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Курс във Факултета по Математика и Информатика към СУ

Решение на CSV Filter от Тодор Димов

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Резултати

  • 15 точки от тестове
  • 0 бонус точки
  • 15 точки общо
  • 15 успешни тест(а)
  • 0 неуспешни тест(а)

Код

pub fn skip_next(input: &str, target: char) -> Option<&str> {
let mut chars = input.chars();
// can't use contains....
match chars.next() {
Some( first ) if first == target => Some( chars.as_str() ),
_ => None,
}
}
pub fn take_until(input: &str, target: char) -> (&str, &str) {
input.split_at( input.find( target ).unwrap_or( input.len() ) )
}
pub fn take_and_skip(input: &str, target: char) -> Option<(&str, &str)> {
let split = take_until( input, target );
skip_next( split.1, target ).map( |s| ( split.0, s ) )
}
#[derive(Debug)]
pub enum CsvError {
IO(std::io::Error),
ParseError(String),
InvalidHeader(String),
InvalidRow(String),
InvalidColumn(String),
}
impl From<std::io::Error> for CsvError {
fn from(error: std::io::Error) -> Self {
CsvError::IO( error )
}
}
use std::collections::HashMap;
type Row = HashMap<String, String>;
use std::io::BufRead;
pub struct Csv<R: BufRead> {
pub columns: Vec<String>,
reader: R,
selection: Option<Box<dyn Fn(&Row) -> Result<bool, CsvError>>>,
}
use std::io::Write;
impl<R: BufRead> Csv<R> {
fn get_columns(header: &str) -> Vec<String>
{
header.split(',').map( |s| s.trim().to_string() ).collect()
}
pub fn new(mut reader: R) -> Result<Self, CsvError> {
let mut header = String::new();
if reader.read_line( &mut header )? == 0
{
return Err( CsvError::InvalidHeader( "Empty file!".to_string() ) );
}
let columns = Self::get_columns( &header );
let mut columns_copy = columns.clone();
columns_copy.sort();
columns_copy.dedup();
if columns_copy.len() != columns.len()
{
return Err( CsvError::InvalidHeader( "Duplicate column names!".to_string() ) );
}
Ok( Self{ columns, reader, selection: None } )
}
pub fn parse_line(&mut self, line: &str) -> Result<Row, CsvError> {
let mut result: Row = Row::new();
let mut line_comps: ( &str, &str ) = ( "", line.trim() );
for column in &self.columns
{
// can't destructure...
line_comps = skip_next( line_comps.1, '"' ).and_then( |s| take_and_skip( s, '"' ) ).ok_or( CsvError::InvalidRow( "Invalid line!".to_string() ) )?;
result.insert( column.clone(), line_comps.0.to_string() );
line_comps.1 = take_until( line_comps.1, '"' ).1;
}
if line_comps.1.len() == 0
{
Ok( result )
}
else
{
Err( CsvError::InvalidRow( format!( "Line [{}] has too many values!", line ) ) )
}
}
pub fn apply_selection<F>(&mut self, callback: F)
where F: Fn(&Row) -> Result<bool, CsvError> + 'static
{
self.selection = Some( Box::new( callback ) )
}
pub fn write_to<W: Write>(mut self, mut writer: W) -> Result<(), CsvError> {
writer.write_fmt( format_args!( "{}\n", self.columns.join( ", " ) ) )?;
while let Some( result ) = self.next()
{
let row = result?;
writer.write_fmt( format_args!( "{}\n", &self.columns.iter().map( |c| format!( "\"{}\"", row[ c ] ) ).collect::<Vec<_>>().join( ", " ) ) )?;
}
Ok( () )
}
}
impl<R: BufRead> Iterator for Csv<R> {
type Item = Result<Row, CsvError>;
fn next(&mut self) -> Option<Self::Item> {
let mut line: String = String::new();
match self.reader.read_line( &mut line )
{
Ok( bytes ) if bytes == 0 => None,
Ok( _ ) =>
match self.parse_line( &line )
{
Ok( row ) =>
match &self.selection
{
Some( pred ) =>
match pred( &row )
{
Ok( false ) => self.next(),
Ok( true ) => Some ( Ok( row ) ),
Err( error ) => Some( Err( error ) ),
},
None => Some( Ok( row ) )
},
error => Some( error ),
},
Err( error ) => Some( Err( CsvError::IO( error ) ) ),
}
}
}

