library

Description

What a library of functions written in Scilab language is made of?

Such a library is made of a directory containing

• an editable XML file always named lib. This file contains
  1. the name of the library
  2. the list of names of public functions belonging to the library.
  This file is generated by genlib(..). It can't be made by hand.

• a set of binary files named with the .bin extension, whose basenames are the names of functions possibly registered in the lib file.

• and possibly -- but it's not mandatory to load and use the library --, the .sci sources files written in Scilab language, whose compilation with genlib(..) has generated the lib and .bin files.

  When the foo.sci source file of a foo() function is not provided in the library's directory, edit foo won't be able to edit its Scilab code, and will open a empty file from scratch.

Loading / declaring a library in the session:

load("/path/to/lib") then loads the targeted library in the Scilab session: a variable whose name is the library's name -- say libname -- is created. Its dedicated type(libname) is 14. Its typeof(libname) is "library". This library's handle contains

• the path to the library's root directory
• the list of public functions names belonging to the library.

Both parts can be retrieved with either the libraryinfo() or the string() functions.

Example: interpolationlib is a native Scilab library:

--> interpolationlib
 interpolationlib  =

Functions files location : SCI\modules\interpolation\macros\.
interp1  mesh2d  interpln  smooth

--> type(interpolationlib)
 ans  =
   14.

--> [typeof(interpolationlib), typeof(interpolationlib, "overload")]
 ans  =
  "library"  "f"

--> string(interpolationlib)
 ans  =
  "SCI\modules\interpolation\macros\"
  "interp1"
  "mesh2d"
  "interpln"
  "smooth"

--> [fnames, libpath] = libraryinfo("interpolationlib")
 fnames  =
  "interp1"
  "mesh2d"
  "interpln"
  "smooth"

 libpath  =
  "SCI\modules\interpolation\macros\"

Autoloading when first calling a function:

When the name of a function -- say foo() -- belonging to the library is called in the session, Scilab does the following:

1. Is foo the name of a builtin function? If so, this builtin is called. Otherwise,

2. Is foo the name of a local variable, possibly the required foo() (provided that it has been already called)? If so, this variable is used. Otherwise,

3. All loaded libraries are scanned -- in anti-alphabetical order of libraries names -- for the searched foo(). The first found is then "loaded" from its .bin file, and finally called. Next calls to foo() will then go up to the step #2 that will be successful, unless the foo handle has been cleared in the meantime.

Without the step #3, a user's function not belonging to any library and that would be cleared can not be automatically retrieved.

If the foo.sci file is modified while foo() has been already called, then recompiling and reloading its library won't update the current foo() behavior: foo() being already known, Scilab will stop at the step #2, without reloading the updated library, and will use the former foo(). Entering clear foo before the next call to foo(..) will force Scilab going up to the step #3 during the next call, and so load and use the updated foo().

Homonymous functions in distinct libraries: libname.foo()

If several loaded libraries have a foo() public function, the anti-alphabetical priority can be unrelevant. Fortunately, it is always possible to force to use the instance of a given library, with the dot-name's resolution syntax: libname.foo(..) will call the foo() instance belonging to the libname library.

Examples

interpolationlib is a native Scilab library:

interpolationlib        //displays the contents of the library
type(interpolationlib)
[typeof(interpolationlib), typeof(interpolationlib, "overload")]
string(interpolationlib)
[fnames, libpath] = libraryinfo("interpolationlib")

The output is illustrated in the above Description section.

Handling calls of homonymous functions:

whereis(blanks)
clear blanks, isdef("blanks","l")
blanks(20)          // loads blanks() and calls it
isdef("blanks","l") // It stays in the workspace

// Building a library with our own homonymous blanks() function
libDir = fullfile(TMPDIR, "mylib");
code = ["function r = blanks(n, nbsp)"
        "    if nbsp, r = part(ascii(160),ones(1,n)),"
        "    else r = ""ABC"","
        "    end"
        "endfunction" ];
mkdir(libDir);
mputl(code, libDir + filesep() + "blanks.sci");
genlib("mylib", libDir);    // Compiling our own library

clear blanks
ascii(blanks(3)) // stringlib.blanks() is called ⇐ "stringlib" > "mylib"
clear blanks
ascii(mylib.blanks(3,%t)) // forced call to mylib.blanks()
blanks(3)        // Next call is with the default stringlib.blanks()

--> whereis(blanks)
 ans  =
  "stringlib"

--> clear blanks, isdef("blanks","l")
 ans  =
  F

--> blanks(20)          // loads blanks() and calls it
 ans  =
  "                    "
--> isdef("blanks","l") // It stays in the workspace
 ans  =
  T

--> // Building a library with our own homonymous blanks() function
--> libDir = fullfile(TMPDIR, "mylib");
--> code = ["function r = blanks(n, nbsp)"
  >         "    if nbsp, r = part(ascii(160),ones(1,n)),"
  >         "    else r = ""ABC"","
  >         "    end"
  >         "endfunction" ];
--> mkdir(libDir);
--> mputl(code, libDir + filesep() + "blanks.sci");
--> genlib("mylib", libDir);    // Compiling our own library

--> clear blanks
--> ascii(blanks(3)) // stringlib.blanks() is called ⇐ "stringlib" > "mylib"
 ans  =
   32.   32.   32.

--> clear blanks
--> ascii(mylib.blanks(3,%t)) // forced call to mylib.blanks()
 ans  =
   194.   160.   194.   160.   194.   160.

--> blanks(3)        // Next call is with the default stringlib.blanks()
 ans  =
  "   "

See also

• load — Loads some archived variables, a saved graphic figure, a library of functions
• lib — loads a library of Scilab functions and variables, and sets its name
• genlib — builds a library from a set of *.sci files defining functions in a given directory
• libraryinfo — retorna macros e endereço de uma biblioteca Scilab
• string — conversão para string (cadeia de caracteres)
• whereis — Returns the name of the loaded library/module a given function belongs to
• librarieslist — retorna as bibliotecas do Scilab

History