{ "id": "banking", "title": "Banking and payments", "summary": "Bank accounts and payments: overdraft interest, savings AER, monthly fee caps, Bacs dates, Faster Payments limits, payee checks and cheque wording.", "synonyms": [ "bank", "banking", "current account", "savings account", "payments", "money transfer", "neobank", "fintech", "digital bank", "overdraft", "open banking", "payee" ], "apps": [ "banking app", "neobank", "savings app", "payments app", "money transfer app", "account statements system", "core banking backend" ], "language": "rust", "includes": [ "money-basics", "dates-basics", "validation-basics" ], "includedBy": [], "caveats": [ "UK first: Bacs cycles, Faster Payments and bank holidays follow UK schemes; not financial advice." ], "sections": [ { "key": "interest", "title": "Interest and fees", "purpose": "Charge and pay interest on balances, and cap the fees an account raises.", "from": "banking", "members": [ { "id": "banking.overdraft-interest", "tier": "core", "why": "Overdraft interest for a statement period from daily balances, with an interest-free buffer.", "section": "interest", "from": "banking", "version": "1.0.0", "summary": "Overdraft interest for a statement period from daily balances, with an interest-free buffer.", "status": "stable", "license": "NOASSERTION", "languages": [ "typescript", "python", "rust" ], "available": true, "group": false, "functions": [ "overdraftInterest" ], "signatures": [ "pub fn overdraft_interest(balances: &[DatedBalance], from_iso: &str, to_iso: &str, annual_rate_basis_points: i64, interest_free_buffer: &Money, convention: &DayCountConvention, mode: &RoundingMode) -> OverdraftInterest" ], "reference": "fune!(banking.overdraft-interest@^1); // then call overdraft_interest(…)", "url": "http://www.functionalweave.com/functions/banking.overdraft-interest" }, { "id": "banking.savings-aer", "tier": "core", "why": "AER from a nominal rate and how often interest is paid, for savings product pages.", "section": "interest", "from": "banking", "version": "1.0.0", "summary": "AER (annual equivalent rate) from a gross nominal rate and how often interest is paid, to two decimal places.", "status": "stable", "license": "NOASSERTION", "languages": [ "typescript", "python", "rust" ], "available": true, "group": false, "functions": [ "savingsAer" ], "signatures": [ "pub fn savings_aer(gross_rate_basis_points: i64, payments_per_year: i64) -> i64" ], "reference": "fune!(banking.savings-aer@^1); // then call savings_aer(…)", "url": "http://www.functionalweave.com/functions/banking.savings-aer" }, { "id": "banking.fees-cap", "tier": "core", "why": "Charges an account's fees in date order up to a monthly cap and waives the rest.", "section": "interest", "from": "banking", "version": "1.0.0", "summary": "Apply a monthly fee cap to a list of account charges: charge up to the cap, waive the rest.", "status": "stable", "license": "NOASSERTION", "languages": [ "typescript", "python", "rust" ], "available": true, "group": false, "functions": [ "applyFeeCap" ], "signatures": [ "pub fn apply_fee_cap(charges: &[FeeCharge], monthly_cap: &Money, cycle_day: i64) -> FeeCapResult" ], "reference": "fune!(banking.fees-cap@^1); // then call apply_fee_cap(…)", "url": "http://www.functionalweave.com/functions/banking.fees-cap" }, { "id": "lending.daily-interest", "tier": "optional", "why": "Interest accrued day by day on a changing balance under a day-count convention.", "section": "interest", "from": "banking", "version": "1.0.1", "summary": "Interest accrued day by day on a changing balance under a day-count convention, summed exactly and rounded once.", "status": "unreviewed", "license": "NOASSERTION", "languages": [ "typescript", "python", "rust" ], "available": true, "group": false, "functions": [ "dailyInterest" ], "signatures": [ "pub fn daily_interest(balances: &[DatedBalance], from_iso: &str, to_iso: &str, annual_rate_basis_points: i64, convention: &DayCountConvention, mode: &RoundingMode) -> DailyInterest" ], "reference": "fune!(lending.daily-interest@^1); // then call daily_interest(…)", "url": "http://www.functionalweave.com/functions/lending.daily-interest" }, { "id": "finance.compound-interest", "tier": "optional", "why": "Compound interest accrued period by period, for savings projections.", "section": "interest", "from": "banking", "version": "1.0.0", "summary": "Compound interest accrued period by period in minor units, the way a statement is built.", "status": "stable", "license": "NOASSERTION", "languages": [ "typescript", "python", "rust" ], "available": true, "group": false, "functions": [ "compoundInterest" ], "signatures": [ "pub fn compound_interest(principal: &Money, annual_rate_basis_points: i64, periods_per_year: i64, years: i64) -> CompoundInterestResult" ], "reference": "fune!(finance.compound-interest@^1); // then call compound_interest(…)", "url": "http://www.functionalweave.com/functions/finance.compound-interest" }, { "id": "finance.uk-bank-rate", "tier": "optional", "why": "Bank of England Bank Rate on a date, for rates that track base.", "section": "interest", "from": "banking", "version": "1.0.1", "summary": "Bank of England Bank Rate (base rate) in force on a date, from the Bank's official history since 2001.", "status": "stable", "license": "NOASSERTION", "languages": [ "typescript", "python", "rust" ], "available": true, "group": false, "functions": [ "ukBankRate" ], "signatures": [ "pub fn uk_bank_rate(on_date: &str) -> BankRate" ], "reference": "fune!(finance.uk-bank-rate@^1); // then call uk_bank_rate(…)", "url": "http://www.functionalweave.com/functions/finance.uk-bank-rate" } ], "gaps": [] }, { "key": "payments", "title": "Payments", "purpose": "Send money: check the payee, the scheme limits and when it arrives.", "from": "banking", "members": [ { "id": "banking.faster-payments-limit", "tier": "core", "why": "Whether a Faster Payment fits the scheme maximum, the per-payment limit and what is left of the daily limit.", "section": "payments", "from": "banking", "version": "1.0.1", "summary": "Whether a Faster Payment fits the scheme maximum, the bank's per-payment limit and what is left of its daily limit.", "status": "stable", "license": "NOASSERTION", "languages": [ "typescript", "python", "rust" ], "available": true, "group": false, "functions": [ "fasterPaymentsCheck" ], "signatures": [ "pub fn faster_payments_check(amount: &Money, sent_today: &Money, per_transaction_limit: &Money, daily_limit: &Money, on_date: &str) -> FasterPaymentsCheck" ], "reference": "fune!