Improve error messages at evaluation time

1 files changed, 26 insertions, 0 deletions

diff --git a/examples/error_chain.py b/examples/error_chain.py
new file mode 100644
index 0000000..31a75ea
--- /dev/null
+++ b/examples/error_chain.py
@@ -0,0 +1,26 @@
+try:
+    import mdpoly
+except ModuleNotFoundError:
+    import sys
+    import pathlib
+    parent = pathlib.Path(__file__).resolve().parent.parent
+    sys.path.append(str(parent))
+
+from mdpoly import State, Variable, Parameter
+from mdpoly.representations import SparseRepr
+
+def make_invalid_expr(x, y):
+    return x ** (-4)
+
+def make_another_invalid(x, y):
+    return x ** -1
+
+def make_ok_expr(x, y):
+    w = make_invalid_expr(x, y)
+    z = make_another_invalid(x, y)
+    return x + z + y + w
+
+x, y, z = Variable.from_names("x, y, z")
+
+bad = make_ok_expr(x, y)
+bad.to_sparse(State())