allow linting from stdin

src/fennel-ls.fnl

@@ -33,7 +33,10 @@
         server (doto {} initialize)]
     (var should-err? false)
     (each [_ filename (ipairs filenames)]
-      (let [file (files.get-by-uri server (.. "file://" filename))]
+      (let [uri (case filename
+                  "-" :stdin
+                  _ (.. "file://" filename))
+            file (files.get-by-uri server uri)]
         (lint.add-lint-diagnostics server file)
         (each [_ {: message : range : severity} (ipairs file.diagnostics)]
           (set should-err? true)

src/fennel-ls/files.fnl

@@ -13,10 +13,13 @@ in the \"server\" object."
 (λ read-file [server uri]
   (case (?. server.preload uri)
     preload {: uri :text preload}
-    _ (case (io.open (utils.uri->path uri) "r")
-        file (let [text (file:read :*a)]
-               (file:close)
-               {: uri : text}))))
+    _ (case uri
+        :stdin (let [text (io.read :*a)]
+                 {: uri : text})
+        _ (case (io.open (utils.uri->path uri) "r")
+            file (let [text (file:read :*a)]
+                   (file:close)
+                   {: uri : text})))))
 
 (λ get-by-uri [server uri]
   (or (. server.files uri)