Monogate Forge — VS Code extension

EML-lang language support for VS Code. Free forever for writing EML; install the licensed Forge CLI to unlock compile, analysis, and verification.

What you get for free (no CLI required)

Syntax highlighting for .eml files (TextMate grammar)
- Keywords: module use as const type fn extern let mut where requires ensures while if else …
- Built-in transcendentals: exp ln log sin cos tan sqrt pow eml abs clamp asin acos atan sinh cosh tanh
Snippets for the common patterns: fn, fnverify, module, usestdlib, requires, ensures, targetfpga, verify, plus the @verify Hoare-contract template with requires/ensures pre-filled
Bracket auto-close, comment toggle, indent rules
Static completion: keyword + builtin suggestions
Outline view: regex-driven document symbols (fn, const, type)

What unlocks with the Forge CLI

The licensed CLI (monogateforge.com/get-started) ships an LSP server and the compiler. Once installed, the extension auto-detects both binaries on PATH and lights up:

Real-time diagnostics — lex, parse, and chain-order errors as you type
Hover — chain order, cost class, FPGA cycles for fns; structural class + chain delta for builtin transcendentals
Rich completion — local decls + 87 stdlib symbols (math, ml, signal, linalg, control, constants)
Cross-file goto-definition — into bundled stdlib + sibling user .eml files
Find all references + workspace-wide rename (rename blocks builtins; validates new names)
Document symbols + outline — typed via the real parser, not regex
Document links — ctrl-click use stdlib::* clauses to jump to source
Format-on-save — re-emit canonical EML in-process via the LSP
Workspace symbol search (Ctrl+T) — fuzzy match across every indexed file
FPGA status bar — LUT / DSP / cycle estimates per file
Inline profile lenses — chain order + cost class above each fn header
Compile commands for all 32 backends (palette + right-click)

The compile commands are tier-gated:

Tier	Backends
Free	C, C++, Rust, Python, Go, Java, Kotlin, C#, JavaScript, WebAssembly, MATLAB, Lean 4
Pro	Verilog, SystemVerilog, VHDL, Chisel, LLVM IR, HLSL, GLSL, GLSL ES, WGSL, Metal, Swift, Ada/SPARK, AUTOSAR, AADL, ROS 2, Coq, Isabelle/HOL, Solidity, Luau, GDScript

Install

Install this extension from the VS Code marketplace.
Open any .eml file — syntax + snippets + outline work immediately.
To enable real-time diagnostics, hover, completion, format, and compile-to-anything: visit https://monogateforge.com/get-started for the licensed CLI.

Architecture

File	Role
`src/extension.ts`	Entry point — registers providers + commands
`src/forgeCli.ts`	Resolves `eml-compile` and `eml-lsp` on PATH
`src/lspClient.ts`	Spawns `eml-lsp` and connects vscode-languageclient
`src/editorOnly.ts`	Static completion + regex outline (free tier)
`src/profileProvider.ts`	CodeLens provider — runs `--profile-only`, parses dashboard
`src/diagnostics.ts`	Save-triggered diagnostics fallback when LSP unavailable
`language-configuration.json`	Bracket auto-close, comment toggle
`syntaxes/eml.tmLanguage.json`	TextMate grammar
`snippets/eml.json`	Snippet library

The LSP discovery happens once per session (cached). When the LSP isn't available, the extension falls back to: static completion provider, regex outliner, and a one-shot install hint pointing at the licensing page (no nag — appears once per session).