Re-organized TODO file

11 files changed, 256 insertions, 155 deletions

diff --git a/TODO.md b/TODO.md
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-# TODO list
-
-This is a list of things that I would like to add or change at some point.
-It's more of a personal reminder than anything else.
-
-## After symcoord
-### Fixing stuff + completing new optimal solver
-- clean up fst, check if more can be improved
-### generic:
-* all files should have an init function, calling the ones
-  of the files includes + doing more stuff. A static "initiliazed"
-  variable is probably needed too.
-### testing!
-* generic test util: function taking an array of tests, an array of testnames
-  (or maybe tests should be their own type?) and running them
-* separate "commands" for testing different parts (e.g. ./test coord)
-* test coordinate (needed anyway to test fst)
-* other tests (start from bottom: utils.c)
-* move test_coord to the testing folder
-### Solving standard coordinates
-* add Void * extradata to DfsArg and a custom move function
-* add optional custom pre-process for generating special table (nx)
-* copy_dfsdata should copy extra too!
-### Solving simplification / refactor
-* Split solve in solve_coord, solve_generic, solve_singlethread...
-* Rework choicesteps: simplify, remove one type of rotation...
-### nx.c
-* implement nxopt with all tables and all tricks
-  (maybe compile time variable for maximum memory to use?)
-* is_valid should also unniss / cleanup the alg
-### Other easy refactor
-* split cubetypes.h into other files
-
-## For version 2.1
-### Changes to Step and Solve
-* remove cube from dfsarg? (i still need to save the scramble somewhere,
-  but I really only use it in dfs_niss)
-* coord.c: all old coordinates (WIP...)
-* steps.c: checkers (use coordinates), all stepalt and steps (WIP...)
-* commands gen and freemem
-* commands.c: twophase, ...?
-### Rotate, not transform, before solving
-* solve should re-orient first if needed and not just give up if centers are off
-### Documentation
-* Document how coordinates and pruning tables work now
-* Write an examples.md file
-* More screenshots!
-### Tables management
-* Check files in tables directory automatically remove old / extraneous files
-* Add checksum to check that tables are generated / downloaded correctly
-### Conditional compiling
-* Option to avoid large tables at compile time
-* option to avoid multithreading (write a simpler solve for t=1, and also
-  check if found enough solutions before checking pruning values)
-### Technical
-* generic option parser
-* scan system to get best number of threads
-### Commands
-* Easy: add option -I (inverse) and -L (linear, like inverse + normal)
-  to do only linear NISS
-* message for -N ignored say -n (lowercase)
-
-## Commands
-
-### Commands that are available in nissy 1.0, but not in this version (yet):
-* drcorners (solve corners after dr)
-* search and improve non-optimal subsequences
-* save and edit algs as "variables"
-  (or just use a "logging system" to keep info about previously run commands,
-including e.g. solutions that were not shown because -c)
-
-### More steps for `solve`
-* QTM optimal solving
-* 5-side solve (for robots)
-* Block-building steps (cross, roux blocks, ...)
-* Other common steps (LSE, ...)
-* Larger table for drudfin (include epe)? About 1Gb uncompressed,
-  500Mb compressed (fallback to noE), 250 compressed + parity trick
-  (is it doable?)
-
-### Improvements to currently implemented commands
-* solve multidfs: do multithread by step, not by alternative (this way
-  if there are multiple alternatives it can make use of more threads)
-* solve should try up to a small bound without loading the large pruning table
-  (maybe this is not necessary if loading the table is fast enough)
-* silent batch mode without >>>
-* Optimal solver: when asking for only one solution, scan for upper bound in
-  parallel using a two-phase solver.
-
-### New features
-* EO analysis (and also DR and HTR analysis): group similar EOs together
-  and such (suggested by Jay)
-* configurability: add an `alias` command, run config file at startup
-* command notation to list available moves
-* make multi-step solve much more general and create command
-* input directly cube status instead of moves
-  (graphical: maybe there is a cubing.js function; command line: ???)
