## Changelog

### v1.4.8 (2024-05-04)

* Add support for `%` for modulo as an alternative to `mod`. Since `%` is also
    used for percentages, the way the operator is interpreted depends on
    context: `5 % 2` or `(348*34)%(293-1)` is parsed as modulo, whereas `5%` or
    `5% + 3` continues to be treated as a percentage.
* Add constants `electron_mass`, `proton_mass` and `neutron_mass`

### v1.4.7 (2024-05-04)

* Add Japanese units `shaku`, `tsubo` and `tatami`
* Significantly improve performance when calculating powers with
    decimal numbers, e.g. `e^27.2`
* Revamp fend's web UI: it is now built with React and runs calculations
    in a background thread. This fixes the timeout issues that used to affect
    long-running calculations.
* Fix a bug where variable serialisation could cause numbers to be negated. This
    only affected fend-wasm and fend-web but could lead to incorrect results
    when using variables across multiple calculations.
* Add some custom TypeScript definitions to fend-wasm

### v1.4.6 (2024-03-28)

* Add function `mean` (or `average`) to compute the mean value of probability
    distributions (by [haykam821](https://github.com/haykam821)). For example:

    ```
    > mean(d6)
    7
    > average(1d20 + 5)
    15.5
    ```
* Add units `nibble` (4 bits) and `U` (rack units, equal to `1.75 inches`)
* Serialised variables are now compatible between 32-bit and 64-bit platforms
* Fix bug where calculating very large roman numerals could crash
    the application

### v1.4.5 (2024-03-13)

* Add support for converting numbers to roman numerals (e.g.
    `45 to roman` becomes `XLV`)
* Add `≠` as an alias for `!=` (by [@haykam821](https://github.com/haykam821))
* Add `<>` as another alias for `!=`
* Update Windows MSI installer to WiX 4
* The fend Telegram bot now directly replies to messages, making it easier to
    use in group chats (by [@frectonz](https://github.com/frectonz))

### v1.4.4 (2024-03-05)

* Add `==` and `!=` operators for equality and inequality (by
    [@frectonz](https://github.com/frectonz))

    For example:

    ```
    > 2 metres == 200 cm
    true
    > 4 kg == 2 lbs
    false
    ```
* The fend CLI now uses `native-tls` by default, instead of `rustls`.
    On Windows this uses SChannel (via the `schannel` crate), on macOS it
    uses Secure Transport via the `security-framework` crate, and on Linux
    it links to OpenSSL with the `openssl` crate.
    You can continue using `rustls` by compiling with the
    `--no-default-features --features rustls` flags.
    See the CLI's `Cargo.toml` for further details.

### v1.4.3 (2024-02-23)

* Add `floor`, `ceil` and `round` functions (by
    [@frectonz](https://github.com/frectonz))
* Add ¥ symbol for Japanese Yen (by [@frectonz](https://github.com/frectonz))
* Support power notation using Unicode superscript digits (by
    [@frectonz](https://github.com/frectonz))

### v1.4.2 (2024-01-23)

* Add ability to convert codepoints to characters, e.g. `97 to character`
    (by [@mat-1](https://github.com/mat-1))
* Fix horsepower value (by [@probablykasper](https://github.com/probablykasper))
* Fix license files not being included in the workspace member packages
    (`fend-core` etc.) (by [@albertlarsan68](https://github.com/albertlarsan68))

### v1.4.1 (2024-01-07)

* Fix bug where fend could return incorrect results when calculating
    exponents or roots of certain units, e.g. `sqrt(milli)`.

### v1.4.0 (2023-12-27)

* The license of fend has changed. As of v1.4.0, fend is available under
    the GPL 3.0 (or later). See
    [LICENSE.md](https://github.com/printfn/fend/blob/main/LICENSE.md)
    for more information.
* Change unit simplification and unit aliasing to be simpler and more
    consistent. Units like `%` and `million` are now simplified unless you
    explicitly convert your result to one of those units. fend will now also
    simplify certain combinations of units, such as `volts / ohms` becoming
    `amperes`.

    For example:

    ```
    > 5%
    0.05
    > 46 million
    46000000
    > 0.5 to %
    50%
    > 34820000 to million
    34.82 million
    > (5 volts) / (2 ohms)
    2.5 amperes
    > 3 feet * 125 kg * s^-2
    114.3 newtons
    ```

    Please open an issue if you encounter any bugs or unexpected behavior.
* Rename Windows installer artifacts (MSI files) to also include the version
    number, e.g. `fend-1.4.0-windows-x64.msi`.
* Replace `nanorand` dependency with `rand`, which is better supported and
    fixes compilation errors on FreeBSD.

