   Give hands-on access to special capabilities of the host machine
      ii.  Enforce transportability; all machine-dependent code is in the form
	   of  micros; these can be re-coded for new machine, the machine
	   dependencies have been isolated.
      iii. Full user-control of compilation
   g. User-defined optimizations.

3. COMPILER
   a. Why write compiler in LISP
   b. Optimization

4. INTERPRETER
   a. Incremental debugging
   b. Single step debugging, at source-code level, not machine-level.
   c. Why you want both a compiler and an interpreter

5. COMPARE & CONTRAST LIL WITH OTHER IMPLEMENTATION LANGUAGES
   a. Detail here that couldn't be included in section 1.
   b. Sample program expressed in several such languages
      (Perhaps do the core of a BASIC interpreter)
   c. BLISS as LIL; show how LISP makes language manipulations easy

6. EXAMPLE AND DESCRIPTION OF WHAT WE'VE IMPLEMENTED
   a. Not a lot yet, but we're trying.