diff options
| author | Dave Beazley <dave-swig@dabeaz.com> | 2000-06-17 23:46:23 +0000 |
|---|---|---|
| committer | Dave Beazley <dave-swig@dabeaz.com> | 2000-06-17 23:46:23 +0000 |
| commit | e560c1d445604abe79ea7b66026acdbfdf015ea7 (patch) | |
| tree | 8748368e38f4f8031d5fb774ff42fe01959923e9 /Examples/perl5/constants | |
| parent | b3e124ac210aa9058d78bca30cd9253448e488a6 (diff) | |
| download | swig-e560c1d445604abe79ea7b66026acdbfdf015ea7.tar.gz | |
More examples
git-svn-id: https://swig.svn.sourceforge.net/svnroot/swig/trunk/SWIG@491 626c5289-ae23-0410-ae9c-e8d60b6d4f22
Diffstat (limited to 'Examples/perl5/constants')
| -rw-r--r-- | Examples/perl5/constants/Makefile | 17 | ||||
| -rw-r--r-- | Examples/perl5/constants/example.i | 24 | ||||
| -rw-r--r-- | Examples/perl5/constants/example.pl | 27 | ||||
| -rw-r--r-- | Examples/perl5/constants/index.html | 55 |
4 files changed, 123 insertions, 0 deletions
diff --git a/Examples/perl5/constants/Makefile b/Examples/perl5/constants/Makefile new file mode 100644 index 000000000..47fd1eb6d --- /dev/null +++ b/Examples/perl5/constants/Makefile @@ -0,0 +1,17 @@ +TOP = ../.. +SWIG = $(TOP)/../swig +SRCS = +TARGET = example +INTERFACE = example.i +SWIGOPT = +all:: + $(MAKE) -f $(TOP)/Makefile SRCS='$(SRCS)' SWIG='$(SWIG)' \ + SWIGOPT='$(SWIGOPT)' TARGET='$(TARGET)' INTERFACE='$(INTERFACE)' perl5 + +static:: + $(MAKE) -f $(TOP)/Makefile SRCS='$(SRCS)' SWIG='$(SWIG)' \ + SWIGOPT='$(SWIGOPT)' TARGET='myperl' INTERFACE='$(INTERFACE)' perl5_static + +clean:: + rm -f *_wrap* *.o core *~ *.so *.pm myperl + diff --git a/Examples/perl5/constants/example.i b/Examples/perl5/constants/example.i new file mode 100644 index 000000000..9b04ebc1d --- /dev/null +++ b/Examples/perl5/constants/example.i @@ -0,0 +1,24 @@ +/* File : example.i */ +%module example + +/* A few preprocessor macros */ + +#define ICONST 42 +#define FCONST 2.1828 +#define CCONST 'x' +#define SCONST "Hello World" + +/* This should work just fine */ +#define EXPR ICONST + 3*(FCONST) + +/* This shouldn't do anything */ +#define EXTERN extern + +/* Neither should this (BAR isn't defined) */ +#define FOO (ICONST + BAR) + +/* The following statements also produce constants */ +const int iconst = 37; +const double fconst = 3.14; + + diff --git a/Examples/perl5/constants/example.pl b/Examples/perl5/constants/example.pl new file mode 100644 index 000000000..0cf207c3c --- /dev/null +++ b/Examples/perl5/constants/example.pl @@ -0,0 +1,27 @@ +# file: example.pl + +use example; + +print "ICONST = ", $example::ICONST, " (should be 42)\n"; +print "FCONST = ", $example::FCONST, " (should be 2.1828)\n"; +print "CCONST = ", $example::CCONST, " (should be 'x')\n"; +print "SCONST = ", $example::SCONST, " (should be 'Hello World')\n"; +print "EXPR = ", $example::EXPR, " (should be 48.5484)\n"; +print "iconst = ", $example::iconst, " (should be 37)\n"; +print "fconst = ", $example::fconst, " (should be 3.14)\n"; + + +if ($example::EXTERN) { + print "EXTERN = ", example.EXTERN, " (Arg! This shouldn't print anything)\n"; +} else { + print "EXTERN isn't defined (good)\n"; +} + +if ($example::FOO) { + print "FOO = ", example.FOO, "(Arg! This shouldn't print anything)\n"; +} else { + print "FOO isn't defined (good)\n"; +} + + + diff --git a/Examples/perl5/constants/index.html b/Examples/perl5/constants/index.html new file mode 100644 index 000000000..267d5b365 --- /dev/null +++ b/Examples/perl5/constants/index.html @@ -0,0 +1,55 @@ +<html> +<head> +<title>SWIG:Examples:perl5:constants</title> +</head> + +<body bgcolor="#ffffff"> + +<tt>SWIG/Examples/perl5/constants/</tt> +<hr> + +<H2>Wrapping C Constants</H2> + +<tt>$Header$</tt><br> + +<p> +When SWIG encounters C preprocessor macros and C declarations that look like constants, +it creates Perl5 variables with an identical value. Click <a href="example.i">here</a> +to see a SWIG interface with some constant declarations in it. + +<h2>Accessing Constants from Perl</h2> + +Click <a href="example.pl">here</a> to see a script that prints out the values +of the constants contained in the above file. + +<h2>Key points</h2> + +<ul> +<li>The values of preprocessor macros are converted into Perl constants. +<li>Types are inferred by syntax (e.g., "3" is an integer and "3.5" is a float). +<li>Character constants such as 'x' are converted into Perl strings. +<li>C string literals such as "Hello World" are converted into Perl strings. +<li>Macros that are not fully defined are simply ignored. For example: +<blockquote> +<pre> +#define EXTERN extern +</pre> +</blockquote> +is ignored because SWIG has no idea what type of variable this would be. + +<p> +<li>Expressions are allowed provided that all of their components are defined. Otherwise, the constant is ignored. + +<li>Certain C declarations involving 'const' are also turned into Perl constants. + +<p> +<li>The constants that appear in a SWIG interface file do not have to appear in any sort +of matching C source file since the creation of a constant does not require linkage +to a stored value (i.e., a value held in a C global variable or memory location). +</ul> + +<hr> + + +</body> +</html> |