From 4edcffdc3a0d8eacf67d90d7200b1abd1183afc9 Mon Sep 17 00:00:00 2001
From: Lassi Kortela <lassi@lassi.io>
Date: Sun, 12 May 2019 16:18:34 +0300
Subject: [PATCH] Parse shebang line too

---
 encoding-reader.scm | 34 +++++++++++++++++++---------------
 test.scm            |  3 +++
 2 files changed, 22 insertions(+), 15 deletions(-)

diff --git a/encoding-reader.scm b/encoding-reader.scm
index 8c5db83..c557a9b 100644
--- a/encoding-reader.scm
+++ b/encoding-reader.scm
@@ -4,7 +4,7 @@
         (scheme read)
         (scheme write))
 
-(define (read-encoding filename)
+(define (read-declarations-from-file filename)
   (let ((bytes (let ((bytes (call-with-port
                              (open-binary-input-file filename)
                              (lambda (port) (read-bytevector 1000 port)))))
@@ -42,11 +42,11 @@
                (eqv? c #\)))))
     (define (skip-char* k)
       (when (read-char? k) (skip-char* k)))
-    (define (skip-rest-of-line)
-      (skip-char* (lambda (c) (not (or (eof-object? c) (eqv? c #\newline))))))
+    (define (read-rest-of-line)
+      (read-char* (lambda (c) (not (or (eof-object? c) (eqv? c #\newline))))))
     (define (skip-whitespace-and-comments)
       (cond ((read-char? #\;)
-             (skip-rest-of-line)
+             (read-rest-of-line)
              (skip-whitespace-and-comments))
             ((read-char? whitespace-char?)
              (skip-char* whitespace-char?)
@@ -77,15 +77,19 @@
             (if symbol-name
                 (string->symbol symbol-name)
                 (eof-object)))))
-    (let* ((form (read-form))
-           (coding-pair (and (list? form) (assoc 'coding (cdr form))))
-           (coding (if (and coding-pair
-                            (pair? (cdr coding-pair))
-                            (null? (cddr coding-pair))
-                            (symbol? (cadr coding-pair)))
-                       (cadr coding-pair)
-                       #f)))
-      coding)))
+    (let* ((shebang (if (and (read-char? #\#) (read-char? #\!))
+                        (read-rest-of-line)
+                        #f))
+           (first-form (read-form))
+           (declarations (and (list? first-form)
+                              (eqv? 'declare-file (car first-form))
+                              (cdr first-form))))
+      (if shebang
+          (cons (list 'shebang shebang) declarations)
+          declarations))))
 
-(display (read-encoding "test.scm"))
-(newline)
+(define (writeln x)
+  (write x)
+  (newline))
+
+(for-each writeln (read-declarations-from-file "test.scm"))
diff --git a/test.scm b/test.scm
index 29839fa..09f94d3 100644
--- a/test.scm
+++ b/test.scm
@@ -1,4 +1,7 @@
+#! /usr/bin/env gosh
+
 (declare-file
  (coding shift_jis))
 
 (display "こんにちは世界")
+(newline)