slangfun.txt

一个C格式的脚本处理函数库源代码,可让你的C程序具有执行C格式的脚本文件

 SYNOPSIS
   The number of parameters passed to a function

 USAGE
   Integer_Type _NARGS

 EXAMPLE
   This example uses the `_NARGS' variable to print the list of
   values passed to the function:

        define print_values ()
        {
           variable arg;
           
           if (_NARGS == 0)
             {
                message ("Nothing to print");
                return;
             }
           foreach (__pop_args (_NARGS))
             {
                arg = ();
                vmessage ("Argument value is: %S", arg.value);
             }
        }


 SEE ALSO
   __pop_args, __push_args, typeof
--------------------------------------------------------------

__get_defined_symbols

 SYNOPSIS
   Get the symbols defined by the preprocessor

 USAGE
   Integer_Type __get_defined_symbols ()

 DESCRIPTION
   The `__get_defined_symbols' functions is used to get the list of
   all the symbols defined by the S-Lang preprocessor.  It pushes each
   of the symbols on the stack followed by the number of items pushed.

 SEE ALSO
   is_defined, _apropos, _get_namespaces
--------------------------------------------------------------

__is_initialized

 SYNOPSIS
   Determine whether or not a variable has a value

 USAGE
   Integer_Type __is_initialized (Ref_Type r)

 DESCRIPTION
   This function returns non-zero of the object referenced by `r'
   is initialized, i.e., whether it has a value.  It returns 0 if the
   referenced object has not been initialized.

 EXAMPLE
   For example, the function:

       define zero ()
       {
          variable f;
          return __is_initialized (&f);
       }

   will always return zero, but

       define one ()
       {
          variable f = 0;
          return __is_initialized (&f);
       }

   will return one.

 NOTES
   It is easy to see why a reference to the variable must be passed to
   `__is_initialized' and not the variable itself; otherwise, the
   value of the variable would be passed and the variable may have no
   value if it was not initialized.

 SEE ALSO
   __get_reference, __uninitialize, is_defined, typeof, eval
--------------------------------------------------------------

_apropos

 SYNOPSIS
   Generate a list of functions and variables

 USAGE
   Array_Type _apropos (String_Type ns, String_Type s, Integer_Type flags)

 DESCRIPTION
   The `_apropos' function may be used to get a list of all defined
   objects in the namespace `ns' whose name matches the regular
   expression `s' and whose type matches those specified by
   `flags'.  It returns an array of strings representing the
   matches. 
   
   The second parameter `flags' is a bit mapped value whose bits
   are defined according to the following table

        1          Intrinsic Function
        2          User-defined Function
        4          Intrinsic Variable
        8          User-defined Variable


 EXAMPLE

       define apropos (s)
       {
         variable n, name, a;
         a = _apropos ("Global", s, 0xF);
         
         vmessage ("Found %d matches:", length (a));
         foreach (a)
           {
              name = ();
              message (name);
           }
       }

   prints a list of all matches.

 NOTES
   If the namespace specifier `ns' is the empty string `""',
   then the namespace will default to the static namespace of the
   current compilation unit.

 SEE ALSO
   is_defined, sprintf, _get_namespaces
--------------------------------------------------------------

_function_name

 SYNOPSIS
   Returns the name of the currently executing function

 USAGE
   String_Type _function_name ()

 DESCRIPTION
   This function returns the name of the currently executing function.
   If called from top-level, it returns the empty string.

 SEE ALSO
   _trace_function, is_defined
--------------------------------------------------------------

_get_namespaces

 SYNOPSIS
   Returns a list of namespace names

 USAGE
   String_Type[] _get_namespaces ()

 DESCRIPTION
   This function returns a string array containing the names of the
   currently defined namespaces.

 SEE ALSO
   _apropos, use_namespace, implements, __get_defined_symbols
--------------------------------------------------------------

_slang_doc_dir

 SYNOPSIS
   Installed documentation directory

 USAGE
   String_Type _slang_doc_dir;

 DESCRIPTION
   The `_slang_doc_dir' variable is a read-only whose value
   specifies the installation location of the S-Lang documentation.

 SEE ALSO
   get_doc_string_from_file
--------------------------------------------------------------

_slang_version

 SYNOPSIS
   The S-Lang library version number

 USAGE
   Integer_Type _slang_version

 DESCRIPTION
   The `_slang_version' variable is read-only and whose
   value represents the number of the S-Lang library.

 SEE ALSO
   _slang_version_string
--------------------------------------------------------------

_slang_version_string

 SYNOPSIS
   The S-Lang library version number as a string

 USAGE
   String_Type _slang_version_string

 DESCRIPTION
   The `_slang_version_string' variable is read-only and whose
   value represents the version number of the S-Lang library.

 SEE ALSO
   _slang_version
--------------------------------------------------------------

get_doc_string_from_file

 SYNOPSIS
   Read documentation from a file

 USAGE
   String_Type get_doc_string_from_file (String_Type f, String_Type t)

 DESCRIPTION
   `get_doc_string_from_file' opens the documentation file `f'
   and searches it for topic `t'.  It returns the documentation for
   `t' upon success, otherwise it returns `NULL' upon error.
   It will fail if `f' could not be opened or does not contain
   documentation for the topic.

 SEE ALSO
   stat_file

 SEE ALSO
   _slang_doc_dir
--------------------------------------------------------------

is_defined

 SYNOPSIS
   Indicate whether a variable or function defined.

