csv-diff

https://docs.rs/csv-diff
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### is_ok_and Example

Source: https://docs.rs/csv-diff/latest/csv_diff/type.Result.html

Example demonstrating the `is_ok_and` method.

```rust
let x: Result<u32, &str> = Ok(2);
assert_eq!(x.is_ok_and(|x| x > 1), true);

let x: Result<u32, &str> = Ok(0);
assert_eq!(x.is_ok_and(|x| x > 1), false);

let x: Result<u32, &str> = Err("hey");
assert_eq!(x.is_ok_and(|x| x > 1), false);

let x: Result<String, &str> = Ok("ownership".to_string());
assert_eq!(x.as_ref().is_ok_and(|x| x.len() > 1), true);
println!("still alive {:?}", x);
```

--------------------------------

### transpose Example

Source: https://docs.rs/csv-diff/latest/csv_diff/type.Result.html

Example demonstrating the `transpose` method for `Result<Option<T>, E>`.

```rust
#[derive(Debug, Eq, PartialEq)]
struct SomeErr;

let x: Result<Option<i32>, SomeErr> = Ok(Some(5));
let y: Option<Result<i32, SomeErr>> = Some(Ok(5));
assert_eq!(x.transpose(), y);
```

--------------------------------

### is_ok Example

Source: https://docs.rs/csv-diff/latest/csv_diff/type.Result.html

Example demonstrating the `is_ok` method.

```rust
let x: Result<i32, &str> = Ok(-3);
assert_eq!(x.is_ok(), true);

let x: Result<i32, &str> = Err("Some error message");
assert_eq!(x.is_ok(), false);
```

--------------------------------

### expect example (recommended message style)

Source: https://docs.rs/csv-diff/latest/csv_diff/type.Result.html

Provides an example of a recommended message style for expect, explaining why a certain condition is expected.

```rust
let path = std::env::var("IMPORTANT_PATH")
    .expect("env variable `IMPORTANT_PATH` should be set by `wrapper_script.sh`");
```

--------------------------------

### flatten Example

Source: https://docs.rs/csv-diff/latest/csv_diff/type.Result.html

Example demonstrating the `flatten` method for `Result<Result<T, E>, E>`.

```rust
let x: Result<Result<&'static str, u32>, u32> = Ok(Ok("hello"));
assert_eq!(Ok("hello"), x.flatten());

let x: Result<Result<&'static str, u32>, u32> = Ok(Err(6));
assert_eq!(Err(6), x.flatten());

let x: Result<Result<&'static str, u32>, u32> = Err(6);
assert_eq!(Err(6), x.flatten());
```

--------------------------------

### Example: create a CsvByteDiffLocal

Source: https://docs.rs/csv-diff/latest/csv_diff/csv_diff/struct.CsvByteDiffLocalBuilder.html

Example demonstrating how to create a CsvByteDiffLocal where column 1 and column 3 are treated as a compound primary key.

```rust
use csv_diff::{csv_diff::{CsvByteDiffLocal, CsvByteDiffLocalBuilder}, csv::Csv};
use csv_diff::diff_row::{ByteRecordLineInfo, DiffByteRecord};
use std::collections::HashSet;
use std::iter::FromIterator;
// some csv data with a header, where the first column and third column represent a compound key
let csv_data_left = "\
                    id,name,commit_sha\n\
                    1,lemon,efae52\n\
                    2,strawberry,a33411"; // this csv line is seen as "Deleted" and not "Modified"
                                          // because "id" and "commit_sha" are different and both columns
                                          // _together_ represent the primary key
let csv_data_right = "\
                    id,name,commit_sha\n\
                    1,lemon,efae52\n\
                    2,strawberry,ddef23"; // this csv line is seen as "Added" and not "Modified",
                                          // because "id" and "commit_sha" are different and both columns
                                          // _together_ represent the primary key

let csv_byte_diff = CsvByteDiffLocalBuilder::new()
    .primary_key_columns(vec![0usize, 2])
    .build()?;

let mut diff_byte_records = csv_byte_diff.diff(
    Csv::with_reader_seek(csv_data_left.as_bytes()),
    Csv::with_reader_seek(csv_data_right.as_bytes()),
)?;

diff_byte_records.sort_by_line();

let diff_byte_rows = diff_byte_records.as_slice();

assert_eq!(
    diff_byte_rows,
    &[
        DiffByteRecord::Delete(ByteRecordLineInfo::new(
            csv::ByteRecord::from(vec!["2", "strawberry", "a33411"]),
            3
        )),
        DiffByteRecord::Add(ByteRecordLineInfo::new(
            csv::ByteRecord::from(vec!["2", "strawberry", "ddef23"]),
            3
        ))
    ]
);
Ok(())

```

--------------------------------

### unwrap_or_default example

Source: https://docs.rs/csv-diff/latest/csv_diff/type.Result.html

Shows how `unwrap_or_default` can be used to get the `Ok` value or a default value if the `Result` is `Err`. This example converts strings to integers, using 0 as the default for invalid strings.

```Rust
let good_year_from_input = "1909";
let bad_year_from_input = "190blarg";
let good_year = good_year_from_input.parse().unwrap_or_default();
let bad_year = bad_year_from_input.parse().unwrap_or_default();

assert_eq!(1909, good_year);
assert_eq!(0, bad_year);
```

--------------------------------

### cloned Example for &mut T

Source: https://docs.rs/csv-diff/latest/csv_diff/type.Result.html

Example demonstrating the `cloned` method for `Result<&mut T, E>`.

```rust
let mut val = 12;
let x: Result<&mut i32, i32> = Ok(&mut val);
assert_eq!(x, Ok(&mut 12));
let cloned = x.cloned();
assert_eq!(cloned, Ok(12));
```

