I can't run test because FiveAM from Gentoo portage (1.2.3) has no FOR-ALL (or is it from other package?). But I tested it manually. ---------------------------------------------------------------------- ;;; Copyright (C) 2006 Ivan Boldyrev ;;; This code is freely redistributable. (cl:defpackage #:quiz2 (:use #:cl)) (cl:in-package #:quiz2) (defvar *stack* nil "Stack for parsed objects") (defun tab-ws (pos) #-dont-blame-tabspace(warn "Tabular is found at pos ~S" pos) (* 8 (floor (+ pos 8) 8))) (defun count-ws (input-stream) (loop :for cnt := 0 :then (case char ((#\Space) (1+ cnt)) ((#\Tab) (tab-ws cnt)) ((#\Return #\Linefeed) ;; Space-only line! Just ignore it (return-from count-ws (count-ws input-stream))) (otherwise (unread-char char input-stream) (return-from count-ws cnt))) :for char := (read-char input-stream))) (defun combine-lines (first rest) (cons first (nreverse rest))) (defun reduce-forms (offset) (let ((tail (cdr (pop *stack*)))) (if (> offset (car (first *stack*))) (push (list offset (nreverse tail)) *stack*) (let ((first (pop (cdr (first *stack*))))) (progn (push (combine-lines first tail) (cdr (first *stack*))) *stack*))))) (defun read-the-line (input-stream) (let ((space-offset (count-ws input-stream)) (data (read-preserving-whitespace input-stream))) ;; Perform all reductions (loop :while (and (rest *stack*) (< space-offset (car (first *stack*)))) :do (reduce-forms space-offset)) (cond ((and (symbolp data) (string= (symbol-name data) "!#")) (throw 'thats-all-folks (cons 'progn (loop :while (rest *stack*) :do (reduce-forms 0) :finally (return (nreverse (cdr (first *stack*)))))))) ((and *stack* (= space-offset (car (first *stack*)))) (push data (cdr (first *stack*))) *stack*) (t (push (cons space-offset (list data)) *stack*))))) (defun read-off-side (stream subchar parameter) (declare (ignore subchar parameter)) (let ((*stack* nil)) ;; Catch is duty hack here. Do not repeat at home! (catch 'thats-all-folks (loop (read-the-line stream))))) ---------------------------------------------------------------------- -- Ivan Boldyrev Ok people, move along, there's nothing to see here.