Add util.showtree to print internals of expressions

1 files changed, 13 insertions, 0 deletions

diff --git a/mdpoly/util.py b/mdpoly/util.py
index c7f3b51..ae726ef 100644
--- a/mdpoly/util.py
+++ b/mdpoly/util.py
@@ -36,3 +36,16 @@ def iszero(x: float, eps: float =NUMERICS_EPS) -> bool:
 def filtertype(t: type, seq: Iterable):
     """ Filter based on type. """
     yield from filter(lambda x: isinstance(x, t), seq)
+
+
+def showtree(expr):
+    """ Pretty print expression tree. """
+    from PrettyPrint import PrettyPrintTree
+    def getval(x):
+        if x.is_leaf:
+            return str(x)
+        return x.__class__.__qualname__
+
+    PrettyPrintTree(lambda x: x.children(), getval)(expr)
+
+