--------------------------------

### cloned Example

Source: https://docs.rs/csv-diff/latest/csv_diff/type.Result.html

Example demonstrating the `cloned` method for `Result<&T, E>`.

```rust
let val = 12;
let x: Result<&i32, i32> = Ok(&val);
assert_eq!(x, Ok(&12));
let cloned = x.cloned();
assert_eq!(cloned, Ok(12));
```

--------------------------------

### copied Example for &mut T

Source: https://docs.rs/csv-diff/latest/csv_diff/type.Result.html

Example demonstrating the `copied` method for `Result<&mut T, E>`.

```rust
let mut val = 12;
let x: Result<&mut i32, i32> = Ok(&mut val);
assert_eq!(x, Ok(&mut 12));
let copied = x.copied();
assert_eq!(copied, Ok(12));
```

--------------------------------

### copied Example

Source: https://docs.rs/csv-diff/latest/csv_diff/type.Result.html

Example demonstrating the `copied` method for `Result<&T, E>`.

```rust
let val = 12;
let x: Result<&i32, i32> = Ok(&val);
assert_eq!(x, Ok(&12));
let copied = x.copied();
assert_eq!(copied, Ok(12));
```

--------------------------------

### into_ok example

Source: https://docs.rs/csv-diff/latest/csv_diff/type.Result.html

Demonstrates the usage of the experimental `into_ok` method, which returns the `Ok` value and is guaranteed not to panic.

```Rust
fn only_good_news() -> Result<String, !> {
    Ok("this is fine".into())
}

let s: String = only_good_news().into_ok();
println!("{s}");
```

--------------------------------

### or() examples

Source: https://docs.rs/csv-diff/latest/csv_diff/type.Result.html

Illustrates the behavior of the `or` method.

```rust
let x: Result<u32, &str> = Ok(2);
let y: Result<u32, &str> = Err("late error");
assert_eq!(x.or(y), Ok(2));

let x: Result<u32, &str> = Err("early error");
let y: Result<u32, &str> = Ok(2);
assert_eq!(x.or(y), Ok(2));

let x: Result<u32, &str> = Err("not a 2");
let y: Result<u32, &str> = Err("late error");
assert_eq!(x.or(y), Err("late error"));

let x: Result<u32, &str> = Ok(2);
let y: Result<u32, &str> = Ok(100);
assert_eq!(x.or(y), Ok(2));
```

--------------------------------

### iter example

Source: https://docs.rs/csv-diff/latest/csv_diff/type.Result.html

Illustrates using iter to get an iterator over the contained value if the Result is Ok.

```rust
let x: Result<u32, &str> = Ok(7);
assert_eq!(x.iter().next(), Some(&7));

let x: Result<u32, &str> = Err("nothing!");
assert_eq!(x.iter().next(), None);
```

--------------------------------

### is_err Example

Source: https://docs.rs/csv-diff/latest/csv_diff/type.Result.html

Example demonstrating the `is_err` method.

```rust
let x: Result<i32, &str> = Ok(-3);
assert_eq!(x.is_err(), false);

let x: Result<i32, &str> = Err("Some error message");
assert_eq!(x.is_err(), true);
```

--------------------------------

### Example: create a CsvByteDiffLocal, where column 1 and column 3 are treated as a compound primary key.

Source: https://docs.rs/csv-diff/latest/src/csv_diff/csv_diff.rs.html

This example shows how to configure `CsvByteDiffLocalBuilder` to use a compound primary key consisting of columns at index 1 and 3 for CSV comparison.

```rust
use csv_diff::{csv_diff::{CsvByteDiffLocal, CsvByteDiffLocalBuilder}, csv::Csv};
use csv_diff::diff_row::{ByteRecordLineInfo, DiffByteRecord};
use std::collections::HashSet;
use std::iter::FromIterator;
# fn main() -> Result<(), Box<dyn std::error::Error>> {

```

--------------------------------

### File metadata example

Source: https://docs.rs/csv-diff/latest/csv_diff/type.Result.html

Shows how to use `and_then` with file metadata operations.

```rust
use std::{io::ErrorKind, path::Path};

// Note: on Windows "/" maps to "C:\"
let root_modified_time = Path::new("/").metadata().and_then(|md| md.modified());
assert!(root_modified_time.is_ok());

let should_fail = Path::new("/bad/path").metadata().and_then(|md| md.modified());
assert!(should_fail.is_err());
assert_eq!(should_fail.unwrap_err().kind(), ErrorKind::NotFound);
```

--------------------------------

### Example: create CsvByteDiffLocal with default values and compare two CSVs byte-wise eagerly

Source: https://docs.rs/csv-diff/latest/src/csv_diff/csv_diff.rs.html

This example demonstrates how to create a `CsvByteDiffLocal` with default settings and then use it to compare two CSV byte strings. It highlights the use of `Csv::with_reader_seek` for handling CSV data that might not be directly seekable and asserts the expected difference in the output.

```rust
use csv_diff::{csv_diff::CsvByteDiffLocal, csv::Csv};
use csv_diff::diff_row::{ByteRecordLineInfo, DiffByteRecord};
use std::collections::HashSet;
use std::iter::FromIterator;
# fn main() -> Result<(), Box<dyn std::error::Error>> {
// some csv data with a header, where the first column is a unique id
let csv_data_left = "id,name,kind\n\
                    1,lemon,fruit\n\
                     2,strawberry,fruit";
let csv_data_right = "id,name,kind\n\
                      1,lemon,fruit\n\
                      2,strawberry,nut";

let csv_byte_diff = CsvByteDiffLocal::new()?;

let mut diff_byte_records = csv_byte_diff.diff(
    Csv::with_reader_seek(csv_data_left.as_bytes()),
    Csv::with_reader_seek(csv_data_right.as_bytes()),
)?;

let diff_byte_rows = diff_byte_records.as_slice();

assert_eq!(
    diff_byte_rows,
    &[DiffByteRecord::Modify {
        delete: ByteRecordLineInfo::new(
            csv::ByteRecord::from(vec!["2", "strawberry", "fruit"]),
            3
        ),
        add: ByteRecordLineInfo::new(csv::ByteRecord::from(vec!["2", "strawberry", "nut"])), 3),
        field_indices: vec![2]
    }]
);
Ok(())
# }