(banking.faster-payments-limit@^1); // then call faster_payments_check(…)", "url": "http://www.functionalweave.com/functions/banking.faster-payments-limit" }, { "id": "banking.bacs-processing-date", "tier": "core", "why": "Bacs input, processing and arrival dates for a submission, skipping weekends and bank holidays.", "section": "payments", "from": "banking", "version": "1.0.0", "summary": "Bacs three-day cycle: input, processing and entry (arrival) dates for a submission, skipping weekends and bank holidays.", "status": "stable", "license": "NOASSERTION", "languages": [ "typescript", "python", "rust" ], "available": true, "group": false, "functions": [ "bacsProcessingDates" ], "signatures": [ "pub fn bacs_processing_dates(submission_iso: &str, after_cutoff: bool) -> BacsCycle" ], "reference": "fune!(banking.bacs-processing-date@^1); // then call bacs_processing_dates(…)", "url": "http://www.functionalweave.com/functions/banking.bacs-processing-date" }, { "id": "banking.cheque-amount-words", "tier": "optional", "why": "The words and figures to print on a cheque (\"One hundred and twenty pounds and fifty pence only\").", "section": "payments", "from": "banking", "version": "1.0.0", "summary": "The words and figures to write on a cheque: \"One hundred and twenty pounds and fifty pence only\", \"£120.50\".", "status": "stable", "license": "NOASSERTION", "languages": [ "typescript", "python", "rust" ], "available": true, "group": false, "functions": [ "chequeAmountWords" ], "signatures": [ "pub fn cheque_amount_words(amount: &Money, pence_style: &str) -> ChequeWording" ], "reference": "fune!(banking.cheque-amount-words@^1); // then call cheque_amount_words(…)", "url": "http://www.functionalweave.com/functions/banking.cheque-amount-words" }, { "id": "text.number-to-words", "tier": "optional", "why": "A money amount in words, for cheques and payment confirmations.", "section": "payments", "from": "banking", "version": "1.0.0", "summary": "Write a money amount in words for a cheque: \"one thousand two hundred and thirty-four pounds and fifty-six pence\".", "status": "stable", "license": "NOASSERTION", "languages": [ "typescript", "python", "rust" ], "available": true, "group": false, "functions": [ "amountInWords" ], "signatures": [ "pub fn amount_in_words(amount: &Money) -> String" ], "reference": "fune!(text.number-to-words@^1); // then call amount_in_words(…)", "url": "http://www.functionalweave.com/functions/text.number-to-words" } ], "gaps": [ { "key": "payment-rails", "text": "Actually moving money: Faster Payments, Bacs and SWIFT submissions, or a payments provider's API.", "section": "payments", "from": "banking" }, { "key": "confirmation-of-payee", "text": "Confirmation of Payee name checks: a network service between banks.", "section": "payments", "from": "banking" } ] }, { "key": "statements", "title": "Statements and transactions", "purpose": "Show customers their transactions and balances.", "from": "banking", "members": [ { "id": "collections.paginate", "tier": "optional", "why": "Pages through transaction lists for statement screens and APIs.", "section": "statements", "from": "banking", "version": "1.0.0", "summary": "Slice a list into a 1-based page and report the totals an API response needs.", "status": "stable", "license": "NOASSERTION", "languages": [ "typescript", "python", "rust" ], "available": true, "group": false, "functions": [ "paginate" ], "signatures": [ "pub fn paginate(items: &[T], page: i64, per_page: i64) -> Page" ], "reference": "fune!(collections.paginate@^1); // then call paginate(…)", "url": "http://www.functionalweave.com/functions/collections.paginate" }, { "id": "collections.group-by-key", "tier": "optional", "why": "Groups transactions by day or category for a statement view.", "section": "statements", "from": "banking", "version": "1.0.0", "summary": "Group records by the value at one key, preserving input order inside each group.", "status": "stable", "license": "NOASSERTION", "languages": [ "typescript", "python", "rust" ], "available": true, "group": false, "functions": [ "groupByKey" ], "signatures": [ "pub fn group_by_key(records: &[Value], key: &str) -> Vec<(String, Vec)>" ], "reference": "fune!(collections.group-by-key@^1); // then call group_by_key(…)", "url": "http://www.functionalweave.com/functions/collections.group-by-key" }, { "id": "finance.bank-reconcile-match", "tier": "optional", "why": "Matches statement lines to expected payments by amount, date window and reference.", "section": "statements", "from": "banking", "version": "1.0.0", "summary": "Match bank statement lines to ledger entries by exact amount, a date window and reference similarity, deterministically.", "status": "stable", "license": "NOASSERTION", "languages": [ "typescript", "python", "rust" ], "available": true, "group": false, "functions": [ "matchBankLines" ], "signatures": [ "pub fn match_bank_lines(bank_lines: &[ReconcileLine], ledger_entries: &[ReconcileLine], date_window_days: i64, min_similarity: i64) -> Reconciliation" ], "reference": "fune!(finance.bank-reconcile-match@^1); // then call match_bank_lines(…)", "url": "http://www.functionalweave.com/functions/finance.bank-reconcile-match" }, { "id": "text.mask", "tier": "optional", "why": "Masks account and card numbers on screens and statements.", "section": "statements", "from": "banking", "version": "1.0.0", "summary": "Mask all but the last n characters of a card, account or phone number, optionally keeping separators.", "status": "stable", "license": "NOASSERTION", "languages": [ "typescript", "python", "rust" ], "available": true, "group": false, "functions": [ "mask" ], "signatures": [ "pub fn mask(value: &str, visible: i64, mask_char: &str, keep_separators: bool) -> String" ], "reference": "fune!(text.mask@^1); // then call mask(…)", "url": "http://www.functionalweave.com/functions/text.mask" } ], "gaps": [ { "key": "categorisation", "text": "Categorising transactions (merchant names to spending categories) is not in caps.", "section": "statements", "from": "banking" } ] }, { "key": "amounts", "title": "Amounts", "purpose": "Hold money as currency-tagged integer minor units and do plain arithmetic on it safely.", "from": "money-basics", "members": [ { "id": "money.amount", "tier": "core", "why": "The Money type ({ minor, currency }) every other money capability takes and returns.", "section": "amounts", "from": "money-basics", "version": "1.0.2", "summary": "A currency-tagged monetary amount held in integer minor units.", "status": "stable", "license": "NOASSERTION", "languages": [ "typescript", "python", "rust" ], "available": true, "group": false, "functions": [ "money" ], "signatures": [ "pub fn money(minor: i64, currency: &str) -> Money" ], "reference": "fune!