Merge pull request #11 from undecidabot/master

Removing error recovery (moving it out to a different branch)

2 files changed, 28 insertions, 237 deletions

diff --git a/relabel.lua b/relabel.lua
index ff2e486..7fe8645 100644
--- a/relabel.lua
+++ b/relabel.lua
@@ -82,15 +82,9 @@ for i, err in ipairs(errinfo) do
   labels[err[1]] = i
 end
 
-local syntaxerrs = {}
-
 local function expect (pattern, labelname)
   local label = labels[labelname]
-  local record = function (input, pos)
-    tinsert(syntaxerrs, { label = label, pos = pos })
-    return true
-  end
-  return pattern + m.Cmt("", record) * m.T(label)
+  return pattern + m.T(label)
 end
 
 
@@ -236,72 +230,20 @@ local function labchoice (...)
   return p
 end
 
--- error recovery
-local skip = m.P { "Skip",
-  Skip = (-m.P"/" * -m.P(name * arrow) * m.V"Ignored")^0 * m.Cc(dummy);
-  Ignored = m.V"Group" + any;
-  Group = "(" * (-m.P")" * m.V"Ignored")^0 * ")"
-        + "{" * (-m.P"}" * m.V"Ignored")^0 * "}"
-        + "[" * (-m.P"]" * m.V"Ignored")^0 * "]"
-        + "'" * (-m.P"'" * m.V"Ignored")^0 * "'"
-        + '"' * (-m.P'"' * m.V"Ignored")^0 * '"';
-}
-
-local ignore = m.Cmt(any, function (input, pos)
-  return syntaxerrs[#syntaxerrs].pos, dummy
-end)
-
-local pointAtStart = m.Cmt(any, function (input, pos)
-  -- like ignore but makes the last syntax error point at the start
-  local ret = syntaxerrs[#syntaxerrs].pos
-  syntaxerrs[#syntaxerrs].pos = pos-1
-  return ret, dummy
-end)
-
-
-local function labify (labelnames)
-  for i, l in ipairs(labelnames) do
-    labelnames[i] = labels[l]
-  end
-  return labelnames
-end
-
-local labelset1 = labify {
-  "ExpPatt2", "ExpPatt3",
-  "ExpPatt4", "ExpPatt5", "ExpPatt6", "ExpPatt7",
-  "ExpPatt8", "ExpPattOrClose",
-  "ExpNum", "ExpCap",
-  "ExpName1", "ExpName2", "ExpName3",
-  "ExpNameOrLab", "ExpItem",
-  "MisClose6", "MisClose7"
-}
-
-local labelset2 = labify {
-  "MisClose1", "MisClose2", "MisClose3", "MisClose4", "MisClose5"
-}
-
-local labelset3 = labify {
-  "ExpPatt1", "ExpLab1", "ExpLab2", "MisClose7"
-}
-
 local exp = m.P{ "Exp",
   Exp = S * ( m.V"Grammar"
-            + (m.V"RecovSeq" * (S * "/" * m.Lc((m.Ct(m.V"Labels") + m.Cc(nil))
-                                                * expect(S * m.V"RecovSeq",
-                                                    "ExpPatt1"),
-                                               m.Cc(nil) * skip,
-                                               unpack(labelset3))
+            + (m.V"Seq" * (S * "/" * (m.Ct(m.V"Labels") + m.Cc(nil))
+                                   * expect(S * m.V"Seq", "ExpPatt1")
                             )^0
               ) / labchoice);
   Labels = m.P"{" * expect(S * m.V"Label", "ExpLab1")
            * (S * "," * expect(S * m.V"Label", "ExpLab2"))^0
            * expect(S * "}", "MisClose7");
-  RecovSeq = m.Lc(m.V"Seq", skip, unpack(labelset1));
   Seq = m.Cf(m.Cc(m.P"") * m.V"Prefix" * (S * m.V"Prefix")^0, mt.__mul);
   Prefix = "&" * expect(S * m.V"Prefix", "ExpPatt2") / mt.__len
          + "!" * expect(S * m.V"Prefix", "ExpPatt3") / mt.__unm
          + m.V"Suffix";
-  Suffix = m.Cf(m.V"RecovPrimary" *
+  Suffix = m.Cf(m.V"Primary" *
           ( S * ( m.P"+" * m.Cc(1, mt.__pow)
                 + m.P"*" * m.Cc(0, mt.__pow)
                 + m.P"?" * m.Cc(-1, mt.__pow)
@@ -318,11 +260,9 @@ local exp = m.P{ "Exp",
                            "ExpName1")
                 )
           )^0, function (a,b,f) return f(a,b) end );
-  RecovPrimary = m.Lc(m.V"Primary", ignore, unpack(labelset2));
   Primary = "(" * expect(m.V"Exp", "ExpPatt4") * expect(S * ")", "MisClose1")
-          + m.Lc(String / mm.P, pointAtStart,
-              labels["MisTerm1"], labels["MisTerm2"])
-          + m.Lc(Class, pointAtStart, labels["MisClose8"])
+          + String / mm.P
+          + Class
           + defined
           + "%" * expect(m.V"Labels", "ExpNameOrLab") / mm.T
           + "{:" * (name * ":" + m.Cc(nil)) * expect(m.V"Exp", "ExpPatt5")
@@ -374,23 +314,20 @@ local function compile (p, defs)
   if mm.type(p) == "pattern" then return p end   -- already compiled
   p = p .. " " -- for better reporting of column numbers in errors when at EOF
   local ok, cp, label, suffix = pcall(function() return pattern:match(p, 1, defs) end)
-  if not ok and #syntaxerrs == 0 then
+  if not ok and cp then
     if type(cp) == "string" then
       cp = cp:gsub("^[^:]+:[^:]+: ", "")
     end
     error(cp, 3)
   end
-  if #syntaxerrs > 0 then
+  if not cp then
     local lines = splitlines(p)
-    local errors = {}
-    for i, err in ipairs(syntaxerrs) do
-      local line, col = lineno(p, err.pos)
-      tinsert(errors, "L" .. line .. ":C" .. col .. ": " .. errmsgs[err.label])
-      tinsert(errors, lines[line])
-      tinsert(errors, rep(" ", col-1) .. "^")
-    end
-    syntaxerrs = {}
-    error("syntax error(s) in pattern\n" .. concat(errors, "\n"), 3)
+    local line, col = lineno(p, #p - #suffix + 1)
+    local err = {}
+    tinsert(err, "L" .. line .. ":C" .. col .. ": " .. errmsgs[label])
+    tinsert(err, lines[line])
+    tinsert(err, rep(" ", col-1) .. "^")
+    error("syntax error(s) in pattern\n" .. concat(err, "\n"), 3)
   end
   return cp
 end
diff --git a/testrelabelparser.lua b/testrelabelparser.lua
index 1c5bb9f..46e01ee 100644
--- a/testrelabelparser.lua
+++ b/testrelabelparser.lua
@@ -199,9 +199,6 @@ testerror([[{ {~ } ~}]], [[
 L1:C5: expected a pattern after '{~'
 { {~ } ~}
     ^
-L1:C10: missing closing '}'
-{ {~ } ~}
-         ^
 ]])
 