### v1.3.3 (2023-12-08)

* Add `pkgx` package (by [@michaelessiet](https://github.com/michaelessiet))
* Add `x86_64-unknown-linux-musl` binary
* Fix terminal issues on some architectures such as MIPS (by
    [@eatradish](https://github.com/eatradish))

### v1.3.2 (2023-11-11)

* Custom units can now be defined in the `~/.config/fend/config.toml`
    configuration file. For example:

    ```toml
    [[custom-units]]
    singular = 'fortnight'
    plural = 'fortnights'  # plural form is optional, defaults
                           # to singular if not specified
    definition = '14 days'
    attribute = 'allow-long-prefix'  # this makes it possible to combine this
                                     # unit with prefixes like 'milli-' or 'giga-'
    ```

    See the [default config file](https://github.com/printfn/fend/blob/main/cli/src/default_config.toml) for more examples.
* You can now tab-complete greek letters in the CLI, e.g. `\alpha` becomes α
    (by [@Markos-Th09](https://github.com/Markos-Th09))
* You can now use the `of` operator to write e.g. `5% of 100`
    (by [@fa993](https://github.com/fa993))
* Add CGS units (by [@Markos-Th09](https://github.com/Markos-Th09))

### v1.3.1 (2023-10-26)

* Add support for additional imperial and US customary units

### v1.3.0 (2023-10-16)

* Support loading exchange rates from the UN treasury, which supports more
    currencies than the European Central Bank. This can be configured via
    the new `exchange-rate-source` option. (by [@Markos-Th09](https://github.com/Markos-Th09))
* Exchange rates are now available in fend-web (by [@Markos-Th09](https://github.com/Markos-Th09))
* Support complex numbers in many more situations, including trigonometric
    functions, logarithms, exponentiation, etc.
    (by [@Markos-Th09](https://github.com/Markos-Th09))
* Add support for unit prefixes for parsecs (e.g. `Mpc`)

### v1.2.2 (2023-09-14)

* Add crate features to control the TLS implementation: enabling `native-tls`
    will cause fend to use the operating system's built-in TLS implementation.
    The `rustls` feature, which is enabled by default, will keep the existing
    native Rust implementation. When both features are disabled, such as when
    compiling with `--no-default-features`, network connectivity will not be
    available and currency conversions will not work.
    (by [@eatradish](https://github.com/eatradish))
* Add "zł" as an alias for Polish złoty (PLN) (by [@twolodzko](https://github.com/twolodzko))
* Add AOSC OS package and installation instructions (by [@eatradish](https://github.com/eatradish))
* Use `windows-sys` instead of `winapi`

### v1.2.1 (2023-09-06)

* Add Chinese units `jin` and `gongjin` (by [@eatradish](https://github.com/eatradish))
* Add Xbps (Void Linux) package (by [@tranzystorek-io](https://github.com/tranzystorek-io))
* Add MacPorts package (by [@herbygillot](https://github.com/herbygillot))

### v1.2.0 (2023-06-02)

* Variable names with underscores can now be correctly referenced
* Combined abbreviated units are now parsed case-insensitively:

    ```
    > 100 kwh
    100 kWh
    > 64 KB
    64 kB
    ```

* Add a new configuration option `enable-internet-access` (defaults to `true`)
* Add `tbs` unit as an abbreviation for tablespoons
* Add `thou` unit, representing a thousandth of an inch

### v1.1.6 (2023-04-03)

* Add cup, tablespoon and teaspoon units (by [@elcste](https://github.com/elcste))
* Add `bin` alias for binary (by [@xfnw](https://github.com/xfnw))
* Change the internal implementation of exchange rate handlers (by [@SekoiaTree](https://github.com/SekoiaTree))
* Fix unit test failures on 32-bit systems

### v1.1.5 (2023-02-06)

* Add `@no_trailing_newline` attribute, which causes fend to not print a trailing
    newline after the calculation.

    ```
    $ fend @no_trailing_newline 5+5
    10
    ```

### v1.1.4 (2023-01-08)

* Add support for subtracting from dates (e.g. `@2023-01-08 - 5 days`)
* Fix some trigonometric functions behaving incorrectly when passing in values with units

### v1.1.3 (2022-11-28)

* Add operators for permutations and combinations (by [@frectonz](https://github.com/frectonz))
    * `n permute k` or `n nPr k`: compute the number of `k`-permutations of `n`
    * `n choose k` or `n nCr k`: number of `k`-combinations of `n`
* Add `@noapprox` attribute to hide the `approx.` annotation in the output:

    ```
    > pi
    approx. 3.1415926535
    > @noapprox pi
    3.1415926535
    ```

* Add `@plain_number` attribute, to remove `approx.` and any units. This is especially useful in automated scripts.