```

--------------------------------

### Compound Primary Key Example

Source: https://docs.rs/csv-diff/latest/src/csv_diff/csv_diff.rs.html

This example shows how to define a compound primary key using two columns (column 0 and column 2) and then diff two CSV datasets. It highlights how records are identified as 'Deleted' or 'Added' based on the compound key.

```rust
let csv_data_left = "\\
id,name,commit_sha\n\\
                    1,lemon,efae52\n\\
                    2,strawberry,a33411"; // this csv line is seen as "Deleted" and not "Modified" and not "Modified"
                                          // because "id" and "commit_sha" are different and both columns
                                          // _together_ represent the primary key
let csv_data_right = "\\
id,name,commit_sha\n\\
                    1,lemon,efae52\n\\
                    2,strawberry,ddef23"; // this csv line is seen as "Added" and not "Modified",
                                          // because "id" and "commit_sha" are different and both columns
                                          // _together_ represent the primary key

let csv_byte_diff = CsvByteDiffLocalBuilder::new()
    .primary_key_columns(vec![0usize, 2])
    .build()?;

let mut diff_byte_records = csv_byte_diff.diff(
    Csv::with_reader_seek(csv_data_left.as_bytes()),
    Csv::with_reader_seek(csv_data_right.as_bytes()),
)?;

diff_byte_records.sort_by_line();

let diff_byte_rows = diff_byte_records.as_slice();

assert_eq!(
    diff_byte_rows,
    &[
        DiffByteRecord::Delete(ByteRecordLineInfo::new(
            csv::ByteRecord::from(vec!["2", "strawberry", "a33411"]),
            3
        ),),
        DiffByteRecord::Add(ByteRecordLineInfo::new(
            csv::ByteRecord::from(vec!["2", "strawberry", "ddef23"]),
            3
        ),)
    ]
);
Ok(())
# }
```

--------------------------------

### CSV Diff Example

Source: https://docs.rs/csv-diff/latest/src/csv_diff/csv_diff.rs.html

Demonstrates how to use CsvByteDiffBuilder to compare two CSV files and assert the differences.

```Rust
let mut csv_left = String::new();
let mut csv_right = String::new();

csv_left.push_str("header1,header2,header3\n");
csv_left.push_str("a,b,c\n");
csv_left.push_str("d,e,f\n");

csv_right.push_str("header1,header2,header3\n");
csv_right.push_str("a,b,x\n");
csv_right.push_str("g,h,i\n");
csv_right.push_str("d,f,f\n");
csv_right.push_str("m,n,o\n");

let diff_res_iter = CsvByteDiffBuilder::<CsvHashTaskSpawnerStdThreads>::new(
    CsvHashTaskSpawnerBuilderStdThreads::new(),
)
.primary_key_columns(vec![0, 1])
.build()? 
.diff(
    Csv::with_reader_seek(csv_left.as_bytes()),
    Csv::with_reader_seek(csv_right.as_bytes()),
);

let mut diff_res_actual: DiffByteRecords = diff_res_iter.try_to_diff_byte_records()?;

let mut diff_res_expected = DiffByteRecords::new(
    vec![
        DiffByteRecord::Modify {
            delete: ByteRecordLineInfo::new(csv::ByteRecord::from(vec!["a", "b", "c"] ), 2),
            add: ByteRecordLineInfo::new(csv::ByteRecord::from(vec!["a", "b", "x"] ), 2),
            field_indices: vec![2],
        },
        DiffByteRecord::Delete(ByteRecordLineInfo::new(
            csv::ByteRecord::from(vec!["d", "e", "f"]),
            3,
        )),
        DiffByteRecord::Add(ByteRecordLineInfo::new(
            csv::ByteRecord::from(vec!["d", "f", "f"]),
            4,
        )),
    ],
    (
        Some(vec!["header1", "header2", "header3"].into()),
        Some(vec!["header1", "header2", "header3"].into()),
    )
        .into(),
    Some(3),
);

diff_res_actual.sort_by_line();
diff_res_expected.sort_by_line();
assert_eq!(diff_res_actual, diff_res_expected);
Ok(())
}

```

--------------------------------

### flattening multiple levels Example

Source: https://docs.rs/csv-diff/latest/csv_diff/type.Result.html

Example showing how `flatten` removes one level of nesting at a time.

```rust
let x: Result<Result<Result<&'static str, u32>, u32>, u32> = Ok(Ok(Ok("hello")));
assert_eq!(Ok(Ok("hello")), x.flatten());
assert_eq!(Ok("hello"), x.flatten().flatten());
```

--------------------------------

### expect example (panic)

Source: https://docs.rs/csv-diff/latest/csv_diff/type.Result.html

Demonstrates the behavior of expect when the Result is an Err, causing a panic.

```rust
let x: Result<u32, &str> = Err("emergency failure");
x.expect("Testing expect"); // panics with `Testing expect: emergency failure`
```

