--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/test/suite_aggrs/mk-cases.lua	Fri Jan 21 15:42:29 2022 +0100
@@ -0,0 +1,155 @@
+require"math"
+local max = math.max
+local maxargs = 0
+
+local n_aggrs = 0
+local seen_aggrs = { }
+
+
+function trim(l) return l:gsub("^%s+",""):gsub("%s+$","") end
+function mkcase(id,sig)
+  local sig = trim(sig)
+  -- @@@ return value hard-guessed by first char, doesn't hold anymore
+  local h = { "/* ",id,":",sig," */ ",sig:sub(1,1), " f", id,"(","" }
+  local t = { "" }
+  local pos = 1
+  local n_nest = 0
+  local aggr
+  local aggr_sig = ''
+  for i = 2, #sig do 
+    local name = "a"..pos
+    local ch   = sig:sub(i,i)
+
+    aggr_sig = aggr_sig..ch
+
+    -- aggregate nest level change?
+    if ch == '{' then
+      n_nest = n_nest + 1
+      aggr = { }
+      aggr_sig = ch  -- @@@ handle nesting
+    else
+      if ch == '}' then  -- @@@ handle nesting, here, by reusing structs
+        n_nest = n_nest - 1
+        -- aggr sig complete?
+        if n_nest == 0 then
+          -- register yet unseen aggregates, key is sig, val is body and name
+          if seen_aggrs[aggr_sig] == nil then
+            n_aggrs = n_aggrs + 1
+            ch = 'A'..n_aggrs
+            seen_aggrs[aggr_sig] = { aggr, ch }
+          end
+          ch = seen_aggrs[aggr_sig][2]
+        end
+      else
+        if n_nest > 0 then
+          aggr[#aggr+1] = ch
+          aggr[#aggr+1] = 'm'..(#aggr >> 1)
+        end
+      end
+    end
+
+    if n_nest == 0 then
+      -- struct types (more than one char) need copying via a func
+      if #ch > 1 then
+        h[#h+1] = 'struct '..ch.." "..name
+        t[#t+1] = 'f_cp'..ch..'(V_a['..pos.."],&"..name..");"
+      else
+        h[#h+1] = ch.." "..name
+        t[#t+1] = "V_"..ch.."["..pos.."]="..name..";"
+      end
+      h[#h+1] = ","
+
+      pos = pos + 1
+    end
+  end
+  maxargs = max(maxargs, pos-1)
+  h[#h] = "){"
+  t[#t+1] = "ret_"..sig:sub(1,1).."("..(pos-1)..")}\n"
+  return table.concat(h,"")..table.concat(t,"")
+end
+
+function mkfuntab(n)
+  local s = { "funptr G_funtab[] = {\n"}
+  for i = 0, n-1 do
+    s[#s+1] = "\t(funptr)&f"..i..",\n"
+  end
+  s[#s+1] = "};\n"
+  return table.concat(s,"")
+end
+
+function mksigtab(sigs)
+  local s = { "char const * G_sigtab[] = {\n"}
+  for k,v in pairs(sigs) do
+    s[#s+1] = '\t"'..v..'",\n'
+  end
+  s[#s+1] = "};\n"
+  return table.concat(s,"")
+end
+
+function mkall()
+  local lineno = 0
+  local sigtab = { }
+  local cases = ''
+  for line in io.lines() do
+    local sig = trim(line)
+    cases = cases..mkcase(lineno,sig)
+    sigtab[#sigtab+1] = sig
+    lineno = lineno + 1
+  end
+
+  agg_sizes = {}
+  agg_sigs  = {}
+  agg_names = {}
+  for k, v in pairs(seen_aggrs) do
+    st = 'struct '..v[2]
+
+    agg_sizes[#agg_sizes + 1] = 'sizeof('..st..')'
+    agg_sigs [#agg_sigs  + 1] = k
+    agg_names[#agg_names + 1] = v[2]
+
+    -- struct def
+    io.write('/* '..k..' */\n')
+    io.write(st..'{ ')
+    for i = 1, #v[1], 2 do
+      io.write(v[1][i]..' '..v[1][i+1]..'; ')
+    end
+    io.write("};\n")
+
+    -- struct cp and cmp funcs
+    s = {
+      'void f_cp'..v[2]..'('..st..' *x, const '..st..' *y) { ',
+      'int f_cmp'..v[2]..'(const '..st..' *x, const '..st..' *y) { return '
+    }
+    o = { '=', '==', '; ', ' && '  }
+    for t = 1, 2 do
+      io.write(s[t])
+      b = {}
+      for i = 1, #v[1], 2 do
+        b[#b+1] = 'x->'..v[1][i+1]..' '..o[t]..' y->'..v[1][i+1];
+      end
+      if #b == 0 then
+        b[1] = '1'  -- to handle empty structs
+      end
+      io.write(table.concat(b,o[t+2]).."; };\n")
+    end
+
+    -- convenient dcnewstruct helper funcs
+    io.write('DCstruct* f_newdcst'..v[2]..'() { DCstruct* st = dcNewStruct('..(#v[1]>>1)..', sizeof('..st..'), 0, 1); ')
+    for i = 1, #v[1], 2 do
+      io.write("dcStructField(st, '"..v[1][i].."', offsetof("..st..', '..v[1][i+1]..'), 1); ')
+    end
+    io.write(" dcCloseStruct(st); return st; };\n")
+  end
+
+  io.write(cases)
+  io.write(mkfuntab(lineno))
+  io.write(mksigtab(sigtab))
+  io.write('const char* G_agg_sigs[]  = {\n\t"'..table.concat(agg_sigs, '",\n\t"')..'"\n};\n')
+  io.write('int G_agg_sizes[] = {\n\t'..table.concat(agg_sizes, ',\n\t')..'\n};\n')
+  io.write('funptr G_agg_newdcstfuncs[] = {\n\t(funptr)&f_newdcst'..table.concat(agg_names, ',\n\t(funptr)&f_newdcst')..'\n};\n')
+  io.write('funptr G_agg_cmpfuncs[] = {\n\t(funptr)&f_cmp'..table.concat(agg_names, ',\n\t(funptr)&f_cmp')..'\n};\n')
+  io.write("int G_maxargs = "..maxargs..";\n")
+end
+
+mkall()
+