Лог от изпълнението

Compiling solution v0.1.0 (/tmp/d20210111-1538662-13dsk9j/solution)
    Finished test [unoptimized + debuginfo] target(s) in 4.19s
     Running target/debug/deps/solution_test-8916805fc40a2dab

running 15 tests
test solution_test::test_csv_basic ... ok
test solution_test::test_csv_duplicate_columns ... ok
test solution_test::test_csv_empty ... ok
test solution_test::test_csv_iterating_with_a_selection ... ok
test solution_test::test_csv_iterating_with_no_selection ... ok
test solution_test::test_csv_parse_line ... ok
test solution_test::test_csv_parse_line_with_commas ... ok
test solution_test::test_csv_selection_and_writing ... ok
test solution_test::test_csv_single_column_no_data ... ok
test solution_test::test_csv_writing_without_a_selection ... ok
test solution_test::test_csv_writing_without_any_rows ... ok
test solution_test::test_parsing_helpers_for_unicode ... ok
test solution_test::test_skip_next ... ok
test solution_test::test_take_and_skip ... ok
test solution_test::test_take_until ... ok

test result: ok. 15 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out

История (4 версии и 0 коментара)

Тодор качи първо решение на 11.01.2021 02:26 (преди над 4 години)

Тодор качи решение на 11.01.2021 14:12 (преди над 4 години)

