
===============================================================================
GENERAL ARCHITECTURE
===============================================================================

Implement better tools for debugging
  * Mechanism to recover all scheme error messages in a dedicated
    TeXmacs buffer, together with foldable backtraces.
  * Provide correct locations for the "texmacs-error" primitive.
  * Provide a clean exception semantics for all routines in the basic APIs.
  * Clean exception semantics for C++ routines which are exported to Scheme.
  * Emergency saving of modified buffers on fatal_error.
  * Throw-catch mechanism in C++ code when compiling with enable-debug
    and replacement of fatal_error when possible.
  * Test-suite of TeXmacs documents for different features and
    automated checks for certain types of correctness.

Hunt down memory leaks
  * Valgrind
  * Implement marking algorithm

===============================================================================
SCHEME INTERFACE
===============================================================================

Internal plug-in for Guile

Integrate menus in new GUI system

Naming conventions
  * Rename "drd-" -> "logic-" for routines from kernel/drd.
  * Appropriate naming convention for routines which operate on markup:
    when to use tmconcat-, concat-, concat/, tree-concat-, ...,
    especially for tags like "tree" which are also used as data types.

More systematic preservation of locality
  * Replace dispatch tables by contextual overloading where possible
    (i.e. LaTeX export).

===============================================================================
TYPESETTER
===============================================================================

General
  * Equivalent of TEX \topsep
    In TEXMACS, the \topsep always equals 0.75em. It should be possible
    to modify this. For symmetry, we might also introduce a ``bottom sep''.
  * Resizing macro expansions
    When attempting to resize a macro application to become smaller than
    the ``x'', the invisible markers may have undesirable side-effects.
  * Font parameters
    Separate environment variables for ``typewriter'', ``sans serif'',
    ``small caps'', ``slant'', etc.
    Find rendering font as a function of selected font and language.
  * Simplification of page parameters
    Should we still reorganize? It should be easy to access to
    the page width and height and some other parameters.

Text
  * Introduction of the paragraph tag
    Distinguish between paragraphs and paragraph units.
  * Page decorations (headers and footers)
    Should the corresponding environment variables become macros?
  * Fine-grained baseline skip
    Associate baseline skip (or ascent and descent) to each individual box
    in concatenation. Next compute maximum over each line. Take maximum of
    maximum after first line and maximum before second line in order to
    obtain final value. Also for other parameters such as baselineskip?
  * Precise scope of variables which affect paragraph layout.
  * User-defined hyphenations of words.
  * Cursor movement is extremely slow for oriental languages.

Mathematics
  * Horizontal grouping instead of \bigop ... \big.
    Introduce grouping primitives in which expressions with big operands
    (and maybe large delimiters) can be encapsulated. The advantage is that
    this eases parsing and an indicative bounding box is shown.
  * Scripts to large delimiters produced by macros
    Such scripts are not put at the right positions
  * Macro for fractions in continued fractions.
  * Less vertical spacing in text style between numerator/denominator and bar.
  * Left-numbering of equation arrays
    Should be possible now using the extern primitive.
  * Consider fractions and scripts as operators
    Consider fractions as operators => spaces before and after.
    Similarly for scripts => small space before left scripts and
    after right scripts.
  * Better spacing
    Determine spacing between two mathematical boxes as a function of
    the rough semantics of the boxes. Application: no need for operators
    like the unary minus.

Style-sheet language
  * Introduce a style options mechanism
    Option -> call back macro which can be enriched by several packages
    Call back macros called at end of reading style files when option selected
    Selected options postpended to name for style-file caching
  * Grey menu entries for parameters which cannot be changed in style
    For instance, a style might provide a limited number of font base sizes.

Boxes
  * Origin of boxes
    Boxes should not have origins; its children should have positions instead.

Current bridges
  * Temporarily inccorect markup
    When pressing A-backspace inside a surround tag, we first remove
    two children of the surround tag (so that it obtains arity 1) and
    next remove the tag itself. The temporarily inccorect surround tag
    of arity 1 may cause bridge_surround to crash.
    Temporary fix: add extra nodes in the bridge.
    Better fix: implement an elementary modification assign_label
    which allows to change the surround tag into another tag like tuple
    before performing incorrect operations.

