hackerbase/doc/modules.md

HackerBase Modules

This file contains documentation of all exported symbols of all modules used. Modules are grouped according to their specificity to this project.

Functional Modules

These modules are specific to this project and their generic usage is questionable.

Configuration

The exact behavior of some algorithms in other modules can be changed via configuration parameters in this global configuration module.

(*current-month* [month])

• month - valid month structure as specified in the month module

Configuration parameter specifying the current month. Defaults to the current month derived from the current system time.

(*member-file-context* [lines])

• lines - number of context lines

How many lines of context are to be shown in source file listing. Mainly used by the member file module parser and processor.

(*member-suspend-max-months* [number])

• number - number of months (nonnegative integer)

Determines how many months the member can be suspended before any action is required.

Member Record

This module encapsulates the data structure representing a single member record.

(make-member-record file-name file-path symlinks . args)

• file-name - a symbol representing the primary filename
• file-path - a string representing the path to the file
• symlinks - a list of symbols representing symlinks
• args - optional keyword arguments

Creates a new member record dictionary. The three mandatory arguments are stored under respective keys and any keyword arguments are stored as keys obtained by converting the keyword to symbol with values following the keyword.

The 'id key is filled with any four-digit file-name or symlink converted to a number. Preferably the four-digit symbol should be the file-name but it is not required.

(member-file-path mr)

• mr - a member record structure

Returns the path used for accessing this member's file.

(member-record-input-file mr)

• mr - a member record structure

Returns an open file port to given member record underlying file. This function should be used by the parser to get the member file contents.

(member-record-set mr . args)

• mr - a member record structure
• args - optional keyword arguments

Any keyword arguments are stored in the member record dictionary as keys obtained by converting the keyword to symbol with values following the keyword.

(member-record-add-highlight mr line message pass type)

• mr - a member record structure
• line - line number in the source file
• message - a string with message for highlight
• pass - parsing stage
• type - symbol representing the highlight type

Adds a new highlight to member record to be used when displaying the source file listing.

Known types are:

• 'error - to denote fatal problem in the source
• 'warning - to signal known problem which does not make the record invalid
• 'info - supplemental information

The structure is perfectly suited for print-source-listing function.

(member-record-sub-ref mr sec key [default])

• mr - a member record structure
• sec - section symbol
• key - key symbol
• default - optional default value

Retrieves given key from dictionary stored as section sec in given mr structure. If no default is provided and the key does not exist it raises an exception.

(member-record-sub-set mr sec key value)

• mr - a member record structure
• sec - section symbol
• key - key symbol
• value - value to set

Sets the value of given key in dictionary stored as section sec in given mr structure to the new value possibly overwriting previous one.

(member-record-sub-prepend mr sec key value)

• mr - a member record structure
• sec - section symbol
• key - key symbol
• value - value to prepend (cons) to the key current value

Prepends (cons) new the value to current value of given key in dictionary stored as section sec in given mr structure replacing the original value.

(member-record-sub-has-key? mr sec key)

• mr - a member record structure
• sec - section symbol
• key - key symbol

Returns #t if given section sec contains the key.

(member-record-sub-ensure mr sec key value)

• mr - a member record structure
• sec - section symbol
• key - key symbol
• value - value to set

Sets the value of given key in dictionary stored as section sec in given mr structure to the new value if and only if it is not already present.

(member-source mr)

• mr - a member record structure

Returns a list of strings representing the source file of this member record.

(member-record-info mr key [default])

• mr - a member record structure
• key - key (symbol) to retrieve
• default - optional default value

Like dict-ref returns the value associated with key in section 'info. If default is provided, it is passed on to the underlying dict-ref.

(member-missing-keys mr)

• mr - a member record structure

Returns a list of keys (symbols) from within the 'info section of given mr that have #f values (indicating they are missing mandatory fields in the source).

(member-has-highlights? mr)

• mr - a member record structure

Returns #t if given mr has at least one source highlight.

(member-record-usable? mr)

• mr - a member record structure

Returns #t if it is possible to work with this member - mainly that the 'info section contains the 'member key.

(member-has-problems? mr)

• mr - a member record structure

Returns #t if there are any 'error type highlights in mr, or it is not member-record-usable? or the member-id is not 4-digit prime number.

(member-destroyed? mr)

• mr - a member record structure

Returns #t if the member is not existing and already has existed in the past.

(member-suspended? mr)

• mr - a member record structure

Returns #t if the current month falls within any of given member's suspended periods.