(money.amount@^1); // then call money(…)", "url": "http://www.functionalweave.com/functions/money.amount" }, { "id": "money.add", "tier": "core", "why": "Adds and subtracts amounts, refusing to mix currencies by accident.", "section": "amounts", "from": "money-basics", "version": "1.0.1", "summary": "Add, subtract and negate monetary amounts, refusing to mix currencies.", "status": "stable", "license": "NOASSERTION", "languages": [ "typescript", "python", "rust" ], "available": true, "group": false, "functions": [ "addMoney" ], "signatures": [ "pub fn add_money(a: &Money, b: &Money) -> Money" ], "reference": "fune!(money.add@^1); // then call add_money(…)", "url": "http://www.functionalweave.com/functions/money.add" }, { "id": "money.sum", "tier": "core", "why": "Totals a list of amounts, with an explicit currency for an empty list.", "section": "amounts", "from": "money-basics", "version": "1.0.1", "summary": "Total a list of monetary amounts, with an explicit currency for the empty case.", "status": "stable", "license": "NOASSERTION", "languages": [ "typescript", "python", "rust" ], "available": true, "group": false, "functions": [ "sumMoney" ], "signatures": [ "pub fn sum_money(amounts: &[Money], currency: &str) -> Money" ], "reference": "fune!(money.sum@^1); // then call sum_money(…)", "url": "http://www.functionalweave.com/functions/money.sum" }, { "id": "money.compare", "tier": "core", "why": "Compares, mins, maxes and clamps amounts of one currency without unwrapping them.", "section": "amounts", "from": "money-basics", "version": "2.0.0", "summary": "Compare two amounts of one currency, refusing to compare across currencies; min, max and clamp too.", "status": "stable", "license": "NOASSERTION", "languages": [ "typescript", "python", "rust" ], "available": true, "group": true, "functions": [ "compareMoney", "minMoney", "maxMoney", "clampMoney" ], "signatures": [ "pub fn compare_money(a: &Money, b: &Money) -> i64", "pub fn min_money(a: &Money, b: &Money) -> Money", "pub fn max_money(a: &Money, b: &Money) -> Money", "pub fn clamp_money(amount: &Money, min: &Money, max: &Money) -> Money" ], "reference": "fune!(money.compare@^2); // then call compare_money, min_money, max_money, clamp_money", "url": "http://www.functionalweave.com/functions/money.compare" } ], "gaps": [] }, { "key": "rates", "title": "Rates and rounding", "purpose": "Apply percentages and divide amounts with the rounding stated, never a float.", "from": "money-basics", "members": [ { "id": "money.apply-rate", "tier": "core", "why": "Applies a basis-point rate (VAT, discount, commission) to an amount with explicit rounding.", "section": "rates", "from": "money-basics", "version": "1.0.1", "summary": "Apply a rate expressed in basis points to a monetary amount, with an explicit rounding mode.", "status": "stable", "license": "NOASSERTION", "languages": [ "typescript", "python", "rust" ], "available": true, "group": false, "functions": [ "applyRate" ], "signatures": [ "pub fn apply_rate(amount: &Money, basis_points: i64, mode: &RoundingMode) -> Money" ], "reference": "fune!(money.apply-rate@^1); // then call apply_rate(…)", "url": "http://www.functionalweave.com/functions/money.apply-rate" }, { "id": "math.round-div", "tier": "core", "why": "Integer division with a named rounding mode, for any money maths the others do not cover.", "section": "rates", "from": "money-basics", "version": "1.0.0", "summary": "Integer division with an explicit rounding mode, for money arithmetic that must not drift.", "status": "stable", "license": "NOASSERTION", "languages": [ "typescript", "python", "rust" ], "available": true, "group": false, "functions": [ "roundDiv" ], "signatures": [ "pub fn round_div(numerator: i64, denominator: i64, mode: &str) -> i64" ], "reference": "fune!(math.round-div@^1); // then call round_div(…)", "url": "http://www.functionalweave.com/functions/math.round-div" }, { "id": "math.basis-points", "tier": "optional", "why": "Converts \"12.5%\" to and from basis points exactly, for rates typed in by users.", "section": "rates", "from": "money-basics", "version": "2.0.0", "summary": "Convert a rate between percent, basis points and a plain ratio exactly, as decimal text or integer basis points.", "status": "stable", "license": "NOASSERTION", "languages": [ "typescript", "python", "rust" ], "available": true, "group": true, "functions": [ "convertRate", "toBasisPoints", "fromBasisPoints" ], "signatures": [ "pub fn convert_rate(value: &str, from_unit: &str, to_unit: &str) -> String", "pub fn to_basis_points(value: &str, unit: &str) -> i64", "pub fn from_basis_points(basis_points: i64, unit: &str) -> String" ], "reference": "fune!(math.basis-points@^2); // then call convert_rate, to_basis_points, from_basis_points", "url": "http://www.functionalweave.com/functions/math.basis-points" }, { "id": "math.percent-change", "tier": "optional", "why": "Percentage change between two figures in basis points, for \"up 4.2% on last month\".", "section": "rates", "from": "money-basics", "version": "1.0.0", "summary": "Percentage change from one value to another, in basis points, with an explicit rounding mode.", "status": "stable", "license": "NOASSERTION", "languages": [ "typescript", "python", "rust" ], "available": true, "group": false, "functions": [ "percentChange" ], "signatures": [ "pub fn percent_change(from_value: i64, to_value: i64, mode: &RoundingMode) -> Option" ], "reference": "fune!(math.percent-change@^1); // then call percent_change(…)", "url": "http://www.functionalweave.com/functions/math.percent-change" }, { "id": "math.rational", "tier": "optional", "why": "Exact fractions for rates that must not drift across many steps.", "section": "rates", "from": "money-basics", "version": "2.0.0", "summary": "Exact fraction arithmetic, always reduced, for rates and ratios that must not drift.", "status": "stable", "license": "NOASSERTION", "languages": [ "typescript", "python", "rust" ], "available": true, "group": true, "functions": [ "calculateRational", "rational", "addRational", "subtractRational", "multiplyRational", "divideRational", "compareRational", "rationalToInteger" ], "signatures": [ "pub fn calculate_rational(a: &Rational, op: &str, b: &Rational) -> Rational", "pub fn rational(numerator: i64, denominator: i64) -> Rational", "pub fn add_rational(a: &Rational, b: &Rational) -> Rational", "pub fn subtract_rational(a: &Rational, b: &Rational) -> Rational", "pub fn multiply_rational(a: &Rational, b: &Rational) -> Rational", "pub fn divide_rational(a: &Rational, b: &Rational) -> Rational", "pub fn compare_rational(a: &Rational, b: &Rational) -> i64", "pub fn rational_to_integer(r: &Rational, mode: &RoundingMode) -> i64" ], "reference": "fune!