Package (.wl, .m)

Background

    ▪ MIME type: application/vnd.wolfram.wl, application/vnd.wolfram.mathematica.package
    ▪ Wolfram Language package source format.
    ▪ Used for storing and exchanging Wolfram Language programs, packages, and data.
    ▪ Plain ASCII text format.
    ▪ Stores Wolfram Language expressions in InputForm.
    ▪ Can represent program code, numerical and textual data, 2D raster and vector images, 3D geometries, sound, and other kinds of data.
    ▪ Developed since 1988 by Wolfram Research.

Import and Export

  • Import["file.m"] reads in a Wolfram Language package, evaluating each expression in it and returning the last one.
  • Export["file.m",expr] exports a single expression to a package source file.
  • The Wolfram Language always uses CharacterEncoding->"ASCII" for package source files.
  • Import["file.m",elem] imports the specified element from a package source file.
  • Import["file.m",{elem,suba,subb,…}] imports a subelement.
  • Import["file.m",{{elem1,elem2,…}}] imports multiple elements.
  • The import format can be specified with Import["file","Package"] or Import["file",{"Package",elem,…}].
  • Import["file.m"] is equivalent to Get["file.m"].
  • Export["file.m",expr,elem] creates a Wolfram Language source file by treating expr as specifying element elem.
  • Export["file.m",{expr1,expr2,…},{{elem1,elem2,…}}] treats each expri as specifying the corresponding elemi.
  • Export["file.m",expr,opt1->val1,…] exports expr with the specified option elements taken to have the specified values.
  • Export["file.m",{elem1->expr1,elem2->expr2,…},"Rules"] uses rules to specify the elements to be exported.
  • Put[expr1,expr2,…,"file.m"] can be used to export multiple expressions.
  • See the reference pages for full general information on Import and Export.
  • ImportString and ExportString support the package format.

Notebook Interface

  • In the notebook front end, Save As can be used to export a notebook as a Wolfram Language package.

Elements

  • General Import elements:
  • "Elements"list of elements and options available in this file
    "Rules"full list of rules for each element and option
    "Options"list of rules for options, properties, and settings
  • Import elements:
  • "ExpressionList"evaluates all expressions and returns the results as a list
    "Get"reads and evaluates all expressions, returning the last one
    "HeldExpressions"list of unevaluated expressions
    "InactivatedExpressions"list of inactivated expressions
    "Comments"code comments
  • Import by default uses the "Get" element for Wolfram Language package files.

Options

Examples

Basic Examples  (3)

Show the Import elements available in a sample file:

In[1]:=
Click for copyable input
Out[1]=

Import unevaluated expressions from this file:

In[2]:=
Click for copyable input
Out[2]=

Import all expressions and run them through Inactivate:

In[1]:=
Click for copyable input
Out[1]=

Import only the first expression from the package in Inactive form:

In[2]:=
Click for copyable input
Out[2]=

Export an arbitrary expression to the package format:

In[1]:=
Click for copyable input
Out[1]=

Import the previous output:

In[2]:=
Click for copyable input
Out[2]=

See Also

"MX"  "ExpressionML"  "NB"

Introduced in 1988
(1.0)
| Updated in 2014
(10.0)