v5.0

  * added an optional term-equivalence predicate to the test--> and
    test-->> forms

  * added R6RS and Racket VM models to examples sub-collection

  * fixed minor bugs
  
v4.2.5

  * reversed the order in which `where' and `side-condition' clauses
    appear in typeset definitions

  * added support for `where' and `side-condition' clauses that do not
    appear in the metafunction's typeset definition

  * added a #:print? flag to redex-check, to control whether it prints
    or returns its result

  * renamed the #:attempts keyword to #:attempt-num in the `generate-term' form

  * changed typesetting to render `where' clauses as `fresh' clauses
    when the right-hand side is a call to `variable-not-in' or 
    `variables-not-in'

  * changed typesetting of meta-variables to render anything following
    a caret (^) as a superscript

  * minor bug fixes

v4.2.4

  * minor bug fixes

v4.2.3

  * added support for collecting metafunction coverage, using the
    'relation-coverage' parameter. This includes a backwards
    incompatible change: the parameter's value is now a list of
    coverage structures, to allow coverage collection for multiple 
    metafunctions and reduction relations at once.

  * redex/reduction-semantics exports the names `hole' and `in-hole'
    (and `term' no longer captures those names).

  * minor bug fixes

v4.2.2

  * minor bug fixes

v4.2.1

  * improved 'where' conditions in metafunctions and
    reduction-relations so that they work with Redex's full pattern
    language. 

    This is a backwards incompatible change. In old versions,
    variables used in a where clause were independent of the pattern
    language. Now, if the variable in a where clause is a literal in
    the grammar, the result of the where clause must be that
    literal. Similarly, if the variable is a non-terminal, the result
    must match that non-terminal.

  * added 'define-relation' 

  * relaxed the restrictions on metafunctions so that multiple
    pattern matches are allowed, as long as the right-hand side
    has the same value for each different pattern binding

  * added metafunction styles 'up-down/compact-side-conditions,
    'left-right/compact-side-conditions, and 
    'left-right/beside-side-conditions.

  * added #:x-spacing and #:y-spacing parameters to traces and
    traces/ps

  * changed the grammar for 'side-condition' clauses
    from (side-condition scheme-expression ... )
    to (side-condition scheme-expression)

v4.2

  * minor bug fixes

v4.1.5

  * renamed test--> to test-->>

  * added a new test--> that only tests for a single step in the
    reduction sequence

  * added #:cycles-ok flag to (what is now called) test-->>

  * define-metafunction and reduction-relation now work better with
    Check Syntax
    
  * added the #:arrow keyword to reduction-relation, which lets you use
    a different main arrow (mostly useful for the typesetting)

  * added domain specifications to reduction relations via
    the #:domain keyword

  * 'traces' copes better with errors during reduction 

  * initial-char-width now accepts functions to give finer grained
    control of the initial widths of the terms.

  * traces & traces/ps: added the ability to specify a mixin
    to be mixed into the graph pasteboard

  * added built-in patterns natural, integer, and real
  
v4.1.4

  * added redex-check, a tool for automatically generating test cases
    for Redex specifications.

  * improved traces for use in generating PostScript:

    - added traces/ps

    - added more coloring arguments to traces: #:scheme-colors? 
    #:default-arrow-highlight-color, and #:default-arrow-color

    - added the #:layout argument to traces 

    - added term-node-set-position! and related term-node functions

  * Added tracing to metafunctions (see current-traced-metafunctions)

  * added caching-enabled? parameter (changed how set-cache-size! 
    works)

v4.1.2

  - added white-bracket-sizing to control how the brackets
    are typeset when rendering a metafunction.

  - added render-* functions that make it easier to experiment
    with typesetting at the REPL.

  - where clauses in metafunctions now are implicitly in
    `term's (they were not documented at all before)

v4.1 (this is the first version that was included in the PLT
      distribution. Before this, Redex was in PLaneT).

  EXTENSIONS:

  - added test-equal, test-pred, test-reduces, and test-results

  - removed restriction on apply-reduction-relation*
    replaced it with additional work while matching
    non-terminals to remove the redundancy

  - added `in-domain?'

  CHANGES:

  - define-metafunction and co. now use a different syntax.

  - got rid of named holes. This means, eg, that (hole #f) now matches
    a two element list, not just the hole directly.

  - zero occurrences of a hole when matching an `in-hole' now
    correctly fails.

  - the `where' keyword in reduction-relation became `with' (and the
    arguments reversed order)

  - renamed the `rib' struct to `bind' (and mismatch-rib =>
    mismatch-bind)

  - merged the various traces functions into a single
    function that accepts keyword arguments.

  - renamed the loc-wrapper struct to lw.

  - language->ps and language->pict's listof-symbols is now
    optional and thus the language->ps's arguments changed
    order to make that work.

  - renamed test-match to redex-match

  - no long export mtch struct or bindings struct and
    test-match's result is not simplified.