(math.rational@^2); // then call calculate_rational, rational, add_rational, subtract_rational, multiply_rational, divide_rational, compare_rational, rational_to_integer", "url": "http://www.functionalweave.com/functions/math.rational" }, { "id": "math.round-div-big", "tier": "optional", "why": "Rounded division on numbers past 2^53, for very large totals.", "section": "rates", "from": "money-basics", "version": "1.0.0", "summary": "Divide two integers of any size with an explicit rounding mode, on decimal strings, for exact money sums past 2^53.", "status": "stable", "license": "NOASSERTION", "languages": [ "typescript", "python", "rust" ], "available": true, "group": false, "functions": [ "roundDivBig" ], "signatures": [ "pub fn round_div_big(numerator: &str, denominator: &str, mode: &RoundingMode) -> String" ], "reference": "fune!(math.round-div-big@^1); // then call round_div_big(…)", "url": "http://www.functionalweave.com/functions/math.round-div-big" } ], "gaps": [] }, { "key": "splitting", "title": "Splitting", "purpose": "Divide an amount between people, periods or lines so the parts add back to the whole.", "from": "money-basics", "members": [ { "id": "money.allocate", "tier": "core", "why": "Splits an amount by ratios (60/40, by quantity) without losing or inventing a penny.", "section": "splitting", "from": "money-basics", "version": "1.0.1", "summary": "Split an amount across ratios without losing or inventing a single minor unit.", "status": "stable", "license": "NOASSERTION", "languages": [ "typescript", "python", "rust" ], "available": true, "group": false, "functions": [ "allocate" ], "signatures": [ "pub fn allocate(amount: &Money, ratios: &[i64]) -> Vec" ], "reference": "fune!(money.allocate@^1); // then call allocate(…)", "url": "http://www.functionalweave.com/functions/money.allocate" }, { "id": "money.split-even", "tier": "optional", "why": "Splits an amount into n near-equal parts that sum exactly, for instalments or shares.", "section": "splitting", "from": "money-basics", "version": "1.0.0", "summary": "Split an amount into n near-equal parts that add back up to exactly the whole.", "status": "stable", "license": "NOASSERTION", "languages": [ "typescript", "python", "rust" ], "available": true, "group": false, "functions": [ "splitEven" ], "signatures": [ "pub fn split_even(amount: &Money, parts: i64) -> Vec" ], "reference": "fune!(money.split-even@^1); // then call split_even(…)", "url": "http://www.functionalweave.com/functions/money.split-even" } ], "gaps": [] }, { "key": "display", "title": "Display and input", "purpose": "Show amounts to people and read what they type.", "from": "money-basics", "members": [ { "id": "money.format", "tier": "core", "why": "Renders an amount as text with the currency's real number of decimal places.", "section": "display", "from": "money-basics", "version": "1.0.0", "summary": "Render a monetary amount as text, using the currency's real minor-unit precision.", "status": "stable", "license": "NOASSERTION", "languages": [ "typescript", "python", "rust" ], "available": true, "group": false, "functions": [ "formatMoney" ], "signatures": [ "pub fn format_money(amount: &Money) -> String" ], "reference": "fune!(money.format@^1); // then call format_money(…)", "url": "http://www.functionalweave.com/functions/money.format" }, { "id": "money.parse", "tier": "optional", "why": "Reads \"£1,234.50\" or \"1.234,50 €\" typed by a user into minor units, strictly.", "section": "display", "from": "money-basics", "version": "1.0.0", "summary": "Parse \"£1,234.50\" or \"1.234,50 €\" into integer minor units, strictly: no guessing, no rounding.", "status": "stable", "license": "NOASSERTION", "languages": [ "typescript", "python", "rust" ], "available": true, "group": false, "functions": [ "parseMoney" ], "signatures": [ "pub fn parse_money(text: &str, currency: &str, style: &str) -> Money" ], "reference": "fune!(money.parse@^1); // then call parse_money(…)", "url": "http://www.functionalweave.com/functions/money.parse" }, { "id": "money.currency-digits", "tier": "optional", "why": "How many decimal places each ISO 4217 currency has, for input boxes and validation.", "section": "display", "from": "money-basics", "version": "1.0.0", "summary": "How many decimal places a currency's minor unit has, from the ISO 4217 list.", "status": "stable", "license": "NOASSERTION", "languages": [ "typescript", "python", "rust" ], "available": true, "group": false, "functions": [ "currencyDigits" ], "signatures": [ "pub fn currency_digits(currency: &str) -> i64" ], "reference": "fune!(money.currency-digits@^1); // then call currency_digits(…)", "url": "http://www.functionalweave.com/functions/money.currency-digits" } ], "gaps": [] }, { "key": "currencies", "title": "Other currencies", "purpose": "Convert between currencies at a rate you hold.", "from": "money-basics", "members": [ { "id": "money.convert", "tier": "optional", "why": "Converts an amount at a supplied exact rate with explicit rounding.", "section": "currencies", "from": "money-basics", "version": "1.0.0", "summary": "Convert an amount to another currency at a supplied exact rate, with an explicit rounding mode.", "status": "stable", "license": "NOASSERTION", "languages": [ "typescript", "python", "rust" ], "available": true, "group": false, "functions": [ "convertMoney" ], "signatures": [ "pub fn convert_money(amount: &Money, rate: &ExchangeRate, mode: &RoundingMode) -> Money" ], "reference": "fune!(money.convert@^1); // then call convert_money(…)", "url": "http://www.functionalweave.com/functions/money.convert" } ], "gaps": [] }, { "key": "date-arithmetic", "title": "Calendar arithmetic", "purpose": "Move and measure ISO dates exactly, with no date library and no clock reads.", "from": "dates-basics", "members": [ { "id": "dates.add-days", "tier": "core", "why": "Shifts a date by whole days, for due dates and windows.", "section": "date-arithmetic", "from": "dates-basics", "version": "1.0.0", "summary": "Shift an ISO date by a whole number of days, forwards or backwards, with exact calendar arithmetic.", "status": "stable", "license": "NOASSERTION", "languages": [ "typescript", "python", "rust" ], "available": true, "group": false, "functions": [ "addDays" ], "signatures": [ "pub fn add_days(iso: &str, days: i64) -> String" ], "reference": "fune!(dates.add-days@^1); // then call add_days(…)", "url": "http://www.functionalweave.com/functions/dates.add-days" }, { "id": "dates.add-months", "tier": "core", "why": "Adds months clamping to month end, so 31 January plus a month is the end of February.", "section": "date-arithmetic", "from": "dates-basics", "version": "1.0.0", "summary": "Add calendar months to an ISO date, clamping to the month end: 31 Jan + 1 month is 28 or 29 Feb.", "status": "stable", "license": "NOASSERTION", "languages": [ "typescript", "python", "rust" ], "available": true, "group": false, "functions": [ "addMonths" ], "signatures": [ "pub fn add_months(iso: &str, months: i64) -> String" ], "reference": "fune!