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Inline-SLang-1.00
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/ Inline::SLang::Config

NAME

Inline::SLang::Config - How to configure Inline::SLang

DESCRIPTION

The Inline documentation describes how you can configure the Inline-specific options. Please review that document if you are unfamiliar with the way Inline works (in particular the section on "Configuration Options"). This document describes the options that are available to configure the S-Lang interface.

Options

BIND_NS - what namespaces should be searched?

This option - which takes either a string or a reference to an array of strings - specifies the S-Lang namespaces which are searched for functions to bind to Perl. The accepted values are:

"Global"

Binds functions in the Global namespace only. This is the default value.

"All"

Binds functions in all the namespaces that are defined at the time of compilation. You can not use the namespace renaming feature discussed below with this option (so "All=foo" does not work).

Array reference

If an array reference is given then it should contain the names of the namespaces to search for S-Lang functions. In most case you will want to ensure that "Global" is contained in this list.

The default behaviour is for functions in the "Global" namespace to be bound to the Perl main package (so they can be used without any package specifier) while functions in other namespaces are placed into the Perl package whose name equals that of the S-Lang namespace (see below for examples). This can be changed by supplying strings matching "foo=bar", which says to bind S-Lang functions from the foo namespace into the Perl package bar. Therefore,

  BIND_NS => [ "Global=foo", "foo" ],

will bind all S-Lang functions from the Global and foo namespaces into Perl's foo package.

Note that no checks are made for over-writing functions when they are bound to Perl. Also, if you are using this functionality you should probably be using the 2-argument form of S-Lang's import and evalfile commands instead.

The following examples are also available in the examples/ sub-directory of the source code (this directory is not installed by make install).

Example of using a single namespace:
 use Inline 'SLang' => Config => BIND_NS => ["foo"];
 use Inline 'SLang' => <<'EOS1';
  define fn_in_global(x) { "in global"; }
  implements( "foo" );
  define fn_in_foo(x) { "in foo"; }
 EOS1

 # this works
 printf "I am %s\n", foo::fn_in_foo("dummyval");

 # this does not work since fn_in_global is in the
 # Global namespace which was not given to the
 # BIND_NS option
 printf "I am %s\n", fn_in_global("dummyval");
Example of using multiple namespaces:
 use Inline 'SLang' => Config => BIND_NS => [ "Global", "foo" ];
 use Inline 'SLang' => <<'EOS1';
  define fn_in_global(x) { "in global"; }
  implements( "foo" );
  define fn_in_foo(x) { "in foo"; }
 EOS1

 # this works
 printf "I am %s\n", foo::fn_in_foo("dummyval");

 # as does this
 printf "I am %s\n", fn_in_global("dummyval");
Example of renaming a namespace:
 use Inline 'SLang' => Config => BIND_NS => [ "Global", "foo=bar" ];
 use Inline 'SLang' => <<'EOS1';
  define fn_in_global(x) { "in global"; }
  implements( "foo" );
  define fn_in_foo(x) { "in foo"; }
 EOS1

 # this works
 printf "I am %s\n", bar::fn_in_foo("dummyval");

 # as does this
 printf "I am %s\n", fn_in_global("dummyval");
Example of using all namespaces:
 use Inline 'SLang' => Config => BIND_NS => "All";
 use Inline 'SLang' => <<'EOS1';
  define fn_in_global(x) { "in global"; }
  implements( "foo" );
  define fn_in_foo(x) { "in foo"; }
 EOS1

 # this works
 printf "I am %s\n", foo::fn_in_foo("dummyval");

 # as does this
 printf "I am %s\n", fn_in_global("dummyval");

BIND_SLFUNCS - which S-Lang intrinsic functions to bind?

This option is used to give a list of S-Lang intrinsic functions which are to be bound to Perl. The default value is [], i.e. no functions.

Note that there are no checks on whether it makes sense to bind the specified function, or whether it conflicts with an existing Perl definition.

Example of binding an intrinsic command into main:
  use Inline 'SLang' => Config => BIND_SLFUNCS => ["typeof"];
  use Inline 'SLang' => "define get_typeof(x) { typeof(x); }";

  # both lines print
  #  The S-Lang type of 'foo' is String_Type
  printf "The S-Lang type of 'foo' is %s\n", get_typeof("foo");
  printf "The S-Lang type of 'foo' is %s\n", typeof("foo");
Example of binding an intrinsic command into the foo package:
  use Inline 'SLang' => Config =>
    BIND_NS => "Global=foo",
    BIND_SLFUNCS => ["typeof"];
  use Inline 'SLang' => " ";

  # This also prints
  #  The S-Lang type of 'foo' is String_Type
  printf "The S-Lang type of 'foo' is %s\n", foo::typeof("foo");

The reason for giving " " as the S-Lang code in the last example is to stop Inline from complaining about being sent no code.

SETUP - how to configure the S-Lang interpreter?