 USAGE
   Integer_Type is_defined (String_Type obj)

 DESCRIPTION
   This function is used to determine whether or not a function or
   variable whose name is `obj' has been defined.  If `obj' is not
   defined, the function returns 0.  Otherwise, it returns a non-zero
   value that defpends on the type of object `obj' represents.
   Specifically, it returns one of the following values:

        +1 if an intrinsic function
        +2 if user defined function
        -1 if intrinsic variable
        -2 if user defined variable
         0 if undefined


 EXAMPLE
    For example, consider the function:

       define runhooks (hook)
       {
          if (2 == is_defined(hook)) eval(hook);
       }

    This function could be called from another S-Lang function to
    allow customization of that function, e.g., if the function
    represents a mode, the hook could be called to setup keybindings
    for the mode.

 SEE ALSO
   typeof, eval, autoload, __get_reference, __is_initialized
--------------------------------------------------------------

Conj

 SYNOPSIS
   Compute the complex conjugate of a number

 USAGE
   z1 = Conj (z)

 DESCRIPTION
   The `Conj' function returns the complex conjugate of a number.
   If its argument is an array, the `Conj' function will be applied to each
   element and the result returned as an array.

 SEE ALSO
   Real, Imag, abs
--------------------------------------------------------------

Imag

 SYNOPSIS
   Compute the imaginary part of a number

 USAGE
   i = Imag (z)

 DESCRIPTION
   The `Imag' function returns the imaginary part of a number.
   If its argument is an array, the `Imag' function will be applied to each
   element and the result returned as an array.

 SEE ALSO
   Real, Conj, abs
--------------------------------------------------------------

Real

 SYNOPSIS
   Compute the real part of a number

 USAGE
   r = Real (z)

 DESCRIPTION
   The `Real' function returns the real part of a number. If its
   argument is an array, the `Real' function will be applied to
   each element and the result returned as an array.

 SEE ALSO
   Imag, Conj, abs
--------------------------------------------------------------

abs

 SYNOPSIS
   Compute the absolute value of a number

 USAGE
   y = abs(x)

 DESCRIPTION
   The `abs' function returns the absolute value of an arithmetic
   type.  If its argument is a complex number (`Complex_Type'),
   then it returns the modulus.  If the argument is an array, a new
   array will be created whose elements are obtained from the original
   array by using the `abs' function.

 SEE ALSO
   sign, sqr
--------------------------------------------------------------

acos

 SYNOPSIS
   Compute the arc-cosine of an number

 USAGE
   y = acos (x)

 DESCRIPTION
   The `acos' function computes the arc-cosine of a number and
   returns the result as an array.  If its argument is an array, the
   `acos' function will be applied to each element and the result returned
   as an array.

 SEE ALSO
   cos, atan, acosh, cosh
--------------------------------------------------------------

acosh

 SYNOPSIS
   Compute the inverse cosh of an number

 USAGE
   y = acosh (x)

 DESCRIPTION
   The `acosh' function computes the inverse cosh of a number and
   returns the result as an array.  If its argument is an array, the
   `acosh' function will be applied to each element and the result returned
   as an array.

 SEE ALSO
   cos, atan, acosh, cosh
--------------------------------------------------------------

asin

 SYNOPSIS
   Compute the arc-sine of an number

 USAGE
   y = asin (x)

 DESCRIPTION
   The `asin' function computes the arc-sine of a number and
   returns the result as an array.  If its argument is an array, the
   `asin' function will be applied to each element and the result returned
   as an array.

 SEE ALSO
   cos, atan, acosh, cosh
--------------------------------------------------------------

asinh

 SYNOPSIS
   Compute the inverse-sinh of an number

 USAGE
   y = asinh (x)

 DESCRIPTION
   The `asinh' function computes the inverse-sinh of a number and
   returns the result as an array.  If its argument is an array, the
   `asinh' function will be applied to each element and the result returned
   as an array.

 SEE ALSO
   cos, atan, acosh, cosh
--------------------------------------------------------------

atan

 SYNOPSIS
   Compute the arc-tangent of an number

 USAGE
   y = atan (x)

 DESCRIPTION
   The `atan' function computes the arc-tangent of a number and
   returns the result as an array.  If its argument is an array, the
   `atan' function will be applied to each element and the result returned
   as an array.

 SEE ALSO
   cos, atan, acosh, cosh
--------------------------------------------------------------

atanh

 SYNOPSIS
   Compute the inverse-tanh of an number

 USAGE
   y = atanh (x)

 DESCRIPTION
   The `atanh' function computes the inverse-tanh of a number and
   returns the result as an array.  If its argument is an array, the
   `atanh' function will be applied to each element and the result returned
   as an array.

 SEE ALSO
   cos, atan, acosh, cosh
--------------------------------------------------------------

cos

 SYNOPSIS
   Compute the cosine of an number

 USAGE
   y = cos (x)

 DESCRIPTION
   The `cos' function computes the cosine of a number and
   returns the result as an array.  If its argument is an array, the
   `cos' function will be applied to each element and the result returned
   as an array.

 SEE ALSO
   cos, atan, acosh, cosh
--------------------------------------------------------------

cosh

 SYNOPSIS
   Compute the hyperbolic cosine of an number

 USAGE
   y = cosh (x)

 DESCRIPTION
   The `cosh' function computes the hyperbolic cosine of a number and
   returns the result as an array.  If its argument is an array, the
   `cosh' function will be applied to each element and the result returned
   as an array.

 SEE ALSO
   cos, atan, acosh, cosh
--------------------------------------------------------------

exp

 SYNOPSIS
   Compute the exponential of an number

 USAGE
   y = exp (x)