(dates.add-months@^1); // then call add_months(…)", "url": "http://www.functionalweave.com/functions/dates.add-months" }, { "id": "dates.days-between", "tier": "core", "why": "Signed calendar days between two dates, for ages of invoices and stays.", "section": "date-arithmetic", "from": "dates-basics", "version": "1.0.0", "summary": "Calendar days from one ISO date to another, signed: negative when the second date is earlier.", "status": "stable", "license": "NOASSERTION", "languages": [ "typescript", "python", "rust" ], "available": true, "group": false, "functions": [ "daysBetween" ], "signatures": [ "pub fn days_between(start_iso: &str, end_iso: &str) -> i64" ], "reference": "fune!(dates.days-between@^1); // then call days_between(…)", "url": "http://www.functionalweave.com/functions/dates.days-between" }, { "id": "dates.month-boundaries", "tier": "core", "why": "First and last day of a date's month, for monthly periods and statements.", "section": "date-arithmetic", "from": "dates-basics", "version": "1.0.0", "summary": "The first day, last day and length of the calendar month containing a date.", "status": "stable", "license": "NOASSERTION", "languages": [ "typescript", "python", "rust" ], "available": true, "group": false, "functions": [ "monthBoundaries" ], "signatures": [ "pub fn month_boundaries(iso: &str) -> MonthBoundaries" ], "reference": "fune!(dates.month-boundaries@^1); // then call month_boundaries(…)", "url": "http://www.functionalweave.com/functions/dates.month-boundaries" }, { "id": "dates.day-of-week", "tier": "core", "why": "ISO weekday of a date, for weekend rules and opening hours.", "section": "date-arithmetic", "from": "dates-basics", "version": "1.0.0", "summary": "The ISO 8601 day of the week for a date: 1 is Monday through 7 is Sunday.", "status": "stable", "license": "NOASSERTION", "languages": [ "typescript", "python", "rust" ], "available": true, "group": false, "functions": [ "dayOfWeek" ], "signatures": [ "pub fn day_of_week(iso: &str) -> i64" ], "reference": "fune!(dates.day-of-week@^1); // then call day_of_week(…)", "url": "http://www.functionalweave.com/functions/dates.day-of-week" }, { "id": "dates.is-leap-year", "tier": "optional", "why": "Whether a year is a leap year, for 365/366-day calculations.", "section": "date-arithmetic", "from": "dates-basics", "version": "1.0.0", "summary": "Whether a year is a Gregorian leap year: every 4th, except centuries, except every 400th.", "status": "stable", "license": "NOASSERTION", "languages": [ "typescript", "python", "rust" ], "available": true, "group": false, "functions": [ "isLeapYear" ], "signatures": [ "pub fn is_leap_year(year: i64) -> bool" ], "reference": "fune!(dates.is-leap-year@^1); // then call is_leap_year(…)", "url": "http://www.functionalweave.com/functions/dates.is-leap-year" }, { "id": "dates.overlap", "tier": "optional", "why": "Days two date ranges share, for prorating and clash checks.", "section": "date-arithmetic", "from": "dates-basics", "version": "1.0.0", "summary": "Days two date ranges have in common, with the end of each range stated as inclusive or exclusive.", "status": "stable", "license": "NOASSERTION", "languages": [ "typescript", "python", "rust" ], "available": true, "group": false, "functions": [ "overlapDays" ], "signatures": [ "pub fn overlap_days(a_start: &str, a_end: &str, b_start: &str, b_end: &str, end_inclusive: bool) -> i64" ], "reference": "fune!(dates.overlap@^1); // then call overlap_days(…)", "url": "http://www.functionalweave.com/functions/dates.overlap" }, { "id": "dates.age", "tier": "optional", "why": "Age in whole years on a date, handling 29 February birthdays.", "section": "date-arithmetic", "from": "dates-basics", "version": "1.0.0", "summary": "Age in whole years on a given date, with 29 February birthdays ageing on 1 March in other years.", "status": "stable", "license": "NOASSERTION", "languages": [ "typescript", "python", "rust" ], "available": true, "group": false, "functions": [ "age" ], "signatures": [ "pub fn age(birth_date: &str, on_date: &str) -> i64" ], "reference": "fune!(dates.age@^1); // then call age(…)", "url": "http://www.functionalweave.com/functions/dates.age" } ], "gaps": [] }, { "key": "reporting-periods", "title": "Periods and reporting dates", "purpose": "Put dates into the periods reports are grouped by.", "from": "dates-basics", "members": [ { "id": "dates.quarter", "tier": "core", "why": "Calendar and fiscal quarter of a date for any year-start month.", "section": "reporting-periods", "from": "dates-basics", "version": "1.0.0", "summary": "Calendar quarter and fiscal quarter of a date, with the fiscal year and quarter date ranges, for any start month.", "status": "stable", "license": "NOASSERTION", "languages": [ "typescript", "python", "rust" ], "available": true, "group": false, "functions": [ "quarter" ], "signatures": [ "pub fn quarter(iso: &str, fiscal_year_start_month: i64) -> Quarter" ], "reference": "fune!(dates.quarter@^1); // then call quarter(…)", "url": "http://www.functionalweave.com/functions/dates.quarter" }, { "id": "dates.week-number", "tier": "optional", "why": "ISO week number and week-year, for weekly reports.", "section": "reporting-periods", "from": "dates-basics", "version": "1.0.0", "summary": "ISO 8601 week number and week-numbering year of a date: weeks start Monday, week 1 holds the first Thursday.", "status": "stable", "license": "NOASSERTION", "languages": [ "typescript", "python", "rust" ], "available": true, "group": false, "functions": [ "weekNumber" ], "signatures": [ "pub fn week_number(iso: &str) -> IsoWeek" ], "reference": "fune!(dates.week-number@^1); // then call week_number(…)", "url": "http://www.functionalweave.com/functions/dates.week-number" }, { "id": "dates.day-count-fraction", "tier": "optional", "why": "Year fraction by ACT/365F, ACT/360, 30/360 or ACT/ACT, for interest periods.", "section": "reporting-periods", "from": "dates-basics", "version": "1.0.0", "summary": "Year fraction between two dates by ACT/365F, ACT/360, 30/360, 30E/360 or ACT/ACT ISDA, as an exact fraction.", "status": "stable", "license": "NOASSERTION", "languages": [ "typescript", "python", "rust" ], "available": true, "group": false, "functions": [ "dayCountFraction" ], "signatures": [ "pub fn day_count_fraction(start_iso: &str, end_iso: &str, convention: &str) -> YearFraction" ], "reference": "fune!