From 81095dd1bf20eb5f7e126adbdc8047f940504180 Mon Sep 17 00:00:00 2001
From: Hans Hagen <pragma@wxs.nl>
Date: Mon, 20 Jul 2020 11:09:33 +0200
Subject: 2020-07-20 10:42:00

---
 tex/context/base/mkiv/node-gcm.lua | 91 ++++++++++++++++++++++++++++++++++++++
 1 file changed, 91 insertions(+)
 create mode 100644 tex/context/base/mkiv/node-gcm.lua

(limited to 'tex/context/base/mkiv/node-gcm.lua')

diff --git a/tex/context/base/mkiv/node-gcm.lua b/tex/context/base/mkiv/node-gcm.lua
new file mode 100644
index 000000000..1085f637f
--- /dev/null
+++ b/tex/context/base/mkiv/node-gcm.lua
@@ -0,0 +1,91 @@
+if not modules then modules = { } end modules ['node-gmc'] = {
+    version   = 1.001,
+    comment   = "companion to node-ini.mkiv",
+    author    = "Hans Hagen, PRAGMA-ADE, Hasselt NL",
+    copyright = "PRAGMA ADE / ConTeXt Development Team",
+    license   = "see context related readme files"
+}
+
+local type, tostring = type, tostring
+
+local nodes          = nodes
+local nodecodes      = nodes.nodecodes
+local ligature_code  = nodes.glyphcodes.ligature
+local nuts           = nodes.nuts
+
+local getnext        = nuts.getnext
+local getsubtype     = nuts.getsubtype
+local getprev        = nuts.getprev
+local setlink        = nuts.setlink
+local nextglyph      = nuts.traversers.glyph
+local copy_node      = nuts.copy
+local isglyph        = nuts.isglyph
+
+local report_error   = logs.reporter("node-aux:error")
+
+local get_components = node.direct.getcomponents
+local set_components = node.direct.setcomponents
+
+local function copy_no_components(g,copyinjection)
+    local components = get_components(g)
+    if components then
+        set_components(g)
+        local n = copy_node(g)
+        if copyinjection then
+            copyinjection(n,g)
+        end
+        set_components(g,components)
+        -- maybe also upgrade the subtype but we don't use it anyway
+        return n
+    else
+        local n = copy_node(g)
+        if copyinjection then
+            copyinjection(n,g)
+        end
+        return n
+    end
+end
+
+local function copy_only_glyphs(current)
+    local head     = nil
+    local previous = nil
+    for n in nextglyph, current do
+        n = copy_node(n)
+        if head then
+            setlink(previous,n)
+        else
+            head = n
+        end
+        previous = n
+    end
+    return head
+end
+
+-- start is a mark and we need to keep that one
+
+local function count_components(start,marks)
+    local char = isglyph(start)
+    if char then
+        if getsubtype(start) == ligature_code then
+            local n = 0
+            local components = get_components(start)
+            while components do
+                n = n + count_components(components,marks)
+                components = getnext(components)
+            end
+            return n
+        elseif not marks[char] then
+            return 1
+        end
+    end
+    return 0
+end
+
+nuts.set_components     = set_components
+nuts.get_components     = get_components
+nuts.copy_only_glyphs   = copy_only_glyphs
+nuts.copy_no_components = copy_no_components
+nuts.count_components   = count_components
+
+nuts.setcomponents = function() report_error("unsupported: %a","setcomponents") end
+nuts.getcomponents = function() report_error("unsupported: %a","getcomponents") end
-- 
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