1 files changed, 163 insertions, 0 deletions
diff --git a/tex/context/base/cldf-scn.lua b/tex/context/base/cldf-scn.lua
new file mode 100644
index 000000000..5f7e0c74b
--- /dev/null
+++ b/tex/context/base/cldf-scn.lua
@@ -0,0 +1,163 @@
+if not modules then modules = { } end modules ['cldf-scn'] = {
+    version   = 1.001,
+    comment   = "companion to cldf-ini.mkiv",
+    author    = "Hans Hagen, PRAGMA-ADE, Hasselt NL",
+    copyright = "PRAGMA ADE / ConTeXt Development Team",
+    license   = "see context related readme files"
+}
+
+local load, type  = load, type
+
+local formatters  = string.formatters
+local char        = string.char
+local concat      = table.concat
+
+local lpegmatch   = lpeg.match
+local p_unquoted  = lpeg.Cs(lpeg.patterns.unquoted)
+
+local f_action_f  = formatters["action%s(%s)"]
+local f_action_s  = formatters["local action%s = action[%s]"]
+local f_command   = formatters["local action = tokens._action\n%\nt\nreturn function(%s) return %s end"]
+
+local interfaces  = interfaces
+local commands    = commands
+local scanners    = interfaces.scanners
+
+local compile     = tokens.compile or function() end
+
+local dummy       = function() end
+
+local report      = logs.reporter("interfaces","implementor")
+
+function interfaces.implement(specification)
+    local actions   = specification.actions
+    local name      = specification.name
+    local arguments = specification.arguments
+    local private   = specification.scope == "private"
+    local onlyonce  = specification.onlyonce
+    if not actions then
+        if name then
+            report("error: no actions for %a",name)
+        else
+            report("error: no actions and no name")
+        end
+        return
+    end
+    if name == "" then
+        name = nil
+    end
+    local scanner
+    local resetter = onlyonce and name and commands.ctxresetter(name)
+    if resetter then
+        local scan = compile(specification)
+        if private then
+            scanner = function()
+                resetter()
+                return scan()
+            end
+        else
+            scanner = function()
+                commands[name] = dummy
+                resetter()
+                return scan()
+            end
+        end
+    else
+        scanner = compile(specification)
+    end
+    if not name then
+        return scanner
+    end
+    if scanners[name] and not specification.overload then
+        report("warning: 'scanners.%s' is redefined",name)
+    end
+    scanners[name] = scanner
+    if private then
+        return
+    end
+    local command
+    if onlyonce then
+        if type(actions) == "function" then
+            actions = { actions }
+        elseif #actions == 1 then
+            actions = { actions[1] }
+        end
+    end
+    if type(actions) == "function" then
+        command = actions
+    elseif #actions == 1 then
+        command = actions[1]
+    else
+        -- this one is not yet complete .. compare tokens
+        tokens._action = actions
+        local f = { }
+        local args
+        if not arguments then
+            args = ""
+        elseif type(arguments) == "table" then
+            local a = { }
+            for i=1,#arguments do
+                local v = arguments[i]
+                local t = type(v)
+                if t == "boolean" then
+                    a[i] = tostring(v)
+                elseif t == "number" then
+                    a[i] = tostring(v)
+                elseif t == "string" then
+                    local s = lpegmatch(p_unquoted,v)
+                    if s and v ~= s then
+                        a[i] = v -- a string, given as "'foo'" or '"foo"'
+                    else
+                        a[i] = char(96+i)
+                    end
+                else
+                    -- nothing special for tables
+                    a[i] = char(96+i)
+                end
+            end
+            args = concat(a,",")
+        else
+            args = "a"
+        end
+        command = args
+        for i=1,#actions do
+            command = f_action_f(i,command)
+            f[#f+1] = f_action_s(i,i)
+        end
+        command = f_command(f,args,command)
+        command = load(command)
+        if command then
+            if resetter then
+                local cmd = command()
+                command = function()
+                    commands[name] = dummy
+                    resetter()
+                    cmd()
+                end
+            else
+                command = command()
+            end
+        end
+        tokens._action = nil
+    end
+    if commands[name] and not specification.overload then
+        report("warning: 'commands.%s' is redefined",name)
+    end
+    commands[name] = command
+ -- return scanner, command
+end
+
+-- it's convenient to have copies here:
+
+interfaces.setmacro = tokens.setters.macro
+interfaces.setcount = tokens.setters.count
+interfaces.setdimen = tokens.setters.dimen
+
+interfaces.strings = table.setmetatableindex(function(t,k)
+    local v = { }
+    for i=1,k do
+        v[i] = "string"
+    end
+    t[k] = v
+    return v
+end)