===============================================================================
EDITOR
===============================================================================

Structured text
  * Icon menu for font size.
  * Buggy title environment: remove author, transform selection
    into title, etc.
  * Strong inside strong, "with color red" inside "with color red", etc.
  * "with color black" at the left/right extreme of "with color red".
  * Remove "document" when applying "strong" to a single paragraph.
  * More generally: automatically turn block content into inline content
    when appropriate.

Editing source trees
  * User-defined macros can be turned into a compound using the backspace key,
    builtin macros can't. Why is that? How do I change the name of the
    call to a buildin macro? Can I avoid removing it and creating a new one?
  * If the first argument of a call to a user defined macro contains a
    <document> tag, I cannot turn it into a compound any more. Why that?
  * There seems to be no way to manually create or remove <document> tags.
  * Edit the "init" part of a file in source code form.
  * Edit as option
    A facility "Edit as" to convert a selection into any other format and
    put the result in an "edit-as" tag for manual editing. When pressing
    return, reconvert back into TEXMACS.
  * More customizable presentation of source tags
    Make the presentation of source code more customizable by user macros.
    Done for syntactic highlighting, but should also be done for special
    rendering of certain primitives and the rendering of tags.
  * Primitive for block arguments
    Currently, we may stretch tags. We also need a primitive for stretching
    tag arguments.
  * Comments
    Tags for short commands inside the program.
  * Visual hints
    Display informative flags at places where tags have been stretched or
    a modification to the source style has been applied.

Styling
  * Assistant for creating your own styles.

===============================================================================
TOOLS AND FREQUENTLY USED SUBROUTINES
===============================================================================

Quoting
  * Implement different routines for quoting and quote/unquote
    using the appropriate routine.

General caching mechanism
  * Optimize performance as a function of cost of recomputation and
    storage requirement

LATEX import
  * Avoid name-clashes with built-in commands
    Importation of LATEX macros whose names coincide with built-in
    commands may lead to incorrect documents (e.g. the point macro
    in publs/1998/zeta.tex). We should probably post-correct imported
    documents.
  * Better parsing of verbatim arguments
    Some commands, like cite, documentclass, etc. take verbatim arguments,
    which should not be parsed in the generic way. The string_arg function
    is a temporary remedy.

===============================================================================
GRAPHICS EDITOR
===============================================================================

Interface
  * Better looking icons.
  * Explanatory messages on the status bar
  * Better "mouse button layout": do as much as possible with left mouse
    button only and reserve right button for contextual menu.
  * Compatability with pen-based devices.
  * Fine-grained resizing using keyboard (also allow modification of grain?).
  * Resizing using mouse.
  * Automatic detection of simple types of curves when dragging
    in drawing mode.
  * Automatic detection of simple ornaments (arrows, dots).
  * Cairo plug-in for nicer looking graphics.
  * Graphical macros and constraint-based drawings.
  * Documentation, reference guide (markup specification) and tutorial.

Reorganization of Scheme code
  * First rough reorganization of code.
  * Clean API for graphical objet and current decorations:
      1) remove/restore one object (while preserving z-order).
      2) remove/restore a selection of objects (while preserving z-order).
      3) specify decorations for current graphical object.
      4) undo and cancel.
  * Clean API for setting/retrieving graphical attributes
    (color, line width, line style, fill color, etc.).
      1) Selecting the value of a given attribute.
      2) Retrieving the value of a given attribute.
      3) Apply attributes to one or more objects.
      4) Retrieve attributes from one (or more) objects.
  * Clean API for global attributes of the entire graphics
      1) Set an attribute.
      2) Retrieve an attribute.
  * Clean API for simple object construction
      1) Different types of arguments: point, length, content, etc.
      2) Adding an argument to the current object.
      3) Removing an argument from a current object.
      4) Event handlers and how to map mouse buttons to different actions.
      5) Computation of decorations.
  * Clean API for groups.
      1) Adding an object / region.
      2) Removing an object / region.
      3) Geometric transformations.
      4) Changing z-order.
      5) Group / ungroup.
      6) Copy and paste.
      7) Computation of decorations.
  * Documentation of all APIs.

