Add a macro for checking hexadecimal number

Author: kakao-jun-e

README.md

@@ -19,9 +19,9 @@ codechain-cuckoo-miner [OPTIONS]
 ```
 
 ### Usage Examples
-* N=16, M=8, L=6, listening on port **3333**, submitting on port **8080**, **1** concurrent jobs :
+* N=0x10, M=0x8, L=6, listening on port **3333**, submitting on port **8080**, **1** concurrent jobs :
 ```
-codechain-cuckoo-miner -n 16 -m 8 -l 6 -p 3333 -s 8080 -j 1
+codechain-cuckoo-miner -n 0x10 -m 0x8 -l 6 -p 3333 -s 8080 -j 1
 ```
 
 ## Configuration

src/main.rs

@@ -34,14 +34,25 @@ use codechain_miner::run;
 
 use self::config::CuckooConfig;
 
+macro_rules! hex_value_t {
+    ($m:ident, $v:expr) => {{
+        let val = value_t!($m, $v, String).map_err(|_| format!("Invalid value"))?;
+        if val.len() > 2 && &val[0..2] == "0x" {
+            usize::from_str_radix(&val[2..], 16).map_err(|_| format!("'{}' isn't parsed", val))
+        } else {
+            Err(format!("'{}' isn't a hexadecimal number", val))
+        }
+    }};
+}
+
 fn get_options() -> Result<CuckooConfig, String> {
     let yaml = load_yaml!("./cli.yml");
     let matches = clap::App::from_yaml(yaml).get_matches();
 
     let listening_port = value_t!(matches, "listening port", u16).map_err(|_| "Invalid listening port")?;
     let submitting_port = value_t!(matches, "submitting port", u16).map_err(|_| "Invalid submitting port")?;
-    let max_vertex = value_t!(matches, "max vertex", usize).map_err(|_| "Invalid max vertex")?;
-    let max_edge = value_t!(matches, "max edge", usize).map_err(|_| "Invalid max edge")?;
+    let max_vertex = hex_value_t!(matches, "max vertex").map_err(|e| format!("Invalid max vertex: {}", e))?;
+    let max_edge = hex_value_t!(matches, "max edge").map_err(|e| format!("Invalid max edge: {}", e))?;
     let cycle_length = value_t!(matches, "cycle length", usize).map_err(|_| "Invalid cycle length")?;
     let concurrent_jobs = value_t!(matches, "concurrent jobs", u16).map_err(|_| "Invalid concurrent jobs")?;