LineSolv User Guide

A beginner-friendly guide to using LineSolv, the natural-language desktop calculator.

LineSolv — Type math naturally, get instant results. No equals button needed.

Plugin Repository: github.com/rkriad585/linesolv-plugins

Future Features: See Future Roadmap for planned features including AI integration, self-updater, image support, voice input, mobile support, and more.

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1. Getting Started

First Open

When you launch LineSolv for the first time, you'll see a splash screen with the LineSolv logo and a progress bar while the app loads. Once ready, a clean, dark-themed window with a single input area appears. There is no sign-up, no telemetry, and no internet connection required. Everything runs locally on your machine.

Typing Your First Expression

Click the input area and start typing. Results appear in real-time as you type — there is no "equals" button. Type anything from simple arithmetic to natural-language phrases:

Input	Result
2 + 2	4
twenty five times 4	100
what is pi	3.14159

Understanding Results

• The left column shows your input lines.
• The right column shows computed results aligned to each line.
• If a line has no valid expression, no result appears for that line.
• Lines are evaluated independently; each line can be a completely separate calculation.

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2. The Interface

LineSolv uses a frameless window with a custom title bar. The main layout is:

+--[ Window Controls ]--[ LineSolv Logo ]--[ Panel Buttons ]--+
|                                                              |
|  +-- Notes Sidebar --+  +-- Main Area --------------------+ |
|  |                   |  |  Line 1 Input     |  Result 1    | |
|  |  Note A           |  |  Line 2 Input     |  Result 2    | |
|  |  Note B (active)  |  |  Line 3 Input     |  Result 3    | |
|  |  Note C           |  |  Line 4 Input     |  Result 4    | |
|  |                   |  |  Line N Input     |  Result N    | |
|  |  [+ New Note]     |  |                   |              | |
|  +-------------------+  +-----------------------------------+ |
|                                                              |
|  +-- Bottom Panels (toggleable) ---------------------------+ |
|  |  History  |  Variables  |  Steps  |  Graph              | |
|  +---------------------------------------------------------+ |
+--------------------------------------------------------------+

Panels

Panel	Toggle	Description
Notes Sidebar	Ctrl/Cmd + B	Manage multiple calculation notebooks
Variables Explorer	Ctrl/Cmd + I	View and manage assigned variables
History	Ctrl/Cmd + H	Searchable list of past calculations
Steps	Ctrl/Cmd + S	Step-by-step evaluation breakdown
Documentation	Ctrl/Cmd + J	Built-in docs viewer
Plugin Marketplace	"..." menu in title bar	Browse and install plugins
Settings	`Ctrl/Cmd + ``	General, Theme, Shortcuts, About
Graph	Auto-activates on plot expressions	Chart.js function plotting

Note: Opening Docs or Plugins automatically closes the Notes panel, and vice versa (panel cross-closing).

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3. Writing Expressions

LineSolv evaluates each line in the input area independently. You can mix numbers, operators, words, functions, units, and variables freely.

Basic Arithmetic

Standard PEMDAS (Parentheses, Exponents, Multiplication/Division, Addition/Subtraction):

Operator	Meaning	Example	Result
+	Addition	5 + 3	8
-	Subtraction	10 - 4	6
*	Multiplication	7 * 3	21
/	Division	20 / 4	5
^	Exponentiation	2 ^ 10	1024
%	Modulo (remainder)	17 % 5	2

Use parentheses to override precedence: (2 + 3) * 4 = 20.

Natural Language

Type conversational phrases — they just work:

Input	Result
one plus one	2
twenty five plus 3	28
what is 2+2	4
calculate 15% of 200	30
hello how much is 5 + 3	8

You can use query prefixes (what is, calculate, show me, etc.) and conversational fillers (hello, hey, ok, well, etc.) — they are all ignored.

Percentages

Input	Result	Meaning
50%	0.5	Percentage as decimal
10% of 200	20	10% * 200
100 + 15%	115	100 + 15% of 100
200 - 10%	180	200 - 10% of 200
100 with 8% tax	108	100 + 8% of 100
200 after 10% discount	180	200 - 10% of 200
10 is what percent of 50	20%	Percentage question

Unit Conversion

Convert between units using in or to:

Input	Result
10 inches in cm	25.4 cm
1 kg in lb	2.205 lb
100 c to f	212.0 °F
1 gal in l	3.785 l
2h30m in minutes	150 minutes

Currency

LineSolv supports 50+ currencies with live exchange rates:

Input	Result
$100 + €20	$122.80
$20 in euro - 5% discount	€18.26
£20 in usd	$26.60

Use currency symbols ($, €, £) or ISO codes (USD, EUR, GBP).

