The files beneath this directory contain source code for almost all of
the nontrivial code fragments in Programming Language Pragmatics, 4e.
In most cases the code in the book does not constitute a complete and
runnable program, so these have been extended.  In general the goal has
been to create as small a program as possible that illustrates the
feature in question.  The result is not always good programming style.

In a few cases (generally when the point is to observe the behavior of
the compiler itself), the example is just a single module, and will not
produce runnable code.  These must typically be compiled with a "-c"
command-line switch.

Comments at the top of the source indicate the corresponding Example,
Figure, or Exercise in the book.  Code that appears both as an Example
or Exercise and as a Figure is provided in a directory named after the
Example or Exercise.

Code has been compiled and tested using the following compilers and
interpreters.  For languages that are still actively evolving, these
were up-to-date implementations as of the time of printing.  Some
historic languages may not compile and run on recent OS releases.

Ada: gnat (gcc) version 4.9 on MacOS 10.10
        available from libre.adacore.com/download/
awk: version 20070501 on MacOS 10.10
C and C++: Apple LLVM version 6.1.0 on MacOS 10.10
        NB: run with --std=c11 or --std=c++11)
C#: mono mcs version 4.0.1 on MacOS 10.10
        available from www.mono-project.com/
Common Lisp: CMU Common Lisp 19e on Fedora Core Linux 2.6.23
elisp: emacs version 24.4.1 on MacOS 10.10
Erlang: erl shell version 7.0 (Erland/OTP release 18.0) on MacOS 10.10
        available from erlang.org/
F#: mono fsharpc version 3.1 on mono 4.0.1 on MacOS 10.10
        available from mono-project.com
Fortran: gfortran 5.1.0 on MacOS 10.10
        available from gcc.gnu.org/fortran/
Go: version 1.4.2 on MacOS 10.10
        available from golang.org
Haskell: ghc version 7.8.3 on MacOS 10.10
        available from www.haskell.org
Icon: version 9.4.2 on MacOS 10.5
        available from www.cs.arizona.edu/icon/
Java: Sun javac 1.8.0_20 on MacOS 10.10
        available from oracle.com/technetwork/java/
JavaScript: version embedded in Safari 8.0.7 browser on MacOS 10.10
Modula-3: cm3 compiler, version 5.4.0 on Fedora Core Linux 2.6.23
        available from modula3.elegosoft.com/
OCaml: version 4.02.1 on MacOS 10.10
        available from ocaml.org
Pascal: gpc version 20070904, based on gcc-3.4.6, on MacOS 10.10
        available from www.microbizz.nl/gpc.html
Perl: version 5.16.3 on MacOS 10.10
PHP: version 5.5.24 under Apache 2.4.10 on MacOS 10.10
Prolog: swipl (SWI-Prolog) version 7.2.3 on MacOS 10.10
        available from www.swi-prolog.org/
Python: version 3.4.3 on MacOS 10.10
        available from python.org
Ruby: version 2.0.0p647 on MacOS 10.10
        available from ruby-lang.org
Scheme: DrRacket version 6.2 on MacOS 10.10, in R5RS mode
        available from download.racket-lang.org
sed: version 4.1.4 on MacOS 10.10
Smalltalk: GNU Smalltalk (gst) version 3.1 on MacOS 10.10
        available from smalltalk.gnu.org
SML: Standard ML of New Jersey (sml) version 110.78 on MacOS 10.10
        available from www.smlnj.org/
SR: version 2.3.3 on Fedora Core Linux 2.6.23
        available from www.cs.arizona.edu/sr
Swift: version 1.2 on MacOS 10.10
        available from www.apple.com/swift/
XSLT: version embedded in Safari 8.0.7 browser on MacOS 10.10