Qalc

Qalc is an interactive calculator that turns any text document into a math processor. Quickly and easily run simple or complex calculations naturally. Lightweight, powerful, simple.

Features

• At its core, Qalc is powered by Math.js, so you have access to hundreds of built in mathemtical functions, constants, units and conversions
  • But, we've also built on top of Math.js to power things like percentages, currencies, date calculations, natural language, and aggregations
• Qalc evaluates your text as you type it, displaying the result at the end of the line
• Works in Plain Text, Markdown and Qalc files by default, but you can enable it in any type of file
• Syntax highlighting when using the Qalc language mode
• Completely configurable and customizable: colors, alignment, precision, formatting, and more

Announcements

The exchange rates API I was using just restricted access to certain features unless you pay a subscription fee. For now I have added a free access key when calling the API, which means currency conversions will still work for now, but we no longer have https support, and are limited to 1000 calls per month, which I imagine will be exceeded at some point. I'll work on finding a new free API.

Release notes

See change log.

Syntax

Basic Operators

See Math.js operators for all available operators and Math.js precedence for order of operations.

Basic Functions

This is just a subset of available functions, see Math.js function documentation for all available functions. Note: the output of random() will update every time the document changes or is reloaded by the UI.

Aggregations

These are built on top of Math.js and are specific to Qalc. Are you looking for more types of aggregations? Let us know.

Dates

Support for dates is built on top of Math.js and is specific to Qalc. Note that any of the relative date keywords, most importantly time and now, will update every time the document is re-evaluated (any time it changes or the window loads it again). If today is 3/1/2021, today will return 3/1/2021 but tomorrow if you load the document again it will return 3/2/2021.

Variables and Objects

See Math.js variables for more about variables or Math.js objects for more about objects.

Text

See Math.js strings for more about working with text.

Constants

This is just a subset. See Math.js physical constants and Math.js constants for all available constants.

Units and Conversions

See Math.js units reference for a list of all units available via Math.js. Qalc also adds a few of its own units:

Name	Aliases	Definition	Note
Pixels	pixel, pixels, px	1 inch = 96 px	Eventually this will be configurable
Points	point, points, pt	1 px = 0.75 pt
Emphemeral Unit	em	1 em = 16px	Eventually this will be configurable
Currency			See currency section
Miles per hour	mph	1 miles/hour = 1 mph
Kilometers per hour	kph	1 kilometers/hour = 1 kph

Currency

Currency data is retrieved from https://exchangeratesapi.io/ and cached for 7 days (eventually this will be configurable). Supported currencies are: AUD, BGN, BRL, CAD, CHF, CNY, CZK, DKK, EUR, GBP, HKD, HRK, HUF, IDR, ILS, INR, ISK, JPY, KRW, MXN, MYR, NOK, NZD, PHP, PLN, RON, RUB, SEK, SGD, THB, TRY, USD, ZAR

Percents

Percents like this are not built into Math.js. We translate %, of, and off of appropriately before passing evaluation to Math.js.

Functions

You can define your own functions. See Math.js functions for more information.

Matrices and Ranges

Matrix indexes are one-based, similar to most math applications (differing from most programming languages). For more about matrices, see Math.js matrices.

Conditionals

All conditional operators are listed in the Math.js operators documentation.

Other Keywords

The last keyword brings up the result of the previous line.

Pixels/Points/em

These units are not native to Math.js, and for good reason: they are not well defined. Depending on the context, pixels to inches can vary drastically, most commonly in the 72-300 pixels per inch range. Emphemeral units (em) by definition are relative to their parent html element. We've chosen default ratios for converting these units currently, and soon we'll offer the ability to customize them.

Binary, Hex and Octal

The Math.js numbers documentation has a little documentation on binary, hex and octal.

Special Comments

These special comments must exist on a line by itself to work

Comment	Description
//qalc:off	Turns off Qalc processing for the rest of the file (or until the next //qalc:on comment)
//qalc:on	Turns Qalc processing back on for the rest of the file (or until the next //qalc:off comment) if it was turned off by //qalc:off. Note: This will not turn on Qalc for files that are not being processed at all due to settings like qalc.enabledLanguages (if your language is missing) and qalc.disabledPatterns

Settings

Qalc offers a variety of settings that allow you to customize its behavior. These settings are explained below.

