truth-table.nvim

Generate and manipulate markdown truth tables from inside Neovim.

Give it a count or a list of variable names and it writes every combination of their values as a centered markdown table. Put your cursor in an existing table and it can append computed columns from a small boolean predicate language, toggle between 0/1 and F/T, or drop the current row or column.

|  A  |  B  | A ∧ B | A → B |
|:---:|:---:|:-----:|:-----:|
|  0  |  0  |   0   |   1   |
|  0  |  1  |   0   |   1   |
|  1  |  0  |   0   |   0   |
|  1  |  1  |   1   |   1   |

Status

Personal plugin, extracted from a single-file Neovim config module (truth-table.lua + truth-table-core.lua). Behavior is preserved; the extraction reworked the structure into a pure, testable core plus a thin Neovim layer.

An LLM was used to convert a long time personally maintained hack to a plugin with testing.

Install

With lazy.nvim:

{ dir = "~/dev/nvim-plugins/truth-table.nvim" }

The plugin self-registers on load (plugin/truth-table.lua calls setup()), so there is nothing else to wire up. which-key is optional (a <leader>tt group label is registered if it is present).

Commands

Command	Effect
:TruthTable {N|names}	Insert a new table: N variables (A, B, ...) or named ones
:TruthTableExpand {preds}	Append a computed column per comma-separated predicate
:TruthTableToggle	Toggle data cells between 0/1 and F/T
:TruthTableDropRow	Drop the row under the cursor
:TruthTableDropColumn	Drop the column under the cursor

:TruthTable 3
:TruthTable p q r
:TruthTableExpand A and B, A xor B

Predicate language

Used by :TruthTableExpand. Operands are existing column names and the literals 0 / 1. Operators, tightest binding first:

Operator	Meaning	Rendered
not / !	negation	¬
and	conjunction	∧
or	disjunction	∨
xor	exclusive or	⊕
implies / ->	implication	→

Parentheses override precedence: (A or B) and !C.

Keymaps

setup() registers these by default:

Key	Action
<leader>ttn	prefill :TruthTable
<leader>tte	prefill :TruthTableExpand
<leader>ttt	toggle 0/1 ↔ F/T
<leader>ttr	drop row
<leader>ttc	drop column

Design

Split along one line, Neovim or not:

• lua/truth-table/core.lua is pure: the predicate tokenizer/parser, evaluator, validation, and markdown formatting, all as plain functions over strings and tables with no vim.*. The one contextual dependency, display-width measurement, is injectable: core.display_width defaults to a pure UTF-8 codepoint count, and setup() swaps in vim.fn.strdisplaywidth for terminal-accurate alignment (they agree for the ASCII names and width-1 logic symbols this tool emits).
• lua/truth-table/init.lua holds the Neovim-facing pieces (finding the table under the cursor, the commands, keymaps) and the public setup().
• plugin/truth-table.lua is the auto-sourced entry point with a load guard.

Testing

The pure core is covered by a busted spec in spec/:

make test

If your busted launcher is broken (a common symptom of a Homebrew Lua version bump: it hard-codes a now-missing lua5.4), install busted into your user rocks tree and point the target at it:

luarocks --local install busted
make test BUSTED=$HOME/.luarocks/bin/busted

The vim-coupled layer is verified by loading the plugin and running the commands. Lint (optional, requires selene):

make lint

Documentation

:help truth-table once the plugin is on your runtimepath.