Clean up lexer mode logic

3 files changed, 4 insertions, 3 deletions

diff --git a/build/lexer b/build/lexer
index 1e5bfd0..e5676cc 100644
--- a/build/lexer
+++ b/build/lexer
@@ -23,7 +23,9 @@ namespace build
   // in the variable mode, we restrict certain character (e.g., /)
   // from appearing in the name. The pairs mode is just like value
   // except that we split names separated by the pair character.
-  // The pairs mode must be set manually.
+  // The alternnative modes must be set manually. The value and
+  // pairs modes are automatically reset after the end of the line.
+  // The variable mode is automatically reset after the name token.
   //
   enum class lexer_mode {normal, value, variable, pairs};
 
diff --git a/build/lexer.cxx b/build/lexer.cxx
index fb4d9ea..88628d3 100644
--- a/build/lexer.cxx
+++ b/build/lexer.cxx
@@ -83,12 +83,10 @@ namespace build
           if (get () != '=')
             fail (c) << "expected = after +";
 
-          next_mode_ = lexer_mode::value;
           return token (token_type::plus_equal, sep, ln, cn);
         }
       case '=':
         {
-          next_mode_ = lexer_mode::value;
           return token (token_type::equal, sep, ln, cn);
         }
       }
diff --git a/build/parser.cxx b/build/parser.cxx
index 6c3e4bc..f140bc7 100644
--- a/build/parser.cxx
+++ b/build/parser.cxx
@@ -637,6 +637,7 @@ namespace build
           ? &scope_->assign (*var)
           : &scope_->append (*var);
         next (t, tt); // Consume =/+=.
+        lexer_->mode (lexer_mode::value);
         next (t, tt);
       }
     }