--------------------------------

### unwrap_or() examples

Source: https://docs.rs/csv-diff/latest/csv_diff/type.Result.html

Shows how `unwrap_or` provides a default value.

```rust
let default = 2;
let x: Result<u32, &str> = Ok(9);
assert_eq!(x.unwrap_or(default), 9);

let x: Result<u32, &str> = Err("error");
assert_eq!(x.unwrap_or(default), default);
```

--------------------------------

### unwrap_unchecked() example

Source: https://docs.rs/csv-diff/latest/csv_diff/type.Result.html

Demonstrates the usage of `unwrap_unchecked`.

```rust
let x: Result<u32, &str> = Ok(2);
assert_eq!(unsafe { x.unwrap_unchecked() }, 2);
```

--------------------------------

### Example: Create a CsvByteDiff with a compound primary key

Source: https://docs.rs/csv-diff/latest/csv_diff/csv_diff/struct.CsvByteDiffBuilder.html

This example demonstrates how to create a CsvByteDiff where column 1 (index 0) and column 3 (index 2) are treated as a compound primary key. It shows how changes in rows with different compound keys are identified as 'Deleted' or 'Added' rather than 'Modified'.

```rust
use csv_diff::{csv_diff::{CsvByteDiff, CsvByteDiffBuilder}, csv::Csv};
use csv_diff::diff_row::{ByteRecordLineInfo, DiffByteRecord};
use csv_diff::diff_result::DiffByteRecords;
use std::convert::TryInto;
// some csv data with a header, where the first column and third column represent a compound key
let csv_data_left = "\
    id,name,commit_sha\n\
    1,lemon,efae52\n\
    2,strawberry,a33411"; // this csv line is seen as "Deleted" and not "Modified"
                          // because "id" and "commit_sha" are different and both columns
                          // _together_ represent the primary key
let csv_data_right = "\
    id,name,commit_sha\n\
    1,lemon,efae52\n\
    2,strawberry,ddef23"; // this csv line is seen as "Added" and not "Modified",
                          // because "id" and "commit_sha" are different and both columns
                          // _together_ represent the primary key

let csv_byte_diff = CsvByteDiffBuilder::new()
    .primary_key_columns(vec![0usize, 2])
    .build()?;

let mut diff_byte_records: DiffByteRecords = csv_byte_diff
    .diff(
        Csv::with_reader(csv_data_left.as_bytes()),
        Csv::with_reader(csv_data_right.as_bytes()),
    )
    .try_to_diff_byte_records()?;

diff_byte_records.sort_by_line();

let diff_byte_rows = diff_byte_records.as_slice();

assert_eq!(
    diff_byte_rows,
    &[
        DiffByteRecord::Delete(ByteRecordLineInfo::new(
            csv::ByteRecord::from(vec!["2", "strawberry", "a33411"]),
            3
        ),),
        DiffByteRecord::Add(ByteRecordLineInfo::new(
            csv::ByteRecord::from(vec!["2", "strawberry", "ddef23"]),
            3
        ),)
    ]
);
Ok(())

```

--------------------------------

### Example: create CsvByteDiff with default values and compare two CSVs byte-wise lazily

Source: https://docs.rs/csv-diff/latest/csv_diff/csv_diff/struct.CsvByteDiff.html

This example demonstrates how to create a CsvByteDiff instance with default settings and then use it to compare two CSV strings. It shows how to iterate over the differences and asserts that a specific modification is found.

```rust
use csv_diff::{csv_diff::CsvByteDiff, csv::Csv};
use csv_diff::diff_row::{ByteRecordLineInfo, DiffByteRecord};
use std::collections::HashSet;
use std::iter::FromIterator;
// some csv data with a header, where the first column is a unique id
let csv_left = "\
header1,header2,header3\n\
a,b,c";
let csv_right = "\
header1,header2,header3\n\
a,b,d";

let csv_diff = CsvByteDiff::new()?;

let mut diff_iterator = csv_diff.diff(
    Csv::with_reader(csv_left.as_bytes()),
    Csv::with_reader(csv_right.as_bytes()),
);

let diff_row_actual = diff_iterator
    .next()
    .ok_or("Expected a difference between the two CSVs, but got none".to_string())??;

let diff_row_expected = DiffByteRecord::Modify {
    delete: ByteRecordLineInfo::new(csv::ByteRecord::from(vec!["a", "b", "c"]),
 2),
    add: ByteRecordLineInfo::new(csv::ByteRecord::from(vec!["a", "b", "d"]),
 2),
    field_indices: vec![2],
};

assert_eq!(diff_row_actual, diff_row_expected);

Ok(())

```

--------------------------------

### or_else() examples

Source: https://docs.rs/csv-diff/latest/csv_diff/type.Result.html

Demonstrates the usage of the `or_else` method for lazy evaluation.

```rust
fn sq(x: u32) -> Result<u32, u32> { Ok(x * x) }
fn err(x: u32) -> Result<u32, u32> { Err(x) }

assert_eq!(Ok(2).or_else(sq).or_else(sq), Ok(2));
assert_eq!(Ok(2).or_else(err).or_else(sq), Ok(2));
assert_eq!(Err(3).or_else(sq).or_else(err), Ok(9));
assert_eq!(Err(3).or_else(err).or_else(err), Err(3));
```

