Calque

Calque formats Clef source. It is a focused fork of Fantomas, with a library, incremental formatting API and CLI hosted on .NET 10. It retains Fantomas's Oak syntax tree, comment and trivia handling, and printing pipeline, adapted to Clef's source conventions.

Formatting scope

Calque currently formats the Clef syntax supported by its inherited parser and explicit syntax checks. Clef's language surface is still developing; a parser refusal can indicate a formatter gap, including in working programs such as HelloArty and HelloWayland. Broader support requires a Clef parser adapter.

• Comments, literal spelling and source order are preserved. Numeric widths, suffixes and conversions are left to the source and compiler.
• Imperative bindings, loops and record updates are supported source forms.
• Typed <@ ... @>, untyped <@@ ... @@> and nested quotations retain their structure and contents without evaluation. Quotation splices (%expr and %%expr) are refused under the current Clef contract; infix % remains valid.
• Nulls, OO syntax and CLR widening such as :> obj are refused.
• Clef admits no .NET task: task { ... } computation expressions are refused. A binding or field named task remains ordinary source.
• Raw pointer types and operations (NativePtr, nativeptr, voidptr, fixed, stackalloc, and unary &&), Unchecked construction, boxing, runtime type tokens and managed P/Invoke are refused before writes. Comments, literals and escaped names remain text; native CHandle, FnPtr, arrays and async remain available to format. CCS owns their semantic and proof checks.

Components and integration

Component	Responsibility
Calque.Core	Oak, trivia handling and source layout
Calque.Syntax	Pinned parser and syntax support
Calque.Incremental	Formatting requests coordinated through Fidelity.FSharp.Incremental
Calque	Command-line formatter
Calque.Tests	Preservation, idempotence, refusal and lifecycle tests

Calque.Incremental binds each request to an immutable document revision and formatting configuration. It shares work between consumers, supports cancellation and rejects superseded results. Bozzetto uses this API to provide formatting previews alongside Composer's incremental compilation sessions. Applying a preview requires a current source revision; compiler diagnostics, proofs and execution remain owned by the compiler workflow.

The coordinator currently parses and formats whole documents. Incremental syntax and trivia reuse, syntax markup and automatic editor application are future work; the current incremental API manages requests and their lifetimes.

Build and use

Use the SDK pinned in global.json:

dotnet build Calque.slnx
dotnet src/Calque/bin/Debug/net10.0/Calque.dll --help
dotnet src/Calque/bin/Debug/net10.0/Calque.dll --check path/to/Program.clef
dotnet src/Calque/bin/Debug/net10.0/Calque.dll path/to/Program.clef
dotnet src/Calque/bin/Debug/net10.0/Calque.dll --stdin < path/to/Program.clef
dotnet vstest src/Calque.Tests/bin/Debug/net10.0/Calque.Tests.dll

The CLI formats UTF-8 .clef files with two-space indentation. --check leaves files unchanged. Exit codes: 0 for success, 1 for changes found by --check, and 2 for diagnostics or I/O errors. Unsupported syntax is refused before writes.

Documentation

• Design, syntax support and integration
• Provenance and bootstrap history
• Contributing and validation
• Apache-2.0 license and upstream changelog