    ```
    > 5 m / (3 s)
    approx. 1.6666666666 m / s
    > @plain_number 5 m / (3 s)
    1.6666666666
    ```

* Add a new date literal syntax, e.g. `@2000-01-01`
* Improve visual feedback when using the Telegram bot (by [@miki-tebe](https://github.com/miki-tebe))
* Add new SI prefixes quecca, ronna, ronto and quecto (by [@frectonz](https://github.com/frectonz))
* Add support for 256 (8-bit) colors in the CLI configuration
* Change `!debug` to `@debug` for consistency and improved shell script interoperability

### v1.1.2 (2022-10-31)

* Add `and` and `or` keywords as alternatives to the `&` and `|` bitwise operators
* Add Homebrew package (by [@rhysmdnz](https://github.com/rhysmdnz))
* Add Chocolatey package (by [@dgalbraith](https://github.com/dgalbraith))
* Fix incorrect description of command-line arguments in
    man page (by [@mcint](https://github.com/mcint))
* Support `_` in fend-web (stores the previous answer)
* Improve fend-web performance by serializing/storing variables properly
* Support case-insensitive currencies
* Support currency exchange rates in fend-wasm (by [@NickGeek](https://github.com/NickGeek))
* Support using any base currency for exchange rate calculations, not just USD

### v1.1.1 (2022-09-23)

* Add bitwise operators:
    * `&`: bitwise AND
    * `|`: bitwise OR
    * `xor`: bitwise XOR (`^` is already used for exponentiation)
    * `<<`: left shift
    * `>>`: right shift

### v1.1.0 (2022-09-22)

* Automatically download up-to-date currency exchange rates,
    e.g. when calculating `10 EUR to USD`
* fend can now read directly from files, e.g. `fend calculation.txt` will
    read and evaluate the contents of `calculation.txt`. Multiple files can be
    specified, as well as combinations of files and expressions.
* Shebangs (e.g. `#!/usr/bin/env fend`) no longer result in parse errors
* You can now use `--` to force fend to interpret arguments literally,
    e.g. `fend -- -V` is interpreted as `-1 volts` instead of showing the version number
* Fix bug where trailing whitespace or comments would result in a parse error
* Add a man page
* Add an MSI installer for Windows
* Remove MSIX installer, which was difficult to use due to it being unsigned
* Change fend website to [https://printfn.github.io/fend](https://printfn.github.io/fend)
* Move fend documentation to
    [https://printfn.github.io/fend/documentation](https://printfn.github.io/fend/documentation)
* Add a fend package to the Windows Package Manager (`winget`)

### v1.0.5 (2022-08-14)

* Add a `fend-wasm-nodejs` NPM package
* Add a [Telegram bot](https://t.me/fend_calc_bot)
* Improve behaviour of percentages (credit to @Techcable), e.g. `5% * 80kg` is now `4 kg`
* Add a Markdown-like parsing mode to the WASM API

### v1.0.4 (2022-07-22)

* Support `kn` for `knots`
* Add an installer for Windows

### v1.0.3 (2022-06-07)

* Support `rad` for `radians` (e.g. `10 RPM to rad/s`)
* Support implicit inches for `feet` (e.g. `5 foot 5 to cm`)
* Ensure fend does not exit when pressing Ctrl-C to clear the current line

### v1.0.2 (2022-06-01)

* Improve CLI colors
* Use Coulomb and Farad for prefixed units like `mC` or `µF`
* Add `sqmm` unit for square millimeters
* Add `point` unit for typographical points (i.e. 1/72 inch)
* Improve CLI behavior when pressing Ctrl-C to clear the current line

### v1.0.1 (2022-03-19)

* Support omitting inches when writing e.g. `5'1`: fend will now automatically
    interpret that as `5'1"`
* Improve reliability when piping data into fend on the command line, e.g.
    when running `echo "1+1" | fend`
* Support compiling fend with Rust 1.56 (rather than requiring Rust 1.59)

### v1.0.0 (2022-03-12)

* Allow `kmh` and `km/h` for kilometers per hour
* Change Planck's constant from `h` to `planck`
* Add support for lambda notation `λx.x` (in addition to the previous
    lambda notations `\x.x`, `x:x` and `x => x`)
* Add a ZSH helper script that makes `fend` more convenient on the
    command line
* Despite the major version bump, this release contains no breaking
    API changes

