[resolvers] allow arbitrary sequence lookups

This primarily affects the “anon” lookup. However, since we cannot any
longer determine the lookup success by crude means, the resolver
signature had to be modified to indicate success or failure via the
return value. This does no longer match the resolver implementation of
Context but the interface has become much cleaner.

1 files changed, 84 insertions, 42 deletions

diff --git a/src/luaotfload-resolvers.lua b/src/luaotfload-resolvers.lua
index 3d7f6b0..05a0656 100644
--- a/src/luaotfload-resolvers.lua
+++ b/src/luaotfload-resolvers.lua
@@ -62,14 +62,18 @@ local logreport           = luaotfload.log.report
 
 local resolve_file
 resolve_file = function (specification)
-    local name   = fonts.names.lookup_font_file (specification.name)
+    local name, _format, success = fonts.names.lookup_font_file (specification.name)
     local suffix = filesuffix (name)
     if fonts.formats[suffix] then
         specification.forced      = stringlower (suffix)
-        specification.forcedname  = fileremovesuffix(name)
+        specification.forcedname  = fileremovesuffix (name)
     else
         specification.name = name
     end
+    if success ~= true then
+        logreport ("log", 1, "resolve", "file lookup of %q unsuccessful", name)
+    end
+    return success
 end
 
 --[[doc--
@@ -85,22 +89,22 @@ end
 local resolve_path
 resolve_path = function (specification)
     local name       = specification.name
-    local exists, _  = lfsisfile(name)
+    local exists, _  = lfsisfile (name)
     if not exists then -- resort to file: lookup
-        logreport ("log", 0, "load",
+        logreport ("log", 1, "resolve",
                    "path lookup of %q unsuccessful, falling back to file:",
                    name)
-        resolve_file (specification)
+        return resolve_file (specification)
+    end
+    local suffix = filesuffix (name)
+    if fonts.formats [suffix] then
+        specification.forced      = stringlower (suffix)
+        specification.name        = fileremovesuffix (name)
+        specification.forcedname  = name
     else
-        local suffix = filesuffix (name)
-        if fonts.formats[suffix] then
-            specification.forced      = stringlower (suffix)
-            specification.name        = fileremovesuffix(name)
-            specification.forcedname  = name
-        else
-            specification.name = name
-        end
+        specification.name = name
     end
+    return true
 end
 
 --[[doc--
@@ -120,18 +124,17 @@ resolve_name = function (specification)
     end
     local resolved, subfont = resolver (specification)
     if resolved then
-        logreport ("log", 0, "load", "Lookup/name: %q -> \"%s%s\"",
-                   specification.name,
-                   resolved,
+        logreport ("log", 1, "resolve", "name lookup %q -> \"%s%s\"",
+                   specification.name, resolved,
                    subfont and stringformat ("(%d)", subfont) or "")
         specification.resolved   = resolved
         specification.sub        = subfont
         specification.forced     = stringlower (filesuffix (resolved) or "")
         specification.forcedname = resolved
         specification.name       = fileremovesuffix (resolved)
-    else
-        resolve_file (specification)
+        return true
     end
+    return resolve_file (specification)
 end
 
 --[[doc--
@@ -158,36 +161,74 @@ end
 
 --doc]]--
 
-local type1_formats = { "tfm", "ofm", "TFM", "OFM", }
+local tex_formats = { "tfm", "ofm", "TFM", "OFM", }
 
-local resolve_anon
-resolve_anon = function (specification)
+local resolve_tex_format = function (specification)
     local name = specification.name
-    for i=1, #type1_formats do
-        local format = type1_formats[i]
+    for i=1, #tex_formats do
+        local format = tex_formats [i]
         local suffix = filesuffix (name)
-        if resolvers.findfile(name, format) then
+        if resolvers.findfile (name, format) then
             local usename = suffix == format and fileremovesuffix (name) or name
             specification.forcedname = file.addsuffix (usename, format)
             specification.forced     = format
-            return
+            return true
         end
     end
-    --- under some weird circumstances absolute paths get
-    --- passed to the definer; we have to catch them
-    --- before the name: resolver misinterprets them.
-    name = specification.specification
-    local exists, _ = lfsisfile(name)
-    if exists then --- garbage; we do this because we are nice,
-                   --- not because it is correct
-        logreport ("log", 1, "load", "file %q exists", name)
-        logreport ("log", 1, "load",
-                   "... overriding borked anon: lookup with path: lookup")
-        specification.name = name
-        resolve_path (specification)
-        return
+    return false
+end
+
+local resolve_path_if_exists = function (specification)
+    local spec = specification.specification
+    local exists, _void = lfsisfile (spec)
+    if exists then
+        --- If this path is taken a file matching the specification
+        --- literally was found. In this situation, Luaotfload is
+        --- expected to load that file directly, even though we provide
+        --- explicit “file” and “path” lookups to address exactly this
+        --- situation.
+        logreport ("log", 1, "resolve",
+                   "file %q exists, performing path lookup", spec)
+        specification.name = spec
+        return resolve_path (specification)
+    end
+    return false
+end
+
+local resolve_methods = {
+    tex  = resolve_tex_format,
+    path = resolve_path_if_exists,
+    name = resolve_name,
+}
+
+local resolve_sequence = function (seq, specification)
+    for i = 1, #seq do
+        local id  = seq [i]
+        local mth = resolve_methods [id]
+        logreport ("both", 0, "resolve", "step %d: apply method %q (%s)", i, id, mth)
+        if mth (specification) == true then
+            logreport ("both", 0, "resolve",
+                       "%d: method %q indicated lookup success", i, id)
+            logreport ("both", 0, "resolve",
+                       "method %q resolved %q -> %s (%s)",
+                       id, specification.specification,
+                       specification.name,
+                       specification.forcedname)
+            return true
+        end
     end
-    resolve_name (specification)
+    logreport ("both", 0, "resolve",
+               "sequence of %d lookups yielded nothing appropriate", #seq)
+    return false
+end
+
+local default_anon_sequence = {
+    "tex", "path", "name",
+}
+
+local resolve_anon
+resolve_anon = function (specification)
+    return resolve_sequence (default_anon_sequence, specification)
 end
 
 --[[doc--
@@ -207,16 +248,17 @@ resolve_kpse = function (specification)
         if resolvers.findfile (name, suffix) then
             specification.forced       = stringlower (suffix)
             specification.forcedname   = name
-            return
+            return true
         end
     end
     for t, format in next, fonts.formats do --- brute force
         if kpsefind_file (name, format) then
             specification.forced = t
             specification.name   = name
-            return
+            return true
         end
     end
+    return false
 end
 
 --[[doc--
@@ -250,5 +292,5 @@ return {
     end, --- [.init]
 }
 
---- vim:ft=lua:ts=8:sw=4:et
+--- vim:ft=lua:ts=8:sw=4:et:tw=79