Making skips in error recovery more intelligent

2 files changed, 15 insertions, 5 deletions

diff --git a/relabel.lua b/relabel.lua
index 7055eaa..e3b7d48 100644
--- a/relabel.lua
+++ b/relabel.lua
@@ -188,9 +188,14 @@ end
 
 local exp = m.P{ "Exp",
   Exp = S * ( m.V"Grammar"
-            + (m.V"Seq" * ("/" * (m.V"Labels" + m.Cc(nil)) * S
-               * m.Lc(m.V"Seq" + throw(4), (-m.P"/" * any)^0, 4, 5, 6, 7, 8, 9, 10))^0) / labchoice );
+            + (m.V"SeqLC" * ("/" * (m.V"Labels" + m.Cc(nil)) * S
+               * m.Lc(m.V"SeqLC" + throw(4), m.V"SkipToSlash", 4))^0) / labchoice );
         Labels = m.Ct(m.P"{" * S * (m.V"Label" + throw(27)) * (S * "," * S * (m.V"Label" + throw(28)))^0 * S * ("}" + throw(29)));
+  SkipToSlash = (-m.P"/" * m.V"Stuff")^0 * m.Cc(mm.P"");
+  Stuff = m.V"GroupedStuff" + any;
+  GroupedStuff = "(" * (-m.P")" * m.V"Stuff")^0 * ")"
+               + "{" * (-m.P"}" * m.V"Stuff")^0 * "}";
+  SeqLC = m.Lc(m.V"Seq", m.V"SkipToSlash", 5, 6, 7, 8, 9, 10);
   Seq = m.Cf(m.Cc(m.P"") * m.V"Prefix"^1 , mt.__mul);
   Prefix = "&" * S * (m.V"Prefix" + throw(5)) / mt.__len
          + "!" * S * (m.V"Prefix" + throw(6)) / mt.__unm
diff --git a/testerrors.lua b/testerrors.lua
index ab1c665..bcab65f 100644
--- a/testerrors.lua
+++ b/testerrors.lua
@@ -100,7 +100,7 @@ local patterns = {
   [[{|@|}]],
   [['p' {| 'q' / 'r' }]],
   -- 71-75
-  [['a'/{1}'b'/'c']],
+  [['a'/{1}'b'/'c']], -- should not fail anymore
   [[x <- {:x:}]],
   [[&'p'/&/!/'p'^'q']],
   [[
@@ -113,7 +113,7 @@ local patterns = {
     A <- 'A again'
     A <- 'and again'
   ]],
-  -- 76 - 79
+  -- 76 - 80
   [[names not in grammar]],
   [[
     A <- %nosuch %def
@@ -121,7 +121,12 @@ local patterns = {
     A <- 'and again'
   ]],
   [[ A <- %nosuch ('error' ]],
-  [[A <- Unknown Rules]]
+  [[A <- Unknown Rules]],
+  [['a' / &@ ('c' / 'd')]],
+  -- 81 - 83
+  [['x' / & / 'y']],
+  [[&/'p'/!/'q']],
+  [['p'//'q']],
 }
 
 for i, patt in ipairs(patterns) do