add custom ast shim to filters called by IDEs

Author: cscheid

src/resources/filters/common/customastshim.lua

@@ -0,0 +1,10 @@
+-- customastshim.lua
+-- Copyright (C) 2020-2023 Posit Software, PBC
+
+_quarto = {
+  ast = {
+    walk = function(el, filter)
+      return el:walk(filter)
+    end
+  }
+}

src/resources/filters/crossref/crossref.lua

@@ -45,8 +45,12 @@ import("../common/meta.lua")
 import("../common/table.lua")
 import("../common/string.lua")
 import("../common/debug.lua")
+
+import("../common/customastshim.lua")
 -- [/import]
 
+-- note that the custom-ast-shim.lua import should _not_ happen on main.lua
+
 initCrossrefIndex()
 
 -- chain of filters

src/resources/filters/quarto-init/quarto-init.lua

@@ -16,8 +16,14 @@ import("../common/filemetadata.lua")
 import("../common/meta.lua")
 import("includes.lua")
 import("resourcerefs.lua")
+import("../common/customastshim.lua")
+
 -- [/import]
 
+-- note that the custom-ast-shim.lua import should _not_ happen on main.lua
+-- it exists for us to be able to support filters that need to exist on IDE
+-- and do not require the full custom AST work.
+
 return {
   readIncludes(),
   combineFilters({