pub fn skip_next(input: &str, target: char) -> Option<&str> {
let mut chars = input.chars();
// can't use contains....
match chars.next() {
Some( first ) if first == target => Some( chars.as_str() ),
_ => None,
}
}
pub fn take_until(input: &str, target: char) -> (&str, &str) {
input.split_at( input.find( target ).unwrap_or( input.len() ) )
}
pub fn take_and_skip(input: &str, target: char) -> Option<(&str, &str)> {
let split = take_until( input, target );
skip_next( split.1, target ).map( |s| ( split.0, s ) )
}
#[derive(Debug)]
pub enum CsvError {
IO(std::io::Error),
ParseError(String),
InvalidHeader(String),
InvalidRow(String),
InvalidColumn(String),
}
impl From<std::io::Error> for CsvError {
fn from(error: std::io::Error) -> Self {
CsvError::IO( error )
}
}
use std::collections::HashMap;
type Row = HashMap<String, String>;
use std::io::BufRead;
pub struct Csv<R: BufRead> {
pub columns: Vec<String>,
reader: R,
selection: Option<Box<dyn Fn(&Row) -> Result<bool, CsvError>>>,
}
use std::io::Write;
impl<R: BufRead> Csv<R> {
fn get_columns(header: &str) -> Vec<String>
{
header.split(',').map( |s| s.trim().to_string() ).collect()
}
pub fn new(mut reader: R) -> Result<Self, CsvError> {
let mut header = String::new();
if reader.read_line( &mut header )? == 0
{
return Err( CsvError::InvalidHeader( "Empty file!".to_string() ) );
}
let columns = Self::get_columns( &header );
let mut columns_copy = columns.clone();
columns_copy.sort();
columns_copy.dedup();
if columns_copy.len() != columns.len()
{
return Err( CsvError::InvalidHeader( "Duplicate column names!".to_string() ) );
}
Ok( Self{ columns, reader, selection: None } )
}
pub fn parse_line(&mut self, line: &str) -> Result<Row, CsvError> {
let mut result: Row = Row::new();
let mut line_comps: ( &str, &str ) = ( "", line.trim() );
for column in &self.columns
{
// can't destructure...
line_comps = skip_next( line_comps.1, '"' ).and_then( |s| take_and_skip( s, '"' ) ).ok_or( CsvError::InvalidRow( "Invalid line!".to_string() ) )?;
result.insert( column.clone(), line_comps.0.to_string() );
line_comps.1 = take_until( line_comps.1, '"' ).1;
}
if line_comps.1.len() == 0
{
Ok( result )
}
else
{
- Err( CsvError::InvalidRow( "Line has too many values!".to_string() ) )
+ Err( CsvError::InvalidRow( format!( "Line [{}] has too many values!", line ) ) )
}
}
pub fn apply_selection<F>(&mut self, callback: F)
where F: Fn(&Row) -> Result<bool, CsvError> + 'static
{
self.selection = Some( Box::new( callback ) )
}
pub fn write_to<W: Write>(mut self, mut writer: W) -> Result<(), CsvError> {
- writer.write( self.columns.join( ", " ).as_bytes() )?;
+ writer.write_fmt( format_args!( "{}\n", self.columns.join( ", " ) ) )?;
let mut line: String = String::new();
while self.reader.read_line( &mut line )? > 0
{
let row = self.parse_line( &line )?;
+ line.clear();
match &self.selection
{
Some( boxed ) if !boxed( &row )? => 0,
- _ => writer.write( &self.columns.iter().map( |c| row.get( c ).unwrap().clone() ).collect::<Vec<String>>().join( ", " ).as_bytes() )?,
+ _ =>
+ {
+ writer.write( &self.columns.iter().map( |c| row.get( c ).unwrap().clone() ).collect::<Vec<String>>().join( ", " ).as_bytes() )?;
+ writer.write( "\n".as_bytes() )?
+ },
};
}
