tabled/ Add Locator::by (ByCondition)

tabled/examples/alphabet.rs

@@ -3,11 +3,51 @@
 //! * Note how [`Range`] [expression syntax](https://doc.rust-lang.org/reference/expressions/range-expr.html)
 //! is used to idiomatically represent the English alphabet.
 
-use std::iter::FromIterator;
+fn main() {
+    use tabled::{
+        settings::{
+            location::Locator,
+            object::{Columns, Object},
+            Alignment, Modify, Padding,
+        },
+        Table, Tabled,
+    };
 
-use tabled::Table;
+    #[derive(Tabled)]
+    struct Reading {
+        link: &'static str,
+        comment: &'static str,
+    }
 
-fn main() {
-    let table = Table::from_iter(['a'..='z']);
-    println!("{table}");
+    let data = [
+        Reading {
+            link: "https://www.gnu.org/software/grub/manual/multiboot/multiboot.html",
+            comment: "todo",
+        },
+        Reading {
+            link: "https://wiki.debian.org/initramfs",
+            comment: "todo",
+        },
+        Reading {
+            link: "http://jdebp.uk/FGA/efi-boot-process.html",
+            comment: "todo,2",
+        },
+        Reading {
+            link: "https://wiki.debian.org/UEFI",
+            comment: "todo,2",
+        },
+    ];
+
+    let mut table = Table::new(data);
+    table.with(Padding::zero());
+    table.with(Modify::new(Locator::column("link")).with(Alignment::right()));
+    table.with(Modify::new(Locator::content("todo")).with("todo,1"));
+    table.with(
+        Modify::new(Columns::single(1).intersect(Locator::by(|text| text.contains("todo"))))
+            .with(Padding::new(4, 0, 0, 0)),
+    );
+
+    let output = table.to_string();
+
+    println!("{output}");
 }

tabled/src/settings/location/by_column_name.rs

@@ -9,7 +9,7 @@ use crate::{
 /// A name is considered be a value in a first row.
 ///
 /// So even if in reality there's no header, the first row will be considered to be one.
-#[derive(Debug, Clone, Copy)]
+#[derive(Debug, Clone, Copy, Default, Hash, PartialEq, Eq, PartialOrd, Ord)]
 pub struct ByColumnName<S>(S);
 
 impl<S> ByColumnName<S> {

tabled/src/settings/location/by_condition.rs

@@ -0,0 +1,74 @@
+use crate::{
+    grid::config::Entity,
+    grid::{
+        config::Position,
+        records::{ExactRecords, PeekableRecords, Records},
+    },
+    settings::location::Location,
+    settings::object::Object,
+};
+
+/// The structure is an implementation of [`Locator`] to search for cells with a specified condition.
+#[derive(Debug, Clone, Copy, Default, Hash, PartialEq, Eq, PartialOrd, Ord)]
+pub struct ByCondition<F>(F);
+
+impl<F> ByCondition<F> {
+    /// Constructs a new object of the structure.
+    pub fn new(search: F) -> Self
+    where
+        F: Fn(&str) -> bool,
+    {
+        Self(search)
+    }
+}
+
+impl<F, R> Location<R> for ByCondition<F>
+where
+    F: Fn(&str) -> bool,
+    R: Records + ExactRecords + PeekableRecords,
+{
+    type Coordinate = Position;
+    type IntoIter = Vec<Position>;
+
+    fn locate(&mut self, records: &R) -> Self::IntoIter {
+        // todo: can be optimized by creating Iterator
+        let cond = &self.0;
+
+        let mut out = vec![];
+        for row in 0..records.count_rows() {
+            for col in 0..records.count_columns() {
+                let text = records.get_text((row, col));
+                if cond(text) {
+                    out.push((row, col));
+                }
+            }
+        }
+
+        out
+    }
+}
+
+impl<F, R> Object<R> for ByCondition<F>
+where
+    F: Fn(&str) -> bool,
+    R: Records + ExactRecords + PeekableRecords,
+{
+    type Iter = std::vec::IntoIter<Entity>;
+
+    fn cells(&self, records: &R) -> Self::Iter {
+        // todo: can be optimized by creating Iterator
+        let cond = &self.0;
+
+        let mut out = vec![];
+        for row in 0..records.count_rows() {
+            for col in 0..records.count_columns() {
+                let text = records.get_text((row, col));
+                if cond(text) {
+                    out.push(Entity::Cell(row, col));
+                }
+            }
+        }
+
+        out.into_iter()
+    }
+}

tabled/src/settings/location/by_content.rs

@@ -8,11 +8,8 @@ use crate::{
     settings::object::Object,
 };
 
