Split read-char? and kin into their own library

read-char-if.scm

@@ -0,0 +1,23 @@
+(define (match-char? k char)
+  (cond ((procedure? k) (not (not (k char))))
+        ((char? k) (equal? k char))
+        (else #f)))
+
+(define (read-char? k)
+  ;;(fprintf (current-error-port) "read-char? ~a~%" k)
+  (and (match-char? k (peek-char))
+       (begin (let ((char (read-char)))
+                ;;(display char (current-error-port))
+                ;;(newline (current-error-port))
+                char))))
+
+(define (read-char* k)
+  (let* ((first-char (read-char? k))
+         (chars (let ((out (open-output-string)))
+                  (let loop ((char first-char))
+                    (cond ((or (equal? #f char) (eof-object? char))
+                           (get-output-string out))
+                          (else
+                           (write-char char out)
+                           (loop (read-char? k))))))))
+    (if (= 0 (string-length chars)) #f chars)))

read-char-if.sld

@@ -0,0 +1,6 @@
+(define-library (read-char-if)
+  (export read-char? read-char*)
+  (import (scheme base)
+          (scheme char)
+          (scheme file))
+  (include "read-char-if.scm"))

tex-parser.scm

@@ -1,27 +1,3 @@
-(define (match-char? k char)
-  (cond ((procedure? k) (not (not (k char))))
-        ((char? k) (equal? k char))
-        (else #f)))
-
-(define (read-char? k)
-  ;;(fprintf (current-error-port) "read-char? ~a~%" k)
-  (and (match-char? k (peek-char))
-       (begin (let ((char (read-char)))
-                ;;(display char (current-error-port))
-                ;;(newline (current-error-port))
-                char))))
-
-(define (read-char* k)
-  (let* ((first-char (read-char? k))
-         (chars (let ((out (open-output-string)))
-                  (let loop ((char first-char))
-                    (cond ((or (equal? #f char) (eof-object? char))
-                           (get-output-string out))
-                          (else
-                           (write-char char out)
-                           (loop (read-char? k))))))))
-    (if (= 0 (string-length chars)) #f chars)))
-
 (define (tex-command-char? ch)
   (or (char-alphabetic? ch)
       (char-numeric? ch)))

tex-parser.sld

@@ -1,4 +1,7 @@
 (define-library (tex-parser)
   (export parse-tex-from-port)
-  (import (scheme base) (scheme char) (scheme file))
+  (import (scheme base)
+          (scheme char)
+          (scheme file)
+          (read-char-if))
   (include "tex-parser.scm"))