Today I want to review not a library but a tool. SBLint is a program,
which can be run from the command-line. It loads your lisp code and
outputs all warnings and notes from SBCL compiler.
I must admit, that SBLint’s output is very readable. You’ll see where you left unused variables or called a function with wrong parameters.
To show you an example, I’ve added this bad code to one of my libraries:
(declaim (ftype (function (fixnum fixnum)
fixnum)
foo))
(defun foo (a b)
(+ a 10))
(defun bar ()
(foo))
(defun blah ()
(foo 2
3.14))
This code is full of problems :) Let’s see how SBLint will highlight them!
[art@poftheday] sblint
src/appenders.lisp:41:0: style-warning: \
The variable B is defined but never used.
src/appenders.lisp:46:2: simple-warning: \
The function FOO is called with zero arguments, but wants exactly two.
src/appenders.lisp:50:2: type-warning: \
Constant 3.14 conflicts with its asserted type FIXNUM.
WARNING: Compilation failed in a system "log4cl-extras".
# But return code is still SUCCESS:
[art@poftheday] echo $?
0
As you can see, all errors are caught. However, SBLint itself exited
with 0 exit code. Because of this, we can’t add it into our CI pipeline.