  - extend-reduction-relation now uses the names of the
    rules to replace existing rules (instead of just
    unioning the rules)

  - in-hole used to substitute into named holes, but now it
    only substitutes into unnamed holes. Use in-named-hole
    on the right-hand side to do the substitution

  - removed hole-here

  BUG FIXES:

  - fixed a (not easily noticed) bug in the way hole
    matching worked for named holes.

  - extending a non-terminal that's been defined together
    with other non-terminals now works as expected.

  - handling of non-terminals uses that have underscores in
    them now works properly (only showed up when using them
    in the definition of a language)

  - an extended language can now define multiple non-terminals
    together

-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
below here were the versions of Redex that appeared in PLaneT
-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-

("robby" "redex.plt" 4 4)

  - undid some changes that broke backwards compatibility

("robby" "redex.plt" 4 3)

  - added extend-reduction-relation
  - fixed a bug whereby reduction relations that reduced to
    false were always ignored

("robby" "redex.plt" 4 2)

  - fixed a bug in the way `in-hole' inside
    an ellipsis on the right-hand side of a
    reduction rule.

("robby" "redex.plt" 4 1)

  - improved stepper so that scrolling works when large
    terms are present.

("robby" "redex.plt" 4 0)

  - changed conventions for subscripts. Now, non-terminals
    w/out subscripts bind in reduction rules (but they still
    do not bind in grammar definitions).

  - wheres and side-conditions now bind as expected in
    reduction-rules

  - fixed a bug in metafunction pict generation (parallel
    fix from 3.28)

  - renamed horizontal-arrow-space to arrow-space.
  - renamed horizontal-label-space to label-space.

("robby" "redex.plt" 3 27)

  - added horizontal-arrow-space, horizontal-label-space
  - number & variable now typeset in italics (to match the other non-terminals)
  - improved fresh variable generation
  - added `where' for bindings in metafunctions
  - added 'up-down mode for metafunction typesetting
  - added optional argument to reduction-relation->pict &
    reduction-relation->ps
  - PR 8957

("robby" "redex.plt" 3 26)

  - fixed a bug in pict generation

("robby" "redex.plt" 3 25)

  - added hole-here support for `term'

("robby" "redex.plt" 3 24)

  - added curly-quotes-for-strings and current-text

("robby" "redex.plt" 3 23)

  - fixed a bug that cause typesetting of grammars that
    defined hole as the first production of some
    non-terminal.

  - added hide-hole pattern

("robby" "redex.plt" 3 22)

  - ??

("robby" "redex.plt" 3 21)

  - added `where' as a binding form in the individual
    clauses of a reduction-relation.

  - typesetting: 

    - improved handling of nested term, quote,
      unquote, and unquote-splicing.

    - fixed up in-named-hole and (hole x) to use subscripts.

    - improved the docs for the loc wrappers to explain
      logical spacing.

    - improved typesetting of languages built with
      extend-language. See extend-language-show-union.

    - added set-arrow-pict!

("robby" "redex.plt" 3 20)

  - improved the interface for rewriting aspects of the typesetting.

  - added linebreaks, with-compound-rewriter, and with-atomic-rewriter

("robby" "redex.plt" 3 19)

  - improved source locations for error messages when misusing ellipses, eg:
    (term-let ([(x ...) '(1 2)] [(y ...) '(1 2 3)]) (term ((x y) ...)))
    or similar things via reduction-relation, metafunctions, etc.

  - fixed PR 8752: `name' patterns only show the name,
    leaving the thing defined to the where clause

("robby" "redex.plt" 3 18)

  - fixed PRS relating to pict generation: 8749 8751 8750
    and a few other bugs along the way.

("robby" "redex.plt" 3 17)

  - initial-char-width now controls both the stepper & traces

("robby" "redex.plt" 3 16)

  - added define-multi-args-metafunction
  - finished first pass of the pict generation rewriting

("robby" "redex.plt" 3 15)

  - fixed a bug in stepper/seed

("robby" "redex.plt" 3 14)

  - fixed some silly mistakes in the packaging

("robby" "redex.plt" 3 13)

  - added variable-not-otherwise-mentioned as a new pattern
  - added stepper/seed
  - added an optional pretty-printing argument to stepper.
  - improved the ps rendering of the arrows
    for --> -> => ==> ~> and ~~>
  - rewrote internals of pict rendering (hopefully no change
    yet, but there may be bugs introduced ...).

("robby" "redex.plt" 3 12)

  - Added pict and .ps generation functions for
    reduction-relations, metafunctions, and grammars. These
    are still primitive; the most obvious missing feature is
    the inability (without secret knowledge) to replace the
    pink stuff.
  - fixed a bug in the way the stepper highlights
    differences in the presence of quote (by disabling the '
    shortcuts printing)

    NOTE this version of redex requires not just any
    369.100, but one from 5/19 in the afternoon (or newer).

("robby" "redex.plt" 3 11)

  - changed the order of the arguments in the new `fresh' clauses
    introduced in the last release.