The SETUP option can be set to one of:

"slsh"

This is the default value. When set, the S-Lang interpreter is set up in a similar manner to that of the slsh interpreter from the S-Lang distribution (v1.4.9):

  • The interpreter's load path - i.e. the path that can be accessed using the get_slang_load_path() and set_slang_load_path() routines from the S-Lang Run-Time Library - is set to the contents of the environment variable SLSH_PATH.

  • The system configuration file slsh.rc is evaluated. This file is looked for in one of:

    a

    The SLSH_CONF_DIR environment variable.

    b

    The SLSH_LIB_DIR environment variable.

    c

    The directories: /usr/local/etc:/usr/local/slsh:/etc:/etc/slsh.

  • The user's configuration file .slshrc is evaluated. This file is searched for in the directory given by the environment variable HOME.

"none"

No additional set up is made to the interpreter.

At present the code used to support the slsh option will only work for UNIX-style file systems/set ups.

EXPORT - how to export Perl functions from Inline::SLang

The Inline::SLang module contains a number of utility routines that are - by default - only available using the fully-qualified package name. If you would rather use sl_array(...) than Inline::SLang::sl_array(...) then you can use the EXPORT option. This resembles the standard Perl export mechanism but is not as feature rich.

The available functions are (see Inline::SLang for a detailed description):

sl_array()

A wrapper around the constructor for the Array_Type class. Useful if you want to ensure that a Perl array reference is converted to the correct array type and size in S-Lang.

sl_array2perl()

Used to read or write the flag that controls how S-Lang arrays are converted to Perl. See Inline::SLang::Array.

sl_eval()

Call S-Lang's eval() routine and, on exit, convert the stack to Perl.

sl_have_pdl()

Determine if the module was compiled with support for PDL.

sl_setup_as_slsh()

Sets up the interpreter in a similar manner to that used by slsh. This routine should be rarely needed.

sl_setup_called()

Returns the number of times the sl_setup_as_slsh() routine has been called.

sl_typeof()

A wrapper around S-Lang's typeof() routine. It is more efficient than using S-Lang's typeof routine.

sl_version()

Returns the version of the S-Lang library used to compile the module.

<datatype name>()

A function is created for each S-Lang datatype known about when the Perl code is executed (so this includes typedef-fed structures and any application-specific datatypes from imported modules). The name of the function matches the name of the S-Lang datatype and returns a Perl DataType_Type object whose value matches the function name - so

  Integer_Type()

is just the same as calling

  DataType_Type->new("Integer_Type");

Note that - as of version 0.12 of Inline::SLang - you can also use the name of synonyms as well as the base classes. For instance, Int32_Type() will return the datatype that corresponds to the S-Lang Int32_Type type.

The EXPORT option accepts a reference to an array that lists the names of the functions to export, e.g.

  use Inline 'SLang' => Config => EXPORT => [ "sl_array" ];

If you want to export the datatype functions then you can either list the names of the required functions in the EXPORT array or give the value !types which includes them all.

Note that we do not accept the full syntax of the Exporter module: the EXPORT option should be thought of as a toy car next to the RV that is the Exporter module.

What functions and namespaces have been bound to Perl?

The info option of Inline can be useful to see what has (and has not) been bound to Perl. As an example try the following (available as examples/info.pl in the source code of the module):

  perl -MInline=info <<FOO
  use Inline SLang;
  # let's not actually do anything
  __END__
  __SLang__
  typedef struct { foo, bar } FooBarStruct_Type;
  variable foobar = "a string";
  define foo()  { return foobar; }
  define bar(x) { foobar = x; }
  FOO

The relevant part of the output (as of version 0.30) is:

  Configuration details
  ---------------------

  Version of S-Lang: 1.4.9
  Perl module version is 0.30 and supports PDL

  The following S-Lang types are recognised:
   Int32_Type UInteger_Type _IntegerP_Type
   FooBarStruct_Type[Struct_Type] Int_Type Struct_Type ULong_Type
   FD_Type Long_Type Float_Type Array_Type UInt32_Type File_Type
   UInt_Type UChar_Type UShort_Type Double_Type Float64_Type
   Float32_Type Int16_Type Null_Type Integer_Type BString_Type Char_Type
   Undefined_Type Short_Type Any_Type Ref_Type Complex_Type Assoc_Type
   String_Type UInt16_Type DataType_Type

  The following S-Lang namespaces have been bound to Perl:

    2 functions from namespace Global are bound to package main
          bar()
          foo()

Any S-Lang intrinsic functions bound to Perl are indicated using the format S-Lang name() -> Perl name(), even when the Perl and S-Lang names match (this may change).

If you have a typedef statement defining a "named" structure then the name of the structure will be followed by [Struct_Type], as with the FooBarStruct_Type variable type in the example above.

The format of this section is liable to change; any suggestions are very welcome.

SEE ALSO

Inline::SLang, Inline