1 files changed, 27 insertions, 0 deletions
diff --git a/api/tables.md b/api/tables.md
index 580488f4..26bfe908 100644
--- a/api/tables.md
+++ b/api/tables.md
@@ -164,3 +164,30 @@ t.set("C", 3)
 = {"A"=1, "B"=2, "C"=3}
 
 ```
+## Table.with_fallback
+
+```tomo
+Table.with_fallback : func(t: {K=V}, fallback: {K=V}? -> {K=V})
+```
+
+Return a copy of a table with a different fallback table.
+
+Argument | Type | Description | Default
+---------|------|-------------|---------
+t | `{K=V}` | The table whose fallback will be replaced.  | -
+fallback | `{K=V}?` | The new fallback table value.  | -
+
+**Return:** The original table with a different fallback.
+
+
+**Example:**
+```tomo
+t := {"A"=1; fallback={"B"=2}}
+t2 = t.with_fallback({"B"=3"})
+>> t2["B"]
+= 3?
+t3 = t.with_fallback(none)
+>> t2["B"]
+= none
+
+```