fisl

commit be6df7f081b8c1d9c10d6149d44c9f512680c229 (patch)
parent 255875cef1a90409e8e002e185ba938838d22d27
Author: Alex Karle <alex@alexkarle.com>
Date:   Tue,  4 Oct 2022 23:47:16 -0400

scanner: Fix line numbers and add basic error handling

This really just adds the first use of set! to maintain the global
had-err value on err!

Diffstat:
M
fisl.scm
 | 
8
++++----
M
scanner.scm
 | 
6
+++---
M
util.scm
 | 
12
+++++++++---

3 files changed, 16 insertions(+), 10 deletions(-)
diff --git a/fisl.scm b/fisl.scm
@@ -10,9 +10,7 @@
         util)
 
 (define (run code fname)
-  (let ((exit-code 0))
-    (map print (scan code fname))
-    exit-code))
+    (map print (scan code fname)))
 
 (define (run-prompt)
   (display "> ")
@@ -20,12 +18,14 @@
     (if (not (eof-object? l))
       (begin
         (run l "repl")
+        (clear-err!)
         (run-prompt))
       (exit 0))))
 
 (define (run-file fname)
   (call-with-input-file fname (lambda (p)
-                                (exit (run (read-string #f p) fname)))))
+                                (run (read-string #f p) fname)
+                                (exit (if had-err 1 0)))))
 
 (define (main args)
   (let ((argc (length args)))
diff --git a/scanner.scm b/scanner.scm
@@ -91,7 +91,7 @@
                                  (advance line)))
             ((eq? in 'string)
              (cond
-               ((not c) (err (format "~A:~A:unterminated string" fname line)))
+               ((not c) (err! (format "~A:~A:unterminated string" fname line)))
                ((eq? #\" c) (tok 'STRING))
                ((eq? #\newline c) (advance (add1 line)))
                (else (advance line))))
@@ -129,8 +129,8 @@
                     ((alpha? c) (get-tokens s (add1 i) line 'alpha))
                     ((eq? #\space c) (skip))
                     ((eq? #\tab c) (skip))
-                    ((eq? #\newline c) (skip))
-                    (else (err (format "~A:~A:unexpected character: ~A" fname 0 c)) (skip))))))))
+                    ((eq? #\newline c) (get-tokens (add1 i) (add1 i) (add1 line) in))
+                    (else (err! (format "~A:~A:unexpected character: ~A" fname line c)) (skip))))))))
 
     (get-tokens 0 0 1 #f))
   ) ; end of module
diff --git a/util.scm b/util.scm
@@ -1,14 +1,20 @@
-(module util (die get err)
+(module util (die get err! had-err clear-err!)
   (import scheme
           (chicken base)
           (chicken io)
           (chicken format))
 
-  (define (err str)
+  (define had-err #f)
+
+  (define (err! str)
+    (set! had-err #t)
     (fprintf (current-error-port) "~A\n" str))
 
+  (define (clear-err!)
+    (set! had-err #f))
+
   (define (die str)
-    (err str)
+    (err! str)
     (exit 1))
 
   (define (get assoc-arr key)