Setting	Key	Default	Description
Output Color	qalc.output.color		Set a custom color for output to display in. This can be either a hex value (e.g. "#FFFFFF"), rgb value (e.g. "rgb(255,255,255)"), or a VSCode ThemeColor id (e.g. "editor.foreground", see https://code.visualstudio.com/docs/getstarted/theme-color-reference for available ids). If no color is specified, this falls back to "terminal.ansiGreen" to get the green matching your current UI theme.
Show Output Delimiter	qalc.output.showDelimiter	false	Controls whether or not to display the delimiter to separate input from output. Default delimiter is "=" and can be overriden with the "qalc.output.delimiter" setting.
Output Delimiter	qalc.output.delimiter	=	Delimiter to display between input and output. Can be turned on/off with the "qalc.output.showDelimiter" setting.
Align Output	qalc.output.align	true	Aligns the left edge of output (on) or displays output immediately at the end of an input line (off).
Max Alignment Column	qalc.output.maxAlignmentColumn	40	When "qalc.output.align" is on, this controls the maximum column that results will align on. This is useful if you have, for example, a Markdown document with a few long lines, but don't want your Qalc results displayed too far out for the majority of your shorter lines.
Digit Grouping Symbol	qalc.output.digitGroupingSymbol	,	Character that groups the digits, usually comma (1,000), space (1 000) or nothing at all (1000). This setting replaces 'qalc.output.displayCommas'.
Decimal Separator	qalc.output.decimalSeparator	.	Character separating the decimals, usually dot (3.14) or comma (3,14).
Trim Trailing Zeros	qalc.output.trimTrailingZeros	true	Turn this on to trim trailing zeros when using 'fixed' notation. For example, with 'fixed' notation, precision set to 4, and this setting off, 1.12 will display as 1.1200, but with the setting on will display 1.12
Notation	qalc.output.notation	fixed	Set the notation for display. See https://mathjs.org/docs/reference/functions/format.html for further documentation.
Precision	qalc.output.precision	2	Set the precision of the output. In case of notations 'exponential', 'engineering', and 'auto', precision defines the total number of significant digits returned. In case of notation 'fixed', precision defines the number of significant digits after the decimal point. No precision is lost in calculations, only the final display. See https://mathjs.org/docs/reference/functions/format.html for further documentation. Note: When using 'auto' notation, you most likely want to set this to 0.
Lower Exponent Bound	qalc.output.lowerExponentBound	-9	Exponent determining the lower boundary for formatting output with an exponent (e.g. setting this to -2 will format 0.01 as 1e-2.
Upper Exponent Bound	qalc.output.upperExponentBound	16	Exponent determining the upper boundary for formatting output with an exponent (e.g. setting this to 2 will format 100 as 1e+2).
Convert Local Currency	qalc.currency.convertLocal	true	Turn this on to use your local currency symbol in both your input and output. Works with "qalc.currency.localSymbol" and "qalc.currency.localCode". For example, setting "$" and "USD" allows your input to contain "$100" which will be evaluated as the equivalent of "100 USD", and similarly will display in the output as "$100" instead of "100 USD".
Local Currency Symbol	qalc.currency.localSymbol	$	Set your local currency symbol. See "qalc.currency.convertLocal" for how this is used".
Local Currency Code	qalc.currency.localCode	USD	Set your local currency code. See "qalc.currency.convertLocal" for how this is used".
Currency API Key	qalc.currency.apiKey		Qalc calls an API for exchange rates that is limited to 1000 calls per month across all Qalc users. If you absolutely require exchange rates and do not want to take a chance that these 1000 calls will run out in a given month, you can get a free API key from openexchangerates.org, and use that key here. Doing so will also refresh your exchanges rates once per day, rather than the default of every 2 weeks.
Temperature Shortcut	qalc.shortcuts.temperature	true	When on, enables you to use oF, oC, f and c as substitutes for degF, degC, fahrenheit, and celsius.
Enabled Languages	qalc.enabledLanguages	["qalc", "plaintext", "markdown"]	Language identifiers for which to enable Qalc processing on. Keep in mind that Qalc will not examine partial matches, but only full lines. If your full line is not parseable, no output is displayed. For example, if you have a line in a JSON file like " 'key': '1 + 1' ", the "1 + 1" will not be evaluated because the full line is not parseable. Defaults to ["qalc", "plaintext", "markdown"].
Explicit Activation Languages	qalc.explicitActivationLanguages	[]	Language identifiers for which Qalc processing will be off by default but can be enabled using //qalc:on. This should be a subset of "qalc.enabledLanguages". In other words, you must first enable the language, and then you can set it to have explicit activation. If a language is enabled, but not marked for explicit activation, Qalc will start processing lines from the beginning. If a language is marked for explicit activation, but not enabled, Qalc will not process files for that language at all.
Disabled Patterns	qalc.disabledPatterns	**/README.md	A list of glob patterns to disable Qalc processing on. These take precedence over "qalc.enabledLanguages", so if you have "markdown" enabled, but "README.md" disabled, you will not get processing on "README.md". This is generally useful for any files that might register as "plaintext" to VSCode, but you don't want Qalc to run on, like configuration files. Defaults to ["**/README.md"]].
Global Declarations	qalc.globalDeclarations	[]	These are declarations that will be available globally to all Qalc files. They are evaluated at the beginning of a file. For example, if you want to make the "hypotenuse" function available to all Qalc files, you would add "hypotenuse(x,y) = sqrt(x^2 + y^2)," to this list. Defaults to [].

Commands

Qalc adds some commands to VSCode:

Title	Command	Note
Qalc: Copy With Result (with delimiter)	qalc.copy.withDelimiter	Copies the selected lines (if a selection exists) or the entire editor to the clipboard, including the output from Qalc with the delimiter (set via qalc.output.delimiter)
Qalc: Copy With Result (without delimiter)	qalc.copy.withoutDelimiter	Same as qalc.copy.withDelimiter, but without the delimiter
Qalc: Copy Result Only	qalc.copy.resultOnly	Copies only the result of the current line (or lines, if you select many)

See these in action:

Acknowledgments

Forked from Mathpad, inspired by Numi and Parsify. I built this because I wanted something cross platform, and integrated with my most common text editor. The theme used in the screenshots and gifs is a slightly modified Gruvbox.