1 files changed, 179 insertions, 0 deletions
diff --git a/Master/texmf-dist/tex/context/base/buff-par.lua b/Master/texmf-dist/tex/context/base/buff-par.lua
new file mode 100644
index 00000000000..2015b0bc0a4
--- /dev/null
+++ b/Master/texmf-dist/tex/context/base/buff-par.lua
@@ -0,0 +1,179 @@
+if not modules then modules = { } end modules ['buff-ini'] = {
+    version   = 1.001,
+    comment   = "companion to buff-ini.mkiv",
+    author    = "Hans Hagen, PRAGMA-ADE, Hasselt NL",
+    copyright = "PRAGMA ADE / ConTeXt Development Team",
+    license   = "see context related readme files"
+}
+
+local trace_parallel = false  trackers.register("buffers.parallel", function(v) trace_parallel = v end)
+
+local report_parallel = logs.reporter("buffers","parallel")
+
+local insert, remove, find, gmatch = table.insert, table.remove, string.find, string.gmatch
+local strip, format = string.strip, string.format
+
+local variables = interfaces.variables
+
+buffers.parallel = { } local parallel = buffers.parallel
+
+local data = { }
+
+function parallel.define(category,tags)
+    local tags = utilities.parsers.settings_to_array(tags)
+    local entries = { }
+    data[category] = {
+        tags    = tags,
+        entries = entries,
+    }
+    for i=1,#tags do
+        entries[tags[i]] = {
+            lines  = { },
+            number = 0,
+        }
+    end
+end
+
+function parallel.reset(category,tags)
+    if not tags or tags == "" or tags == variables.all then
+        tags = table.keys(entries)
+    else
+        tags = utilities.parsers.settings_to_array(tags)
+    end
+    for i=1,#tags do
+        entries[tags[i]] = {
+            lines  = { },
+            number = 0,
+        }
+    end
+end
+
+function parallel.next(category)
+    local dc = data[category]
+    local tags = dc.tags
+    local entries = dc.entries
+    for i=1,#tags do
+        insert(entries[tags[i]].lines, { })
+    end
+end
+
+function parallel.save(category,tag,content)
+    local dc = data[category]
+    if not dc then
+        return
+    end
+    local entries = dc.entries[tag]
+    if not entries then
+        return
+    end
+    local lines = entries.lines
+    if not lines then
+        return
+    end
+    local line = lines[#lines]
+    if not line then
+        return
+    end
+    -- maybe no strip
+    -- use lpeg
+    if find(content,"^%s*%[") then
+        local done = false
+        for label, content in gmatch(content,"%s*%[(.-)%]%s*([^%[]+)") do
+            if done then
+                line = { }
+                insert(lines,line)
+            else
+                done = true
+            end
+            if trace_parallel and label ~= "" then
+                report_parallel("reference found: category '%s', tag '%s', label '%s'",category,tag,label)
+            end
+            line.label   = label
+            line.content = strip(content)
+        end
+    else
+        line.content = strip(content)
+        line.label = ""
+    end
+end
+
+function parallel.hassomecontent(category,tags)
+    local dc = data[category]
+    if not dc then
+        return false
+    end
+    local entries = dc.entries
+    if not tags or tags == "" or tags == variables.all then
+        tags = table.keys(entries)
+    else
+        tags = utilities.parsers.settings_to_array(tags)
+    end
+    for t=1,#tags do
+        local tag = tags[t]
+        local lines = entries[tag].lines
+        for i=1,#lines do
+            local content = lines[i].content
+            if content and content ~= "" then
+                return true
+            end
+        end
+    end
+    return false
+end
+
+local save = resolvers.savers.byscheme
+
+function parallel.place(category,tags,options)
+    local dc = data[category]
+    if not dc then
+        return
+    end
+    local entries = dc.entries
+    local tags = utilities.parsers.settings_to_array(tags)
+    local options = utilities.parsers.settings_to_hash(options)
+    local start, n, criterium = options.start, options.n, options.criterium
+    start, n = start and tonumber(start), n and tonumber(n)
+    local max = 1
+    if n then
+        max = n
+    elseif criterium == variables.all then
+        max = 0
+        for t=1,#tags do
+            local tag = tags[t]
+            local lines = entries[tag].lines
+            if #lines > max then
+                max = #lines
+            end
+        end
+    end
+    for i=1,max do
+        for t=1,#tags do
+            local tag = tags[t]
+            local entry = entries[tag]
+            if entry then
+                local lines = entry.lines
+                local number = entry.number + 1
+                entry.number = number
+                local line = remove(lines,1)
+                if line and line.content then
+                    local content = format("\\input{%s}",save("virtual","parallel",line.content))
+                    context.doflushparallel(tag,1,number,line.label,content)
+                else
+                    context.doflushparallel(tag,0,number,"","")
+                end
+            end
+        end
+    end
+end
+
+-- interface
+
+commands.defineparallel = parallel.define
+commands.nextparallel   = parallel.next
+commands.saveparallel   = parallel.save
+commands.placeparallel  = parallel.place
+commands.resetparallel  = parallel.reset
+
+function commands.doifelseparallel(category,tags)
+    commands.testcase(parallel.hassomecontent(category,tags))
+end