9_b_1: Add solution

1 files changed, 22 insertions, 0 deletions

diff --git a/ch09/9_b_1.hs b/ch09/9_b_1.hs
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+-- What you should pass to 'traverse' to traverse a directory tree in reverse
+-- alphabetic order?
+
+-- ghci> :l ControlledVisit.hs
+-- [1 of 1] Compiling ControlledVisit  ( ControlledVisit.hs, interpreted )
+-- Ok, one module loaded.
+
+-- Import Data.List module for getting the 'sort' function
+-- ghci> :m +Data.List
+
+-- Output of the following command is manually shortened and formatted for clarity
+-- traverse' (reverse.sort) "test-9_b_1"
+-- ghci> traverse' (reverse.sort) "test-9_b_1"
+-- [Info {infoPath = "test-9_b_1/dirD/H", ...},
+--  Info {infoPath = "test-9_b_1/dirD/G", ...},
+--  Info {infoPath = "test-9_b_1/dirD", ...},
+--  Info {infoPath = "test-9_b_1/dirC/F", ...},
+--  Info {infoPath = "test-9_b_1/dirC/E", ...},
+--  Info {infoPath = "test-9_b_1/dirC", ...},
+--  Info {infoPath = "test-9_b_1/B", ...},
+--  Info {infoPath = "test-9_b_1/A", ...},
+--  Info {infoPath = "test-9_b_1", ...}]