From 5403931dfa4f9416f62c7d10653d7c60d12e6454 Mon Sep 17 00:00:00 2001
From: Matthew Butterick <mb@mbtype.com>
Date: Tue, 19 Apr 2016 20:17:45 -0700
Subject: [PATCH] simplify grammar

---
 beautiful-racket/br/demo/basic/expander.rkt |  6 +++---
 beautiful-racket/br/demo/basic/parser.rkt   | 12 +++++------
 beautiful-racket/br/demo/basic/reader.rkt   |  2 +-
 beautiful-racket/br/demo/basic/sinewave.bas | 24 ++++++---------------
 4 files changed, 16 insertions(+), 28 deletions(-)

diff --git a/beautiful-racket/br/demo/basic/expander.rkt b/beautiful-racket/br/demo/basic/expander.rkt
index 77dbcd7..36fce71 100644
--- a/beautiful-racket/br/demo/basic/expander.rkt
+++ b/beautiful-racket/br/demo/basic/expander.rkt
@@ -20,7 +20,7 @@
   #'(basic-run CR-LINE ...))
 
 (define (basic-run . lines)
-  (define program-lines (list->vector lines))
+  (define program-lines (list->vector (filter (λ(ln) (not (equal? ln "cr"))) lines)))
   (void (for/fold ([line-idx 0])
                   ([i (in-naturals)]
                    #:break (= line-idx (vector-length program-lines)))
@@ -34,8 +34,8 @@
                              idx)))
               (add1 line-idx)))))
 
-(define #'(cr-line "cr" ARG ...)
-  #'(begin ARG ...))
+(define-cases #'cr-line
+  [#'(_ ARG ...) #'(begin ARG ...)])
 
 (define #'(line NUMBER STATEMENT ...)
   #'(cons NUMBER (λ _ STATEMENT ...)))
diff --git a/beautiful-racket/br/demo/basic/parser.rkt b/beautiful-racket/br/demo/basic/parser.rkt
index 63138ff..e73ffce 100644
--- a/beautiful-racket/br/demo/basic/parser.rkt
+++ b/beautiful-racket/br/demo/basic/parser.rkt
@@ -1,8 +1,6 @@
 #lang ragg
 
-basic-program : cr-line* [CR]
-
-cr-line : CR line [cr-line]
+basic-program : line [CR line]*
 
 line: INTEGER statement+
 
@@ -16,13 +14,13 @@ statement : "END"
 | "PRINT" print-list
 | REM-COMMENT
 
-print-list : [expr [";" [print-list]*]]
+print-list : [expr [";" [print-list]]]
 
-expr : sum [("=" | "<>" | "><" | ">" | ">=" | "<" | "<=") expr]
+expr : sum [("=" | ">" | "<" | "<>") expr]
 
-sum : product [("+" | "-") sum]+
+sum : product [("+" | "-") sum]
 
-product : value [("*" | "/") product]+
+product : value [("*" | "/") product]
 
 value : "(" expr ")"
 | ID ["(" expr* ")"]
diff --git a/beautiful-racket/br/demo/basic/reader.rkt b/beautiful-racket/br/demo/basic/reader.rkt
index c936ec3..699e020 100644
--- a/beautiful-racket/br/demo/basic/reader.rkt
+++ b/beautiful-racket/br/demo/basic/reader.rkt
@@ -4,4 +4,4 @@
 (define-read-and-read-syntax (source-path input-port)
   (strip-context
    #`(module bf-mod br/demo/basic/expander
-       #,(parse source-path (tokenize input-port)))))
+       #,(parse source-path (tokenize (open-input-string (string-trim (port->string input-port))))))))
diff --git a/beautiful-racket/br/demo/basic/sinewave.bas b/beautiful-racket/br/demo/basic/sinewave.bas
index 2eb140e..4ba83c7 100644
--- a/beautiful-racket/br/demo/basic/sinewave.bas
+++ b/beautiful-racket/br/demo/basic/sinewave.bas
@@ -1,18 +1,8 @@
 #lang br/demo/basic
-10 PRINT TAB(30);"SINE WAVE"
-20 PRINT TAB(15);"CREATIVE COMPUTING  MORRISTOWN, NEW JERSEY"
-30 PRINT: PRINT: PRINT: PRINT: PRINT
-40 REMARKABLE PROGRAM BY DAVID AHL
-50 B=0
-100 REM  START LONG LOOP
-110 FOR T=0 TO 40 STEP .25
-120 A=INT(26+25*SIN(T))
-130 PRINT TAB(A);
-140 IF B=1 THEN 180
-150 PRINT "CREATIVE"
-160 B=1
-170 GOTO 200
-180 PRINT "COMPUTING"
-190 B=0
-200 NEXT T
-999 END
\ No newline at end of file
+
+
+10 PRINT 2 + 3 * 10 + 1
+
+20 PRINT 6 * 7 / 8
+
+