Merge pull request #30 from matagus/taking-rust-knowledge-to-the-next…

…-level-pt2

 Added structs to hold groups and rows, rustfmt config, and modules

README.md

@@ -52,20 +52,20 @@ shelve -c 2 example.csv
 
 Done:
 
-2, Fix bug B, Done, Jane Doe, Low
-6, Write missing documentation for feature A, Done, Peter Foo, Medium
+2, Fix bug B, Jane Doe, Low
+6, Write missing documentation for feature A, Peter Foo, Medium
 
 In Progress:
 
-1, Implement feature A, In Progress, John Doe, High
-3, Write tests for feature A, In Progress, John Doe, Medium
-8, Write tests for feature A, In Progress, John Doe, Low
+1, Implement feature A, John Doe, High
+3, Write tests for feature A, John Doe, Medium
+8, Write tests for feature A, John Doe, Low
 
 To Do:
 
-4, Refactor code, To Do, Jane Doe, High
-5, Deploy to production A and B, To Do, John Doe, Low
-7, Fix bug C, To Do, Alice Bar, High
+4, Refactor code, Jane Doe, High
+5, Deploy to production A and B, John Doe, Low
+7, Fix bug C, Alice Bar, High
 ```
 
 Grouping by the `Priority` column (column number 4):
@@ -75,20 +75,20 @@ shelve -c 4 example.csv
 
 High:
 
-1, Implement feature A, In Progress, John Doe, High
-4, Refactor code, To Do, Jane Doe, High
-7, Fix bug C, To Do, Alice Bar, High
+1, Implement feature A, In Progress, John Doe
+4, Refactor code, To Do, Jane Doe
+7, Fix bug C, To Do, Alice Bar
 
 Low:
 
-2, Fix bug B, Done, Jane Doe, Low
-5, Deploy to production A and B, To Do, John Doe, Low
-8, Write tests for feature A, In Progress, John Doe, Low
+2, Fix bug B, Done, Jane Doe
+5, Deploy to production A and B, To Do, John Doe
+8, Write tests for feature A, In Progress, John Doe
 
 Medium:
 
-3, Write tests for feature A, In Progress, John Doe, Medium
-6, Write missing documentation for feature A, Done, Peter Foo, Medium
+3, Write tests for feature A, In Progress, John Doe
+6, Write missing documentation for feature A, Done, Peter Foo
 ```
 
 Grouping by the `Assignee` column (column number 3):
@@ -98,23 +98,23 @@ shelve -c 3 example.csv
 
 Alice Bar:
 
-7, Fix bug C, To Do, Alice Bar, High
+7, Fix bug C, To Do, High
 
 Jane Doe:
 
-2, Fix bug B, Done, Jane Doe, Low
-4, Refactor code, To Do, Jane Doe, High
+2, Fix bug B, Done, Low
+4, Refactor code, To Do, High
 
 John Doe:
 
-1, Implement feature A, In Progress, John Doe, High
-3, Write tests for feature A, In Progress, John Doe, Medium
-5, Deploy to production A and B, To Do, John Doe, Low
-8, Write tests for feature A, In Progress, John Doe, Low
+1, Implement feature A, In Progress, High
+3, Write tests for feature A, In Progress, Medium
+5, Deploy to production A and B, To Do, Low
+8, Write tests for feature A, In Progress, Low
 
 Peter Foo:
 
