feat: consolidates API

src/api.rs

@@ -0,0 +1,43 @@
+//! # Common Interfaces and API
+//!
+//! This module provides interfaces and uniform API with simple conventions
+//! that are used in other modules for supervised and unsupervised learning.
+
+use crate::error::Failed;
+
+/// An estimator for unsupervised learning, that provides method `fit` to learn from data
+pub trait UnsupervisedEstimator<X, P> {
+    /// Fit a model to a training dataset, estimate model's parameters.
+    /// * `x` - _NxM_ matrix with _N_ observations and _M_ features in each observation.
+    /// * `parameters` - hyperparameters of an algorithm
+    fn fit(x: &X, parameters: P) -> Result<Self, Failed>
+    where
+        Self: Sized,
+        P: Clone;
+}
+
+/// An estimator for supervised learning, , that provides method `fit` to learn from data and training values
+pub trait SupervisedEstimator<X, Y, P> {
+    /// Fit a model to a training dataset, estimate model's parameters.
+    /// * `x` - _NxM_ matrix with _N_ observations and _M_ features in each observation.
+    /// * `y` - target training values of size _N_.
+    /// * `parameters` - hyperparameters of an algorithm
+    fn fit(x: &X, y: &Y, parameters: P) -> Result<Self, Failed>
+    where
+        Self: Sized,
+        P: Clone;
+}
+
+/// Implements method predict that estimates target value from new data
+pub trait Predictor<X, Y> {
+    /// Estimate target values from new data.
+    /// * `x` - _NxM_ matrix with _N_ observations and _M_ features in each observation.
+    fn predict(&self, x: &X) -> Result<Y, Failed>;
+}
+
+/// Implements method transform that filters or modifies input data
+pub trait Transformer<X> {
+    /// Transform data by modifying or filtering it
+    /// * `x` - _NxM_ matrix with _N_ observations and _M_ features in each observation.
+    fn transform(&self, x: &X) -> Result<X, Failed>;
+}