Variables

Assign variables and reference them in later expressions:

Input	Result
x = 42	x = 42
x * 2	84
y = x + 8	y = 50

Variable names are case-insensitive. You can use any alphanumeric name (no spaces, must start with a letter).

Context References

After evaluating an expression, reference the previous result:

Input	Result
42	42
of that * 2	84
then + 10	94
result / 2	47

Math Functions

All 40+ built-in functions:

Category	Functions
Trigonometry	sin, cos, tan, asin, acos, atan, atan2
Hyperbolic	sinh, cosh, tanh
Logarithmic	log, log2, log10, ln, exp
Roots & Power	sqrt, cbrt, pow
Rounding	round, ceil, floor, trunc, sign
Absolute	abs
Statistics	avg, median, mode, stdev, variance, range
Aggregation	sum, min, max
Combinatorics	fact/factorial, gcd, lcm, ncr/choose
Random	rand, random
Geometry	hypot/pythag/hypotenuse
Utility	fract, deg, rad
Number Theory	isprime/is_prime

Constants

pi (π), e, speed_of_light, gravity, planck, boltzmann, gas_constant, avogadro, stefan_boltzmann, electron_mass, proton_mass, neutron_mass, electron_charge, bohr_radius, rydberg.

Purchase Math

LineSolv handles shopping calculations with items, discounts, and tax:

Input	Result
5 items at \$20 each	$100.00
5 items at \$20 each with a 15% discount	$85.00
5 items at \$20 each with a 15% discount and 8% sales tax	$91.80
I bought 8 items at \$5 each with a 10% discount and 6% sales tax	$40.76

Date Math

Input	Result
today + 14 days	Date 14 days from now
today - 7 days	Date 7 days ago
March 1 + 30 days	March 31
last month	Previous month
next week	Next week

Age Calculation

Input	Result
born in 2007	Age since 2007
born 1990	Age since 1990
40 years old	40

Graphing Functions

Type a graph expression and the Graph panel auto-activates:

Input	Description
plot x^2	Plot a parabola
graph sin(x)	Plot a sine wave
y = 2*x + 3	Plot a linear equation

Specify a range: plot x^2 from -5 to 5

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4. Managing Notes

Notes are persistent calculation notebooks stored in a local SQLite database.

Create a New Note

• Press Ctrl/Cmd + N or click the + button at the bottom of the notes sidebar.
• A new note with a randomly generated name is created and activated.

Switch Notes

• Click any note name in the notes sidebar to switch to it.
• The input area and results update to show that note's content.

Rename a Note

• Right-click a note in the sidebar and select Rename.
• Type the new name and press Enter.

Delete a Note

• Right-click a note and select Delete.
• A confirmation dialog appears (unless "Don't ask again" is enabled in Settings).
• Deleted notes cannot be recovered.

Export a Note

Right-click a note and choose an export format. Six formats are available:

Format	Extension	Description
LineSolv	.lv	Raw input content only (default)
Text	.txt	Title, creation date, and content
Markdown	.md	Formatted with heading and metadata
JSON	.json	Structured data with id, name, timestamps, content
TOML	.toml	TOML-formatted metadata and content
PDF	.pdf	A4-formatted PDF with title, dates, content, and footer

Import a Note

• Click the import button in the notes sidebar.
• Select a .json file exported from LineSolv.

Drag-and-Drop Reorder

Click and drag any note in the sidebar to reorder them. The new order is persisted to the database.

Search Notes

• Press Ctrl/Cmd + F to focus the search input in the notes sidebar.
• Type to filter notes by name in real time.

Folders

Notes can be organized into hierarchical folders using drag-and-drop.

• Right-click the notes sidebar to create a new folder.
• Folders use sequential naming: New Folder, New Folder 2, New Folder 3, etc.
• Drag notes into folders or reorder them within folders.
• Right-click a folder for options: New Note, New Subfolder, Rename, Change Icon, Move to..., Delete.

Note Icons

Each note can have a custom icon (63 available). Right-click a note and select Change Icon to pick one. A random icon is assigned when a note is created.

