Automata Diags — VS Code Extension
Visualize and analyze DFAs, NFAs, CFGs, PDAs, Turing machines, Mealy machines, and more — directly from the VS Code Command Palette. Powered by the automata-diags Python package.
Prerequisites
- Python 3.8+ with the Python extension installed
- automata-diags is auto-installed on activation (no manual pip required)
- Graphviz (required for diagram commands):
Getting Started
- Install the extension —
automata-diags is auto-installed on first activation
- Open any text file and write a definition:
type: dfa
start: q0
accept: q2
transitions: q0,a,q1; q1,b,q2
- Select the text, then
Cmd+Shift+P → "Automata Diags: Run from Editor"
- Pick an action (Draw, Accept, Minimize, etc.)
That's it. No pip commands, no terminal, no configuration.
The "Run from Editor" workflow
Write a simple definition block in any file, select it, and run. The extension auto-detects the automaton type and does what you ask. Supported definition fields:
type: dfa | nfa | cfg | pda | tm | mealy
start: q0
accept: q2, q3
transitions: q0,a,q1; q1,b,q2
word: ab
blank: _
method: hopcroft
For grammars, just write the rules directly:
S -> a S b | a b
You can also use each command individually via the Command Palette — see below.
Commands
General
| Command |
Description |
| Verify Installation |
Check that automata-diags is installed, show version and Graphviz status |
| Install / Upgrade Package |
Run pip install --upgrade automata-diags in the active environment |
| Run Current File |
Execute the active Python file and show output |
| Run File & Show Diagram |
Execute the active file and open the most recent generated diagram |
DFA (Deterministic Finite Automaton)
| Command |
Description |
| DFA — Test Word Acceptance |
Parse a DFA from a transition string and test if it accepts a word |
| DFA — Draw Diagram |
Render a DFA state diagram |
| DFA — Minimize (Hopcroft / Myhill-Nerode) |
Minimize a DFA and show equivalence classes |
| KMP Pattern Search |
Find all occurrences of a pattern in text using KMP |
NFA (Nondeterministic Finite Automaton)
| Command |
Description |
| NFA — Test Word Acceptance |
Parse an NFA and test word acceptance |
| NFA — Draw Diagram |
Render an NFA state diagram |
| NFA → DFA Conversion |
Convert NFA to DFA via subset construction, render both |
| Regex → NFA (Thompson Construction) |
Build an NFA from a regular expression and render it |
CFG (Context-Free Grammar)
| Command |
Description |
| CFG — CYK Membership Check |
Test if a string belongs to a CFG using the CYK algorithm |
| CFG — Convert to CNF |
Convert a grammar to Chomsky Normal Form |
| CFG — BFS Acceptance Check |
Test string acceptance on any CFG (no CNF required) |
| CFG — Show Derivation |
Show the step-by-step derivation of a string |
| CFG — Generate Strings |
Generate all derivable strings up to a given length |
PDA (Pushdown Automaton)
| Command |
Description |
| PDA — Test Word Acceptance |
Parse a PDA and test word acceptance |
| PDA — Configuration Trace |
Show the state/position/stack at each step of acceptance |
| PDA — Draw Diagram |
Render a PDA transition diagram |
| CFG → PDA Conversion |
Convert a grammar to an equivalent PDA and render it |
Turing Machine
| Command |
Description |
| Turing Machine — Test Word Acceptance |
Parse a TM and test word acceptance (handles non-halting) |
| Turing Machine — Draw Diagram |
Render a TM transition diagram |
Mealy Machine (Transducer)
| Command |
Description |
| Mealy Machine — Transduce Word |
Run a word through a Mealy machine and see the output |
| Mealy Machine — Draw Diagram |
Render a Mealy machine diagram |
SCFG (Stochastic Context-Free Grammar)
| Command |
Description |
| SCFG — Probabilistic Parse (CYK) |
Compute the probability of a sentence under a weighted grammar |
Commands accept the same string formats as the Python package's from_string methods:
- DFA:
q0,a,q1;q1,b,q2 (from,symbol,to)
- NFA:
q0,a,q0,q1;q1,b,q2 (from,symbol,to1,to2,...)
- PDA:
q0,a,Z,q0,aZ;q0,b,a,q1,e (from,input,stack_top,to,push — use e for epsilon)
- TM:
q0,0,q0,0,R;q0,_,qa,_,N (state,read,next,write,direction)
- CFG:
S -> a S b | a b (one rule per line, | for alternatives)
- SCFG:
S -> NP VP [0.8] (weighted rules)
- Mealy transitions:
q0,0,q0;q0,1,q1 + output function q0,0,1;q0,1,0
You can also select text in the editor — many commands will use the selection as input instead of prompting.
Settings
| Setting |
Default |
Description |
automataDiags.pythonPath |
"" |
Explicit Python path (leave empty to use the Python extension's selection) |
automataDiags.outputFormat |
png |
Diagram format: png, svg, or pdf |
Links
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