From 49fae419a907c364b1ff65f57e1ed4dac804f497 Mon Sep 17 00:00:00 2001
From: chriseth <chris@ethereum.org>
Date: Fri, 28 Oct 2022 16:01:21 +0200
Subject: [PATCH] Fix argument order.

---
 README.md      |  4 ++--
 src/bin/cli.rs | 13 +++++++++----
 2 files changed, 11 insertions(+), 6 deletions(-)

diff --git a/README.md b/README.md
index 1e5db1d..6e03955 100644
--- a/README.md
+++ b/README.md
@@ -35,7 +35,7 @@ and the maximum amount of circles to transfer.
 
 The options are:
 
-`cargo run --release --bin cli <from> <to> [<max_hops> [<max_amount>]] <edges.dat>] [--dot <dotfile>]`
+`cargo run --release --bin cli <from> <to> <edges.dat> [<max_hops> [<max_amount>]] [--dot <dotfile>]`
 
 For example 
 
@@ -43,4 +43,4 @@ For example
 
 Computes a transfer of at most `1000000000000000000`, exploring 3 hops.
 
-If you specify `--dot <dotfile>`, a graphviz/dot representation of the transfer graph is written to the given file.
\ No newline at end of file
+If you specify `--dot <dotfile>`, a graphviz/dot representation of the transfer graph is written to the given file.
diff --git a/src/bin/cli.rs b/src/bin/cli.rs
index ea12f6d..83eeb66 100644
--- a/src/bin/cli.rs
+++ b/src/bin/cli.rs
@@ -23,22 +23,27 @@ fn main() {
 
     if args.len() < 4 {
         println!("Usage: cli <from> <to> <edges.dat> [--dot <dotfile>]");
-        println!("Usage: cli <from> <to> <max_hops> <edges.dat> [--dot <dotfile>]");
-        println!("Usage: cli <from> <to> <max_hops> <max_flow> <edges.dat> [--dot <dotfile>]");
+        println!("Usage: cli <from> <to> <edges.dat> <max_hops>  [--dot <dotfile>]");
+        println!("Usage: cli <from> <to> <edges.dat> <max_hops> <max_flow> [--dot <dotfile>]");
         return;
     }
     let mut max_hops = None;
     let mut max_flow = U256::MAX;
     let (from_str, to_str, edges_file) = (&args[1], &args[2], &args[3]);
     if args.len() >= 5 {
-        max_hops = Some(args[4].parse().unwrap());
+        max_hops = Some(
+            args[4]
+                .parse()
+                .unwrap_or_else(|_| panic!("Expected number of hops, but got: {}", args[4])),
+        );
         if args.len() >= 6 {
             max_flow = args[5].as_str().into();
         }
     }
 
     println!("Computing flow {from_str} -> {to_str} using {edges_file}");
-    let edges = io::read_edges_binary(edges_file).expect("Error loading edges.");
+    let edges = io::read_edges_binary(edges_file)
+        .unwrap_or_else(|_| panic!("Error loading edges from file \"{edges_file}\"."));
     println!("Read {} edges", edges.len());
     let (flow, transfers) = graph::compute_flow(
         &Address::from(from_str.as_str()),