-
-## Distribution
-* webapp (cgi)
-
-## Technical stuff
-
-### Memory management
-* free pruning table after solve is done? if I do this I need to deafault to a
-  small table for < 8 moves solutions or smth
-* improve multi-threading when solving multiple scrambles
-* nissy -M maxmem option for running with at most maxmem memory; if exceeded
-  when loading a pruning table, return failure (or make every solve command
-  use tiny tables instead?); if maxmem is very 600Mb or
-  less do not use invtables (the performance loss is minimal anyway). If the
-  limit is really tiny, do not use mtables or ttables (but this would be
-  very slow and probably nobody will ever use it)
-* Check if memory is enough for loading pruning tables; if not, abort
-* For optimal solver: choose largest that fits in memory between nxopt and light
-
-### Structural changes
-* client/server architecture: run a server process in the background so that
-  multiple client processess can send it queries and get results; this would
-  open up the door for a web-based version or graphical clients
-
-### Cleanup
-* sort again functions alphabetically in their files
-* change some function and variable names to make everything consistent
-* more stuff to load at start (or when suitable command is called) rather
-  than when called directly, to avoid nasty problems with threading
-* parse command args: one function per arg type, then each command has
-  a list of options that it accepts (as a string)
-
-### Style
-* do not declare all variables at the beginning of a function
-* remove var names from prototypes
-* various stuff from style(9)
-
-### Random
-Collect random info like this somewhere:
-
-Table pt_nxopt31_HTM
-Base value: 9
-0               1
-1               6
-2              29
-3             164
-4            1433
-5           16772
-6          205033
-7         2513871
-8        30329976
-9       342440769
-10     2815191126
-11     6147967200
-12      524918774
-13           3546
-14              0
-15              0
diff --git a/TODO/2.1.md b/TODO/2.1.md
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+# TODO-list for version 2.1 (or is it 3.0 at this point?)
+
+## Rework solver
+
+* Split solve in solve_coord, solve_generic (and maybe solve_singlethread, see
+  notes about build options).
+* Add a void * extradata to DfsArg.
+* remove cube from dfsarg? (i still need to save the scramble somewhere,
+  but I really only use it in dfs_niss)
+* Re-work prepare_step process for solve_generic (nxopt table is special).
+* is_valid should also unnis and / or cleanup the alg.
+
+## New optimal solver (use fst)
+
+* Implement nxopt31 with fst_cube. Remember that the function
+  move_check_solved() should do one axis at the time, so that we don't move
+  everything before checking.
+
+## Simplify steps
+
+* Remove one type of rotation.
+* Change steps to choicestep and stepalt to step (or was this already done?).
+
+## Add missing coordinates and steps
+
+* Check the old file for a list. Many are missing.
+* Checkers in steps.c should use coordinates.
+
+## Missing and new commands
+
+* gen
+* freemem
+* twophase
+
+## Easy improvements
+
+* Solve should re-orient the cube if centers are off
+* Solve: add options for -I (inverse only) and -L (linear = normal + inverse).
diff --git a/TODO/build-options.md b/TODO/build-options.md
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+# Build options for memory and multithreading
+
+## Investigate
+
+* Check exactly how much memory is needed for everything.
+* Take note of which parts use threading (solving, genptable, other?).
+
+## Prepare code
+
+* Use define / ifdef or similar to compile and build tables only for the
+  parts to be used.
+* If threads = 1, use a much simpler version of the solve method. Remember
+  that checking if enough solutions have been found is the first thing to
+  do in singlethread (no locking).
+* Do not include pthread if threads = 1. 
+* Only one optimal solver should be compiled.
+* Some simple steps may also need alternatives with smaller tables
+  (e.g. for staying sub 1Gb). For example dr and drfin.
+* If necessary, work out alternatives to "twophase" for low-resource versions.
+
+## Makefile
+
+* Figure out how to change these options via makefile. For example: one
+  variable for the maximum allowed ram and one for the number of threads.
+* (Optional) use a configure script?
+* (Optional) interactive installation script?
+
+## Automate
+
+* Scout for resources during installation and choose best configuration
+  automatically.
+* How to do this in Linux / POSIX?
+* How to do this in Windows?
diff --git a/TODO/documentation.md b/TODO/documentation.md
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+# Documentation
+
+## Big documentation file on nissy's internals
+
+* Coordinates
+* Symcoordinates
+* Pruning tables
+* Coordinate solving
+* fst cube
+* Optimized solver
+* Multithreading
+* Commands etc...
+* Code architecture
+
+## examples.md
+
+* Example file for nissy's website and documentation folder
+* With screenshots!
+
+## Random info
+
+Where to collect random information like this table?
+
+Table pt_nxopt31_HTM
+Base value: 9
+0               1
+1               6
+2              29
+3             164
+4            1433
+5           16772
+6          205033
+7         2513871
+8        30329976
+9       342440769
+10     2815191126
+11     6147967200
+12      524918774
+13           3546
+14              0
+15              0
diff --git a/TODO/easy.md b/TODO/easy.md
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+# Easy things to improve or add
+
+## Improvements
+
+* Silent batch mode without >>>
+* Solutions should be shown sorted: by length first, then by normal moves
+  (no niss) first, then it depends on the step (e.g. EO by axis).