(dates.day-count-fraction@^1); // then call day_count_fraction(…)", "url": "http://www.functionalweave.com/functions/dates.day-count-fraction" } ], "gaps": [] }, { "key": "working-days", "title": "Working days and holidays", "purpose": "Skip weekends and public holidays when counting or adding days.", "from": "dates-basics", "members": [ { "id": "dates.bank-holidays", "tier": "core", "why": "UK bank holidays for a region and year, as gov.uk publishes them.", "section": "working-days", "from": "dates-basics", "version": "1.0.1", "summary": "UK bank and public holidays for a region and year, as published by gov.uk, including one-off holidays.", "status": "stable", "license": "NOASSERTION", "languages": [ "typescript", "python", "rust" ], "available": true, "group": false, "functions": [ "bankHolidays" ], "signatures": [ "pub fn bank_holidays(region: &str, year: i64) -> Vec" ], "reference": "fune!(dates.bank-holidays@^1); // then call bank_holidays(…)", "url": "http://www.functionalweave.com/functions/dates.bank-holidays" }, { "id": "dates.add-business-days", "tier": "core", "why": "Moves a date by working days, skipping weekends and a holiday list.", "section": "working-days", "from": "dates-basics", "version": "1.0.0", "summary": "Move a date forward or back by working days, skipping weekends and a caller-supplied holiday list.", "status": "stable", "license": "NOASSERTION", "languages": [ "typescript", "python", "rust" ], "available": true, "group": false, "functions": [ "addBusinessDays" ], "signatures": [ "pub fn add_business_days(iso: &str, days: i64, holidays: &[String]) -> String" ], "reference": "fune!(dates.add-business-days@^1); // then call add_business_days(…)", "url": "http://www.functionalweave.com/functions/dates.add-business-days" }, { "id": "dates.business-days-between", "tier": "core", "why": "Working days between two dates, for SLAs and notice periods.", "section": "working-days", "from": "dates-basics", "version": "1.0.0", "summary": "Working days between two dates, excluding weekends and a caller-supplied holiday list.", "status": "stable", "license": "NOASSERTION", "languages": [ "typescript", "python", "rust" ], "available": true, "group": false, "functions": [ "businessDaysBetween" ], "signatures": [ "pub fn business_days_between(start_iso: &str, end_iso: &str, holidays: &[String]) -> i64" ], "reference": "fune!(dates.business-days-between@^1); // then call business_days_between(…)", "url": "http://www.functionalweave.com/functions/dates.business-days-between" } ], "gaps": [] }, { "key": "repeating-dates", "title": "Repeating schedules", "purpose": "Generate the dates of something that repeats.", "from": "dates-basics", "members": [ { "id": "dates.recurrence", "tier": "optional", "why": "The next n dates of a rule: monthly on the 31st, last Friday, every two weeks.", "section": "repeating-dates", "from": "dates-basics", "version": "1.0.0", "summary": "The next n dates of a repeating rule: monthly on a day, last weekday of the month, every k days or weeks, yearly.", "status": "stable", "license": "NOASSERTION", "languages": [ "typescript", "python", "rust" ], "available": true, "group": false, "functions": [ "recurrence" ], "signatures": [ "pub fn recurrence(rule: &RecurrenceRule, start_iso: &str, count: i64) -> Vec" ], "reference": "fune!(dates.recurrence@^1); // then call recurrence(…)", "url": "http://www.functionalweave.com/functions/dates.recurrence" } ], "gaps": [] }, { "key": "times", "title": "Times and durations", "purpose": "Work with times of day, durations and timestamps.", "from": "dates-basics", "members": [ { "id": "time.duration", "tier": "optional", "why": "Parses and adds durations like 1h30m in whole minutes, and formats the total.", "section": "times", "from": "dates-basics", "version": "1.0.0", "summary": "Parse durations written as 1h30m, 90m or 01:30, add them up in whole minutes, and format the total.", "status": "stable", "license": "NOASSERTION", "languages": [ "typescript", "python", "rust" ], "available": true, "group": false, "functions": [ "duration" ], "signatures": [ "pub fn duration(parts: &[String]) -> Duration" ], "reference": "fune!(time.duration@^1); // then call duration(…)", "url": "http://www.functionalweave.com/functions/time.duration" }, { "id": "time.minutes-between", "tier": "optional", "why": "Minutes between two local date-times, across midnight.", "section": "times", "from": "dates-basics", "version": "1.0.0", "summary": "Minutes from one local date and time to another, correct across midnight; wall-clock time, no time zones.", "status": "stable", "license": "NOASSERTION", "languages": [ "typescript", "python", "rust" ], "available": true, "group": false, "functions": [ "minutesBetween" ], "signatures": [ "pub fn minutes_between(start_date: &str, start_time: &str, end_date: &str, end_time: &str) -> i64" ], "reference": "fune!(time.minutes-between@^1); // then call minutes_between(…)", "url": "http://www.functionalweave.com/functions/time.minutes-between" }, { "id": "time.round-to-increment", "tier": "optional", "why": "Rounds minutes to a billing increment such as 6 or 15.", "section": "times", "from": "dates-basics", "version": "1.0.0", "summary": "Round a duration in minutes to a billing increment such as 6 or 15 minutes, up, down or to nearest.", "status": "stable", "license": "NOASSERTION", "languages": [ "typescript", "python", "rust" ], "available": true, "group": false, "functions": [ "roundToIncrement" ], "signatures": [ "pub fn round_to_increment(minutes: i64, increment: i64, mode: &RoundingMode) -> i64" ], "reference": "fune!(time.round-to-increment@^1); // then call round_to_increment(…)", "url": "http://www.functionalweave.com/functions/time.round-to-increment" }, { "id": "time.iso-to-unix", "tier": "optional", "why": "RFC 3339 timestamps to Unix seconds.", "section": "times", "from": "dates-basics", "version": "1.0.0", "summary": "An RFC 3339 timestamp with a Z or offset, such as 2026-09-26T13:00:00+01:00, to Unix time in whole seconds.", "status": "stable", "license": "NOASSERTION", "languages": [ "typescript", "python", "rust" ], "available": true, "group": false, "functions": [ "isoToUnix" ], "signatures": [ "pub fn iso_to_unix(timestamp: &str) -> i64" ], "reference": "fune!(time.iso-to-unix@^1); // then call iso_to_unix(…)", "url": "http://www.functionalweave.com/functions/time.iso-to-unix" }, { "id": "time.unix-to-iso", "tier": "optional", "why": "Unix seconds to an ISO 8601 UTC timestamp.", "section": "times", "from": "dates-basics", "version": "1.0.0", "summary": "Unix time in seconds to an ISO 8601 UTC timestamp such as 2026-09-26T12:00:00Z, for years 0001 to 9999.", "status": "stable", "license": "NOASSERTION", "languages": [ "typescript", "python", "rust" ], "available": true, "group": false, "functions": [ "unixToIso" ], "signatures": [ "pub fn unix_to_iso(seconds: i64) -> String" ], "reference": "fune!