--------------------------------

### Example: use `Csv` together with `CsvByteDiffLocal` to compare CSV data

Source: https://docs.rs/csv-diff/latest/src/csv_diff/csv.rs.html

This example demonstrates how to use the `Csv` struct with `CsvByteDiffLocal` to compare CSV data. It shows creating `Csv` instances from byte slices using `Csv::with_reader_seek` and then performing a diff operation.

```rust
use csv_diff::{csv_diff::CsvByteDiffLocal, csv::Csv};
# fn main() -> Result<(), Box<dyn std::error::Error>> {
let csv_data_left = "id,name,kind\n\
                    1,lemon,fruit\n\
                    2,strawberry,fruit";
let csv_data_right = "id,name,kind\n\
                    1,lemon,fruit\n\
                    2,strawberry,fruit";

let csv_byte_diff = CsvByteDiffLocal::new()?;

let mut diff_byte_records = csv_byte_diff.diff(
    // bytes are not `Seek`able by default, but trait `CsvReadSeek` makes them seekable
    Csv::with_reader_seek(csv_data_left.as_bytes()),
    Csv::with_reader_seek(csv_data_right.as_bytes()),
)?;

let num_of_rows_different = diff_byte_records.as_slice().len();

assert_eq!(
    num_of_rows_different,
    0
);
Ok(())
# }

```

--------------------------------

### as_deref_mut example

Source: https://docs.rs/csv-diff/latest/csv_diff/type.Result.html

Shows converting a mutable Result<T, E> to Result<&mut <T as DerefMut>::Target, &mut E> by coercing the Ok variant via DerefMut.

```rust
let mut s = "HELLO".to_string();
let mut x: Result<String, u32> = Ok("hello".to_string());
let y: Result<&mut str, &mut u32> = Ok(&mut s);
assert_eq!(x.as_deref_mut().map(|x| { x.make_ascii_uppercase(); x }), y);

let mut i = 42;
let mut x: Result<String, u32> = Err(42);
let y: Result<&mut str, &mut u32> = Err(&mut i);
assert_eq!(x.as_deref_mut().map(|x| { x.make_ascii_uppercase(); x }), y);
```

--------------------------------

### Example: create CsvByteDiffLocal with default values and compare two CSVs byte-wise eagerly

Source: https://docs.rs/csv-diff/latest/csv_diff/csv_diff/struct.CsvByteDiffLocal.html

This example demonstrates how to instantiate CsvByteDiffLocal with default settings and then use its diff method to compare two CSV byte strings, highlighting the differences found.

```rust
use csv_diff::{csv_diff::CsvByteDiffLocal, csv::Csv};
use csv_diff::diff_row::{ByteRecordLineInfo, DiffByteRecord};
use std::collections::HashSet;
use std::iter::FromIterator;
// some csv data with a header, where the first column is a unique id
let csv_data_left = "id,name,kind\n\
                     1,lemon,fruit\n\
                     2,strawberry,fruit";
let csv_data_right = "id,name,kind\n\
                      1,lemon,fruit\n\
                      2,strawberry,nut";

let csv_byte_diff = CsvByteDiffLocal::new()?;

let mut diff_byte_records = csv_byte_diff.diff(
    Csv::with_reader_seek(csv_data_left.as_bytes()),
    Csv::with_reader_seek(csv_data_right.as_bytes()),
)?;

let diff_byte_rows = diff_byte_records.as_slice();

assert_eq!(
    diff_byte_rows,
    &[DiffByteRecord::Modify {
        delete: ByteRecordLineInfo::new(
            csv::ByteRecord::from(vec!["2", "strawberry", "fruit"]),
            3
        ),
        add: ByteRecordLineInfo::new(csv::ByteRecord::from(vec!["2", "strawberry", "nut"]), 3),
        field_indices: vec![2]
    }]
);
Ok(())

```

--------------------------------

### unwrap_err_unchecked() example

Source: https://docs.rs/csv-diff/latest/csv_diff/type.Result.html

Demonstrates the usage of `unwrap_err_unchecked`.

```rust
let x: Result<u32, &str> = Err("emergency failure");
assert_eq!(unsafe { x.unwrap_err_unchecked() }, "emergency failure");
```

--------------------------------

### and method example

Source: https://docs.rs/csv-diff/latest/csv_diff/type.Result.html

Illustrates the behavior of the `and` method, which returns the second `Result` if the first is `Ok`, otherwise returns the `Err` from the first `Result`.

```Rust
let x: Result<u32, &str> = Ok(2);
let y: Result<&str, &str> = Err("late error");
assert_eq!(x.and(y), Err("late error"));

let x: Result<u32, &str> = Err("early error");
let y: Result<&str, &str> = Ok("foo");
assert_eq!(x.and(y), Err("early error"));

let x: Result<u32, &str> = Err("not a 2");
let y: Result<&str, &str> = Err("late error");
assert_eq!(x.and(y), Err("not a 2"));

let x: Result<u32, &str> = Ok(2);
let y: Result<&str, &str> = Ok("different result type");
assert_eq!(x.and(y), Ok("different result type"));
```

--------------------------------

### inspect example

Source: https://docs.rs/csv-diff/latest/csv_diff/type.Result.html

Shows how to use inspect to perform a side effect (like printing) when the Result is Ok, without changing the Result itself.

```rust
let x: u8 = "4"
    .parse::<u8>()
    .inspect(|x| println!("original: {x}"))
    .map(|x| x.pow(3))
    .expect("failed to parse number");
```

--------------------------------

### as_deref example

Source: https://docs.rs/csv-diff/latest/csv_diff/type.Result.html

Demonstrates converting a Result<T, E> to Result<&<T as Deref>::Target, &E> by coercing the Ok variant via Deref.

```rust
let x: Result<String, u32> = Ok("hello".to_string());
let y: Result<&str, &u32> = Ok("hello");
assert_eq!(x.as_deref(), y);

let x: Result<String, u32> = Err(42);
let y: Result<&str, &u32> = Err(&42);
assert_eq!(x.as_deref(), y);
```