-6, Write missing documentation for feature A, Done, Peter Foo, Medium
+6, Write missing documentation for feature A, Done, Medium
 ```
 
 The command can also read input from `stdin`:
@@ -124,20 +124,20 @@ The command can also read input from `stdin`:
 
 High:
 
-1, Implement feature A, In Progress, John Doe, High
-4, Refactor code, To Do, Jane Doe, High
-7, Fix bug C, To Do, Alice Bar, High
+1, Implement feature A, In Progress, John Doe
+4, Refactor code, To Do, Jane Doe
+7, Fix bug C, To Do, Alice Bar
 
 Low:
 
-2, Fix bug B, Done, Jane Doe, Low
-5, Deploy to production A and B, To Do, John Doe, Low
-8, Write tests for feature A, In Progress, John Doe, Low
+2, Fix bug B, Done, Jane Doe
+5, Deploy to production A and B, To Do, John Doe
+8, Write tests for feature A, In Progress, John Doe
 
 Medium:
 
-3, Write tests for feature A, In Progress, John Doe, Medium
-6, Write missing documentation for feature A, Done, Peter Foo, Medium
+3, Write tests for feature A, In Progress, John Doe
+6, Write missing documentation for feature A, Done, Peter Foo
 ```
 
 Or reading multiple files at once:

rustfmt.toml

@@ -0,0 +1,7 @@
+indent_style = "Block"
+reorder_imports = true
+reorder_modules = true
+reorder_impl_items = true
+max_width = 120
+chain_width = 120
+attr_fn_like_width = 100

src/cli.rs

@@ -0,0 +1,11 @@
+use clap::Parser;
+
+#[derive(Parser)]
+#[command(version, about, long_about = None)]
+pub struct Cli {
+    pub filenames: Vec<String>,
+
+    /// Column number to group by
+    #[arg(short, long, default_value = "0")]
+    pub column_number: Option<u8>,
+}

src/groups.rs

@@ -0,0 +1,86 @@
+use std::collections::btree_map::Entry;
+use std::collections::BTreeMap;
+use std::error::Error;
+use std::fs::File;
+
+#[derive(Debug)]
+pub struct Row {
+    data: Vec<String>,
+    index: usize,
+}
+
+impl std::fmt::Display for Row {
+    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+        let mut cloned_data = self.data.clone();
+        cloned_data.remove(self.index);
+        write!(f, "{}", cloned_data.join(", "))
+    }
+}
+
+#[derive(Debug)]
+pub struct GroupedData {
+    groups: BTreeMap<String, Vec<Row>>,
+    index: usize,
+}
+
+impl Row {
+    fn new(data: Vec<String>, index: usize) -> Self {
+        Row { data, index }
+    }
+}
+
+impl GroupedData {
+    fn new(index: usize) -> Self {
+        GroupedData {
+            groups: BTreeMap::new(),
+            index,
+        }
+    }
+
+    fn process<R: std::io::Read>(&mut self, rdr: &mut csv::Reader<R>) -> Result<(), Box<dyn Error>> {
+        for result in rdr.records() {
+            let record = result?;
+            let key = record[self.index].to_string();
+            let row = Row::new(record.iter().map(|s| s.to_string()).collect(), self.index);
+            self.add(&key, row);
+        }
+        Ok(())
+    }
+
+    pub fn from_files(filename_vec: &[String], index: usize) -> Result<Self, Box<dyn Error>> {
+        let mut groups = GroupedData::new(index);
+
+        if filename_vec.is_empty() {
+            let stdin = std::io::stdin().lock();
+            let mut rdr = csv::Reader::from_reader(stdin);
+            groups.process(&mut rdr)?;
+        } else {
+            for filename in filename_vec {
+                // Create a CSV reader
+                let mut rdr = csv::Reader::from_reader(File::open(filename)?);
+                groups.process(&mut rdr)?;
+            }
+        }
+
+        Ok(groups)
+    }
+
+    pub fn add(&mut self, group_name: &str, row: Row) {
+        match self.groups.entry(group_name.to_string()) {
+            Entry::Occupied(mut entry) => {
+                entry.get_mut().push(row);
+            }
+            Entry::Vacant(entry) => {
+                entry.insert(vec![row]);
+            }
+        }
+    }
+
+    pub fn get_groups(&self) -> Vec<&String> {
+        self.groups.keys().collect()
+    }
+
+    pub fn get_rows(&self, group_name: &str) -> Option<&Vec<Row>> {
+        self.groups.get(group_name)
+    }
+}

src/main.rs

@@ -1,20 +1,12 @@
 use clap::Parser;
-use std::collections::btree_map::Entry;
-use std::collections::BTreeMap;
 use std::error::Error;
-use std::fs::File;
 use std::io::{self, Write};
 use std::process;
 