(time.unix-to-iso@^1); // then call unix_to_iso(…)", "url": "http://www.functionalweave.com/functions/time.unix-to-iso" }, { "id": "time.countdown", "tier": "optional", "why": "Seconds left until a moment and a 4:05 style timer text.", "section": "times", "from": "dates-basics", "version": "1.0.0", "summary": "Seconds left until a Unix time, whether it has passed, and a timer text like 4:05, for tokens or retry waits.", "status": "stable", "license": "NOASSERTION", "languages": [ "typescript", "python", "rust" ], "available": true, "group": false, "functions": [ "countdown" ], "signatures": [ "pub fn countdown(until: i64, now: i64) -> Countdown" ], "reference": "fune!(time.countdown@^1); // then call countdown(…)", "url": "http://www.functionalweave.com/functions/time.countdown" } ], "gaps": [] }, { "key": "contact", "title": "Contact details", "purpose": "Check and normalise a person's contact details before storing them.", "from": "validation-basics", "members": [ { "id": "validation.email", "tier": "core", "why": "Is an email address plausible, by a documented subset of RFC 5322.", "section": "contact", "from": "validation-basics", "version": "1.0.0", "summary": "Is this a plausible email address? A documented, pragmatic subset of RFC 5322, not the full grammar.", "status": "stable", "license": "NOASSERTION", "languages": [ "typescript", "python", "rust" ], "available": true, "group": false, "functions": [ "isEmail" ], "signatures": [ "pub fn is_email(value: &str) -> bool" ], "reference": "fune!(validation.email@^1); // then call is_email(…)", "url": "http://www.functionalweave.com/functions/validation.email" }, { "id": "validation.phone-e164", "tier": "core", "why": "Normalises a phone number to +44… E.164 for a default country.", "section": "contact", "from": "validation-basics", "version": "2.0.0", "summary": "Normalise a phone number to E.164 (+447700900123) using a default country's trunk and dialling prefixes.", "status": "stable", "license": "NOASSERTION", "languages": [ "typescript", "python", "rust" ], "available": true, "group": false, "functions": [ "validatePhoneE164" ], "signatures": [ "pub fn validate_phone_e164(value: &str, default_country: &str) -> PhoneE164" ], "reference": "fune!(validation.phone-e164@^2); // then call validate_phone_e164(…)", "url": "http://www.functionalweave.com/functions/validation.phone-e164" }, { "id": "validation.uk-postcode", "tier": "core", "why": "Validates a UK postcode and puts it in canonical form.", "section": "contact", "from": "validation-basics", "version": "2.0.0", "summary": "Validate a UK postcode and normalise it to canonical upper case with one space before the inward code.", "status": "stable", "license": "NOASSERTION", "languages": [ "typescript", "python", "rust" ], "available": true, "group": false, "functions": [ "validateUkPostcode" ], "signatures": [ "pub fn validate_uk_postcode(value: &str) -> UkPostcode" ], "reference": "fune!(validation.uk-postcode@^2); // then call validate_uk_postcode(…)", "url": "http://www.functionalweave.com/functions/validation.uk-postcode" }, { "id": "text.normalise-name", "tier": "optional", "why": "Tidies a typed name: spacing and title case with Mc, O' and hyphen rules.", "section": "contact", "from": "validation-basics", "version": "1.0.0", "summary": "Tidy a personal name: trim, collapse whitespace and title-case, with Mc, Mac, O', hyphen and van/de rules.", "status": "stable", "license": "NOASSERTION", "languages": [ "typescript", "python", "rust" ], "available": true, "group": false, "functions": [ "normaliseName" ], "signatures": [ "pub fn normalise_name(value: &str) -> String" ], "reference": "fune!(text.normalise-name@^1); // then call normalise_name(…)", "url": "http://www.functionalweave.com/functions/text.normalise-name" }, { "id": "auth.normalise-email", "tier": "optional", "why": "Lower-cases an email's domain for storage and lookup.", "section": "contact", "from": "validation-basics", "version": "1.0.0", "summary": "Trim an email address and lower-case its domain for storage and lookup, or null if it is not a plausible address.", "status": "stable", "license": "NOASSERTION", "languages": [ "typescript", "python", "rust" ], "available": true, "group": false, "functions": [ "normaliseEmail" ], "signatures": [ "pub fn normalise_email(value: &str) -> Option" ], "reference": "fune!(auth.normalise-email@^1); // then call normalise_email(…)", "url": "http://www.functionalweave.com/functions/auth.normalise-email" } ], "gaps": [] }, { "key": "bank", "title": "Bank details", "purpose": "Check payee and customer bank details before money moves.", "from": "validation-basics", "members": [ { "id": "validation.iban", "tier": "core", "why": "Checks an IBAN's mod-97 checksum and its country's length.", "section": "bank", "from": "validation-basics", "version": "1.0.0", "summary": "Check an IBAN against the ISO 13616 mod-97-10 checksum and the registered length for its country.", "status": "stable", "license": "NOASSERTION", "languages": [ "typescript", "python", "rust" ], "available": true, "group": false, "functions": [ "isIban" ], "signatures": [ "pub fn is_iban(value: &str) -> bool" ], "reference": "fune!(validation.iban@^1); // then call is_iban(…)", "url": "http://www.functionalweave.com/functions/validation.iban" }, { "id": "validation.bic", "tier": "optional", "why": "Checks a SWIFT/BIC code's format and splits it.", "section": "bank", "from": "validation-basics", "version": "1.0.0", "summary": "Check the format of a SWIFT/BIC code (8 or 11 characters) and split it into its parts.", "status": "stable", "license": "NOASSERTION", "languages": [ "typescript", "python", "rust" ], "available": true, "group": false, "functions": [ "validateBic" ], "signatures": [ "pub fn validate_bic(value: &str) -> BicCheck" ], "reference": "fune!(validation.bic@^1); // then call validate_bic(…)", "url": "http://www.functionalweave.com/functions/validation.bic" }, { "id": "validation.uk-sort-code-account", "tier": "optional", "why": "Checks a UK sort code and account number by the Vocalink modulus rules, against a table you supply.", "section": "bank", "from": "validation-basics", "version": "3.0.0", "summary": "Check a UK sort code and account number with the Vocalink/Pay.UK modulus rules, against a table you supply.", "status": "stable", "license": "NOASSERTION", "languages": [ "typescript", "python", "rust" ], "available": true, "group": false, "functions": [ "validateUkSortCodeAccount" ], "signatures": [ "pub fn validate_uk_sort_code_account(sort_code: &str, account_number: &str, table: &UkModulusTable) -> UkSortCodeAccount" ], "reference": "fune!