(member-active? mr)

• mr - a member record structure

Returns #t if given member exists, is a member and is currently not suspended.

(member-student? mr)

• mr - a member record structure

Returns #t if given member exists, is a member, is currently not suspended and current month falls within any member's suspended periods.

(member-existing? mr)

• mr - a member record structure

Returns #t if given member exists - that is the current month is within any of the member (membership) periods.

(member-flags mr)

• mr - a member record structure

Returns a list of member flags which can be any of the following:

• 'student
• 'suspended
• 'active
• 'destroyed
• 'existing

The 'existing and 'destroyed are mutually exclusive. Also 'active and 'suspended are mutually exclusive.

(member-nick mr)

• mr - a member record structure

Returns member's nick from its 'info section.

(member-id mr)

• mr - a member record structure

Returns given member's id.

(member-suspended-months mr)

• mr - a member record structure

Returns the number of months this member is suspended in (*current-month*). If the member is not suspended, returns 0.

(member-format fmt mr)

• fmt - format string
• mr - a member record structure

Fills the following template substitutions in the fmt string:

• ~N - member's nick
• ~I - member's id
• ~S - number of months this member has been suspended
• ~E - number of highlights in square brackets if there is at least one
• ~~ - literal ~

Other parts of the string are retained.

(member<? a b)

• a - a member record structure
• b - a member record structure

Returns true if member a's nick comes before b's nick in the lexicographical order.

(member-record-add-payment mr pt)

• mr - a member record structure
• pt - bank transaction of the payment

Adds (prepends) given transaction pt to given member record mr's 'payments' key list.

(member-payments mr)

• mr - a member record structure

Returns the payments (bank transactions) list of given member record mr defaulting to an empty list.

Member Parser

This module exports only one function - the load-member-file which loads and parses given file as member file. The specification of this file format is in a separate document MEMBERS.md.

The module implements this specification as multi-pass parser with important definitions being at the top of the module.

mandatory-keys

A list of symbols containing keys which must be present in the file. If any of them is missing, it is added to the resulting structure with the #f value.

optional-keys

A list of symbols of keys which the parser recognizes and adds them to the resulting data structure.

ignored-keys

A list of symbols with keys that are parsed, and albeit not added to the result they do not generate warnings.

known-multikeys

A list of keys that can appear multiple times and in the 2nd pass they are collected as lists of values.

start-stop-markers-lookup

A list of start/stop specifications - each key is paired with given key and start/stop tag.

(load-member-file mr)

• mr - (almost) empty member record structure

It must be possible to get the member file using member-record-input-file function. Loads the file as a list of lines, processes these lines with 1st and 2nd pass parsers, interprets the result using 3rd passes and finalizes the result in the 4th pass.

Members Directory

This module encapsulates the members base directory format as documented in MEMBERS.md document.

Each member file should have a 4-digit name identical to member id and optional symlinks with human-known names of the members. The module can correctly handle a situation where the 4-digit id is a symlink to arbitrarily named file.

In first pass it extracts all files and symlinks to them, binds them together and makes sure the 4-digit name is used as id and the regular file is read when loading its contents.

(load-members-dir dn)

• dn - directory name (path)

Scans given directory and returns a dictionary of canonical names as keys and lists of alias symlinks as values.

(members-dir-load-member mdir fname symlinks)

• mdir - members directory name (path)
• fname - file name inside mdir (without path)
• symlinks - a list of symlinks to fname

Creates an initial member record and uses load-member-file to load, parse and interpret its contents.

Members Base

This module uses the members directory module to load and parse all members files and provides a simple interface for accessing the data.

(load-members dn [progress?])

• dn - directory with member files
• progress? - if #t, displays loading progress

Loads all member files and creates a members base data structure.

(members-base-members mb)

• mb - members base structure

Returns the list of all member records loaded.

(find-member-by-id mb id)

• mb - members base structure
• id - member identifier (4-digit prime number)

Returns the member record associated with the provided id.

(find-member-by-nick mb nick)

• mb - members base structure
• nick - member nick

Returns the member record identified by its nick.

(find-members-by-nick mb nick)

• mb - members base structure
• nick - member nick

Returns the list of all member records with substring matching of nick. May return empty list, list with one member or multiple member records.

(list-members-ids mb)

• mb - members base structure

Returns a list of all members' ids.

(filter-members-by-predicate mb pred)

• mb - members base structure
• pred - predicate procedure

Returns a list of all member records matching the given predicate.

(list-members-nicks mb)

• mb - members base structure

Returns a list of all member nicks.