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5. Keyboard Shortcuts

Navigation

Shortcut	Action
Arrow Keys	Move cursor
Ctrl/Cmd + Left/Right	Jump word left/right
Home / End	Start/end of line
Ctrl/Cmd + Home/End	Start/end of text
Page Up / Page Down	Scroll page up/down

Text Editing

Shortcut	Action
Ctrl/Cmd + Z	Undo
Ctrl/Cmd + Shift + Z or Ctrl/Cmd + Y	Redo
Ctrl/Cmd + X	Cut
Ctrl/Cmd + C	Copy
Ctrl/Cmd + V	Paste
Ctrl/Cmd + A	Select all
Ctrl/Cmd + D	Duplicate line or selection
Ctrl/Cmd + L	Select current line
Ctrl/Cmd + Shift + K	Delete current line
Alt + Shift	Toggle case (lower -> UPPER -> Title)
Alt + Up	Move current line up
Alt + Down	Move current line down
Tab	Insert 2 spaces

App Actions

Shortcut	Action
Shift + Enter	Force evaluate now
Escape	Close modal / clear input / close panel
Ctrl/Cmd + B	Toggle notes sidebar
Ctrl/Cmd + I	Toggle variables panel
Ctrl/Cmd + H	Toggle history panel
Ctrl/Cmd + S	Toggle step-by-step panel
Ctrl/Cmd + J	Open documentation
`Ctrl/Cmd + ``	Open settings
Ctrl/Cmd + K	Clear all (input, history, variables)
Ctrl/Cmd + N	Create new note
? or Cmd + /	Show shortcuts reference
Ctrl/Cmd + Up	History: previous input
Ctrl/Cmd + Down	History: next input
Ctrl/Cmd + F	Search notes
Ctrl/Cmd + P	Print current note
Double-click title bar	Toggle fullscreen/maximize

All shortcuts are customizable in Settings > Keyboard Shortcuts.

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6. Printing

How to Print

• Press Ctrl/Cmd + P or select Print from the ... dropdown menu in the title bar.
• The system print dialog opens with the A4-formatted PDF.

A4 Formatting

The print function generates A4-formatted output with:

• 20mm margins on all sides
• Auto page breaks with 25mm bottom margin
• Title in 18pt bold Helvetica
• Creation date in 9pt gray
• Body content in 10pt Helvetica with 5.5mm line spacing
• Footer on every page: "Generated by LineSolv — Page X/Y"

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7. Autocomplete

LineSolv includes a real-time autocomplete popup that suggests functions, constants, units, variables, plugins, and keywords as you type.

How It Works

• The popup appears after typing 2+ characters and filters results in real time.
• 236+ keywords across 6 categories: function, constant, unit, variable, plugin, keyword.
• Matching is prefix-based — type sq to see sqrt, square, square root of, etc.
• Navigate with Arrow Up/Arrow Down, select with Enter, dismiss with Escape.

Toggling

Enable or disable autocomplete in Settings > General > Autocomplete.

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8. Troubleshooting

See the FAQ & Troubleshooting Guide for common issues including:

• App won't start on Linux (missing WebKit2GTK)
• Gatekeeper warning on macOS
• Currency rates not updating
• Graph not appearing
• Plugins not loading
• Notes not saving

For bug reports, visit the GitHub Issues page.

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All Documentation

Document	Description
User Guide	Beginner-friendly guide to using LineSolv
Expression Reference	Complete expression syntax reference
Interface Details	Documentation viewer, plugin marketplace, settings, design tokens
Screenshots	All screenshots of the LineSolv interface
Getting Started	Quick start for new users
Configuration	Settings, config file options, and data storage
FAQ & Troubleshooting	Frequently asked questions and common issues
Architecture	High-level architecture and component overview
Frontend	Frontend component structure and styling guide
Plugin Development	How to create and install plugins
Themes	Theme customization guide
Development	Development setup, build, and code standards
API Reference	Wails-bound Go method reference
Calculator Engine	How the natural-language calculation engine works
From Words to Numbers	End-to-end pipeline walkthrough
Accessibility	WCAG 2.1 AA compliance and assistive technology support
Future Features	Planned features: AI, self-updater, image/voice, mobile
Examples	Input examples
Changelog	Version history
Contributing	Contribution guidelines
Security Policy	Security policy and vulnerability reporting
Code of Conduct	Community standards
License	MIT License