(validation.uk-sort-code-account@^3); // then call validate_uk_sort_code_account(…)", "url": "http://www.functionalweave.com/functions/validation.uk-sort-code-account" }, { "id": "validation.uk-modulus-table", "tier": "optional", "why": "Parses Vocalink's VALACDOS and SCSUBTAB files into that table.", "section": "bank", "from": "validation-basics", "version": "1.0.0", "summary": "Parse Vocalink's VALACDOS.txt and SCSUBTAB.txt into the table UK sort code modulus checking needs.", "status": "stable", "license": "NOASSERTION", "languages": [ "typescript", "python", "rust" ], "available": true, "group": false, "functions": [ "parseUkModulusTable" ], "signatures": [ "pub fn parse_uk_modulus_table(valacdos: &str, scsubtab: &str) -> UkModulusTable" ], "reference": "fune!(validation.uk-modulus-table@^1); // then call parse_uk_modulus_table(…)", "url": "http://www.functionalweave.com/functions/validation.uk-modulus-table" } ], "gaps": [] }, { "key": "check-digits", "title": "Identifiers and check digits", "purpose": "Catch mistyped reference numbers by their check digits.", "from": "validation-basics", "members": [ { "id": "validation.luhn", "tier": "optional", "why": "Luhn mod-10 check, for card numbers and many reference numbers.", "section": "check-digits", "from": "validation-basics", "version": "1.0.0", "summary": "Check a digit string against the Luhn mod-10 checksum used by payment cards and many identifiers.", "status": "stable", "license": "NOASSERTION", "languages": [ "typescript", "python", "rust" ], "available": true, "group": false, "functions": [ "isLuhn" ], "signatures": [ "pub fn is_luhn(value: &str) -> bool" ], "reference": "fune!(validation.luhn@^1); // then call is_luhn(…)", "url": "http://www.functionalweave.com/functions/validation.luhn" }, { "id": "validation.uk-company-number", "tier": "optional", "why": "Checks a Companies House number's format and prefix.", "section": "check-digits", "from": "validation-basics", "version": "2.0.1", "summary": "Check a Companies House company number's format and prefix (SC, NI, OC, LP...) and zero-pad it to eight characters.", "status": "stable", "license": "NOASSERTION", "languages": [ "typescript", "python", "rust" ], "available": true, "group": false, "functions": [ "validateUkCompanyNumber" ], "signatures": [ "pub fn validate_uk_company_number(value: &str) -> UkCompanyNumber" ], "reference": "fune!(validation.uk-company-number@^2); // then call validate_uk_company_number(…)", "url": "http://www.functionalweave.com/functions/validation.uk-company-number" }, { "id": "validation.lei", "tier": "optional", "why": "Checks a Legal Entity Identifier's check digits.", "section": "check-digits", "from": "validation-basics", "version": "1.0.0", "summary": "Check a 20-character Legal Entity Identifier against its ISO 17442 / ISO 7064 MOD 97-10 check digits.", "status": "stable", "license": "NOASSERTION", "languages": [ "typescript", "python", "rust" ], "available": true, "group": false, "functions": [ "validateLei" ], "signatures": [ "pub fn validate_lei(value: &str) -> LeiCheck" ], "reference": "fune!(validation.lei@^1); // then call validate_lei(…)", "url": "http://www.functionalweave.com/functions/validation.lei" }, { "id": "validation.gtin", "tier": "optional", "why": "Checks an EAN/UPC/GTIN barcode number.", "section": "check-digits", "from": "validation-basics", "version": "1.1.0", "summary": "Check an EAN-8, UPC-A, EAN-13 or GTIN-14 barcode number against the GS1 mod-10 check digit.", "status": "stable", "license": "NOASSERTION", "languages": [ "typescript", "python", "rust" ], "available": true, "group": false, "functions": [ "validateGtin" ], "signatures": [ "pub fn validate_gtin(value: &str) -> GtinCheck" ], "reference": "fune!(validation.gtin@^1); // then call validate_gtin(…)", "url": "http://www.functionalweave.com/functions/validation.gtin" } ], "gaps": [] } ], "gaps": [ { "key": "payment-rails", "text": "Actually moving money: Faster Payments, Bacs and SWIFT submissions, or a payments provider's API.", "section": "payments", "from": "banking" }, { "key": "confirmation-of-payee", "text": "Confirmation of Payee name checks: a network service between banks.", "section": "payments", "from": "banking" }, { "key": "categorisation", "text": "Categorising transactions (merchant names to spending categories) is not in caps.", "section": "statements", "from": "banking" }, { "key": "kyc-aml", "text": "Know-your-customer checks, sanctions screening and anti-money-laundering monitoring are services and policy caps does not have.", "section": null, "from": "banking" }, { "key": "ledger-of-record", "text": "A core banking ledger (accounts, holds, postings, idempotent transfers) to keep balances is yours; caps works out the figures.", "section": null, "from": "banking" }, { "key": "card-issuing", "text": "Card issuing, authorisations and chargebacks go through a card processor.", "section": null, "from": "banking" }, { "key": "fx-rate-source", "text": "Where exchange rates come from: money.convert takes a rate you supply; fetching and storing daily rates (ECB, a provider's API) is yours.", "section": null, "from": "money-basics" }, { "key": "money-storage", "text": "Storing amounts: the database columns (integer minor units plus a currency code) and their migrations are yours.", "section": null, "from": "money-basics" }, { "key": "time-zones", "text": "Time zones and daylight saving: caps works in ISO dates, UTC and wall-clock times; converting with the IANA tz rules is yours.", "section": null, "from": "dates-basics" }, { "key": "locale-formatting", "text": "Showing dates in a user's language and format (\"3 octobre 2026\"): caps returns ISO dates, not localised text.", "section": null, "from": "dates-basics" }, { "key": "non-uk-holidays", "text": "Public holidays outside the UK: dates.bank-holidays is UK only; pass another country's list to the working-day functions yourself.", "section": null, "from": "dates-basics" }, { "key": "address-lookup", "text": "Turning a postcode into a list of addresses (Royal Mail PAF or a lookup API) is network work and not in caps.", "section": null, "from": "validation-basics" }, { "key": "email-deliverability", "text": "Whether a mailbox exists (MX lookups, a confirmation email): validation.email checks the syntax only.", "section": null, "from": "validation-basics" }, { "key": "vocalink-data", "text": "The Vocalink modulus tables themselves: download them from Pay.UK under its terms; caps parses them but does not ship them.", "section": null, "from": "validation-basics" } ], "counts": { "members": 64, "core": 26, "optional": 38, "unreviewed": 1, "deprecated": [], "unavailable": [], "missing": [], "gaps": 14 }, "warnings": [ "1 optional capability is unreviewed too: lending.daily-interest", "UK first: Bacs cycles, Faster Payments and bank holidays follow UK schemes; not financial advice." ], "url": "http://www.functionalweave.com/suites/banking", "owner": null }