Initial LSP implementation/vscode support

Makefile

@@ -58,3 +58,17 @@ clean:
 audit: .PHONY
 	(cd playground && npm audit)
 	(cd newt-vscode && npm audit)
+
+lsp.js: ${SRCS}
+	node newt.js src/LSP.newt -o lsp.js
+
+newt-vscode-lsp/src/newt.js: lsp.js .PHONY
+	echo "import fs from 'fs'\nlet mods = { fs }\nlet require = key => mods[key]\n" > $@
+	# HACK
+	perl -p -e "s/(const LSP_(?:updateFile|checkFile|hoverInfo))/export \$$1/" lsp.js >> $@
+
+newt-vscode-lsp/dist/lsp.js: newt-vscode-lsp/src/lsp.ts newt-vscode-lsp/src/newt.js
+	(cd newt-vscode-lsp && node esbuild.js)
+
+lsp: newt-vscode-lsp/dist/lsp.js
+