From: Mike D. Lowis <mike@mdlowis.com>
Date: Thu, 12 Jul 2012 20:58:46 +0000 (-0400)
Subject: Added comment to parser describing the EBNF grammar I hope to implement
X-Git-Url: https://git.mdlowis.com/?a=commitdiff_plain;h=9cf07f59514b7c48ee31036b729d50736cf9c0db;p=archive%2Fdlang-scm.git

Added comment to parser describing the EBNF grammar I hope to implement
---

diff --git a/source/parser.scm b/source/parser.scm
index bdcd7a0..e64f670 100644
--- a/source/parser.scm
+++ b/source/parser.scm
@@ -1,5 +1,22 @@
 (declare (unit parser)
          (uses buf))
+; Formal EBNF Syntax:
+;
+; Program := Expression*
+;
+; Expression := CoreForm
+;             | BasicExpr
+;             | BasicExpr ArgList
+; CoreForm
+;
+; BasicExpr := '(' Expression Operator Expression ')'
+;            | Literal
+;
+; Operator
+;
+; Literal := ID | CHAR | STRING | SYMBOL | NUMBER
+;
+; ArgList := '(' Expression (',' Expression)* ')'
 
 (define (dlang/program in)
   (define result '())
@@ -21,7 +38,8 @@
 (define (dlang/core-form in) '())
 
 (define (dlang/basic-expr in)
-  (if (buf-lookahead! in 1)
+  (define tok (buf-lookahead! in 1))
+  (if (equal? 'lpar (token-type tok))
     (dlang/operator-app in)
     (dlang/literal in)))