Conformal: MATLAB Shape Analyzer

Static shape and dimension analysis for MATLAB.

Conformal finds matrix dimension errors before the code runs. If A is 3 x 4 and B is 5 x 2, it can tell you that A * B has an inner dimension mismatch, and that [A; B] has mismatched column counts. It follows shapes through assignments, function calls, control flow, and across sibling .m files in the same directory, and it carries symbolic dimensions like n, m, and n+m the whole way.

Screenshots

Dimension mismatches appear as underlines while typing.

Hover any variable to see its inferred shape.

Inlay hints show shapes on the first assignment of each variable.

What it catches

The bulk of what it catches is dimension mismatches, whether in multiplication, concatenation, element-wise operations, or backslash solves. It can also flag type errors, a struct or a cell used where a number is expected, and it checks for out-of-bounds indexing, division by zero, and negative dimensions when it can prove them from the code. That tracking reaches through user-defined functions, including the older end-less definitions and no-argument procedures, through anonymous functions with closure capture, and through cross-file calls to sibling .m files.

By default, only high-confidence warnings show. The strict setting adds low-confidence codes like W_SUSPICIOUS_COMPARISON, mostly the kind of thing that could turn out to be a false positive.

In the editor

Diagnostics appear as underlines as code is typed, and hovering any variable shows its inferred shape, like matrix[3 x n]. Go-to-definition works for user-defined functions and for external functions in sibling files. When * is used where .* was probably intended, or && where & should be, the extension offers the fix. Function definitions populate the sidebar and breadcrumbs through document symbols, and the status bar carries the warning and error counts along with the active modes.

Most files analyze in under a tenth of a second, even ones with dozens of warnings.

Analysis is on by default as code is typed, behind a short debounce, and cross-file workspace analysis runs in the same range. The extension also registers its own MATLAB grammar, so the MathWorks extension is not needed.

Install

Search "Conformal" in VS Code Extensions, or run:

code --install-extension EthanDoughty.conformal

There should be nothing to configure. The extension bundles the analyzer directly, so there is nothing else to install and no Python or .NET runtime to manage.

Commands

Settings

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