From 5c00b978b0bc0c1eeb64682cba6aa338fea320bf Mon Sep 17 00:00:00 2001
From: NanoTech
Date: Sun, 11 Dec 2016 23:27:36 -0600
Subject: Start implementing error explanations

---
 src/errors/HandlerNotAFunction.txt | 32 ++++++++++++++++++++++++++++++++
 1 file changed, 32 insertions(+)
 create mode 100644 src/errors/HandlerNotAFunction.txt

(limited to 'src/errors/HandlerNotAFunction.txt')

diff --git a/src/errors/HandlerNotAFunction.txt b/src/errors/HandlerNotAFunction.txt
new file mode 100644
index 0000000..ff87443
--- /dev/null
+++ b/src/errors/HandlerNotAFunction.txt
@@ -0,0 +1,32 @@
+Explanation: You can ❰merge❱ the alternatives of a union using a record with one
+handler per alternative, like this:
+
+
+    ┌─────────────────────────────────────────────────────────────────────┐
+    │     let union    = < Left = +2 | Right : Bool >                     │
+    │ in  let handlers = { Left = Natural/even, Right = λ(x : Bool) → x } │
+    │ in  merge handlers union : Bool                                     │
+    └─────────────────────────────────────────────────────────────────────┘
+
+
+... as long as each handler is a function
+
+For example, the following expression is $_NOT valid:
+
+
+    ┌─────────────────────────────────────────┐
+    │ merge { Foo = True } < Foo = 1 > : Bool │
+    └─────────────────────────────────────────┘
+                    ⇧
+                    Invalid: Not a function
+
+
+Your handler for this alternative:
+
+↳ $txt0
+
+... has the following type:
+
+↳ $txt1
+
+... which is not the type of a function
-- 
cgit v1.2.3