fix most line numbers in errors

this might be a bit of a hack;
i feel like nextc() should always happen after yield(),
not a mix of before and after.

lips/Dumper.lua

@@ -124,7 +124,7 @@ function Dumper:add_directive(line, name, a, b)
 end
 
 function Dumper:desym(tok)
-    -- FIXME: errors can give wrong filename, also off by one
+    -- FIXME: errors can give wrong filename
     if type(tok[2]) == 'number' then
         return tok[2]
     elseif tok[1] == 'LABELSYM' then

lips/Lexer.lua

@@ -154,8 +154,8 @@ function Lexer:lex_hex(yield)
     local entered = false
     while true do
         if self.chr == '\n' then
-            self:nextc()
             yield('EOL', '\n')
+            self:nextc()
         elseif self.ord == self.EOF then
             self:error('unexpected EOF; incomplete hex directive')
         elseif self.chr == ';' then
@@ -206,8 +206,8 @@ end
 function Lexer:lex_block_comment(yield)
     while true do
         if self.chr == '\n' then
-            self:nextc()
             yield('EOL', '\n')
+            self:nextc()
         elseif self.ord == self.EOF then
             self:error('unexpected EOF; incomplete block comment')
         elseif self.chrchr == '*/' then
@@ -230,8 +230,8 @@ function Lexer:lex_string(yield)
     while true do
         if self.chr == '\n' then
             self:error('unimplemented')
-            self:nextc()
             yield('EOL', '\n')
+            self:nextc()
         elseif self.ord == self.EOF then
             self:nextc()
             self:error('unexpected EOF; incomplete string')
@@ -288,8 +288,8 @@ function Lexer:lex(_yield)
     end
     while true do
         if self.chr == '\n' then
-            self:nextc()
             yield('EOL', '\n')
+            self:nextc()
         elseif self.ord == self.EOF then
             yield('EOF', self.EOF)
             break

lips/Parser.lua

@@ -258,10 +258,8 @@ function Parser:instruction()
     local h = data.instructions[name]
     self:advance()
 
-    -- FIXME: errors thrown here probably have the wrong line number (+1)
-
     if h == nil then
-        self:error('undefined instruction')
+        error('Internal Error: undefined instruction')
     elseif overrides[name] then
         overrides[name](self, name)
     elseif h[2] == 'tob' then -- TODO: or h[2] == 'Tob' then