===============================================================================
UPCOMING STYLE REWRITING TOOL
===============================================================================

Reminders
  * Attention to implicitly changed variables, such as the-tags,
    the-label, etc., which may cause the entire document to be retypeset.
  * Attention to base-file-name, cur-file-name, current-part.
    Also put these variables in vars.hpp.
  * Replace "arg" primitive by quasi-quoting mechanism.
    This seems to be quite necessary: consider <assign|foo|<macro|body|...>>
    and a document piece <\foo>...</foo> with a large body. When making
    changes to the body; the environment for typesetting the body
    also changes, because we need to store the body in the "foo" environment
    argument variable. For this reason, we implemented an alternative
    mechanism, which is enabled using #define ALTERNATIVE_MACRO_EXPANSION.
  * More systematic usage of symbols instead of strings.
  * Should BibTeX labels really be prefixed by "bib-"?
  * Links and multiple views: which view should be selected when
    following a hyperlink. More generally: refine criteria for
    automatically preferring one locus over another one in presence
    of ambiguities.

Problem with auxiliary data in hidden markup (eg. labels, loci, links, indexes)
  * Analogy: hidden markup <-> loaded file which is not in a buffer.
    We might want to associate auxiliary data to tree nodes instead of files.
    Notice that there are different types of hidden structures:
      1) Contents should *not* be evaluated when hidden, but we need to
         keep track of auxiliary data. Example: a hidden chapter.
      2) Contents are evaluated but not typeset: auxiliary data may
         be kept in macro expander. Example: fold.
      3) Contents are not evaluated, not typeset and no auxiliary data
         are attached to the contents. Example: a comment or any piece of
         markup which has to be completely ignored.

===============================================================================
UPCOMING MARKUP-BASED GUI
===============================================================================

Remaining issues
  * Attach the action to be applied after popup input to a specific buffer.
  * Cleaner implementation of read-only parts in documents.
  * Cleaner implementation of size computation of widget.
    Also: notebooks and folding constructs, which may require
    to update the size later on.
  * Cleaner implementation of widget fields (i.e. the way we associate
    data to names).
  * Don't require the specification of a body for hidden input fields.
  * Argument history and browsing suggestions using keyboard.
  * Destroy call backs associated to a widget when the corresponding
    window is closed using another method than "dismiss".
    Idea: potentially associate a dismiss routine to each buffer.

===============================================================================
MANAGEMENT AND ADMINISTRATION
===============================================================================

Publicity

Mirror sites
  * CVS mirror at Savannah and automatic update scheme.
  * Also search for other mirror sites (increases availability and
    visibility on the web).

===============================================================================
TUTORIAL OR SERIES OF INTRODUCTORY ARTICLES (E.G. FOR LINUX MAGAZINE)
===============================================================================

General introduction/quick overview
  * Different purposes of TEXMACS
  * Writing a simple text
  * Style-sheets and writing a simple macro
  * Running a computer algebra system
  * Inserting an action tag which launches an xterm (and mutator tag?)

Writing simple structured texts
  * Why are structured documents useful?
  * How to enter structure into TEXMACS, redundancy of the interface
  * Understanding the visual indications, cursor movement
  * Editing the structure (removing structure, improper nesting, variants,
    numbering)
  * Exploiting structure: spell checking, searching
  * Reminders about correct typography

Writing mathematical texts
  * Entering math mode, equations, equation arrays
  * Simple mathematical formulas, recall cursor movement
  * Mathematical symbols, variants
  * Semantics of multiplication, function application and
    other implicit semantics
  * Simple matrices and other tabular environments

Writing simple macros and style-sheets
  * Rendering of source code, what is source code?
  * A simple macro
  * A simple style package
  * Customization of some existing macros

Etc.
