From 5c644624c42c12c0b5180574d428bfa62e78bad2 Mon Sep 17 00:00:00 2001
From: Tony Garnock-Jones <tonyg@leastfixedpoint.com>
Date: Tue, 25 May 2021 11:04:51 +0200
Subject: [PATCH] detect-preserve-syntax, file->preserves

---
 .../racket/preserves/preserves/main.rkt       | 40 ++++++++++++++-----
 1 file changed, 30 insertions(+), 10 deletions(-)

diff --git a/implementations/racket/preserves/preserves/main.rkt b/implementations/racket/preserves/preserves/main.rkt
index ae92210..cc435ac 100644
--- a/implementations/racket/preserves/preserves/main.rkt
+++ b/implementations/racket/preserves/preserves/main.rkt
@@ -11,7 +11,12 @@
          (all-from-out "write-binary.rkt")
          (all-from-out "write-text.rkt")
 
-         read-preserve)
+         detect-preserve-syntax
+         read-preserve
+         file->preserves)
+
+(require racket/match)
+(require (only-in racket/file file->list))
 
 (require "record.rkt")
 (require "float.rkt")
@@ -23,16 +28,31 @@
 (require "write-binary.rkt")
 (require "write-text.rkt")
 
+(define (detect-preserve-syntax [in-port (current-input-port)])
+  (define b (peek-byte in-port))
+  (cond [(eof-object? b) b]
+        [(<= #x80 b #xBF) 'binary]
+        [else 'text]))
+
 (define (read-preserve [in-port (current-input-port)]
                        #:read-syntax? [read-syntax? #f]
                        #:decode-embedded [decode-embedded #f]
                        #:source [source (object-name in-port)])
-  (define b (peek-byte in-port))
-  (cond [(eof-object? b) b]
-        [(<= #x80 b #xBF) (read-preserve/binary in-port
-                                                #:read-syntax? read-syntax?
-                                                #:decode-embedded decode-embedded)]
-        [else (read-preserve/text in-port
-                                  #:read-syntax? read-syntax?
-                                  #:decode-embedded decode-embedded
-                                  #:source source)]))
+  (match (detect-preserve-syntax in-port)
+    [(? eof-object? e) e]
+    ['binary (read-preserve/binary in-port
+                                   #:read-syntax? read-syntax?
+                                   #:decode-embedded decode-embedded)]
+    ['text (read-preserve/text in-port
+                               #:read-syntax? read-syntax?
+                               #:decode-embedded decode-embedded
+                               #:source source)]))
+
+(define (file->preserves path
+                         #:read-syntax? [read-syntax? #f]
+                         #:decode-embedded [decode-embedded #f])
+  (file->list path (lambda (in-port)
+                     (read-preserve in-port
+                                    #:read-syntax? read-syntax?
+                                    #:decode-embedded decode-embedded
+                                    #:source path))))