beta 2013.06.04 19:42

1 files changed, 31 insertions, 16 deletions

diff --git a/tex/context/base/data-exp.lua b/tex/context/base/data-exp.lua
index 8a2fd0320..c67e97bb1 100644
--- a/tex/context/base/data-exp.lua
+++ b/tex/context/base/data-exp.lua
@@ -9,7 +9,7 @@ if not modules then modules = { } end modules ['data-exp'] = {
 local format, find, gmatch, lower, char, sub = string.format, string.find, string.gmatch, string.lower, string.char, string.sub
 local concat, sort = table.concat, table.sort
 local lpegmatch, lpegpatterns = lpeg.match, lpeg.patterns
-local Ct, Cs, Cc, P, C, S = lpeg.Ct, lpeg.Cs, lpeg.Cc, lpeg.P, lpeg.C, lpeg.S
+local Ct, Cs, Cc, Carg, P, C, S = lpeg.Ct, lpeg.Cs, lpeg.Cc, lpeg.Carg, lpeg.P, lpeg.C, lpeg.S
 local type, next = type, next
 
 local ostype = os.type
@@ -26,21 +26,21 @@ local resolvers = resolvers
 -- all, when working on the main resolver code, I don't want to scroll
 -- past this every time. See data-obs.lua for the gsub variant.
 
-local function f_first(a,b)
-    local t, n = { }, 0
-    for s in gmatch(b,"[^,]+") do
-        n = n + 1 ; t[n] = a .. s
-    end
-    return concat(t,",")
-end
-
-local function f_second(a,b)
-    local t, n = { }, 0
-    for s in gmatch(a,"[^,]+") do
-        n = n + 1 ; t[n] = s .. b
-    end
-    return concat(t,",")
-end
+-- local function f_first(a,b)
+--     local t, n = { }, 0
+--     for s in gmatch(b,"[^,]+") do
+--         n = n + 1 ; t[n] = a .. s
+--     end
+--     return concat(t,",")
+-- end
+--
+-- local function f_second(a,b)
+--     local t, n = { }, 0
+--     for s in gmatch(a,"[^,]+") do
+--         n = n + 1 ; t[n] = s .. b
+--     end
+--     return concat(t,",")
+-- end
 
 -- kpsewhich --expand-braces '{a,b}{c,d}'
 -- ac:bc:ad:bd
@@ -69,6 +69,21 @@ local function f_both(a,b)
     return concat(t,",")
 end
 
+local comma   = P(",")
+local nocomma = (1-comma)^1
+local docomma = comma^1/","
+local before  = Cs((nocomma * Carg(1) + docomma)^0)
+local after   = Cs((Carg(1) * nocomma + docomma)^0)
+local both    = Cs(((C(nocomma) * Carg(1))/function(a,b) return lpegmatch(before,b,1,a) end + docomma)^0)
+
+local function f_first (a,b) return lpegmatch(after, b,1,a) end
+local function f_second(a,b) return lpegmatch(before,a,1,b) end
+local function f_both  (a,b) return lpegmatch(both,  b,1,a) end
+
+-- print(f_first ("a",    "x,y,z"))
+-- print(f_second("a,b,c","x"))
+-- print(f_both  ("a,b,c","x,y,z"))
+
 local left  = P("{")
 local right = P("}")
 local var   = P((1 - S("{}" ))^0)