--------------------------------

### unwrap_or_else() examples

Source: https://docs.rs/csv-diff/latest/csv_diff/type.Result.html

Illustrates `unwrap_or_else` for computing a default value lazily.

```rust
fn count(x: &str) -> usize { x.len() }

assert_eq!(Ok(2).unwrap_or_else(count), 2);
assert_eq!(Err("foo").unwrap_or_else(count), 3);
```

--------------------------------

### Product Examples

Source: https://docs.rs/csv-diff/latest/csv_diff/type.Result.html

This multiplies each number in a vector of strings, if a string could not be parsed the operation returns Err.

```rust
let nums = vec!["5", "10", "1", "2"];
let total: Result<usize, _> = nums.iter().map(|w| w.parse::<usize>()).product();
assert_eq!(total, Ok(100));
let nums = vec!["5", "10", "one", "2"];
let total: Result<usize, _> = nums.iter().map(|w| w.parse::<usize>()).product();
assert!(total.is_err());
```

--------------------------------

### into_err example

Source: https://docs.rs/csv-diff/latest/csv_diff/type.Result.html

Demonstrates the usage of the experimental `into_err` method, which returns the `Err` value and is guaranteed not to panic.

```Rust
fn only_bad_news() -> Result<!, String> {
    Err("Oops, it failed".into())
}

let error: String = only_bad_news().into_err();
println!("{error}");
```

--------------------------------

### Sum Examples

Source: https://docs.rs/csv-diff/latest/csv_diff/type.Result.html

This sums up every integer in a vector, rejecting the sum if a negative element is encountered.

```rust
let f = |&x: &i32| if x < 0 { Err("Negative element found") } else { Ok(x) };
let v = vec![1, 2];
let res: Result<i32, _> = v.iter().map(f).sum();
assert_eq!(res, Ok(3));
let v = vec![1, -2];
let res: Result<i32, _> = v.iter().map(f).sum();
assert_eq!(res, Err("Negative element found"));
```

--------------------------------

### Example: use Csv together with CsvByteDiffLocal to compare CSV data

Source: https://docs.rs/csv-diff/latest/csv_diff/csv/struct.Csv.html

Demonstrates how to use the Csv struct with CsvByteDiffLocal to compare two CSV datasets represented as byte strings.

```rust
use csv_diff::{csv_diff::CsvByteDiffLocal, csv::Csv};
let csv_data_left = "id,name,kind\n\
                    1,lemon,fruit\n\
                    2,strawberry,fruit";
let csv_data_right = "id,name,kind\n\
                    1,lemon,fruit\n\
                    2,strawberry,fruit";

let csv_byte_diff = CsvByteDiffLocal::new()?;

let mut diff_byte_records = csv_byte_diff.diff(
    // bytes are not `Seek`able by default, but trait `CsvReadSeek` makes them seekable
    Csv::with_reader_seek(csv_data_left.as_bytes()),
    Csv::with_reader_seek(csv_data_right.as_bytes()),
)?;

let num_of_rows_different = diff_byte_records.as_slice().len();

assert_eq!(
    num_of_rows_different,
    0
);
Ok(())

```

--------------------------------

### Example of using as_slice()

Source: https://docs.rs/csv-diff/latest/csv_diff/diff_result/struct.DiffByteRecords.html

Demonstrates how to get the DiffByteRecords as a slice and assert its length.

```rust
use csv_diff::{csv_diff::CsvByteDiffLocal, csv::Csv};
use std::collections::HashSet;
use std::iter::FromIterator;
// some csv data with a header, where the first column is a unique id
let csv_data_left = "id,name,kind\n\
                     1,lemon,fruit\n\
                     2,strawberry,fruit";
let csv_data_right = "id,name,kind\n\
                      1,lemon,fruit\n\
                      2,strawberry,nut\n\
                      3,cherry,fruit";

let csv_byte_diff = CsvByteDiffLocal::new()?;

let mut diff_byte_records = csv_byte_diff.diff(
    Csv::with_reader_seek(csv_data_left.as_bytes()),
    Csv::with_reader_seek(csv_data_right.as_bytes()),
)?;

let diff_byte_record_slice = diff_byte_records.as_slice();

assert_eq!(
    diff_byte_record_slice.len(),
    2
);
Ok(())

```

--------------------------------

### Example of using CsvByteDiffLocal::new() and diff()

Source: https://docs.rs/csv-diff/latest/src/csv_diff/csv_diff.rs.html

Demonstrates how to create a `CsvByteDiffLocal` instance using the default constructor and then compare two CSV datasets. It highlights the process of reading CSV data, performing the diff, sorting the results, and asserting the expected differences.

```rust
use csv_diff::{csv_diff::CsvByteDiffLocal, csv::Csv};
use csv_diff::diff_row::{ByteRecordLineInfo, DiffByteRecord};
use std::collections::HashSet;
use std::iter::FromIterator;
# fn main() -> Result<(), Box<dyn std::error::Error>> {
// some csv data with a header, where the first column is a unique id
let csv_data_left = "id,name,kind\n\
                        1,lemon,fruit\n\
                        2,strawberry,fruit";
let csv_data_right = "id,name,kind\n\
                         1,lemon,fruit\n\
                         2,strawberry,nut";

let csv_byte_diff = CsvByteDiffLocal::new()?;

let mut diff_byte_records = csv_byte_diff.diff(
    Csv::with_reader_seek(csv_data_left.as_bytes()),
    Csv::with_reader_seek(csv_data_right.as_bytes()),
)?;

diff_byte_records.sort_by_line();

let diff_byte_rows = diff_byte_records.as_slice();

assert_eq!(
    diff_byte_rows,
    &[DiffByteRecord::Modify {
        delete: ByteRecordLineInfo::new(
            csv::ByteRecord::from(vec!["2", "strawberry", "fruit"]),
            3
        ),
        add: ByteRecordLineInfo::new(csv::ByteRecord::from(vec!["2", "strawberry", "nut"])),
        field_indices: vec![2]
    }]
);
Ok(())
# }

