Add support for for-loop

The semantics is similar to the C++11 range-based for:

list = 1 2 3
for i: $list
  print $i

Note that there is no scoping of any kind for the loop variable ('i' in
the above example).

See tests/loop/for.test for some examples/ideas.

In the future the plan is to also support more general while-loop as well
as break and continue.

1 files changed, 5 insertions, 1 deletions

diff --git a/build2/test/script/lexer.hxx b/build2/test/script/lexer.hxx
index a262764..5e013b2 100644
--- a/build2/test/script/lexer.hxx
+++ b/build2/test/script/lexer.hxx
@@ -49,7 +49,11 @@ namespace build2
                const path& name,
                lexer_mode m,
                const char* escapes = nullptr)
-            : base_lexer (is, name, nullptr, false)
+            : base_lexer (is,
+                          name,
+                          1       /* line */,
+                          nullptr /* escapes */,
+                          false   /* set_mode */)
         {
           mode (m, '\0', escapes);
         }