-#[derive(Parser)]
-#[command(version, about, long_about = None)]
-struct Cli {
-    filenames: Vec<String>,
-
-    /// Column number to group by
-    #[arg(short, long, default_value = "0")]
-    column_number: Option<u8>,
-}
+mod groups;
+use groups::GroupedData;
+mod cli;
+use cli::Cli;
 
 fn main() {
     let cli = Cli::parse();
@@ -27,69 +19,8 @@ fn main() {
     }
 }
 
-#[derive(Debug)]
-struct Row {
-    data: Vec<String>,
-}
-
-#[derive(Debug)]
-struct GroupedData {
-    groups: BTreeMap<String, Vec<Row>>,
-}
-
-impl Row {
-    fn new(data: Vec<String>) -> Self {
-        Row { data }
-    }
-
-    fn join_without_col(&self, separator: &str, index: usize) -> String {
-        let mut data = self.data.clone();
-        data.remove(index);
-        data.join(separator)
-    }
-}
-
-impl GroupedData {
-    fn new() -> Self {
-        GroupedData {
-            groups: BTreeMap::new(),
-        }
-    }
-
-    fn add(&mut self, group_name: &str, row: Row) {
-        match self.groups.entry(group_name.to_string()) {
-            Entry::Occupied(mut entry) => {
-                entry.get_mut().push(row);
-            }
-            Entry::Vacant(entry) => {
-                entry.insert(vec![row]);
-            }
-        }
-    }
-
-    fn get_groups(&self) -> Vec<&String> {
-        self.groups.keys().collect()
-    }
-
-    fn get_rows(&self, group_name: &str) -> Option<&Vec<Row>> {
-        self.groups.get(group_name)
-    }
-}
-
 fn run(filename_vec: &[String], index: usize) -> Result<(), Box<dyn Error>> {
-    let mut groups: GroupedData = GroupedData::new();
-
-    if filename_vec.is_empty() {
-        let stdin = std::io::stdin().lock();
-        let mut rdr = csv::Reader::from_reader(stdin);
-        process_reader(&mut rdr, &mut groups, index)?;
-    } else {
-        for filename in filename_vec {
-            // Create a CSV reader
-            let mut rdr = csv::Reader::from_reader(File::open(filename)?);
-            process_reader(&mut rdr, &mut groups, index)?;
-        }
-    }
+    let groups: GroupedData = GroupedData::from_files(filename_vec, index)?;
 
     // Use a BufWriter to improve performance by reducing the number of write calls
     let stdout = io::stdout();
@@ -100,32 +31,11 @@ fn run(filename_vec: &[String], index: usize) -> Result<(), Box<dyn Error>> {
 
         if let Some(rows) = groups.get_rows(group) {
             for row in rows {
-                let display_row = row.join_without_col(", ", index);
-                writeln!(stream, "{}", display_row)?;
+                writeln!(stream, "{}", row)?;
             }
         }
         writeln!(stream)?;
     }
 
     Ok(())
 }
-
-fn process_reader<R: std::io::Read>(
-    rdr: &mut csv::Reader<R>,
-    groups: &mut GroupedData,
-    index: usize,
-) -> Result<(), Box<dyn Error>> {
-    for result in rdr.records() {
-        let record = result?;
-
-        // Check if the column index is within bounds
-        if index >= record.len() {
-            return Err(format!("Column index {} is out of bounds", index).into());
-        }
-
-        let key = record[index].to_string();
-        let row = Row::new(record.iter().map(|s| s.to_string()).collect());
-        groups.add(&key, row);
-    }
-    Ok(())
-}