From 1181bdfed10442de0e68eaa916262eedde07d017 Mon Sep 17 00:00:00 2001
From: Matthew Butterick <mb@mbtype.com>
Date: Thu, 7 Apr 2016 12:42:28 -0700
Subject: [PATCH] br-bf start

---
 br-bf/main.rkt      | 14 ++++++++++++++
 br-bf/parser.rkt    | 10 ++++++++++
 br-bf/reader.rkt    | 10 ++++++++++
 br-bf/tokenizer.rkt | 24 ++++++++++++++++++++++++
 4 files changed, 58 insertions(+)
 create mode 100644 br-bf/main.rkt
 create mode 100644 br-bf/parser.rkt
 create mode 100644 br-bf/reader.rkt
 create mode 100644 br-bf/tokenizer.rkt

diff --git a/br-bf/main.rkt b/br-bf/main.rkt
new file mode 100644
index 0000000..4e95b69
--- /dev/null
+++ b/br-bf/main.rkt
@@ -0,0 +1,14 @@
+#lang br
+
+
+(module reader syntax/module-reader
+  #:language 'br-bf
+  #:read bf-read
+  #:read-syntax bf-read-syntax
+  
+  (require "tokenizer.rkt" "parser.rkt")
+  (define (bf-read in)
+    (syntax->datum (bf-read-syntax #f in)))
+  
+  (define (bf-read-syntax src ip)
+    (list (parse src (tokenize ip)))))
diff --git a/br-bf/parser.rkt b/br-bf/parser.rkt
new file mode 100644
index 0000000..b80844d
--- /dev/null
+++ b/br-bf/parser.rkt
@@ -0,0 +1,10 @@
+#lang ragg
+
+<expr> : ">"
+       | "<" 
+       | "+" 
+       | "-" 
+       | "." 
+       | "," 
+       | <loop>
+<loop> : "["<expr>*"]"
\ No newline at end of file
diff --git a/br-bf/reader.rkt b/br-bf/reader.rkt
new file mode 100644
index 0000000..b80844d
--- /dev/null
+++ b/br-bf/reader.rkt
@@ -0,0 +1,10 @@
+#lang ragg
+
+<expr> : ">"
+       | "<" 
+       | "+" 
+       | "-" 
+       | "." 
+       | "," 
+       | <loop>
+<loop> : "["<expr>*"]"
\ No newline at end of file
diff --git a/br-bf/tokenizer.rkt b/br-bf/tokenizer.rkt
new file mode 100644
index 0000000..d68b7f7
--- /dev/null
+++ b/br-bf/tokenizer.rkt
@@ -0,0 +1,24 @@
+#lang racket/base
+(require parser-tools/lex ragg/support)
+(provide tokenize)
+
+(define (tokenize ip)
+  (port-count-lines! ip)
+
+  (define my-lexer
+    (lexer-src-pos
+     [(repetition 1 +inf.0 numeric)
+      (token 'INTEGER (string->number lexeme))]
+     [upper-case
+      (token 'STRING lexeme)]
+     ["b"
+      (token 'STRING " ")]
+     [";"
+      (token ";" lexeme)]
+     [whitespace
+      (token 'WHITESPACE lexeme #:skip? #t)]
+     [(eof)
+      (void)]))
+  
+  (define (next-token) (my-lexer ip))
+  next-token)
\ No newline at end of file