+
+## Old commands and steps
+
+* drcorners (solve corners after DR)
+* Search and improve suboptimal subsequences
+
+## New commands
+
+* notation: show valid moves
diff --git a/TODO/installation.md b/TODO/installation.md
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+# Simplify and improve installation
+
+## Tables
+
+* Make install should generate tables, or add a "make tables" target to
+  generate tables.
+* Make tables should also check for existing files and remove old ones
+  (maybe more for nissy's command than for makefile).
+
+## Correctness
+
+* Add checksum for all generated files.
+* Hard-code results? Check for compatibility problems between different OSes
+  and filesystems - but there should not be any, since we use stdint.h.
diff --git a/TODO/new-feature-ideas.md b/TODO/new-feature-ideas.md
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+# Possible new features and improvements
+
+This file contains non-refined ideas. Once an idea gets refined, it will
+get its own file and more details.
+
+## Steps
+
+* QTM solver
+* 5-side solver (for robots)
+* Other steps (cross, blocks, LSE...)
+
+## UX features
+
+* Save algs as variables and edit them (like in old nissy)
+* Use a logging system for previously run commands, info, results...
+  (e.g. when solving with -c solutions are not shown, they can be logged here)
+* Configurability: add an "alias" command, run config file at startup
+* Input cube state directly instead of moves (ugly from command line / file)
+
+## Improvements
+
+* Optimal solver: when asking only for one solution, scan for upper bound in
+  parallel using a non-optimal (but fast) solver (e.g. twophase).
+* Optimal solver: up to a small bound, try with a small pruning table.
+* Multi-step solver: make more general
+
+## New features
+
+* EO analysis (and also DR and HTR analysis): group similar EOs (Jay)
+* HTR "maze" analysis?
diff --git a/TODO/parser.md b/TODO/parser.md
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+++ b/TODO/parser.md
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+# Improve command parser
+
+First, expand this TODO file to be more precise.
+
+## Refactor
+
+* The syntax of a command's options should be described by data, not by a
+  parser function.
+* A single parser function can then parse options for all commands.
+
+## Usability
+
+* Better error messages!
diff --git a/TODO/refactoring.md b/TODO/refactoring.md
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+# Refactoring
+
+## Init functions
+
+* All .h files should have a single init function.
+* This function should initialize everything that this module needs, including
+  calling the init functions of the modules it depends on.
+* To avoid multiple initialization of the same module, each should have a
+  static bool initialized variable.
+* Everything that a module needs should be initialized by init(), avoid
+  initializing stuff when solving. Exception: pruning tables, move tables.
+* Most functions should generate some tables and save them to disk.
+* Init functions should have a consistent structure (e.g. the way they check
+  if the tables are already generated should be the same).
+
+## Cube types
+
+* Get rid of cubetype.h, split type definitionss into the other modules.
+* Every type definition should be in the most fundamental module that needs it.
+
+## Code style
+
+* Stop declaring all variables at the beginning of a function.
+* Remove variable names from prototypes.
+* Sort function implementations alphabetically, ignore static vs non static.
+* Rename functions and variable to have a consistent naming scheme.
+* Functions that copy data: swap src and dest, follow memcpy standard.
+* Read style(9) and decide what to implement.
diff --git a/TODO/testing.md b/TODO/testing.md
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+# Testing
+
+## Architecture
+
+* Folder structure: each module (.h file) has a corresponding test/module_name
+  folder containing the important tests.
+* How to test pre / post -init()?
+* Makefile: one target for each module with correct dependencies.
+* Makefile: perhaps write a specific makefile for testing in test folder.
+
+## Test sttructure
+
+* Make consistent
+* Little output for success
+* Stop on first failed? (automatic with makefile)
+
+## Write tests
+
+* Pretty much all are missing, except fst.
+* Start from bottom (utils.c)
+
+## Other
+
+* Move test_coord from coord.c to test folder.
diff --git a/TODO/webapp.md b/TODO/webapp.md
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+# Towards a nissy webapp
+
+## Architecture
+
+* Split in client / server.
+* Server can load and keep in memory all the tables, client(s) send messages to
+  the server to run commands.
+* Use UNIX sockets only first, maybe later try WinSock.
+
+## Simple webapp
+
+* Investigate how to use fastcgi, try simple program first.
+* Decide what limits to put in terms of resources and write a "filter" script
+  to block big requests (maybe use a timeout).
+
+## Advanced webapp
+
+* Use cubing.js for nice graphics.
+* Port it to a graphical desktop version too.