Ok( () )
}
}
impl<R: BufRead> Iterator for Csv<R> {
type Item = Result<Row, CsvError>;
fn next(&mut self) -> Option<Self::Item> {
- todo!()
+ let mut line: String = String::new();
+
+ match self.reader.read_line( &mut line )
+ {
+ Ok( bytes ) if bytes == 0 => None,
+ Ok( _ ) =>
+ match self.parse_line( &line )
+ {
+ Ok( row ) =>
+ {
+ match &self.selection
+ {
+ Some( pred ) =>
+ {
+ match pred( &row )
+ {
+ Ok( false ) => self.next(),
+ Ok( true ) => Some ( Ok( row ) ),
+ Err( error ) => Some( Err( error ) ),
+ }
+ },
+ None => Some( Ok( row ) )
+ }
+ },
+ error => Some( error ),
+ },
+ Err( error ) => Some( Err( CsvError::IO( error ) ) ),
+ }
}
}
#[test]
pub fn test_skip_next()
{
assert_eq!(skip_next("ьала", 'ь'), Some("ала"));
assert_eq!(skip_next("ьала", 'ѝ'), None);
assert_eq!(skip_next("", 'ѝ'), None);
}
#[test]
pub fn test_take_untill()
{
assert_eq!(take_until(" алаѝбала ", 'ѝ'), (" ала", "ѝбала "));
assert_eq!(take_until("алабала", 'ѝ'), ("алабала", ""));
}
#[test]
pub fn test_take_and_skip()
{
assert_eq!(take_and_skip(" алаѝбала ", 'ѝ'), Some((" ала", "бала ")));
assert_eq!(take_and_skip("алабала", 'ѝ'), None);
}
macro_rules! assert_match {
($expr:expr, $pat:pat) => {
if let $pat = $expr {
// all good
} else {
assert!(false, "Expression {:?} does not match the pattern {:?}", $expr, stringify!($pat));
}
}
}
#[test]
pub fn test_new()
{
let data = r#"
name, age, birth date, age
"#.trim().as_bytes();
assert_match!(Csv::new(BufReader::new(data)).err(), Some(CsvError::InvalidHeader(_)));
let data = r#"
"#.trim().as_bytes();
assert_match!(Csv::new(BufReader::new(data)).err(), Some(CsvError::InvalidHeader(_)));
let data = r#""#.trim().as_bytes();
assert_match!(Csv::new(BufReader::new(data)).err(), Some(CsvError::InvalidHeader(_)));
}
#[test]
pub fn test_parse_line()
{
let data = r#"
name, age, birth date
"#.trim().as_bytes();
let mut csv = Csv::new(BufReader::new(data)).unwrap();
let data = r#"
"Douglas Adams", "42"
"#.trim();
assert_match!(csv.parse_line(data).err(), Some(CsvError::InvalidRow(_)));
let data = r#"
"Douglas Adams", "42", "1952-03-11", "1952-03-11"
"#.trim();
assert_match!(csv.parse_line(data).err(), Some(CsvError::InvalidRow(_)));
let data = r#"
"Douglas, Adams", "42", "1952-03-11"
"#.trim();
assert_match!(csv.parse_line(data).err(), None);
}
use std::io::BufReader;
pub fn main()
{
-let reader = BufReader::new(r#"
- name, age, birth date
- "Douglas Adams", "42", "1952-03-11"
- "Gen Z. Person", "20", "2000-01-01"
- "Ada Lovelace", "36", "1815-12-10"
-"#.trim().as_bytes());
-
- println!("{:?}", Csv::new(reader).unwrap().columns);
+ let reader = BufReader::new(r#"
+ name, age ,birth date
+ "Douglas Adams","42","1952-03-11"
+ "Gen Z. Person", "20" , "2000-01-01"
+ "Gen Z. Person, the 2nd", "20" , "2000-01-01"
+ "Ada Lovelace","36","1815-12-10"
+ "#.trim().as_bytes());
+
+ let mut csv = Csv::new(reader).unwrap();
+ csv.apply_selection(|row| {
+ Ok(row["age"].parse::<u32>().unwrap() < 40)
+ });
+
+ let mut output = Vec::new();
+ csv.write_to(&mut output).unwrap();
+
+ println!("{}", String::from_utf8(output).unwrap());
+ // name, age, birth date
+ // "Gen Z. Person", "20", "2000-01-01"
+ // "Ada Lovelace", "36", "1815-12-10"
}
-
-
-
-
-
-
-
-