### v0.1.29 (2022-02-23)

* The locations for the config and history files have changed on some operating
    systems. On Linux and macOS, fend will now look in `~/.config/fend/config.toml`
    for its configuration file, and store history in `~/.local/state/fend/history`.
    You can run `fend help` to see which paths fend uses, and override them
    via the `FEND_CONFIG_DIR` and `FEND_STATE_DIR` environment variables
    if necessary.
* Colors in the CLI are now enabled by default. They can be disabled via the
    `enable-colors` config option, or via the `NO_COLOR` environment variable.
    `CLICOLOR` and `CLICOLOR_FORCE` environment variables are also respected.
    See https://bixense.com/clicolors/ and https://no-color.org for more info.
* Add a `max-history-size` config option to control how many history entries are
    saved by default.
* Improve error-checking when reading the config file. Minor errors will now only
    produce warnings, and no longer cause parsing to fail entirely.
* There are now Linux ARM builds available, for both `armv7-gnueabihf` and
    `aarch64` architectures.

### v0.1.28 (2022-02-12)

* Add base names `ternary` and `senary`
* Reduce CLI binary sizes

### v0.1.27 (2021-11-02)

* Improve command-line argument parsing, including support for multiple arguments
* The most recent calculation result is now stored in a special variable `_` (or `ans`):

    ```
    > 5 * 10
    50
    > _ + 5
    55
    > _ * 2
    110
    > ans * 2
    220
    ```

### v0.1.26 (2021-09-27)

* Fix minor bug in the `fend-wasm-web` NPM package

### v0.1.25 (2021-09-27)

* Add `stone` unit
* Add initial support for date arithmetic, e.g. `('2020-05-04' to date) + 500 days`
* There is now a `fend-wasm-web` NPM package available, built with the `--target web` option

### v0.1.24 (2021-08-09)

* Add basic tab completion support to the CLI interface
* Improve output for `()` types in the CLI and in `fend-wasm`

### v0.1.23 (2021-08-06)

* Fully support empty statements and trailing semicolons

### v0.1.22 (2021-07-29)

* Add amp hour abbreviation (e.g. `mAh`)
* Improve error message when attempting to convert between incompatible units

### v0.1.21 (2021-07-11)

* Add support for D&D-style dice syntax. For example, `d6` refers to a standard 6-sided die.

    ```
    > roll d6
    4
    > roll d20 # 20-sided die
    17
    > roll 2d6 # sum of two 6-sided dice
    7
    > 2d6 # view the probability distribution
      2:  2.78%  #####
      3:  5.56%  ##########
      4:  8.33%  ###############
      5: 11.11%  ####################
      6: 13.89%  #########################
      7: 16.67%  ##############################
      8: 13.89%  #########################
      9: 11.11%  ####################
     10:  8.33%  ###############
     11:  5.56%  ##########
     12:  2.78%  #####
    > roll(d20 + d6 + 4) # arithmetic operations
    14
    ```

* Fix `lux` unit definition
* Remove the `->` conversion syntax: use `to` instead

### v0.1.20 (2021-06-29)

* Support modulo with arbitrarily large integers
* Add a config option to use `C` and `F` as coulomb and farad instead of
  degrees celsius and degrees fahrenheit
* Add more units: `horsepower`, `lumen`, `lux`, `decare` etc.

### v0.1.19 (2021-06-29)

* Add more units: `atmosphere`, `mmHg`, `inHg`, `dB`, `mil` and more
* Support variables over multiple statements in the wasm API

### v0.1.18 (2021-06-28)

* Add variables and multiple statements (e.g. `a = 4; b = 10; a * b` is `40`)
* Add `mixed_frac` as an alias for `mixed_fraction`
* Support the `£` symbol for GBP
* Allow `$` and `£` before the associated number, e.g. `$100/4` is `$25`

### v0.1.17 (2021-06-08)

* Add `k`, `M`, `G` and `T` suffixes for numbers (e.g. `5k` is `5000`)
* Add a modulo operator `mod` (e.g. `5 mod 2` is `1`)
* Improve error messages for invalid unit conversions
* Add the golden ratio constant phi ϕ (`phi` is `approx. 1.6180339886`)
* Fix incorrect currency exchange rates
* Add `true`, `false`, and a `not()` function
* Add `sqm` and `sqft` units for square meters and square feet respectively

### v0.1.16 (2021-05-21)

* Add support for Unicode operators, such as ✕ or ÷
* Add color customization to the command-line interface by editing the
    `config.toml` file. Refer to the default `config.toml` file
    [here](https://github.com/printfn/fend/blob/main/cli/src/default_config.toml).

