backtrack: rename generically named require

diff --git a/extra/backtrack/backtrack.factor b/extra/backtrack/backtrack.factor
index 27c40b637fcf9026a02bd264b52867725815acdb..2b4c771c9365eab4032d76bfa0516db64bee24c2 100644 (file)
--- a/extra/backtrack/backtrack.factor
+++ b/extra/backtrack/backtrack.factor
@@ -15,7 +15,7 @@ M: amb-failure summary drop "Backtracking failure" ;
 : fail ( -- )\r
     failure get [ continue ] [ amb-failure ] if* ;\r
 \r
-: require ( ? -- )\r
+: must-be-true ( ? -- )\r
     [ fail ] unless ;\r
 \r
 MACRO: checkpoint ( quot -- quot' )\r
@@ -66,7 +66,7 @@ MACRO: amb-execute ( seq -- quot )
 : if-amb ( true false -- ? )\r
     [\r
         [ { t f } amb ]\r
-        [ '[ @ require t ] ]\r
+        [ '[ @ must-be-true t ] ]\r
         [ '[ @ f ] ]\r
         tri* if\r
     ] amb-preserve ; inline\r