("robby" "redex.plt" 3 10)

  - fixed bugs in the way that ..._x patterns work (they 
    didn't handle binding well).
  - fixed misc bugs in the stepper
  - added the ability to generate a sequence of fresh variables
    in a single rule

("robby" "redex.plt" 3 9)

  - added side-condition specs to metafunctions
  - added test-reduces and test-reduces/multiple to schemeunit.ss
  - fixed a bug in the handling of _!_
  - improved the "found the same binder" error message to show
    the source locations of the two offending binders

("robby" "redex.plt" 3 8)

  - fixed a bug in the way (hole #f) patterns matched.
  - fixed a bug in the initial height of the boxes in `traces' 
  - added reduction->relation-names
  - added ability to step until a particular reduction (and
    the reduction labels) in the stepper.

("robby" "redex.plt" 3 7) 

  - improved syntax error message (PR 8576)
  - added difference highlighting for adjacent terms in the stepper

("robby" "redex.plt" 3 6)

  - added stepper

("robby" "redex.plt" 3 5)

  - bugfix (I think ... this version's changes seem to have been forgotten)

("robby" "redex.plt" 3 4)

  - added term-node-children

("robby" "redex.plt" 3 3)

  - added term-match and term-match/single
  - added variables-not-in
  - fixed a bug in metafunctions

("robby" "redex.plt" 3 2)

  - added language-nts
  - added better error messages when using parts of the
    pattern language as ordinary things in the grammar.

("robby" "redex.plt" 3 1) 

  - adds the ability to have multi-colored terms, not just
    pink ones.

("robby" "redex.plt" 3 0)

This release changes the syntax of the reduction relations
to make it more consistent and more in line with the way
reduction relations are written in papers. This is the
precise set of removals and additions:

  - added extend-language
  - added reduction-rule & apply-reduction-relation
  - added union-reduction-relations
  - added define-language

  - changed compatible-closure & context-closure so that the
    pattern argument is not quoted, but is just the pattern
    in the last argument.

  - changed term-node-labels so that it can return #f (in
    the list) when a reduction doesn't have a label.

  - removed language->predicate, compile-pattern,
    match-pattern (use test-match instead)

  - removed reduction, reduction/name, reduction/context,
    reduction/context/name (use reduction-relation instead)

  - removed red? (use reduction-relation? instead)

  - removed reduce (use apply-reduction-relation instead)

  - removed reduce-all (use apply-reduction-relation* insetad)

  - removed reduce/tag-with-reduction (use
    apply-reduction-relation/tag-with-names instead)

  - removed red-name, reduction->name, give-name

  - removed language (use define-language instead)

  - removed helper.ss

Other improvements:

  - check syntax draws arrows for the non-terminals in a
    `language' now, both to the language and to the
    reduction rules.

("robby" "redex.plt" 2 6)

  - added reduce-all and note about bad parsing performance
    issues.

  - added `test-match' and note about how to debug redex
    programs to doc.txt
 
  - added redex-specific 'check' functions for use with
    schemeunit.

  - add `metafunction' for defining meta functions using the
    pattern matching notation used in reductions and grammars.

("robby" "redex.plt" 2 5) 

  - fixed bugs in compatible-closure & context-closure

("robby" "redex.plt" 2 4) 

  - reduced the amount of memory used for caching
    significantly (with some small speedup for 
    a largeish reduction semantics test suite)

  - added set-cache-size!

  - added variable-prefix pattern

  - added ..._<id> pattern that can be used to ensure matching
    lengths of repeated patterns.

  - added _!_ subscripts (both in ... and regular) to ensure
    that the matched things are different (or have different
    lengths in the case of ..._!_ subscripts)

("robby" "redex.plt" 2 3) 

  - added the ability to traverse the graph generated by
    traces in order to decide if a term should be
    highlighted in red. See the traces/pred documentation
    for details.

  - added term-node functions

  - added red-name function

  - removed make-plt.ss from archive

("robby" "redex.plt" 2 2)

  - added a blurb, fixed a typo in the docs.

("robby" "redex.plt" 2 1)

  - changed the way a contract is specified on the matcher
    to get a 30% speed up on the beginner test suite.
    Thanks, Matthew for spotting that!

("robby" "redex.plt" 2 0)

  - fixed a bug in compatible-closure handling that could
    result in duplicate matches when there should only have
    been a single match.

  - added labels to edges for reductions
    when shown in GUI. See docs for
    reduction/name

  - small performance improvement to matcher 
    (10-20% on non-trivial examples)

  - added letrec.ss example (and improved some
    of the examples to use labels)

("robby" "redex.plt" 1 3)

  - Fixed a bug in the compatible closure function; otherwise the
    same as 1.1

("robby" "redex.plt" 1 2)

  - Obsolete'd version. It used to be a first attempt at the 2.0
    revision, but now should be avoided. 

    Use 2.0 instead of this version.

("robby" "redex.plt" 1 1)

  - fixed packaging error

("robby" "redex.plt" 1 0)

  - initial release to PLaneT

