1 files changed, 81 insertions, 0 deletions
diff --git a/tex/context/base/mkiv/meta-nod.lua b/tex/context/base/mkiv/meta-nod.lua
new file mode 100644
index 000000000..422b4ee14
--- /dev/null
+++ b/tex/context/base/mkiv/meta-nod.lua
@@ -0,0 +1,81 @@
+if not modules then modules = { } end modules ['meta-nod'] = {
+    version   = 1.001,
+    comment   = "companion to meta-nod.mkiv",
+    author    = "Hans Hagen, PRAGMA-ADE, Hasselt NL",
+    copyright = "PRAGMA ADE / ConTeXt Development Team",
+    license   = "see context related readme files"
+}
+
+local tonumber = tonumber
+local P, R, Cs, lpegmatch = lpeg.P, lpeg.R, lpeg.Cs, lpeg.match
+
+local references = { }
+local trace      = false
+local report     = logs.reporter("metapost","nodes")
+
+local context    = context
+local implement  = interfaces.implement
+
+trackers.register("metapost.nodes", function(v) trace = v end)
+
+local word     = R("AZ","az","__")^1
+
+local pattern = Cs (
+    (
+        word / function(s) return references[s] or s end
+      + P("{") / "["
+      + P("}") / "]"
+      + P(1)
+    )^1
+)
+
+implement {
+    name    = "grph_nodes_initialize",
+    actions = function()
+        references = { }
+    end
+}
+
+implement {
+    name    = "grph_nodes_reset",
+    actions = function()
+        references = { }
+    end
+}
+
+implement {
+    name      = "grph_nodes_register",
+    arguments = { "string", "integer" },
+    actions   = function(s,r)
+        if not tonumber(s) then
+            if trace then
+                report("register %i as %a",t,s)
+            end
+            references[s] = r
+        end
+    end
+}
+
+implement {
+    name      = "grph_nodes_resolve",
+    arguments = "string",
+    actions   = function(s)
+        local r = references[s]
+        if r then
+            if trace then
+                report("resolve %a to %i",s,r)
+            end
+            context(r)
+            return
+        end
+        local n = lpegmatch(pattern,s)
+        if s ~= n then
+            if trace then
+                report("resolve '%s' to %s",s,n)
+            end
+            context(n)
+            return
+        end
+        context(s)
+    end
+}