A VS Code extension that renders certain source-code patterns as pretty
mathematical symbols — purely visually, using editor decorations. The file
contents are never modified.
Subscripts: names starting with an uppercase letter followed by an
underscore and a suffix are rendered with the suffix as a subscript,
e.g. X_i is shown as X with a small lowered i.
Superscripts: the power operator with a simple exponent (number or
identifier) is rendered as a superscript: x**2 → x², r ** n → rⁿ,
x**-1 → x⁻¹, and combined with the Greek rule x**alpha → x^α.
**kwargs and f(**opts) are unaffected (no left operand), and the
spacing must be symmetric, so Markdown **bold** in comments is left
alone.
Matrix notation:A.T is rendered with a superscript T (transpose)
and argument-less A.inv() / A.invert() calls with a superscript -1
(inverse). Calls like .T(...), longer attribute names like .Type
and inv(...) calls with arguments are left alone.
Absolute value and norms: bare abs(x) calls are rendered as |x|
and bare norm(x) calls as ‖x‖; a simple second norm argument becomes
a subscript: norm(M, 2) → ‖M‖₂, norm(M, 'fro') → ‖M‖ with a fro
subscript. Qualified calls (np.linalg.norm(...)) and method calls
(s.abs()) are intentionally left alone — import the bare name
(from numpy.linalg import norm) to opt in. Calls with a complex
second argument or more than two arguments are untouched.
Greek letters: Greek letter names are rendered as Greek characters
when they stand alone as a whole identifier (alpha → α, math.pi →
math.π — including the lambda keyword → λ) or carry a trailing
underscore (lambda_ → λ). Greek bases of subscripted names are
replaced too: Sigma_k → Σ with a subscript k, sigma_i → σ with a
subscript i, alpha_max → α with a subscript max. Uppercase names
are only replaced when the Greek capital is visually distinct from the
Latin letter (Γ Δ Θ Λ Ξ Π Σ Φ Ψ Ω).
Lines containing the cursor or a selection are shown with the original
text so editing stays predictable.
Usage
Works in Python files by default (mathcode.languages).
Toggle with the eye button in the editor title bar (shown for the
configured languages), with the MathCode: Toggle command, or via
mathcode.enabled.
Settings
Setting
Default
Description
mathcode.enabled
true
Enable/disable substitution.
mathcode.languages
["python"]
Language ids where substitution is active.
mathcode.operators
see above
Operator → symbol map; fully customizable.
mathcode.greekLetters
true
Enable Greek letter rendering (lambda_ → λ, Sigma_k → Σₖ).
mathcode.superscripts
true
Enable superscript rendering of the power operator (x**2 → x²).
mathcode.matrixNotation
true
Render .T as ᵀ and .inv()/.invert() as ⁻¹.
mathcode.absNorm
true
Render bare abs(...) as |...| and bare norm(...) as ‖...‖.
mathcode.subscripts
true
Enable subscript rendering.
mathcode.subscriptIgnoreAllCaps
true
Skip all-uppercase names (MAX_VALUE) — treat them as constants, not subscripts.
Caveats
Substitution is purely textual: it also applies inside strings and
comments, and a<-b (meaning a < -b) is rendered as an arrow.
Greek names in prose (e.g. "beta release") are rendered too; use the
eye button or mathcode.greekLetters if that gets in the way.
ALL_CAPS constants such as MAX_VALUE are skipped by default (see
mathcode.subscriptIgnoreAllCaps); set it to false to subscript them
too.
Development
npm install
npm run compile # or: npm run watch
Press F5 in VS Code to launch an Extension Development Host, then open
examples/demo.py to see the substitutions in action.
