improved messages clarity, following suggestions by D. Manura

diff --git a/src/compiler/gg.lua b/src/compiler/gg.lua
index afab9965042afba47315f509078d52a46a15ffc4..67ed3a9598d9045649d42aea098776c1e1693cb7 100644 (file)
--- a/src/compiler/gg.lua
+++ b/src/compiler/gg.lua
@@ -90,11 +90,11 @@ local function raw_parse_sequence (lx, p)
       e=p[i]
       if type(e) == "string" then 
          if not lx:is_keyword (lx:next(), e) then
       e=p[i]
       if type(e) == "string" then 
          if not lx:is_keyword (lx:next(), e) then

-            parse_error (lx, "Keyword '%s' expected", e) end
+            parse_error (lx, "A keyword was expected, probably `%s'.", e) end

       elseif is_parser (e) then
          table.insert (r, e (lx)) 
       else 
       elseif is_parser (e) then
          table.insert (r, e (lx)) 
       else 

-         gg.parse_error (lx,"Sequence `%s': element #%i is not a string "..
+         gg.parse_error (lx,"Sequence `%s': element #%i is neither a string "..

                          "nor a parser: %s", 
                          p.name, i, table.tostring(e))
       end
                          "nor a parser: %s", 
                          p.name, i, table.tostring(e))
       end


@@ -460,7 +460,7 @@ function expr (p)
          -- Check for non-associative operators, and complain if applicable. 
          -----------------------------------------
          elseif p2.assoc=="none" and p2.prec==prec then
          -- Check for non-associative operators, and complain if applicable. 
          -----------------------------------------
          elseif p2.assoc=="none" and p2.prec==prec then

-            parser_error (lx, "non-associative operator!")
+            parse_error (lx, "non-associative operator!")

 
          -----------------------------------------
          -- No infix operator suitable at that precedence
 
          -----------------------------------------
          -- No infix operator suitable at that precedence

diff --git a/src/compiler/metalua.mlua b/src/compiler/metalua.mlua
index 3c3564d0c37b167e47cf329f27cde1ae0ad92d63..203925f3ce851409ec63e3c4ab2ce1d010f6c7e6 100644 (file)
--- a/src/compiler/metalua.mlua
+++ b/src/compiler/metalua.mlua
@@ -70,7 +70,7 @@ Compile and/or execute metalua programs. Parameters passed to the
 compiler should be prefixed with an option flag, hinting what must be
 done with them: take tham as file names to compile, as library names
 to load, as parameters passed to the running program... When option
 compiler should be prefixed with an option flag, hinting what must be
 done with them: take tham as file names to compile, as library names
 to load, as parameters passed to the running program... When option

-flags lack, metalua tries to adopt a "Do What I Mean" approach:
+flags are absent, metalua tries to adopt a "Do What I Mean" approach:

 
 - if no code (no library, no literal expression and no file) is
   specified, the first flag-less parameter is taken as a file name to
 
 - if no code (no library, no literal expression and no file) is
   specified, the first flag-less parameter is taken as a file name to

diff --git a/src/compiler/mlp_expr.lua b/src/compiler/mlp_expr.lua
index 091f92e2c26bf381ec574d2ef5555e0704113a57..a0ded1eaab5d54b19a2a7e705e9d13093a4f30fc 100644 (file)
--- a/src/compiler/mlp_expr.lua
+++ b/src/compiler/mlp_expr.lua
@@ -108,8 +108,16 @@ local _func_val = function (lx) return func_val(lx) end
 function id_or_literal (lx)
    local a = lx:next()
    if a.tag~="Id" and a.tag~="String" and a.tag~="Number" then
 function id_or_literal (lx)
    local a = lx:next()
    if a.tag~="Id" and a.tag~="String" and a.tag~="Number" then

-      gg.parse_error (lx, "Unexpected expr token %s",
-                      _G.table.tostring (a, 'nohash'))
+      local msg
+      if a.tag=='Eof' then
+         msg = "End of file reached when an expression was expected"
+      elseif a.tag=='Keyword' then
+         msg = "An expression was expected, and `"..a[1]..
+            "' can't start an expression"
+      else
+         msg = "Unexpected expr token " .. _G.table.tostring (a, 'nohash')
+      end
+      gg.parse_error (lx, msg)

    end
    return a
 end
    end
    return a
 end

diff --git a/src/compiler/mlp_misc.lua b/src/compiler/mlp_misc.lua
index c09483d47be4d335c238778429d9eee3103ec380..51d180eb632cc25e752e341a2dbb9e7a82b02214 100644 (file)
--- a/src/compiler/mlp_misc.lua
+++ b/src/compiler/mlp_misc.lua
@@ -135,7 +135,7 @@ function id2string (id)
       -- That is, without sugar:
       return {tag="String",  {tag="Index", {tag="Splice", id[1] }, 
                                            {tag="Number", 1 } } }
       -- That is, without sugar:
       return {tag="String",  {tag="Index", {tag="Splice", id[1] }, 
                                            {tag="Number", 1 } } }

-   else error ("Identifier expected: "..table.tostring(id)) end
+   else error ("Identifier expected: ".._G.table.tostring(id)) end

 end
 
 --------------------------------------------------------------------------------
 end
 
 --------------------------------------------------------------------------------

diff --git a/src/compiler/mlp_stat.lua b/src/compiler/mlp_stat.lua
index b959d96551bc3908b46d8c9faf7c1c874a35c451..282954edcb3231748a0d3ed305ea1808355208d0 100644 (file)
--- a/src/compiler/mlp_stat.lua
+++ b/src/compiler/mlp_stat.lua
@@ -169,11 +169,18 @@ local function assign_or_call_stat_parser (lx)
    else 
       assert (#e > 0)
       if #e > 1 then 
    else 
       assert (#e > 0)
       if #e > 1 then 

-         gg.parse_error (lx, "comma is not a valid statement separator") end
+         gg.parse_error (lx, 
+            "comma is not a valid statement separator; statement can be "..
+            "separated by semicolons, or not separated at all") end

       if e[1].tag ~= "Call" and e[1].tag ~= "Invoke" then
       if e[1].tag ~= "Call" and e[1].tag ~= "Invoke" then

-         gg.parse_error (lx, "This expression is of type '%s'; "..
-            "only function and method calls make valid statements", 
-            e[1].tag or "<list>")
+         local typename
+         if e[1].tag == 'Id' then typename = "an identifier"
+         elseif e[1].tag == 'Op' then typename = "an arithmetic operation"
+         else typename = "of type '"..(e[1].tag or "<list>".."'" end
+
+         gg.parse_error (lx, "This expression is " .. typename ..
+            "; only function and method call expressions "..
+            "can be used as statements");

       end
       return e[1]
    end
       end
       return e[1]
    end