```

--------------------------------

### iter_mut example

Source: https://docs.rs/csv-diff/latest/csv_diff/type.Result.html

Shows using iter_mut to get a mutable iterator over the contained value if the Result is Ok.

```rust
let mut x: Result<u32, &str> = Ok(7);
match x.iter_mut().next() {
    Some(v) => *v = 40,
    None => {},
}
assert_eq!(x, Ok(40));

let mut x: Result<u32, &str> = Err("nothing!");
assert_eq!(x.iter_mut().next(), None);
```

--------------------------------

### Keyboard Shortcuts

Source: https://docs.rs/csv-diff/latest/help.html

A list of keyboard shortcuts available in Rustdoc for navigation and interaction.

```text
`?`
    Show this help dialog

`S` / `/`
    Focus the search field

`↑`
    Move up in search results

`↓`
    Move down in search results

`←` / `→`
    Switch result tab (when results focused)

`⏎`
    Go to active search result

`+` / `=`
    Expand all sections

`-`
    Collapse all sections

`_`
    Collapse all sections, including impl blocks
```

--------------------------------

### Search Tricks

Source: https://docs.rs/csv-diff/latest/help.html

Tips for using the search functionality in Rustdoc, including type prefixes and exact name matching.

```text
Prefix searches with a type followed by a colon (e.g., `fn:`) to restrict the search to a given item kind.
Accepted kinds are: `fn`, `mod`, `struct`, `enum`, `trait`, `type`, `macro`, and `const`.
Search functions by type signature (e.g., `vec -> usize` or `-> vec` or `String, enum:Cow -> bool`)
You can look for items with an exact name by putting double quotes around your request: `"string"`
Look for functions that accept or return slices and arrays by writing square brackets (e.g., `-> [u8]` or `[] -> Option`)
Look for items inside another one by searching for a path: `vec::Vec`
```

--------------------------------

### Example Usage of CsvByteDiffLocal

Source: https://docs.rs/csv-diff/latest/csv_diff/csv_diff/struct.CsvByteDiffLocal.html

This example demonstrates how to use CsvByteDiffLocal to compare two CSV datasets, identify modified rows, and assert the differences.

```rust
use csv_diff::{csv_diff::CsvByteDiffLocal, csv::Csv};
use csv_diff::diff_row::{ByteRecordLineInfo, DiffByteRecord};
use std::collections::HashSet;
use std::iter::FromIterator;
// some csv data with a header, where the first column is a unique id
let csv_data_left = "id,name,kind\n\
                     1,lemon,fruit\n\
                     2,strawberry,fruit";
let csv_data_right = "id,name,kind\n\
                      1,lemon,fruit\n\
                      2,strawberry,nut";

let csv_byte_diff = CsvByteDiffLocal::new()?;

let mut diff_byte_records = csv_byte_diff.diff(
    Csv::with_reader_seek(csv_data_left.as_bytes()),
    Csv::with_reader_seek(csv_data_right.as_bytes()),
)?;

diff_byte_records.sort_by_line();

let diff_byte_rows = diff_byte_records.as_slice();

assert_eq!(
    diff_byte_rows,
    &[DiffByteRecord::Modify {
        delete: ByteRecordLineInfo::new(
            csv::ByteRecord::from(vec!["2", "strawberry", "fruit"]),
            3
        ),
        add: ByteRecordLineInfo::new(csv::ByteRecord::from(vec!["2", "strawberry", "nut"]), 3),
        field_indices: vec![2]
    }]
);
Ok(())

```

--------------------------------

### DiffResult as Slice

Source: https://docs.rs/csv-diff/latest/src/csv_diff/diff_result.rs.html

Demonstrates how to get a slice of `DiffByteRecord`s from a `DiffResult`.

```rust
use csv_diff::{csv_diff::CsvByteDiffLocal, csv::Csv};
use std::collections::HashSet;
use std::iter::FromIterator;
# fn main() -> Result<(), Box<dyn std::error::Error>> {
// some csv data with a header, where the first column is a unique id
let csv_data_left = "id,name,kind\n\
                        1,lemon,fruit\n\
                        2,strawberry,fruit";
let csv_data_right = "id,name,kind\n\
                         1,lemon,fruit\n\
                         2,strawberry,nut\n\
                         3,cherry,fruit";

let csv_byte_diff = CsvByteDiffLocal::new()?;

let mut diff_byte_records = csv_byte_diff.diff(
    Csv::with_reader_seek(csv_data_left.as_bytes()),
    Csv::with_reader_seek(csv_data_right.as_bytes()),
)?;

let diff_byte_record_slice = diff_byte_records.as_slice();

assert_eq!(
    diff_byte_record_slice.len(),
    2
);
Ok(())
# }

