Added Set infix operations, as well as Table.with_fallback() and fixed

some bugs with update assignment.

2 files changed, 47 insertions, 1 deletions

diff --git a/api/sets.yaml b/api/sets.yaml
index 6bf0d8cc..08111932 100644
--- a/api/sets.yaml
+++ b/api/sets.yaml
@@ -229,4 +229,25 @@ Set.without:
   example: |
     >> |1, 2|.without(|2, 3|)
     = |1|
-    
+
+Table.xor:
+  short: symmetric difference
+  description: >
+    Return set with the elements in one, but not both of the arguments. This is
+    also known as the symmetric difference or disjunctive union.
+  return:
+    type: '|T|'
+    description: >
+      A set with the symmetric difference of the arguments.
+  args:
+    a:
+      type: '|T|'
+      description: >
+        The first set.
+    b:
+      type: '|T|'
+      description: >
+        The second set.
+  example: |
+    >> |1, 2, 3|.xor(|2, 3, 4|)
+    = |1, 4|
diff --git a/api/tables.yaml b/api/tables.yaml
index 6a58e818..f3b648da 100644
--- a/api/tables.yaml
+++ b/api/tables.yaml
@@ -160,3 +160,28 @@ Table.set:
     >> t
     = {"A"=1, "B"=2, "C"=3}
     
+Table.with_fallback:
+  short: return a table with a new fallback
+  description: >
+    Return a copy of a table with a different fallback table.
+  return:
+    type: '{K=V}'
+    description: >
+      The original table with a different fallback.
+  args:
+    t:
+      type: '{K=V}'
+      description: >
+        The table whose fallback will be replaced.
+    fallback:
+      type: '{K=V}?'
+      description: >
+        The new fallback table value.
+  example: |
+    t := {"A"=1; fallback={"B"=2}}
+    t2 = t.with_fallback({"B"=3"})
+    >> t2["B"]
+    = 3?
+    t3 = t.with_fallback(none)
+    >> t2["B"]
+    = none