Тодор качи решение на 11.01.2021 14:44 (преди над 4 години)

pub fn skip_next(input: &str, target: char) -> Option<&str> {
let mut chars = input.chars();
// can't use contains....
match chars.next() {
Some( first ) if first == target => Some( chars.as_str() ),
_ => None,
}
}
pub fn take_until(input: &str, target: char) -> (&str, &str) {
input.split_at( input.find( target ).unwrap_or( input.len() ) )
}
pub fn take_and_skip(input: &str, target: char) -> Option<(&str, &str)> {
let split = take_until( input, target );
skip_next( split.1, target ).map( |s| ( split.0, s ) )
}
#[derive(Debug)]
pub enum CsvError {
IO(std::io::Error),
ParseError(String),
InvalidHeader(String),
InvalidRow(String),
InvalidColumn(String),
}
impl From<std::io::Error> for CsvError {
fn from(error: std::io::Error) -> Self {
CsvError::IO( error )
}
}
use std::collections::HashMap;
type Row = HashMap<String, String>;
use std::io::BufRead;
pub struct Csv<R: BufRead> {
pub columns: Vec<String>,
reader: R,
selection: Option<Box<dyn Fn(&Row) -> Result<bool, CsvError>>>,
}
use std::io::Write;
impl<R: BufRead> Csv<R> {
fn get_columns(header: &str) -> Vec<String>
{
header.split(',').map( |s| s.trim().to_string() ).collect()
}
pub fn new(mut reader: R) -> Result<Self, CsvError> {
let mut header = String::new();
if reader.read_line( &mut header )? == 0
{
return Err( CsvError::InvalidHeader( "Empty file!".to_string() ) );
}
let columns = Self::get_columns( &header );
let mut columns_copy = columns.clone();
columns_copy.sort();
columns_copy.dedup();
if columns_copy.len() != columns.len()
{
return Err( CsvError::InvalidHeader( "Duplicate column names!".to_string() ) );
}
Ok( Self{ columns, reader, selection: None } )
}
pub fn parse_line(&mut self, line: &str) -> Result<Row, CsvError> {
let mut result: Row = Row::new();
let mut line_comps: ( &str, &str ) = ( "", line.trim() );
for column in &self.columns
{
// can't destructure...
line_comps = skip_next( line_comps.1, '"' ).and_then( |s| take_and_skip( s, '"' ) ).ok_or( CsvError::InvalidRow( "Invalid line!".to_string() ) )?;
result.insert( column.clone(), line_comps.0.to_string() );
line_comps.1 = take_until( line_comps.1, '"' ).1;
}
if line_comps.1.len() == 0
{
Ok( result )
}
else
{
Err( CsvError::InvalidRow( format!( "Line [{}] has too many values!", line ) ) )
}
}
pub fn apply_selection<F>(&mut self, callback: F)
where F: Fn(&Row) -> Result<bool, CsvError> + 'static
{
self.selection = Some( Box::new( callback ) )
}
pub fn write_to<W: Write>(mut self, mut writer: W) -> Result<(), CsvError> {
writer.write_fmt( format_args!( "{}\n", self.columns.join( ", " ) ) )?;
- let mut line: String = String::new();
- while self.reader.read_line( &mut line )? > 0
+ while let Some( result ) = self.next()
{
- let row = self.parse_line( &line )?;
- line.clear();
- match &self.selection
- {
- Some( boxed ) if !boxed( &row )? => 0,
- _ =>
- {
- writer.write( &self.columns.iter().map( |c| row.get( c ).unwrap().clone() ).collect::<Vec<String>>().join( ", " ).as_bytes() )?;
- writer.write( "\n".as_bytes() )?
- },
- };
+ let row = result?;
+ writer.write_fmt( format_args!( "{}\n", &self.columns.iter().map( |c| "\"".to_owned() + &row.get( c ).unwrap() + "\"" ).collect::<Vec<String>>().join( ", " ) ) )?;
}
Ok( () )
}
}
impl<R: BufRead> Iterator for Csv<R> {
type Item = Result<Row, CsvError>;
fn next(&mut self) -> Option<Self::Item> {
let mut line: String = String::new();
match self.reader.read_line( &mut line )
{
Ok( bytes ) if bytes == 0 => None,
Ok( _ ) =>
match self.parse_line( &line )
{
Ok( row ) =>
{
match &self.selection
{
Some( pred ) =>
{
match pred( &row )
{
Ok( false ) => self.next(),
Ok( true ) => Some ( Ok( row ) ),
Err( error ) => Some( Err( error ) ),
}
},
None => Some( Ok( row ) )
}
},
error => Some( error ),
},
Err( error ) => Some( Err( CsvError::IO( error ) ) ),
}
}
-}
-
+}
-#[test]
-pub fn test_skip_next()
-{
- assert_eq!(skip_next("ьала", 'ь'), Some("ала"));
- assert_eq!(skip_next("ьала", 'ѝ'), None);
- assert_eq!(skip_next("", 'ѝ'), None);
-}
-
-#[test]
-pub fn test_take_untill()
-{
- assert_eq!(take_until(" алаѝбала ", 'ѝ'), (" ала", "ѝбала "));
- assert_eq!(take_until("алабала", 'ѝ'), ("алабала", ""));
-}
-
-#[test]
-pub fn test_take_and_skip()
-{
- assert_eq!(take_and_skip(" алаѝбала ", 'ѝ'), Some((" ала", "бала ")));
- assert_eq!(take_and_skip("алабала", 'ѝ'), None);
-}
-
-macro_rules! assert_match {
- ($expr:expr, $pat:pat) => {
- if let $pat = $expr {
- // all good
- } else {
- assert!(false, "Expression {:?} does not match the pattern {:?}", $expr, stringify!($pat));
- }
- }
-}
-
-#[test]
-pub fn test_new()
-{
- let data = r#"
- name, age, birth date, age
-"#.trim().as_bytes();
- assert_match!(Csv::new(BufReader::new(data)).err(), Some(CsvError::InvalidHeader(_)));
-
- let data = r#"
-"#.trim().as_bytes();
- assert_match!(Csv::new(BufReader::new(data)).err(), Some(CsvError::InvalidHeader(_)));
-
- let data = r#""#.trim().as_bytes();
- assert_match!(Csv::new(BufReader::new(data)).err(), Some(CsvError::InvalidHeader(_)));
-}
-
-#[test]
-pub fn test_parse_line()
-{
- let data = r#"
- name, age, birth date
-"#.trim().as_bytes();
- let mut csv = Csv::new(BufReader::new(data)).unwrap();
-
- let data = r#"
- "Douglas Adams", "42"
-"#.trim();
- assert_match!(csv.parse_line(data).err(), Some(CsvError::InvalidRow(_)));
-
- let data = r#"
- "Douglas Adams", "42", "1952-03-11", "1952-03-11"
-"#.trim();
- assert_match!(csv.parse_line(data).err(), Some(CsvError::InvalidRow(_)));
-
- let data = r#"
- "Douglas, Adams", "42", "1952-03-11"
-"#.trim();
- assert_match!(csv.parse_line(data).err(), None);
-}
-
-use std::io::BufReader;
-
-pub fn main()
-{
- let reader = BufReader::new(r#"
- name, age ,birth date
- "Douglas Adams","42","1952-03-11"
- "Gen Z. Person", "20" , "2000-01-01"
- "Gen Z. Person, the 2nd", "20" , "2000-01-01"
- "Ada Lovelace","36","1815-12-10"
- "#.trim().as_bytes());
-
- let mut csv = Csv::new(reader).unwrap();
- csv.apply_selection(|row| {
- Ok(row["age"].parse::<u32>().unwrap() < 40)
- });
-
- let mut output = Vec::new();
- csv.write_to(&mut output).unwrap();
-
- println!("{}", String::from_utf8(output).unwrap());
- // name, age, birth date
- // "Gen Z. Person", "20", "2000-01-01"
- // "Ada Lovelace", "36", "1815-12-10"
-}
-

