LACE: Update simple match with generic matchers

This updates the simple match routine to have a table of match functions.
Initially this only supports the exact and pattern matches, but we can add
more.

1 files changed, 27 insertions, 22 deletions

diff --git a/lib/gitano/lace.lua b/lib/gitano/lace.lua
index 4927e1c..926d49e 100644
--- a/lib/gitano/lace.lua
+++ b/lib/gitano/lace.lua
@@ -44,46 +44,46 @@ local function _loader(ctx, _name)
    return real_name, tree[blob_name].obj.content
 end
 
-local matchers = {}
+local match_types = {
+   exact = function(want, have)
+	      return want == have
+	   end,
+   pattern = function(want, have)
+		return (have:match(want) ~= nil)
+	     end
+}
+
+do
+   local inverted_matches = {}
+   for k, v in pairs(match_types) do
+      inverted_matches["!" .. k] = function(...) return not v(...) end
+   end
+   for k, v in pairs(inverted_matches) do
+      match_types[k] = v
+   end
+end
 
 local function _do_simple_match(ctx, key, matchtype, value)
    value = util.process_expansion(ctx, value)
-   local inv = matchtype:sub(1,1) == "!"
-   if inv then
-      matchtype = matchtype:sub(2)
-   end
-   local pat = (matchtype == "pattern") and value
    local kk = ctx[key] or ""
-   local function check(v)
-      if pat then
-	 if inv then
-	    return (v:match(pat) == nil)
-	 else
-	    return (v:match(pat) ~= nil)
-	 end
-      end
-      if inv then
-	 return v ~= value
-      end
-      return v == value
-   end
+   local check = match_types[matchtype]
    if type(kk) == "function" then
       -- Realise the value first
       ctx[key] = kk(ctx)
       kk = ctx[key]
    end
    if type(kk) == "string" then
-      return check(kk)
+      return check(value, kk)
    else
       if pat and kk[1] ~= nil then
 	 for i = 1, #kk do
-	    if check(kk[i]) then
+	    if check(value, kk[i]) then
 	       return true
 	    end
 	 end
 	 return false
       else
-	 if inv then
+	 if matchtype:sub(1,1) == "!" then
 	    return kk[value] == nil
 	 end
 	 return kk[value] ~= nil
@@ -114,6 +114,9 @@ local function _simple_match(ctx, key, matchtype, value, guard)
 	 matchtype = matchtype .. "exact"
       end
    end
+   if match_types[matchtype] == nil then
+      return lace.compiler.error("Unknown match type", {2})
+   end
    return {
       fn = _do_simple_match,
       args = { key, matchtype, util.prep_expansion(value) }
@@ -138,6 +141,8 @@ local simples = {
    "member/prefix", "member/suffix",
 }
 
+local matchers = {}
+
 for _, s in ipairs(simples) do
    matchers[s] = _simple_match
 end