Miranda Static Helper is a Visual Studio Code extension for Miranda files (.m, .mir). It adds syntax highlighting and lightweight static analysis aimed at catching common issues early while you edit.

Features

Syntax highlighting based for Miranda files (.m, .mir)
Editor-aware diagnostics for brackets, indentation, definitions, style, and complexity heuristics.
Workspace-aware rule configuration so you can tune which warnings are shown.
A command to re-run analysis on the current file.
Quick fixes for a few supported diagnostics.
Auto fix support for safe formatting and placeholder repairs.
Document formatter support for Miranda source files.

Usage

Open any Miranda file in VS Code and the extension will analyze it automatically on open, change, and save. Diagnostic messages appear directly in the editor, and you can also run the manual analysis command from the Command Palette:

Miranda: Analyze Current File
Miranda: Auto Fix Current File
Miranda: Fix All Auto-Fixable Issues
Miranda: Format Document

Requirements

Visual Studio Code 1.86.0 or newer.
Miranda source files with the .m or .mir extension.

Rules

The extension reads diagnostic rules from mirandaStaticHelper.rules. You can define them in workspace settings or in a root .mirandarc.json or .mirandarc file.

Accepted values:

off
warn or warning
error

Example:

{
  "mirandaStaticHelper.rules": {
    "miranda.definition.incomplete": "error",
    "miranda.definition.unused": "off",
    "miranda.style.parenthesesUsage": "warn"
  }
}

Rule value	Effect
`off`	Hides the diagnostic.
`warn` / `warning`	Shows the diagnostic as a warning.
`error`	Shows the diagnostic as an error.
Not defined	Keeps the analyzer's default severity.

The formatter can be disabled with:

{
  "miranda.formatter.enabled": false
}

Rules Reference

Brackets

miranda.brackets.unclosed: Opening bracket without matching close (e.g., [ without ]).
miranda.brackets.unmatchedClose: Closing bracket without matching open.
miranda.brackets.mismatch: Mismatched bracket types (e.g., [ closed with )).

Definitions and Types

miranda.definition.incomplete: Definition right-hand side (RHS) is missing or empty.
miranda.definition.unbalancedRhs: RHS contains mismatched brackets or incomplete expressions.
miranda.definition.duplicate: Function or type defined multiple times without a catch-all clause.
miranda.definition.undefined: Reference to a symbol not defined in the document or prelude.
miranda.definition.unused: Function or type defined but never used in the code.
miranda.definition.redefinesPrelude: Local symbol shadows a known Miranda prelude function.
miranda.definition.keywordCollision: Symbol name collides with a Miranda keyword.
miranda.definition.guardNotExhaustive: Multiple clauses exist but patterns may not cover all cases.
miranda.definition.callArity: Function called with incorrect number of arguments.
miranda.type.incomplete: Type definition right-hand side is missing or empty.
miranda.type.duplicate: Type defined multiple times in the same scope.

Indentation

miranda.indentation.mixedWhitespace: Line uses both tabs and spaces for indentation.
miranda.indentation.where: where block indentation does not match expected structure.
miranda.indentation.decrease: Unexpected decrease in indentation level between lines.

Style

miranda.style.equalsSpacing: Missing or inconsistent whitespace around = in definitions.
miranda.style.commaSpacing: Missing or inconsistent whitespace around , in lists/tuples.
miranda.style.parenthesesUsage: Unnecessary or unbalanced use of parentheses.
miranda.style.trailingWhitespace: Line ends with unnecessary whitespace.
miranda.style.guardSpacing: Guard pipe is missing a following space.
miranda.style.guardOtherwise: Catch-all guard uses True instead of otherwise.
miranda.style.lineLength: Line exceeds 80 characters.
miranda.style.incompleteConditional: Conditional expression has if and then but no else.

Complexity

miranda.complexity.high: Function body exceeds recommended complexity threshold.
miranda.complexity.recursive: Function is recursive; consider iterative approaches or tail-call optimization.

Commands

Press ctrl + shift + P or cmd + shift + P in VSCode and execute:

> mirandaStaticHelper.analyzeCurrentFile
> mirandaStaticHelper.autoFixCurrentFile
> mirandaStaticHelper.fixAllAutoFixableIssues
> mirandaStaticHelper.formatCurrentFile

This command re-runs analysis on the active Miranda document and shows a summary message with the number of diagnostics.

The auto-fix command applies every safe fix available for the active Miranda document.

Quick Fixes

For miranda.definition.incomplete and miranda.type.incomplete:
- Insert a placeholder RHS (undef for values, num for type declarations).
For miranda.indentation.mixedWhitespace:
- Replace leading tabs with spaces.
For miranda.indentation.where and miranda.indentation.decrease:
- Align declarations inside a where block.
For miranda.style.trailingWhitespace:
- Remove trailing whitespace.
For miranda.style.guardSpacing:
- Insert the missing space after a guard pipe (|).
For miranda.style.guardOtherwise:
- Replace | True catch-all guards with | otherwise.
For miranda.style.equalsSpacing:
- Normalize spacing around =.
For miranda.style.commaSpacing:
- Normalize spacing after ,.
For miranda.style.parenthesesUsage:
- Remove unnecessary parentheses around simple RHS expressions.
For miranda.definition.redefinesPrelude:
- Rename symbol to avoid prelude shadowing.

Auto Fix

Miranda Static Helper exposes VS Code's source.fixAll action for supported Miranda diagnostics. You can run it from the editor's Quick Fix menu, from Command Palette with Miranda: Auto Fix Current File, or on save with workspace settings:

{
  "editor.codeActionsOnSave": {
    "source.fixAll.miranda": "explicit"
  }
}

Auto fix intentionally skips diagnostics that need a human choice, such as undefined symbols, duplicate definitions, arity warnings, or renaming prelude shadowing.

You can also run Miranda: Fix All Auto-Fixable Issues with Shift+Alt+X.

Formatter

Run Miranda: Format Document or VS Code's standard Format Document action (Shift+Alt+F) to normalize common Miranda spacing:

Spaces around ::, ->, ++, ==, ~=, <=, >=, and +.
Spaces after commas.
Repeated blank lines collapsed to one.
Trailing whitespace removed.

Release Notes

See the repository history or GitHub releases for version-by-version changes.

Contributing

If you want to work on the extension itself, the project scripts and development workflow are defined in package.json.

References

Miranda open-source repository:
- https://github.com/ncihnegn/miranda
Prelude source used as symbol and behavior reference:
- https://github.com/ncihnegn/miranda/blob/master/miralib/prelude
Additional Miranda documentation:
- https://github.com/garrett-may/miranda-documentation

AI Usage

GitHub Copilot was used as an assistant for implementation of this extension.

Miranda Static Helper