What's New in CQL 6.2

CQL 6.2 explores certain syntactical and semantic ideas that allow more natural and concise expression of chess themes. New features include:

• A more powerful and more concise syntax for moves, the ―― . The ―― (ASCII: --) filter is designed to replace the move syntax.
• A replacement for line, ⊢ . The ⊢ (ASCII: path) filter is much more concise and more powerful than the old line filter, which it is intended to replace. ⊢ also supports several CQLi features: atomic variables and keepallbest parameter.
• ◎, which allows the ⊢ filter to restrict its attention to moves by specified pieces. ◎ is intended to work closely with the piecepath parameter of ⊢ to facilitate clear and informative annotation of complex movement patterns in the generated PGN files.
• Support for chess figurine notation (♔, ♜).
• other unicode special symbols for common operations like ⬓ and ✵ . See palette for a concise list of the new symbols.
• More concise iteration syntax to iterate through squares or pieces in a set, or through a dictionary.
• Filters for puremate, modelmate, idealmate, purestalemate, modelstalemate, idealstalemate.
• More concise and clearer annotation filter replacing most usages of comment
• New symbols ≺, ≻, ≼, and ≽ which replace the older ancestor and descendant filters.
• More concise and clearer symbols → and ← replacing attacks, attackedby, and xray.
• More powerful dictionaries. Dictionaries can be local and can have arbritrary types for their keys and values.
• The similarposition filter, which compares all the positions in another pgn file to the current position.

To get used to the new syntax, we recommending browsing through the links below:

Subject	description
unicode	how Unicode is used in CQL
――	The new ―― syntax, for making a move
⊢	The new ⊢ syntax, for sequences of moves
examples	Examples of the new syntax

CQL 6.2 also introduces some new filters:

Name	Description
piecename	get the character representing the type and color of a square
typename	get a character representing the type of a square
try	the current position derives from a try (for endgame studies)
current move filters	determine information associated with the move leading to the current position, including from, to, o-o, o-o-o, castle, nullmove
///	concise annotation syntax
∊	concise iteration syntax
lastgamenumber	number of games in input file
local dictionaries	dictionaries that are not persistent
dictionary	dictionaries now accept any CQL type (strings, numbers, sets, positions) as key or value

Windows GUI

Emil Vlasák has contributed a new version of his Windows GUI for CQL that supports Unicode.

compatibility with CQL 6.1

CQL 6.2 is almost entirely back compatible with CQL 6.1: any CQL 6.1 file should run unchanged in CQL 6.2. (There are some very minor differences - for example in the datatype of chained relational operators on positions - that will virtually never arise in practice).