* Makefile (%.ok: %.txr): Use unified diff for showing

differences between expected and actual test output.

* parser.l (yybadtoken): Handle new terminal symbol, SPACE.
New rule for producing SPACE token out of an extent of
tabs and spaces.

* parser.y (SPACE): New terminal symbol.
(o_var): New nonterminal.  I noticed that the var rule was
being used for output elements, and the var rule refers to
elem rather than o_elem. A new o_var rule is a simplified
duplicate of var.
(elem): Handle SPACE token. Transform to regex if it is
a single space, otherwise to literal text.
(o_elem): Handle SPACE token in output.

* tests/001/query-2.txr: This query depends on matching
single spaces and so needs to use escapes.

* tests/001/query-4.txr, test/001/query-4.expected: New test
case, based on query-2.txr.  It produces the same output,
but is simpler thanks to the new semantics of space.

* txr.1: Documented.

1 files changed, 1 insertions, 1 deletions

diff --git a/Makefile b/Makefile
index c18fc9ec..fa62e9fb 100644
--- a/Makefile
+++ b/Makefile
@@ -98,7 +98,7 @@ tests/002/%: TXR_SCRIPT_ON_CMDLINE := y
 	  $(PROG) $(TXR_DBG_OPTS) $(TXR_OPTS) -c "$$(cat $^)" \
 	    $(TXR_ARGS) > $(@:.ok=.out),\
 	  $(PROG) $(TXR_DBG_OPTS) $(TXR_OPTS) $^ $(TXR_ARGS) > $(@:.ok=.out))
-	diff $(^:.txr=.expected) $(@:.ok=.out)
+	diff -u $(^:.txr=.expected) $(@:.ok=.out)
 
 %.expected: %.txr
 	$(PROG) $(TXR_OPTS) $^ $(TXR_ARGS) > $@