```

--------------------------------

### Create a CsvByteDiff with compound primary key

Source: https://docs.rs/csv-diff/latest/src/csv_diff/csv_diff.rs.html

This example demonstrates how to create a `CsvByteDiff` where a compound primary key (columns 1 and 3) is used for comparison. It shows how lines with different compound keys are treated as 'Deleted' or 'Added' rather than 'Modified'.

```Rust
use csv_diff::{csv_diff::{CsvByteDiff, CsvByteDiffBuilder}, csv::Csv};
use csv_diff::diff_row::{ByteRecordLineInfo, DiffByteRecord};
use csv_diff::diff_result::DiffByteRecords;
use std::convert::TryInto;
fn main() -> Result<(), Box<dyn std::error::Error>> {
// some csv data with a header, where the first column and third column represent a compound key
let csv_data_left = "\
id,name,commit_sha\n\
    1,lemon,efae52\n\
    2,strawberry,a33411"; // this csv line is seen as "Deleted" and not "Modified"
                          // because "id" and "commit_sha" are different and both columns
                          // _together_ represent the primary key
let csv_data_right = "\
id,name,commit_sha\n\
    1,lemon,efae52\n\
    2,strawberry,ddef23"; // this csv line is seen as "Added" and not "Modified",
                          // because "id" and "commit_sha" are different and both columns
                          // _together_ represent the primary key

let csv_byte_diff = CsvByteDiffBuilder::new()
    .primary_key_columns(vec![0usize, 2])
    .build()?;

let mut diff_byte_records: DiffByteRecords = csv_byte_diff
    .diff(
        Csv::with_reader(csv_data_left.as_bytes()),
        Csv::with_reader(csv_data_right.as_bytes()),
    )
    .try_to_diff_byte_records()?;

diff_byte_records.sort_by_line();

let diff_byte_rows = diff_byte_records.as_slice();

assert_eq!(
    diff_byte_rows,
    &[
        DiffByteRecord::Delete(ByteRecordLineInfo::new(
            csv::ByteRecord::from(vec!["2", "strawberry", "a33411"]),
            3
        ),),
        DiffByteRecord::Add(ByteRecordLineInfo::new(
            csv::ByteRecord::from(vec!["2", "strawberry", "ddef23"]),
            3
        ),)
    ]
);
Ok(())
}

```

--------------------------------

### Basic usage of unwrap

Source: https://docs.rs/csv-diff/latest/csv_diff/type.Result.html

Demonstrates the basic usage of the `unwrap` method on a `Result` type, extracting the `Ok` value.

```Rust
let x: Result<u32, &str> = Ok(2);
assert_eq!(x.unwrap(), 2);
```

--------------------------------

### Pointable::init method

Source: https://docs.rs/csv-diff/latest/csv_diff/csv_hash_task_spawner/struct.CsvHashTaskSpawnerLocalBuilderRayon.html

Implementation of the init method from the Pointable trait.

```rust
unsafe fn init(init: <T as Pointable>::Init) -> usize
```

--------------------------------

### csv_diff/lib.rs

Source: https://docs.rs/csv-diff/latest/src/csv_diff/lib.rs.html

Find the difference between two CSVs - with ludicrous speed!🚀

`csv-diff` finds the difference between two CSVs. It is the fastest CSV-diffing library in the world! Comparing two 1,000,000 rows x 9 columns CSVs takes __under 600ms__ (when using [raw bytes](csv_diff::CsvByteDiffLocal::diff)). It is *thread-pool-agnostic*, meaning you can provide your own existing thread-pool or you can use the default [rayon thread-pool](https://docs.rs/rayon/1.5.0/rayon/struct.ThreadPool.html) that is used in this crate.

# Use Case
This crate should be used on CSV data that has some sort of *primary key* for uniquely identifying a record. It is __not__ a general line-by-line diffing crate. You can imagine dumping a database table in CSV format from your *test* and *production* system and comparing it with each other to find differences.

# Overview
The most important types you will use are:
1. [`CsvByteDiffLocal`](csv_diff::CsvByteDiffLocal) for comparing two CSVs byte-wise in a blocking fashion and getting the result as [`DiffByteRecords`](diff_result::DiffByteRecords).
2. [`CsvByteDiff`](csv_diff::CsvByteDiff) for comparing two CSVs byte-wise lazily and getting the result as an [`Iterator`](diff_result::DiffByteRecordsIterator).

```rust
/*!
Find the difference between two CSVs - with ludicrous speed!🚀

`csv-diff` finds the difference between two CSVs.
It is the fastest CSV-diffing library in the world!
Comparing two 1,000,000 rows x 9 columns CSVs takes __under 600ms__ (when using [raw bytes](csv_diff::CsvByteDiffLocal::diff)).
It is *thread-pool-agnostic*, meaning you can provide your own existing thread-pool
or you can use the default [rayon thread-pool](https://docs.rs/rayon/1.5.0/rayon/struct.ThreadPool.html)
that is used in this crate.

# Use Case
This crate should be used on CSV data that has some sort of *primary key* for uniquely identifying a record.
It is __not__ a general line-by-line diffing crate.
You can imagine dumping a database table in CSV format from your *test* and *production* system and comparing it
with each other to find differences.

# Overview
The most important types you will use are:
1. [`CsvByteDiffLocal`](csv_diff::CsvByteDiffLocal) for comparing two CSVs byte-wise in a blocking fashion and getting the result as [`DiffByteRecords`](diff_result::DiffByteRecords).
2. [`CsvByteDiff`](csv_diff::CsvByteDiff) for comparing two CSVs byte-wise lazily and getting the result as an [`Iterator`](diff_result::DiffByteRecordsIterator).
*/

#![forbid(unsafe_code)]

pub mod csv;
pub mod csv_diff;
mod csv_hash_comparer;
pub mod csv_headers;
// TODO: try to make it more private
pub mod csv_hash_receiver_comparer;
pub mod csv_hash_task_spawner;
mod csv_hasher;
pub mod csv_parse_result;
mod csv_parser_hasher;
pub mod diff_result;
pub mod diff_row;
mod thread_scope_strategy; // TODO: do we really need this?

#[doc(inline)]
pub use ::csv::Result;

```
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