[io] New package io, implemented doread-lines and ask-for-stream

2 files changed, 25 insertions, 0 deletions

diff --git a/src/io.lisp b/src/io.lisp
new file mode 100644
index 0000000..85e9b31
--- /dev/null
+++ b/src/io.lisp
@@ -0,0 +1,19 @@
+(in-package :senzill.io)
+
+(defmacro doread-lines ((var &key (ends '("end")) read-line-options) &rest body)
+  "Reads lines until NIL or input is inside ends. Each line is stored in var."
+  `(let ((,var (read-line ,@read-line-options)))
+     (loop until (or (member ,var ',ends :test 'string=) (not ,var)) do
+           ,@body
+           (setf ,var (read-line ,@read-line-options)))))
+
+(defmacro ask-for-stream ((var) &rest body)
+  "var is either *standard-input* or file stream, where the file stream is handled by with-open-stream"
+  `(let ((filename))
+     (format t "File name (nothing for *standard-input*): ")
+     (force-output)
+     (setf filename (read-line))
+     (if (string= filename "")
+      (let ((,var *standard-input*))
+           ,@body)
+      (with-open-stream (,var (open filename)) ,@body))))
diff --git a/src/packages.lisp b/src/packages.lisp
index 441101d..802ec3a 100644
--- a/src/packages.lisp
+++ b/src/packages.lisp
@@ -19,3 +19,9 @@
            :pop-back
            :slice)
   (:documentation "List functions"))
+
+(defpackage senzill.io
+  (:use :cl)
+  (:export :doread-lines
+           :ask-for-stream)
+  (:documentation "I/O functions"))