-/// The structure is an implementation of [`Locator`] to search for cells with a specified content by it's name.
-/// A name is considered be a value in a first row.
-///
-/// So even if in reality there's no header, the first row will be considered to be one.
-#[derive(Debug, Clone, Copy)]
+/// The structure is an implementation of [`Locator`] to search for cells with a given content.
+#[derive(Debug, Clone, Copy, Default, Hash, PartialEq, Eq, PartialOrd, Ord)]
 pub struct ByContent<S>(S);
 
 impl<S> ByContent<S> {

tabled/src/settings/location/locator.rs

@@ -1,4 +1,4 @@
-use super::{ByColumnName, ByContent};
+use super::{ByColumnName, ByCondition, ByContent};
 
 /// An abstract factory for locations, to be used to find different things on the table.
 #[derive(Debug, Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Default, Hash)]
@@ -20,4 +20,15 @@ impl Locator {
     {
         ByColumnName::new(text)
     }
+
+    /// Constructs a new location searcher with a specified condition closure.
+    ///
+    /// Return `true` if it shall be included in output.
+    /// Otherwise return `false`.
+    pub fn by<F>(condition: F) -> ByCondition<F>
+    where
+        F: Fn(&str) -> bool,
+    {
+        ByCondition::new(condition)
+    }
 }

tabled/src/settings/location/mod.rs

@@ -3,10 +3,13 @@
 //! # Example
 //!
 //! ```
-//! use tabled::{Table, Tabled};
-//! use tabled::settings::{
-//!     Modify, object::{Object, Rows},
-//!     location::Locator, Padding, Alignment,
+//! use tabled::{
+//!     settings::{
+//!         location::Locator,
+//!         object::{Columns, Object},
+//!         Alignment, Modify, Padding,
+//!     },
+//!     Table, Tabled,
 //! };
 //!
 //! #[derive(Tabled)]
@@ -24,36 +27,42 @@
 //!
 //! let mut table = Table::new(data);
 //! table.with(Padding::zero());
-//! table.with(Modify::new(Locator::content("todo,2").intersect(Rows::last())).with(Alignment::right()));
-//! table.with(Modify::new(Locator::content("todo")).with(Alignment::center()));
+//! table.with(Modify::new(Locator::column("link")).with(Alignment::right()));
+//! table.with(Modify::new(Locator::content("todo")).with("todo,1"));
+//! table.with(
+//!     Modify::new(Columns::single(1).intersect(Locator::by(|text| text.contains("todo"))))
+//!         .with(Padding::new(4, 0, 0, 0)),
+//! );
 //!
 //! let output = table.to_string();
 //!
 //! assert_eq!(
 //!     output,
 //!     concat!(
-//!         "+-----------------------------------------------------------------+-------+\n",
-//!         "|link                                                             |comment|\n",
-//!         "+-----------------------------------------------------------------+-------+\n",
-//!         "|https://www.gnu.org/software/grub/manual/multiboot/multiboot.html| todo  |\n",
-//!         "+-----------------------------------------------------------------+-------+\n",
-//!         "|https://wiki.debian.org/initramfs                                | todo  |\n",
-//!         "+-----------------------------------------------------------------+-------+\n",
-//!         "|http://jdebp.uk/FGA/efi-boot-process.html                        |todo,2 |\n",
-//!         "+-----------------------------------------------------------------+-------+\n",
-//!         "|https://wiki.debian.org/UEFI                                     | todo,2|\n",
-//!         "+-----------------------------------------------------------------+-------+",
+//!         "+-----------------------------------------------------------------+----------+\n",
+//!         "|                                                             link|comment   |\n",
+//!         "+-----------------------------------------------------------------+----------+\n",
+//!         "|https://www.gnu.org/software/grub/manual/multiboot/multiboot.html|    todo,1|\n",
+//!         "+-----------------------------------------------------------------+----------+\n",
+//!         "|                                https://wiki.debian.org/initramfs|    todo,1|\n",
+//!         "+-----------------------------------------------------------------+----------+\n",
+//!         "|                        http://jdebp.uk/FGA/efi-boot-process.html|    todo,2|\n",
+//!         "+-----------------------------------------------------------------+----------+\n",
+//!         "|                                     https://wiki.debian.org/UEFI|    todo,2|\n",
+//!         "+-----------------------------------------------------------------+----------+",
 //!     ),
 //! );
 //! ```
 
