add main.scm

tools/main.scm

@@ -0,0 +1,89 @@
+(define-library (picrin user)
+  (import (scheme base)
+          (scheme load)
+          (scheme process-context)
+          (scheme read)
+          (scheme write)
+          (scheme file)
+          (scheme inexact)
+          (scheme cxr)
+          (scheme lazy)
+          (scheme time)
+          (picrin macro)))
+
+(define-library (picrin repl)
+  (import (scheme base)
+          (scheme read)
+          (scheme file)
+          (scheme write)
+          (scheme eval)
+          (scheme process-context))
+
+  (define (file->string file)
+    (with-input-from-file file
+      (lambda ()
+        (let loop ((line (read-line)))
+          (if (eof-object? line)
+              ""
+              (string-append line (loop (read-line))))))))
+
+  (define (print-help)
+    (display "picrin scheme\n")
+    (display "\n")
+    (display "Usage: picrin [options] [file]\n")
+    (display "\n")
+    (display "Options:\n")
+    (display "  -e [program]		run one liner script\n")
+    (display "  -h			show this help\n"))
+
+  (define (getopt)
+    (let ((args (cdr (command-line))))
+      (if (null? args)
+          #f
+          (case (car args)
+            (("-h")
+             (print-help)
+             (exit 0))
+            (("-e")
+             (cadr args))
+            (else
+             (file->string (car args)))))))
+
+  (define (print obj)
+    (write obj)
+    (newline))
+
+  (define (main-loop)
+    (display "> ")
+    (let ((expr (read)))
+      (if (eof-object? expr)
+          (begin
+            (newline)
+            (exit 0))
+          (begin
+            (call/cc
+             (lambda (leave)
+              (with-exception-handler
+               (lambda (condition)
+                 (display (error-object-message condition))
+                 (newline)
+                 (leave))
+               (lambda ()
+                 (print (eval expr '(picrin user)))))))
+            (main-loop)))))
+
+  (define (repl)
+    (let ((program (getopt)))
+      (parameterize
+          ((current-input-port
+            (if program
+                (current-input-port)
+                (open-input-string program))))
+        (main-loop))))
+
+  (export repl))
+
+(import (picrin repl))
+
+(repl)
+