(members-base-info mb)

• mb - members base structure

Returns a dictionary with basic information about given members base. The dictionary contains the following keys:

• 'invalid - a list of all invalid member records
• 'active - a list of all active member records
• 'suspended - a list of all suspended member records
• 'students - a list of all student member records
• 'destroyed - a list of all destroyed member records
• 'month - the current month for this info dictionary
• 'total - a list of all member records contained

This procedure is used for further printing of information about given members base.

(members-base-stats mb)

• mb - members base structure

Creates a list of lists of statistical information about given members base through time. The first row of the resulting list contains column headers and the rows are sorted chronologically by month.

(get-free-members-ids mb)

• mb - members base structure

Returns a list of valid member ids which are not already used in given members base.

(gen-member-id mb)

• mb - members base structure

Generates a random 4-digit prime number which is not yet used as a member id.

(members-base-update mb pred? proc)

• mb - members base structure
• pred? - member record predicate
• proc - processing procedure

Updates given members base by applying proc to all member records matching pred?.

Bank Account

This module creates a thin abstraction layer for bank accounts and transactions.

(make-bank-account number bank [transactions])

• number - account number
• bank - bank code
• transactions - optional list of initial transactions

Creates a new bank account data structure.

The data structure has the following accessors:

• (bank-account-transactions ba) - returns the transactions list
• (bank-account-number ba)- retrieves the bank account number
• (bank-account-bank ba) - returns the bank account bank code

The underlying implementation is currently a plain list but is subject to change in the future.

(bank-account-insert account transaction)

• account - bank account structure
• transaction - transaction structure to add

Adds (prepends) given transaction to the list of transactions of given bank account.

(make-bank-transaction i d a c v m t)

• i - transaction id
• d - date
• a - amount
• c - currency
• v - variable symbol
• m - message
• t - transaction type

Creates new bank transaction data structure. The underlying implementation is currently a record.

The following accessors are provided:

• bank-transaction-id
• bank-transaction-date
• bank-transaction-amount
• bank-transaction-currency
• bank-transaction-varsym
• bank-transaction-message
• bank-transaction-type

More fields with accessors will be added as other modules will need them.

Bank Fio

Members Payments Processor

Members Info Printer

Cards

Web Static

Specific Support Modules

Primes

A very simple module for generating and checking 4-digit prime numbers.

(is-4digit-prime? n)

• n - a number

Returns true if the given number n has four digits and it is a prime number.

(gen-all-4digit-primes)

Returns a list of all 4-digit prime numbers.

Generic Support Modules

These modules are not specific to this project but had to be implemented anyway to not require any external dependencies.

ANSI

A simple module for creating ANSI (ECMA-48) sequence strings.

(ansi . args)

• args - a list of color/style keywords

Produces an ANSI CSI (Control Sequence Introducer) SGR (Select Graphic Rendition) strings with given attributes (re)set.

It understands the following keywords:

• #:black - black text foreground color
• #:red - red text foreground color
• #:green - green text foreground color
• #:yellow - yellow text foreground color
• #:blue - blue text foreground color
• #:magenta - magenta text foreground color
• #:cyan - cyan text foreground color
• #:white or #:grey - white (grey) text foreground color
• #:brightblack or #:darkgrey- dark grey (bright black) text foreground color
• #:brightred - bright red text foreground color
• #:brightgreen - bright green text foreground color
• #:brightyellow - bright yellow text foreground color
• #:brightblue - bright blue text foreground color
• #:brightmagenta or #:pink - pink (bright magenta) text foreground color
• #:brightcyan - bright cyan text foreground color
• #:brightwhite - bright white (real white) text foreground color
• #:bgblack - black text background color
• #:bgred - red text background color
• #:bggreen - green text background color
• #:bgyellow - yellow text background color
• #:bgblue - blue text background color
• #:bgmagenta - magenta text background color
• #:bgcyan - cyan text background color
• #:bgwhite or #:bggrey - white (grey) text background color
• #:bgbrightblack or #:darkgrey- dark grey (bright black) text background color
• #:bgbrightred - bright red text background color
• #:bgbrightgreen - bright green text background color
• #:bgbrightyellow - bright yellow text background color
• #:bgbrightblue - bright blue text background color
• #:bgbrightmagenta or #:pink - pink (bright magenta) text background color
• #:bgbrightcyan - bright cyan text background color
• #:bgbrightwhite - bright white (real white) text background color
• #:default - reset all attributes to terminal defaults
• #:bold - bold font (and/or bright foreground color on some terminals)

The order is important as the #:default resets all attributes given even in the same attribute list.

a:error

Used to signal errors. Defaults to red bold text.

a:warning

Used to signal non-fatal warnings. Defaults to regular yellow text.

a:success

Signals success of an operation. Defaults to bold green text.

a:neutral

Used for generic text. Defaults to regular white (grey) text.

a:default

Special style which just resets the terminal output attributes to terminal defaults.

a:muted

Used for displaying the text "muted" (dimmed). Defaults to bold/bright black text.

a:highlight

Generic highlight of given text. Defaults to bold blue text.

