For some time, I have been considering rewriting my original pocket money ledger program in Haskell, but am not sure as to which packages would be most useful. My original pocket money ledger program was first written in circa 1983 in N80-BASIC (a JIS-compatible ROM-based line BASIC) on an NEC PC-8001 mkII [1]. The main difficulty is that I would like to preserve the original look and feel of my original program while still rewriting it in Haskell. However, my original program ran in an age before any kind of Macintosh-style or Windows-style GUI had become common, and used basic built-in ROM-based graphics and sound commands to draw a double-line colored graphical border on a centered-colored-text screen, and saved files to a floppy disk drive (floppy disks were actually considered advanced for that age, since most personal computers then used a cassette tape drive for external file storage). As a result, I am uncertain as to which packages would be useful for preserving the original look and feel of my program. At minimum, I would like my program to exhibit the following behavior: 1. Start out by drawing a lime-green-colored double two-pixel wide box surrounding the screen, with the title and author name displayed as separately-colored text centered in the screen. 2. If possible, play a suitable music file while on this screen. Also, display an option to mute this music, and if this music is once muted, save this option for future runs of this program, so that the program will start out with the music muted as the default option. Also, display an option to control the volume of this music, and if possible, also display a separate option to choose a different tune to play. The tunes should be selectable from a selectable, expandable menu. 3. If possible, include a suitable screen saver to be displayed automatically, separate from the GUI screen saver, upon a user-defined period in which there has been no user input. The screen saver should be configurable in a separate configuration menu. 4. Upon the user hitting the Return key, stop playing the music (if playing), and move to the main menu screen. 5. The options displayed in the menu screen should include, at minimum, the following: a. Create a new ledger book. b. Load a ledger book (preferably from floppy disk). c. Add an entry to the ledger book. d. Delete an entry from the ledger book. e. Erase the ledger book. f. Save the current ledger book (preferably to floppy disk). g. Tabulate and display income and expenditures (leads to a separate screen requesting a time period for tabulation). (The income and expenditures should be displayed in detail both as numerical charts and as colored graphs in a preferred form (pie chart, bar graph, etc.).) h. Set configuration options (leads to a separate screen for configuring default background music, default volume, default application screen saver, default theme, default fonts, default menu behavior, default keyboard remappings, default screen height/width ratio, etc.). i. Exit the application. 5. For each option (except for option i), move to a separate sub-menu screen. When input/output and processing have been completed on the separate sub-menu screen, return to the main menu screen. Most of the functionality of this program is related to some form of input and output: colored formatted combined graphical and textual title screen with background music, manual data entry by a user, saving files to a floppy disk, reading files off a floppy disk, deleting files from a floppy disk, configuring various default music/volume/screen saver/theme/font/menu behavior/keyboard remapping/screen height and width ratio options, and combined numerical and graphical representation of statistical ledger information. Most of the computation involves only simple arithmetic (mainly addition and subtraction, with perhaps some multiplication and/or division, and no matrix manipulation). The main point of this program is that program usage should be interactive, and not require a separately entered file. The idea is that the program will play the role of an interactive personal ledger assistant. However, I am not sure as to how to implement this program in Haskell easily. Because most of the program is mainly concerned with side effects, it is difficult to write it easily while preserving referential transparency. This type of program seems relatively straightforward to write in N80-BASIC (which is no longer available in the original version), but is relatively less trivial in a purely functional programming language such as Haskell. However, I am tired of spaghetti code, and although writing each line of code in N80-BASIC is trivial, managing control flow is not. It is very difficult to manage control flow without writing spaghetti code in a dialect of line BASIC. However, most of the associated graphics and sound commands are proprietary and implementation-dependent, and I am not sure how to rewrite that part of the functionality in an implementation-independent language without spending lots of time on API-related issues. -- Benjamin L. Russell [1] _OLD-COMPUTERS.COM Museum ~ NEC PC 8001 MK 2_. NYI (New York Internet). n.d. Web. May 25, 2011. http://www.old-computers.com/museum/computer.asp?st=1&c=396. -- Benjamin L. Russell / DekuDekuplex at Yahoo dot com http://dekudekuplex.wordpress.com/ Translator/Interpreter / Mobile: +011 81 90-6526-1406 "Furuike ya, kawazu tobikomu mizu no oto." -- Matsuo Basho^