 testerror([[{~ ^_^ ~}]], [[
@@ -421,9 +418,6 @@ testerror([[{: group: 'p' :}]], [[
 L1:C9: missing closing ':}'
 {: group: 'p' :}
         ^
-L1:C9: unexpected characters after the pattern
-{: group: 'p' :}
-        ^
 ]])
 
 testerror([[S <- {: 'p'  T <- 'q']], [[
@@ -447,9 +441,6 @@ testerror([['p' {| 'q' / 'r' }]], [[
 L1:C17: missing closing '|}'
 'p' {| 'q' / 'r' }
                 ^
-L1:C18: unexpected characters after the pattern
-'p' {| 'q' / 'r' }
-                 ^
 ]])
 
 -- testing MisClose5
@@ -485,186 +476,49 @@ L1:C12: missing closing '}'
 -- testing MisClose8
 
 testerror([[[]], [[
-L1:C1: missing closing ']'
+L1:C2: missing closing ']'
 [
-^
+ ^
 ]])
 
 testerror([[[^]], [[
-L1:C1: missing closing ']'
+L1:C3: missing closing ']'
 [^
-^
+  ^
 ]])
 
 testerror([[[] ]], [[
-L1:C1: missing closing ']'
+L1:C4: missing closing ']'
 []
-^
+   ^
 ]])
 
 testerror([[[^]         ]], [[
-L1:C1: missing closing ']'
+L1:C6: missing closing ']'
 [^]
-^
+     ^
 ]])
 
 testerror([[[_-___-_|]], [[
-L1:C1: missing closing ']'
+L1:C10: missing closing ']'
 [_-___-_|
-^
+         ^
 ]])
 
