From d5faeeab1d2115c02a330ac9c95d63ba225faabc Mon Sep 17 00:00:00 2001
From: Boris Kolpackov <boris@codesynthesis.com>
Date: Wed, 10 Jun 2020 10:00:55 +0200
Subject: Handle special variable names in base lexer via mode data

---
 libbuild2/build/script/lexer.cxx | 39 +++++++++------------------------------
 libbuild2/build/script/lexer.hxx |  3 ---
 2 files changed, 9 insertions(+), 33 deletions(-)

(limited to 'libbuild2/build')

diff --git a/libbuild2/build/script/lexer.cxx b/libbuild2/build/script/lexer.cxx
index a58f794..d849ac9 100644
--- a/libbuild2/build/script/lexer.cxx
+++ b/libbuild2/build/script/lexer.cxx
@@ -80,7 +80,15 @@ namespace build2
           }
         default:
           {
-            base_lexer::mode (m, ps, esc);
+            // Recognize special variable names ($>, $<, $~).
+            //
+            if (m == lexer_mode::variable)
+            {
+              assert (data == 0);
+              data = reinterpret_cast<uintptr_t> ("><~");
+            }
+
+            base_lexer::mode (m, ps, esc, data);
             return;
           }
         }
@@ -235,35 +243,6 @@ namespace build2
         unget (c);
         return word (st, sep);
       }
-
-      token lexer::
-      word (state st, bool sep)
-      {
-        lexer_mode m (st.mode);
-
-        // Customized implementation that handles special variable names ($>,
-        // $<, $~).
-        //
-        // @@ TODO: $(<), $(>): feels like this will have to somehow be
-        //          handled at the top-level lexer level. Maybe provide a
-        //          string of one-char special variable names as state::data?
-        //
-        if (m != lexer_mode::variable)
-          return base_lexer::word (st, sep);
-
-        xchar c (peek ());
-
-        if (c != '>' && c != '<' && c != '~')
-          return base_lexer::word (st, sep);
-
-        get ();
-
-        state_.pop (); // Expire the variable mode.
-        return token (string (1, c),
-                      sep,
-                      quote_type::unquoted, false,
-                      c.line, c.column);
-      }
     }
   }
 }
diff --git a/libbuild2/build/script/lexer.hxx b/libbuild2/build/script/lexer.hxx
index 7d919e5..646d3b9 100644
--- a/libbuild2/build/script/lexer.hxx
+++ b/libbuild2/build/script/lexer.hxx
@@ -69,9 +69,6 @@ namespace build2
       private:
         token
         next_line ();
-
-        virtual token
-        word (state, bool) override;
       };
     }
   }
-- 
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