(ansi-string-length str)

• str - string that may contain ANSI CSI SGR sequences

Returns the string length in characters without any ANSI CSI SGR sequences contained.

(ansi-paragraph-format str width)

• str - a string that may contain ANSI CSI SGR sequences
• width - a number representing themaximum number of characters per line

If the string str is longer than the supplied width, splits it into multiple lines on word boundaries to wrap it nicely. The resulting string is free of ANSI CSI SGR sequences and may contain newline characters.

(ansi-string . args)

• args - a list of strings and/or ANSI keywords

Returns a string created by appending all the strings given and ansi function produced ones with consecutive keywords passed to single ansi evaluation.

(clrscr)

Clears the terminal screen and places the cursor in the top left corner.

Command Line parsing

Generic syntax-based implementation of command-line options parsing with focus on generated help and ergonomic binding of option arguments.

(command-line print-help (opt (args ...) help body ...) ...)

• print-help - identifier binding for the help printing procedure
• opt - command-line option name as identifier (unquoted symbol)
• args ... - optional arguments of given option
• help - help string for this option
• body ... - expressions to be evaluated upon option match

Parses command-line arguments based on the specification given. If evaluated inside csi script, only options and arguments after the -- meta-option are parsed. If evaluated inside compiled binary, all arguments are parsed as usual.

Each option is represented by the opt option identifier (unquoted symbol), optional arguments args which become bound in the option specification body ... expressions, help string and the actual expressions to be evaluated when the option (and possibly its arguments) match.

If an option is encountered on the command-line and not enough arguments (according to the option specification) are provided for it, an exception is raised.

Within any of the body ... expressions the print-help procedure can be used to print the options, their argument names and help strings in a nice, human-readable format.

Listing

This module implements listing a text file with line numbers and optional highlights of given source lines, optionally with comments for those lines.

(print-source-listing lines highlights
	[#:highligh-rules `((error ,(ansi #:bold #:red) ,(ansi #:default))
	                    (warning ,(ansi #:yellow) ,(ansi #:default))
						(info ,(ansi #:cyan) ,(ansi #:default)))]
	[#:ellipsis "..."]
	[#:context 3]
	[#:hl-pre ""]
	[#:hl-post ""]
	[#:ctx-pre ""]
	[#:ctx-post ""])

• lines - list of string representing lines of the text file
• highlights - list of highlights (see below)
• highlight-rules - assq rules for highlight types pre and post
• context - number of context lines to be shown around highlighted lies
• hl-pre - string introducing highlighted lines
• hl-post - string terminating highlighted lines
• ctx-pre - string introducing context lines
• ctx-post - string terminating context lines
• ellipsis - string representing lines omitted from the output

Prints given text file represented by the lines list of strings.

Lines to be highlighted can be specified in the highlights list. The highlight specification a list containing the following:

• line number (number)
• message (string)
• pass stage (number)
• type (symbol)

By default the lines are actually highlighted by prepending them with hl-pre string and the highlight is finished by appending hl-post to them. Usually some constants from the ansi module are used. If the highlight type is found in highlight-rules, given pre/post strings are used instead.

If some lines are highlighted a number of context lines surrounding them may be printed as well. If this argument is negative, all non-highlighted lines are printed as context lines.

Context lines are prepended with ctx-pre string and terminated by ctx-post string.

If some lines between highlight and/or context lines are omitted, ellipsis string is printed on single line as a substitute.

Progress

Provides syntax forms and procedures for showing progress of a process.

(with-progress echo? pre post body ...)

• echo? - flag enabling progress output
• pre - string to be printed at start
• post - string to be printed after finish
• body ... - expressions of the process tracked

Displays process progress starting with the pre string, adding arbitrary string to the output using the progress-advance during each and every step. If the process reaches its finish, the output line is finished with the post string and cursor is moved to new line.

During the steps, the whole line is always refreshed when the progress gets updated.

If echo? is #f (false), nothing is output.

(progress-advance [str])

• str - string to add to progress, defaults to "."

