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5.10.1.3 Write some code

1. open $HOME/src/lisp/swatchblade/swatchblade.lisp and start hacking.

   I define variables with defvar and defparameter, functions with defun and defgeneric, macros with defmacro, classes with defclass, etc.

   As I write each one, I compile it immediately with ‘C-c C-c’ and occasionally switch over to the REPL to run some code.

2. As I use symbols from other projects, I update the defpackage form in package.lisp to import symbols. For example, I might want to use several Vecto symbols without package prefixes, so I could do this:

   (defpackage #:swatchblade
     (:use #:cl)
     (:shadowing-import-from #:vecto
                             #:with-canvas
                             #:rounded-rectangle
                             #:set-rgb-fill
                             #:save-png-stream))
   

3. I don’t put any library management code directly into Lisp source files. If I decide to use more external projects, I edit swatchblade.asd and add to the :depends-on list,

   (asdf:defsystem #:swatchblade
     :serial t
     :depends-on (#:vecto
                  #:hunchentoot
                  #:cl-colors)
     :components ((:file "package")
                  (:file "swatchblade")))
   

   Reloading the system with ql:quickload will install (if necessary) and load any newly-required systems.