 // todo: Add .modify method for Table
 
 mod by_column_name;
+mod by_condition;
 mod by_content;
 mod locator;
 
 pub use by_column_name::ByColumnName;
+pub use by_condition::ByCondition;
 pub use by_content::ByContent;
 pub use locator::Locator;
 
@@ -211,7 +220,7 @@ mod tests {
         grid::config::Entity,
         grid::records::vec_records::CellInfo,
         grid::records::vec_records::VecRecords,
-        settings::location::{ByColumnName, ByContent},
+        settings::location::{ByColumnName, ByCondition, ByContent},
         settings::object::Object,
     };
 
@@ -303,6 +312,70 @@ mod tests {
         );
     }
 
+    #[test]
+    fn object_by_condition_test() {
+        let data = [
+            vec![vec![1, 2, 3], vec![1, 2, 3], vec![1, 2, 3]],
+            vec![vec![1, 2, 3], vec![1, 1, 3], vec![1, 2, 1]],
+            vec![vec![1, 1, 3], vec![1, 1, 3], vec![1, 1, 1]],
+            vec![vec![1, 1, 1], vec![1, 1, 3], vec![1, 1, 1]],
+            vec![vec![0, 1, 1], vec![1, 1, 3], vec![1, 1, 1]],
+            vec![vec![0, 0, 0], vec![1, 1, 3], vec![1, 1, 1]],
+        ];
+
+        assert_eq!(cells(by_cond("1"), &[]), []);
+        assert_eq!(cells(by_cond("1"), &[vec![], vec![], vec![]]), []);
+        assert_eq!(
+            cells(by_cond("1"), &data[0]),
+            [Cell(0, 0), Cell(1, 0), Cell(2, 0)]
+        );
+        assert_eq!(
+            cells(by_cond("1"), &data[1]),
+            [Cell(0, 0), Cell(1, 0), Cell(1, 1), Cell(2, 0), Cell(2, 2)]
+        );
+        assert_eq!(
+            cells(by_cond("1"), &data[2]),
+            [
+                Cell(0, 0),
+                Cell(0, 1),
+                Cell(1, 0),
+                Cell(1, 1),
+                Cell(2, 0),
+                Cell(2, 1),
+                Cell(2, 2)
+            ]
+        );
+        assert_eq!(
+            cells(by_cond("1"), &data[3]),
+            [
+                Cell(0, 0),
+                Cell(0, 1),
+                Cell(0, 2),
+                Cell(1, 0),
+                Cell(1, 1),
+                Cell(2, 0),
+                Cell(2, 1),
+                Cell(2, 2)
+            ]
+        );
+        assert_eq!(
+            cells(by_cond("1"), &data[4]),
+            [
+                Cell(0, 1),
+                Cell(0, 2),
+                Cell(1, 0),
+                Cell(1, 1),
+                Cell(2, 0),
+                Cell(2, 1),
+                Cell(2, 2)
+            ]
+        );
+        assert_eq!(
+            cells(by_cond("1"), &data[5]),
+            [Cell(1, 0), Cell(1, 1), Cell(2, 0), Cell(2, 1), Cell(2, 2)]
+        );
+    }
+
     fn by_colname(text: &str) -> ByColumnName<&str> {
         ByColumnName::new(text)
     }
@@ -311,6 +384,10 @@ mod tests {
         ByContent::new(text)
     }
 
+    fn by_cond(text: &'static str) -> ByCondition<impl Fn(&str) -> bool> {
+        ByCondition::new(move |content| content == text)
+    }
+
     fn cells<O>(o: O, data: &[Vec<usize>]) -> Vec<Entity>
     where
         O: Object<VecRecords<CellInfo<String>>>,