Adds given string to current progress and refreshes the progress line. Must be evaluated within with-progress expression.

(progress-break body ...)

• body ... - arbitrary expressions to be evaluated

Evaluates the body ... expressions. Hides current progress line before the evaluation and redisplays it when finished.

(*progress%-width* [width])

• width - width of the progress bar

Parameter configuring the progress% bar size.

(*progress%-step* [step])

• step - minimal step before re-drawing the bar

Parameter configuring the minimal step before the current progress% bar is redrawn. The progress value is a number from 0 to 1 and the step must be specified on the same scale.

(with-progress% echo? name body ...)

• echo? - flag enabling progress output
• name - name to be used at the end of progress line
• body ... - expressions to be evaluated while tracking progress%

Displays progress while the body ... is evaluated. Current progress% value must be updated with progress%-advance.

(progress%-advance new-value)

• new-value - new value of progress

If the new-value differs from last value shown more than (*progress%-step*), redisplays the current progress%.

Testing

This module provides simple syntax forms for (unit) testing of other modules.

(run-tests name body ...)

• name - identifier describing the module being tested
• body ... - test expressions

Runs all tests specified on the body .... Firstly it prints "[test] name " at the beginning of the line. Secondly it runs all tests, printing "." for each test successfully passed. If all tests pass, prints " ok." and moves the cursor to the next line.

In case any of the tests fails, exception is raised and program terminates.

(test-eq? name expression expected-result)

• name - identifier representing the name of the test
• expression - expression to be evaluated
• expected-result - expected result of the test expression

Evaluates the test expression and compares the result with expected-result using eq?. If the comparison fails, an exception is raised with the name of the test added to the exception. If the test passes, prints "." like all tests from this module do.

(test-equal? name expression expected-result)

• name - identifier representing the name of the test
• expression - expression to be evaluated
• expected-result - expected result of the test expression

Evaluates the test expression and compares the result with expected-result using equal?. If the comparison fails, an exception is raised with the name of the test added to the exception. If the test passes, prints "." like all tests from this module do.

(test-true name expression)

• name - identifier representing the name of the test
• expression - expression to be evaluated

Evaluates the test expression and checks whether the result is #t (true). An exception is raised if it is not with the name of the test added to the exception. If the test passes, prints "." like all tests from this module do.

(test-false name expression)

• name - identifier representing the name of the test
• expression - expression to be evaluated

Evaluates the test expression and checks whether the result is #f (false). An exception is raised if it is not with the name of the test added to the exception. If the test passes, prints "." like all tests from this module do.

(test-exn name expression)

• name - identifier representing the name of the test
• expression - expression to be evaluated

Evaluates the test expression and checks whether it raised an exception. An exception is raised if no exception was raised during the evaluation. If the test passes, prints "." like all tests from this module do.

Table

This module provides moderately complex terminal table rendering.

(*table-border-style* [style])

• style - symbol representing the style

Valid styles are:

• 'debug - special style to see any rendering problems
• 'ascii - plain ASCII (7-bit)
• 'unicode - nice box-drawing table (UTF-8)

If invalid style is provided, 'debug style is automatically substituted.

(table->string tbl
               [#:table-border #f]
               [#:row-border #f]
               [#:col-border #f]
               [#:row0-border #f]
               [#:col0-border #f]
               [#:border-style (*table-border-style*)]
               [#:ansi #f])

• tbl - list of lists with cell data
• #:table-border - if #t, the table has outer border
• #:row-border - if #t, the rows are separated by borders
• #:col-border - if #t, the columns are separated by borders
• #:row0-border - if #t, the first row is separated by border
• #:col0-border - if #t, the first column is separated by border
• #:border-style - which border style to use (see *table-border-style* which is the default)
• #:ansi - if #t, all cell line strings are terminated with a:default

The table tbl is represented as a list of rows where each row is a list of cells that hold arbitrary values that are converted to string when rendering the table.

Before rendering the table, the following steps are performed:

• The table is made rectangular - that is all rows are extended by empty strings to have the same length.
• All non-string cells are converted to string using sprintf
• All cells are split into list of strings representing the lines of text inside them.
• For each row, all cells are extended by empty strings to have matching number of lines of text inside them.
• For each column, all lines of text inside all of the cells are padded with spaces to have uniform width.

Then each table row is converted to list of strings adding column separators and table borders as required. These lists are then joined with row separators and possibly prefixed and suffixed by top and bottom table border.

The resulting list of strings is joined with newline character as the separator.

Environment