Тодор качи решение на 11.01.2021 15:12 (преди над 4 години)

pub fn skip_next(input: &str, target: char) -> Option<&str> {
let mut chars = input.chars();
// can't use contains....
match chars.next() {
Some( first ) if first == target => Some( chars.as_str() ),
_ => None,
}
}
pub fn take_until(input: &str, target: char) -> (&str, &str) {
input.split_at( input.find( target ).unwrap_or( input.len() ) )
}
pub fn take_and_skip(input: &str, target: char) -> Option<(&str, &str)> {
let split = take_until( input, target );
skip_next( split.1, target ).map( |s| ( split.0, s ) )
}
#[derive(Debug)]
pub enum CsvError {
IO(std::io::Error),
ParseError(String),
InvalidHeader(String),
InvalidRow(String),
InvalidColumn(String),
}
impl From<std::io::Error> for CsvError {
fn from(error: std::io::Error) -> Self {
CsvError::IO( error )
}
}
use std::collections::HashMap;
type Row = HashMap<String, String>;
use std::io::BufRead;
pub struct Csv<R: BufRead> {
pub columns: Vec<String>,
reader: R,
selection: Option<Box<dyn Fn(&Row) -> Result<bool, CsvError>>>,
}
use std::io::Write;
impl<R: BufRead> Csv<R> {
fn get_columns(header: &str) -> Vec<String>
{
header.split(',').map( |s| s.trim().to_string() ).collect()
}
pub fn new(mut reader: R) -> Result<Self, CsvError> {
let mut header = String::new();
if reader.read_line( &mut header )? == 0
{
return Err( CsvError::InvalidHeader( "Empty file!".to_string() ) );
}
let columns = Self::get_columns( &header );
let mut columns_copy = columns.clone();
columns_copy.sort();
columns_copy.dedup();
if columns_copy.len() != columns.len()
{
return Err( CsvError::InvalidHeader( "Duplicate column names!".to_string() ) );
}
Ok( Self{ columns, reader, selection: None } )
}
pub fn parse_line(&mut self, line: &str) -> Result<Row, CsvError> {
let mut result: Row = Row::new();
let mut line_comps: ( &str, &str ) = ( "", line.trim() );
for column in &self.columns
{
// can't destructure...
line_comps = skip_next( line_comps.1, '"' ).and_then( |s| take_and_skip( s, '"' ) ).ok_or( CsvError::InvalidRow( "Invalid line!".to_string() ) )?;
result.insert( column.clone(), line_comps.0.to_string() );
line_comps.1 = take_until( line_comps.1, '"' ).1;
}
if line_comps.1.len() == 0
{
Ok( result )
}
else
{
Err( CsvError::InvalidRow( format!( "Line [{}] has too many values!", line ) ) )
}
}
pub fn apply_selection<F>(&mut self, callback: F)
where F: Fn(&Row) -> Result<bool, CsvError> + 'static
{
self.selection = Some( Box::new( callback ) )
}
pub fn write_to<W: Write>(mut self, mut writer: W) -> Result<(), CsvError> {
writer.write_fmt( format_args!( "{}\n", self.columns.join( ", " ) ) )?;
while let Some( result ) = self.next()
{
let row = result?;
- writer.write_fmt( format_args!( "{}\n", &self.columns.iter().map( |c| "\"".to_owned() + &row.get( c ).unwrap() + "\"" ).collect::<Vec<String>>().join( ", " ) ) )?;
+ writer.write_fmt( format_args!( "{}\n", &self.columns.iter().map( |c| format!( "\"{}\"", row[ c ] ) ).collect::<Vec<_>>().join( ", " ) ) )?;
}
Ok( () )
}
}
impl<R: BufRead> Iterator for Csv<R> {
type Item = Result<Row, CsvError>;
fn next(&mut self) -> Option<Self::Item> {
let mut line: String = String::new();
match self.reader.read_line( &mut line )
{
Ok( bytes ) if bytes == 0 => None,
Ok( _ ) =>
match self.parse_line( &line )
{
Ok( row ) =>
- {
match &self.selection
{
Some( pred ) =>
- {
match pred( &row )
{
Ok( false ) => self.next(),
Ok( true ) => Some ( Ok( row ) ),
Err( error ) => Some( Err( error ) ),
- }
- },
+ },
None => Some( Ok( row ) )
- }
- },
+ },
error => Some( error ),
},
Err( error ) => Some( Err( CsvError::IO( error ) ) ),
}
}
}