X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=blobdiff_plain;f=pod%2Fperlcall.pod;h=e691e759a1d22b0971b27bf1a5e475283b8f3677;hb=a3dfe201291c96fc01babd3d4782d52ba945f2a3;hp=2b837808a19ad9c398e4321e919dbfb8afdc72d3;hpb=c2611fb358d57faaf2390cf4e8c5224abf2c4cc4;p=p5sagit%2Fp5-mst-13.2.git diff --git a/pod/perlcall.pod b/pod/perlcall.pod index 2b83780..e691e75 100644 --- a/pod/perlcall.pod +++ b/pod/perlcall.pod @@ -116,7 +116,7 @@ subroutine are stored on the Perl stack. As a general rule you should I check the return value from these functions. Even if you are expecting only a particular number of values to be returned from the Perl subroutine, there is nothing to -stop someone from doing something unexpected - don't say you haven't +stop someone from doing something unexpected--don't say you haven't been warned. =head1 FLAG VALUES @@ -505,9 +505,9 @@ returned from I. It will always be 0. =head2 Passing Parameters Now let's make a slightly more complex example. This time we want to -call a Perl subroutine, C, which will take 2 parameters - a -string (C<$s>) and an integer (C<$n>). The subroutine will simply -print the first C<$n> characters of the string. +call a Perl subroutine, C, which will take 2 parameters--a +string ($s) and an integer ($n). The subroutine will simply +print the first $n characters of the string. So the Perl subroutine would look like this @@ -555,7 +555,7 @@ as C. =item 2. If you are going to put something onto the Perl stack, you need to know -where to put it. This is the purpose of the macro C - it declares +where to put it. This is the purpose of the macro C--it declares and initializes a I copy of the Perl stack pointer. All the other macros which will be used in this example require you to @@ -563,7 +563,7 @@ have used this macro. The exception to this rule is if you are calling a Perl subroutine directly from an XSUB function. In this case it is not necessary to -use the C macro explicitly - it will be declared for you +use the C macro explicitly--it will be declared for you automatically. =item 3. @@ -578,12 +578,12 @@ The C macro tells Perl to make a mental note of the current stack pointer. Even if you aren't passing any parameters (like the example shown in the section I) you must still call the C macro before you can call any of the -I functions - Perl still needs to know that there are no +I functions--Perl still needs to know that there are no parameters. The C macro sets the global copy of the stack pointer to be the same as our local copy. If we didn't do this I -wouldn't know where the two parameters we pushed were - remember that +wouldn't know where the two parameters we pushed were--remember that up to now all the stack pointer manipulation we have done is with our local copy, I the global copy. @@ -922,7 +922,7 @@ and here is a C function to call it. To be able to access the two parameters that were pushed onto the stack after they return from I it is necessary to make a note -of their addresses - thus the two variables C and C. +of their addresses--thus the two variables C and C. The reason this is necessary is that the area of the Perl stack which held them will very likely have been overwritten by something else by @@ -1175,11 +1175,11 @@ the version of Perl you are using) Not a CODE reference at ... Undefined subroutine &main::47 called ... -The variable C<$ref> may have referred to the subroutine C +The variable $ref may have referred to the subroutine C whenever the call to C was made but by the time C gets called it now holds the number C<47>. Because we saved only a pointer to the original SV in C, any changes to -C<$ref> will be tracked by the pointer C. This means that +$ref will be tracked by the pointer C. This means that whenever C gets called, it will attempt to execute the code which is referenced by the SV* C. In this case though, it now refers to the integer C<47>, so expect Perl to complain @@ -1351,7 +1351,7 @@ So the methods C and C can be invoked like this call_PrintID('Mine', 'PrintID') ; The only thing to note is that in both the static and virtual methods, -the method name is not passed via the stack - it is used as the first +the method name is not passed via the stack--it is used as the first parameter to I. =head2 Using GIMME_V @@ -1485,9 +1485,9 @@ enclosing scope at some stage. In the event driven scenario that may never happen. This means that as time goes on, your program will create more and more temporaries, none of which will ever be freed. As each of these temporaries consumes some memory your program will -eventually consume all the available memory in your system - kapow! +eventually consume all the available memory in your system--kapow! -So here is the bottom line - if you are sure that control will revert +So here is the bottom line--if you are sure that control will revert back to the enclosing Perl scope fairly quickly after the end of your callback, then it isn't absolutely necessary to dispose explicitly of any temporaries you may have created. Mind you, if you are at all @@ -1579,7 +1579,7 @@ require is a means of storing the mapping between the opened file and the Perl subroutine we want to be called for that file. Say the i/o library has a function C which associates a C -function C with a file handle C - this assumes that it +function C with a file handle C--this assumes that it has also provided some routine to open the file and so obtain the file handle. @@ -1948,7 +1948,7 @@ L, L, L =head1 AUTHOR -Paul Marquess > +Paul Marquess Special thanks to the following people who assisted in the creation of the document.