improve help, implement From trait, remove getters

src/csv/args.rs

@@ -3,18 +3,18 @@ use clap::Parser;
 #[derive(Parser, Debug)]
 #[command(author, version, about, long_about = None)]
 pub struct MyArgs {
-    #[arg(name = "source")] // Define the argument without a short or long version
+    #[arg(name = "source", help = "First file of the comparision.")]
     pub source: String,
 
-    #[arg(name = "compare")] // Define the argument without a short or long version
+    #[arg(name = "compare", help = "Second file of the comparision.")]
     pub compare: String,
 
-    #[arg(short, long)]
+    #[arg(short, long, help = "Column which is base of the comparision.")]
     pub column: usize,
 
-    #[arg(short, long)]
+    #[arg(short, long, help = "Optional output filename.")]
     pub output: Option<String>,
 
-    #[arg(short, long, default_value_t = ';'.to_string())]
+    #[arg(short, long, default_value_t = ';'.to_string(), help = "Column separator.")]
     pub delimiter: String,
 }

src/csv/compare.rs

@@ -9,46 +9,27 @@ use super::args::MyArgs;
 
 #[derive(Debug)]
 pub struct Params {
-    delimiter: String,
-    source: String,
-    compared: String,
-    column: usize,
-    output: Option<String>,
+    pub delimiter: String,
+    pub source: String,
+    pub compared: String,
+    pub column: usize,
+    pub output: Option<String>,
 }
 
-impl Params {
-    pub fn new_from_matches(matches: MyArgs) -> Self {
-        Self {
+impl From<MyArgs> for Params {
+
+    fn from(matches: MyArgs) -> Self {
+        Params {
             delimiter: matches.delimiter,
             source: matches.source,
             compared: matches.compare,
             column: matches.column,
             output: {
                 let this = matches.output;
-                this.map(|x| x.to_string())
+                this.map(|x| ToString::to_string(&x))
             },
         }
     }
-
-    pub fn delimiter(&self) -> &String {
-        &self.delimiter
-    }
-
-    pub fn source(&self) -> &String {
-        &self.source
-    }
-
-    pub fn compared(&self) -> &String {
-        &self.compared
-    }
-
-    pub fn column(&self) -> usize {
-        self.column
-    }
-
-    pub fn output_mut(&mut self) -> &Option<String> {
-        &self.output
-    }
 }
 
 pub struct CsvLine {
@@ -88,7 +69,11 @@ pub fn write_to_file(filename: String, diff: Vec<CsvLine>) {
     }
 }
 
-pub fn compare(reader: BufReader<File>, reader2: BufReader<File>, params: &Params) -> Vec<CsvLine> {
+pub fn compare(
+    reader: BufReader<File>,
+    reader2: BufReader<File>,
+    params: &Params,
+) -> Result<Vec<CsvLine>, String> {
     let vec1: Vec<CsvLine> = reader
         .lines()
         .map(|line| {
@@ -105,8 +90,8 @@ pub fn compare(reader: BufReader<File>, reader2: BufReader<File>, params: &Param
         })
         .collect();
 
-    let mut diff1: Vec<CsvLine> = find_diff(&vec1, &vec2, params);
-    let mut diff2: Vec<CsvLine> = find_diff(&vec2, &vec1, params);
+    let mut diff1: Vec<CsvLine> = find_diff(&vec1, &vec2, params)?;
+    let mut diff2: Vec<CsvLine> = find_diff(&vec2, &vec1, params)?;
 
     if params.output.is_none() {
         print_lines(&diff1, &diff2, params);
@@ -114,19 +99,22 @@ pub fn compare(reader: BufReader<File>, reader2: BufReader<File>, params: &Param
 
     diff1.append(&mut diff2);
 
-    diff1
+    Ok(diff1)
 }
 
-fn find_diff(vec1: &[CsvLine], vec2: &[CsvLine], params: &Params) -> Vec<CsvLine> {
+fn find_diff(vec1: &[CsvLine], vec2: &[CsvLine], params: &Params) -> Result<Vec<CsvLine>, String> {
     let mut diff: Vec<CsvLine> = Vec::new();
     for i in vec1.iter() {
-        let splitter: Vec<&str> = i.line.split(params.delimiter()).collect();
-        let value = splitter[params.column];
+        let splitter: Vec<&str> = i.line.split(&params.delimiter).collect();
+        if splitter.len() <= params.column {
+            return Err("Column out of bound".to_string());
+        }
+        let value: &str = splitter[params.column];
 
         let found = !matches!(
             vec2.iter().position(|r| {
-                let splitter_b: Vec<&str> = r.line.split(params.delimiter()).collect();
-                let search = splitter_b[params.column()];
+                let splitter_b: Vec<&str> = r.line.split(&params.delimiter).collect();
+                let search = splitter_b[params.column];
                 search == value
             }),
             None
@@ -137,7 +125,7 @@ fn find_diff(vec1: &[CsvLine], vec2: &[CsvLine], params: &Params) -> Vec<CsvLine
         }
     }
 
-    diff
+    Ok(diff)
 }
 
 #[cfg(test)]
@@ -167,7 +155,7 @@ mod test {
             column: 1,
             output: Some("./assets/result.csv".to_owned()),
         };
-        let result: Vec<CsvLine> = compare(file1, file2, &params);
+        let result: Vec<CsvLine> = compare(file1, file2, &params).unwrap();
         assert_eq!(3, result.len());
     }
 }

src/main.rs

@@ -8,24 +8,44 @@ use csv::compare;
 use crate::csv::args::MyArgs;
 use crate::csv::compare::{write_to_file, Params};
 
-/// # Panics
-///
-/// Panics if delimter is set wrong and column to compare
-/// is not available.
 fn main() {
     let args = MyArgs::parse();
 
-    let mut params = Params::new_from_matches(args);
+    let params: Params = Params::from(args);
 
-    let file = File::open(params.source()).expect("Can't find source file");
-    let file2 = File::open(params.compared()).expect("Cant't find compared file");
+    let file: File = {
+        let this = File::open(&params.source);
+        match this {
+            Ok(file) => file,
+            Err(e) => {
+                eprintln!("Can't find source file: {}", e);
+                return;
+            }
+        }
+    };
+    let file2 = {
+        let this = File::open(&params.compared);
+        match this {
+            Ok(file) => file,
+            Err(e) => {
+                eprintln!("Cant't find compared file: {}", e);
+                return;
+            }
+        }
+    };
 
-    let reader = BufReader::new(file);
-    let reader2 = BufReader::new(file2);
+    let reader: BufReader<File> = BufReader::new(file);
+    let reader2: BufReader<File> = BufReader::new(file2);
 
-    let diff = compare::compare(reader, reader2, &params);
+    let diff: Vec<compare::CsvLine> = match compare::compare(reader, reader2, &params) {
+        Ok(d) => d,
+        Err(e) => {
+            eprintln!("{e}");
+            return;
+        }
+    };
 
-    let option_string_ref = params.output_mut();
+    let option_string_ref: Option<String> = params.output;
     if let Some(string_ref) = option_string_ref {
         write_to_file(string_ref.clone(), diff);
     }