From fb15212ce50d9255797afd4546555a02df0a602e Mon Sep 17 00:00:00 2001
From: Matthew Butterick <mb@mbtype.com>
Date: Mon, 12 Feb 2018 17:26:30 -0600
Subject: [PATCH] tty

---
 quad/quad/tty-test.rkt |  4 +++
 quad/quad/tty.rkt      | 62 ++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 66 insertions(+)
 create mode 100644 quad/quad/tty-test.rkt
 create mode 100644 quad/quad/tty.rkt

diff --git a/quad/quad/tty-test.rkt b/quad/quad/tty-test.rkt
new file mode 100644
index 00000000..6064051d
--- /dev/null
+++ b/quad/quad/tty-test.rkt
@@ -0,0 +1,4 @@
+#lang quad/tty
+'(doc
+  (page (line (char "a") (char " ") (char "b")) (line (char "c") (char "d")))
+  (page (line (char "e") (char "f")) (line (char "g") (char " ") (char "h"))))
\ No newline at end of file
diff --git a/quad/quad/tty.rkt b/quad/quad/tty.rkt
new file mode 100644
index 00000000..0079b807
--- /dev/null
+++ b/quad/quad/tty.rkt
@@ -0,0 +1,62 @@
+#lang debug br/quicklang
+(require racket/contract "qexpr.rkt")
+(provide (except-out (all-from-out br/quicklang) #%module-begin)
+         (rename-out [mb #%module-begin]))
+
+(define/contract (render-tty qexpr)
+  (qexpr? . -> . string?)
+  (define page 0) (define row 0) (define col 0)
+  (define (increment-page!) (set! page (add1 page)) page)
+  (define (increment-row!) (set! row (add1 row)) row)
+  (define (increment-col!) (set! col (add1 col)) col)
+  (define strs
+    (let loop ([x qexpr])
+      (match x
+        [`(char ,x) (list (format "move to col ~a" (increment-col!)) (format "draw char ~a" (char->integer (car (string->list x)))))]
+        [`(line ,@xs) (list (format "move to row ~a" (increment-row!)) (map loop xs) (begin (set! col 0) #f) )]
+        [`(page ,@xs) (list (format "move to page ~a" (increment-page!)) (map loop xs) (begin (set! row 0) #f))]
+        [`(doc ,@xs) (map loop xs)])))
+  (string-join (map string-downcase (filter values (flatten strs))) "\n"))
+
+(module+ test
+  (require rackunit)
+  (define q '(doc
+              (page (line (char "a") (char " ") (char "b")) (line (char "c") (char "d")))
+              (page (line (char "e") (char "f")) (line (char "g") (char " ") (char "h")))))
+  (check-equal? (render-tty q)
+                "move to page 1
+move to row 1
+move to col 1
+draw char 97
+move to col 2
+draw char 32
+move to col 3
+draw char 98
+move to row 2
+move to col 1
+draw char 99
+move to col 2
+draw char 100
+move to page 2
+move to row 1
+move to col 1
+draw char 101
+move to col 2
+draw char 102
+move to row 2
+move to col 1
+draw char 103
+move to col 2
+draw char 32
+move to col 3
+draw char 104"))
+      
+(define-macro (mb ARG)
+  #'(#%module-begin
+     (display (render-tty ARG))))
+
+(module reader syntax/module-reader
+  quad/tty
+  #:read read
+  #:read-syntax read-syntax
+  (require racket/base))
\ No newline at end of file