feat: support save to png

add missing docs

Cargo.toml

@@ -15,8 +15,15 @@ dyn-clone = "1.0.17"
 num-traits = "0.2.19"
 plotters = "0.3.7"
 polars = { version = "0.45.1", features = ["csv", "partition_by"] }
+thiserror = "2.0.8"
 # thiserror = "1.0.63"
 typed-builder = "0.20.0"
 
-# [dev-dependencies]
+[dev-dependencies]
 # trybuild = "1.0.99"
+polars = { version = "0.45.1", features = [
+    "dtype-u8",
+    "dtype-u16",
+    "lazy",
+    "parquet",
+] }

src/aes.rs

@@ -1,28 +1,45 @@
+//! Aesthetic mappings
+
 use std::ops::{Add, AddAssign};
 
 use derive_builder::Builder;
 
 pub mod color;
 
+/// Aesthetic mappings
+///
+/// Aesthetic mappings describe how variables in the data are mapped to visual
+/// properties (aesthetics) of geoms. Aesthetic mappings are constructed with
+/// the [`aes!`](crate::aes!) marco or [`Aes::builder`] method.
+///
+/// TODO: some aesthetics are not used as "mapping" but as "constant" values.
 #[derive(Clone, Debug, Default, PartialEq, Builder)]
 #[builder(default, setter(into, strip_option))]
 pub struct Aes {
+    /// The column name to map to the x-axis
     pub x: Option<&'static str>,
 
+    /// The column name to map to the y-axis
     pub y: Option<&'static str>,
 
+    /// The color aesthetic
     pub color: Option<color::Color>,
 
+    /// The fill aesthetic
     pub fill: Option<bool>,
 
+    /// The size aesthetic
     pub size: Option<i32>,
 
+    /// The shape aesthetic
     pub shape: Option<u8>,
 
+    /// The label aesthetic
     pub label: Option<String>,
 }
 
 impl Aes {
+    /// Create a new [`Aes`] object via the builder pattern
     pub fn builder() -> AesBuilder {
         AesBuilder::default()
     }
@@ -51,10 +68,12 @@ impl Add for Aes {
 }
 
 impl AesBuilder {
+    /// Set the color aesthetic, alias for [`AesBuilder::color`]
     pub fn colour<T: Into<color::Color>>(&mut self, colour: T) -> &mut Self {
         self.color(colour)
     }
 
+    /// Set the color aesthetic, alias for [`AesBuilder::color`]
     pub fn col<T: Into<color::Color>>(&mut self, col: T) -> &mut Self {
         self.color(col)
     }
@@ -63,7 +82,47 @@ impl AesBuilder {
 // Trick to hide internal implementation details from the docs
 macro_rules! __aes {
     ($aes: item) => {
-        /// Construct Aesthetic Mappings
+        /// # aes!: Construct Aesthetic Mappings
+        ///
+        /// This macro is used to create an [`Aes`] object in a more concise way
+        /// like `ggplot2`. It is a wrapper around [`Aes::builder`].
+        ///
+        /// ## Usage
+        ///
+        /// ```ignore
+        /// aes!(
+        ///     x = <X_COLUMN>,
+        ///     y = <Y_COLUMN>,
+        ///     ...
+        /// )
+        /// ```
+        ///
+        /// ### Arguments
+        ///
+        /// #### `x` and `y`
+        ///
+        /// The column names to map to the x-axis and y-axis, respectively.
+        ///
+        /// If they are the first two arguments, they can be passed without the
+        /// named argument.
+        ///
+        /// ```
+        /// # use gongbi::*;
+        /// let a1 = aes!(x);
+        /// let a2 = aes!(x, y);
+        ///
+        /// assert_eq!(a1.x, Some("x"));
+        /// assert_eq!(a2.x, Some("x"));
+        /// assert_eq!(a2.y, Some("y"));
+        /// ```
+        ///
+        /// #### Other Aesthetics
+        ///
+        /// Other aesthetics can be set with the named argument.
+        ///
+        /// - `color`
+        /// - `size`
+        /// - `shape`
         $aes
     };
 }

src/aes/color.rs

@@ -1,3 +1,10 @@
+//! Color module
+//!
+//! This module contains predefined colors and utilities to work with colors.
+
+// TODO: remove this when color is fully implemented
+#![allow(missing_docs)]
+
 use std::str::FromStr;
 
 use plotters::style::RGBColor;

src/data.rs

@@ -1,15 +1,21 @@
-use std::fmt::Debug;
+//! Data module
+//!
+//! This module defines the `Data` trait and its implementations.
 
-use dyn_clone::DynClone;
+use std::fmt::Debug;
 
 pub mod polars;
 
-pub trait Data: Debug + DynClone {
+/// # Data trait
+///
+/// This trait abstracts the data source for the [`Plot`](crate::Plot) struct.
+pub trait Data: Debug {
+    /// Get a column as a vector of f64 values.
     fn column_f64(&self, column_name: &str) -> Vec<f64>;
 
+    /// Get the minimum and maximum values of a column.
     fn column_range_f64(&self, column_name: &str) -> (f64, f64);
 
+    /// Get the length of a column.
     fn column_len(&self, column_name: &str) -> usize;
 }
-
-dyn_clone::clone_trait_object!(Data);

src/data/polars.rs

@@ -1,3 +1,5 @@
+//! `Data` implementation for `polars` DataFrame
+
 use polars::prelude::*;
 
 impl super::Data for DataFrame {

src/label.rs

@@ -1,23 +1,52 @@
+//! Label module.
+
 use std::ops::Add;
 
 use derive_builder::Builder;
 
+/// # Label layer
+///
+/// This layer is used to add important information to the plot.
 #[derive(Clone, Debug, Default, PartialEq, Builder)]
 #[builder(default, setter(into, strip_option))]
 pub struct Label {
+    /// The caption of the label.
     pub caption: Option<String>,
 
+    /// The x-axis description.
     pub x: Option<String>,
 
+    /// The y-axis description.
     pub y: Option<String>,
 }
 
 impl Label {
+    /// Create a [`Label`] via the builder pattern.
     pub fn builder() -> LabelBuilder {
         LabelBuilder::default()
     }
 }
 
+/// # labs!: Construct a new [`Label`] layer.
+///
+/// This macro is used to construct a new [`Label`] layer in a more concise like `ggplot2`.
+/// It is a wrapper around the [`Label::builder`] method.
+///
+/// ## Usage
+///
+/// ```ignore
+/// labs!(
+///     caption = <Caption>,
+///     x = <X>,
+///     y = <Y>,
+/// )
+/// ```
+///
+/// ### Arguments
+///
+/// - `caption`: Also known as the title of the plot.
+/// - `x`: The x-axis description.
+/// - `y`: The y-axis description.
 #[macro_export]
 macro_rules! labs {
     ($($arg: ident = $val: expr),* $(,)?) => {