1 files changed, 46 insertions, 0 deletions
diff --git a/EXPRESSIONS b/EXPRESSIONS
new file mode 100644
index 0000000..f1ca6f4
--- /dev/null
+++ b/EXPRESSIONS
@@ -0,0 +1,46 @@
+{ "stage_singleton_field":
+  { "vars": ["fieldname", "transition", "location"]
+  , "expression":
+    { "type": "assert_non_empty"
+    , "msg":
+      ["No artifact specified in field", {"type": "var", "name": "fieldname"}]
+    , "$1":
+      { "type": "disjoint_map_union"
+      , "msg":
+        [ "Expecting (essentially) a single artifact in field"
+        , {"type": "var", "name": "fieldname"}
+        ]
+      , "$1":
+        { "type": "foreach"
+        , "var": "src"
+        , "range":
+          {"type": "FIELD", "name": {"type": "var", "name": "fieldname"}}
+        , "body":
+          { "type": "disjoint_map_union"
+          , "$1":
+            { "type": "foreach"
+            , "var": "artifact"
+            , "range":
+              { "type": "values"
+              , "$1":
+                { "type": "DEP_ARTIFACTS"
+                , "dep": {"type": "var", "name": "src"}
+                , "transition":
+                  { "type": "var"
+                  , "name": "transition"
+                  , "default": {"type": "empty_map"}
+                  }
+                }
+              }
+            , "body":
+              { "type": "singleton_map"
+              , "key": {"type": "var", "name": "location"}
+              , "value": {"type": "var", "name": "artifact"}
+              }
+            }
+          }
+        }
+      }
+    }
+  }
+}