### v0.1.15 (2021-05-20)

* Case-insensitive units: you can now write `5 Meters`
* Experimental date support:
  * You can create a date object like so:

    ```
    > "2021-05-20" to date
    Thursday, 20 May 2021
    ```

  * No other date-related functionality has been implemented yet, including no
    times/timezones, durations, date arithmetic or different date formats.
* fend now parses single and double quotes as feet and inches (instead of
    as string literals) in more situations, so you can once again write:

    ```
    > 1.2192 m to '
    4'
    ```

* The CLI program can now read options from a config file. Type `help` to
    find out where it is stored. The `config.toml` file can contain the
    following options:

    ```toml
    prompt = '> '
    color = false
    ```

* Terminal color support: this is disabled by default, so you'll need to create a config file containing `color = true` first.
* Added a `conjugate` function that computes the complex conjugate of a number: e.g. `conjugate(i)` is `-i`.
* Improve consistency around error messages

### v0.1.14 (2021-02-14)

* Add support for strings and string literals. They can be in single or double quotes, and support a variety of escape sequences.
* Support conversions of numbers to strings
* Use `b` as shorthand for bits (including e.g. `Gb/s`)
* Remove the `0d` number prefix

### v0.1.13 (2021-01-20)

* Add °C and °F (including temperature conversions)
* Automatically simplify units in some calculations (e.g. `100 km/hr * 36 seconds` becomes `1 km`)
* Add initial support for objects (try e.g. `mass of earth`)
* Add `square` and `cubic` functions
* Add hectares and acres

### v0.1.12 (2020-11-27)

This build was only released on NPM.

* Fix NPM package

### v0.1.11 (2020-11-27)

* Improve debug representation (using e.g. `!debug 1`)

### v0.1.10 (2020-11-23)

* Allow leading zeroes for decimal numbers
* Allow upper-case "E" for exponential numbers (e.g. `1E3` is `1000`)
* Add `in` as an alias for `to` (so you can now write `3.14 in binary`)
* Add `log()` function as shorthand for `log10()`
* Fix `kWh` unit definition

### v0.1.9 (2020-11-06)

* Include `LICENSE.md` files as part of the package on [crates.io](https://crates.io)

### v0.1.8 (2020-11-06)

* Add `version` command to get the current fend version
* Support `-sin pi` and `3 sin pi` without parentheses
* Support function inverses: e.g. `sin^-1` becomes `asin`
* Add `to sf` to convert numbers to a fixed number of significant figures
* Make many calculations involving `sin` and `cos` exact
* Add `tau` (`τ`), equal to `2π`
* Add Yi- and Zi- binary prefixes
* Use decimal approximations instead of fractions by default
* `x to exact` will now convert `x` to an exact representation whenever possible, including using multiples of π
* Add `cis` as a shorthand for `cos θ + i * (sin θ)`

### v0.1.7 (2020-10-14)

* Ensure that approximate numbers are always marked as such
* Fix a bug involving sin/cos/tan of negative numbers
* Make some calculations involving pi exact
* Fix parsing of recurring decimals in bases other than 10

### v0.1.6 (2020-10-05)

* Support outputting mixed fractions (implicitly or via `to mixed_fraction`)
* Support unmatched parentheses (e.g. `2+3)*(1+2` is `15`)
* Support parsing of numbers with recurring digits (e.g. `0.(3)` is equal to `1/3`)
* Allow numbers that start with a decimal point, such as `.1`

### v0.1.5 (2020-09-29)

* Add support for lambda functions (e.g. `\x.x`)
* Change precedence of `to` and `as`
* Add live CLI output

### v0.1.4 (2020-09-15)

* Add the GNU units database, containing several thousand unit definitions
* Add support for square roots of numbers with units
* Add unary division as a shorthand for `1/x` (e.g. `/ second`, `64^/2`)
* Support `+` in exponential notation (e.g. `1.5e+2`)
* Allow `,` as a digit separator (e.g. `1,048,576`)

### v0.1.3 (2020-09-05)

* Use correct singular/plural unit names
* Base conversions using `to`
* Make exponents in other bases more consistent

### v0.1.2 (2020-09-02)

* Allow leading zeroes for non-decimal numbers
* Support interrupting an ongoing calculation with Ctrl-C

### v0.1.1 (2020-09-01)

* Save history continuously instead of only on program exit
* Fix parsing of `log10()` and `log2()`
* Add factorial operator (`!`)

### v0.1.0 (2020-08-31)

Initial release:

* Arbitrary-precision arithmetic using rational numbers
* Support for complex numbers
* Binary, octal, hexadecimal and other number bases between 2 and 36.
* Keeps track of units, with support for SI and US customary units.
* Support for Emacs-style CLI shortcuts
* Trigonometric functions
* Useful physical and mathematical constants