[This documentation seems to have been omitted from the repository
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for some time.
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+Hat 2.00 Wish List
+
+
+
+ 
+ Hat 2.00 Wish List
+
+
+
+
+This is a list of wishes (not bugs) to improve Hat 2.00.
+Elsewhere, there is a bug list of things
+that are incorrect. Please report any more wishes you can
+think of to: hat@haskell.org.
+
+
Little Wishes
+
+
+-
+1. backspace to correct slips in : command-lines
+ (Use stty erase ^H)
+
+
-
+2. separate cutoff length for strings from general cutoff depth
+
+
-
+3. advice for users wishing to use hat but not hmake
+
+
-
+4. in hat-trail :o [application-pattern] should work
+ (Done)
+
+
-
+5. in hat-observe :o [application-pattern] => new window not wizard!
+ (Done)
+
+
-
+6. in hat-observe support :i [module-name] -- if no module specified,
+ split listing into sections headed by module name
+ (Done)
+
+
-
+7. in hat-observe allow variables in application patterns to be
+ qualifed by module name
+ (Done)
+
+
-
+8. in hat-observe :I to list recorded constructor applications
+ (Done)
+
+
-
+9. in hat-observe an option to suppress display of results
+ (Done)
+
+
-
+10. in hat-observe allow application patterns after "in"
+
+
-
+11. in hat-observe an option to show the number of instances of
+ each uniquely represented application
+
+
-
+12. in hat-observe bring back % progress indicators
+
+
-
+13. in any viewing tool accept :S [qualified] name
+
+
-
+14. scrolling and resizing of source windows (with line numbers instead
+ of fixed source reference line)
+
+
-
+15. viewing tools compare time-stamps of trace files with those
+ of sources and issue warning if appropriate
+
+
-
+16. get priority info from .hat file to avoid need for extra brackets
+ when infix operators are used (eg in application patterns)
+ (Done)
+
+
-
+17. notation: replace (_IO_) by {IO}; replace {_} by {?}
+ (Done)
+
+
+
+Bigger Wishes
+
+
+-
+1. combine traced and untraced modules by a more drastic wrapping
+ (eg. data structures of type T computed within the wrapped module
+ recorded as {T}) and subclassing to get around mismatch of
+ method types (eg. Ord T => TOrd T and Ord a => Ord (R a))
+
+
-
+2. support tracing of locally defined functions by recording
+ bindings for free variables (eg. add refs to static parent
+ names in local name nodes and extend local argument lists to
+ include free variables defined within top-level parent with
+ the name entries for these variables)
+
+
-
+3. with or without 2, hat-observe to support observation of
+ locally defined functions or data values if :set locals on.
+ Locals to be listed by :i (indented below their parents?)
+ and observations of locals to be split into same-instance
+ groups (headed by whatever contextual bindings for variables
+ are available)
+
+
-
+4. extensional observation by hat-observe of a (\..) selected
+ in hat-trail (important to ensure that all observations
+ are of exactly this function not just a function with same
+ source)
+
+
-
+5. evaluation windows with bindings to selected expressions
+ from trace viewers (quite easy for expressions that only contain
+ top-level function names and/or fully evaluated data; anything
+ else poses representation problems)
+
+
-
+6. hat-trail to list the sequence of IO actions, not just text
+ output to stdout
+
+
-
+7. further decompose textual output into pieces connected by ++
+
+
-
+8. hat-trail to support multiple steps along trails Eg:
+ - to nearest ancestral application of any top-level function
+ - to nearest ancestral application of a named function
+ - to nearest non-recursive ditto
+
+
-
+9. hat-trail to support single-step forward reduction from a redex
+ (perhaps shown as indented lines starting ->)
+
+
-
+10. option to assert trust in named modules or top-level functions
+ in all trace-viewing tools
+
+
-
+11. hat-detect for new-format traces including correct handling
+ of untrusted computation in a trusted context and an option
+ to show all children of current EDT node
+
+
-
+12. generalise hat-observe to hat-query, with a user-programmable
+ query language for more general and powerful access to the
+ hat trace than current commands
+
+
-
+13. user-programmable display of expressions in textual or graphical
+ form
+
+
-
+14. hat-observe option to see arguments and results of trusted
+ (and perhaps other) functions that have 0-arity definitions
+
+
-
+15. a coordinating environment for tracing that, for example,
+ automatically closes trace windows when program is modified
+ and/or run again
+
+
-
+16. a tool that cleanly truncates a trace file as if the computation
+ had been interrupted at some specified break-point
+
+
-
+17. more support in hat-trail for tracing parent uses of zero-arity
+ definitions and their source locations
+
+
-
+18. run-time options to report the number of reductions (or other
+ computational steps) in an untraced computation and to report
+ corresponding numbers (or better still, a % indicator) at
+ intervals during a traced computation
+
+
-
+19. make source windows active, for example allowing selection of
+ an application or function for observation in hat-observe
+
+
-
+20. editable command lines with readline functionality
+
+
-
+21. special-purpose tool to locate black-holes in traces
+
+
-
+22. add an evaluation bit to projection/forward nodes allowing
+ {_}/{?} to be displayed as _ where appropriate
+
+
+
+Controversial Wishes
+
+
+-
+1. option to show lambda expressions in full
+
+
-
+2. a graphical user interface for hat viewers
+
+
-
+3. always display error "... message ..." if available, not _|_
+
+
-
+4. a Free Navigation viewer
+
+
-
+5. support for tracing stateful monadic computations in terms
+ of sequences of states
+
+
-
+6. option to use unification instead of one-way matching with
+ application patterns in hat-observe
+
+
-
+7. :o in hat-trail to use the currently selected expression as
+ the implicit application pattern to observe
+
+
+
+
+
+This page last updated: 5th February 2003
+
+
}