 -- testing MisTerm1
 
 testerror([['That is the question...]], [[
-L1:C1: missing terminating single quote
+L1:C25: missing terminating single quote
 'That is the question...
-^
+                        ^
 ]])
 
 -- testing MisTerm2
 
 testerror([[Q <- "To be or not to be...]], [[
-L1:C6: missing terminating double quote
+L1:C28: missing terminating double quote
 Q <- "To be or not to be...
-     ^
-]])
-
--- testing error recovery, more complex grammars (multiline),
--- and pointer positions in error recovery
-
-testerror([[&'p'/&/!/'p'^'q']], [[
-L1:C7: expected a pattern after '&'
-&'p'/&/!/'p'^'q'
-      ^
-L1:C9: expected a pattern after '!'
-&'p'/&/!/'p'^'q'
-        ^
-L1:C14: expected a number after '^', '+' or '-' (no space)
-&'p'/&/!/'p'^'q'
-             ^
-]])
-
-testerror([[
-  A <- 'a' (B 'b'
-  B <- 'x' / !
-  C <- 'c'
-]], [[
-L1:C18: missing closing ')'
-  A <- 'a' (B 'b'
-                 ^
-L2:C15: expected a pattern after '!'
-  B <- 'x' / !
-              ^
-]])
-
-testerror([['a' / &@ ('c' / 'd')]], [[
-L1:C8: expected a pattern after '&'
-'a' / &@ ('c' / 'd')
-       ^
-]])
-
-testerror([['x' / & / 'y']], [[
-L1:C8: expected a pattern after '&'
-'x' / & / 'y'
-       ^
-]])
-
-testerror([[&/'p'/!/'q']], [[
-L1:C2: expected a pattern after '&'
-&/'p'/!/'q'
- ^
-L1:C8: expected a pattern after '!'
-&/'p'/!/'q'
-       ^
-]])
-
-testerror([['p'//'q']], [[
-L1:C5: expected a pattern after '/' or the label(s)
-'p'//'q'
-    ^
-]])
-
-testerror([[
-  S <- 'forgot to close / T
-  T <- 'T' & / 't'
-]], [[
-L1:C8: missing terminating single quote
-  S <- 'forgot to close / T
-       ^
-L2:C13: expected a pattern after '&'
-  T <- 'T' & / 't'
-            ^
-]])
-
-testerror([[
-  S <- [a-z / T
-  T <- 'x' / & / 'y'
-]], [[
-L1:C8: missing closing ']'
-  S <- [a-z / T
-       ^
-L2:C15: expected a pattern after '&'
-  T <- 'x' / & / 'y'
-              ^
-]])
-
-testerror([[
-  S <- ('p' -- comment
-]], [[
-L1:C12: missing closing ')'
-  S <- ('p' -- comment
-           ^
-]])
-
--- an unfortunate second error exists because we don't know
--- what's part of the quotation
-testerror([[
-  X <- ('p / Q (R
-    / S))
-  Q <- 'q'
-  R <- 'r'
-  S <- 's'
-]], [[
-L1:C9: missing terminating single quote
-  X <- ('p / Q (R
-        ^
-L2:C9: unexpected characters after the pattern
-    / S))
-        ^
-]])
-
-testerror([[
-  A <- 'A' /{'lab'} B / !
-
-  B <- %{1, 2 3} 'b' / '6' & / 'B'
-
-  C <- A^B
-]], [[
-L1:C14: expected at least one label after '{'
-  A <- 'A' /{'lab'} B / !
-             ^
-L1:C26: expected a pattern after '!'
-  A <- 'A' /{'lab'} B / !
-                         ^
-L3:C15: missing closing '}'
-  B <- %{1, 2 3} 'b' / '6' & / 'B'
-              ^
-L3:C29: expected a pattern after '&'
-  B <- %{1, 2 3} 'b' / '6' & / 'B'
-                            ^
-L5:C10: expected a number after '^', '+' or '-' (no space)
-  C <- A^B
-         ^
-]])
-
-testerror([['p'/{1/'q'/&]], [[
-L1:C7: missing closing '}'
-'p'/{1/'q'/&
-      ^
-L1:C13: expected a pattern after '&'
-'p'/{1/'q'/&
-            ^
+                           ^
 ]])
 
 -- testing non-syntax errors