experimentation: write experiment for enum architecture

crates/prowocessing/src/lib.rs

@@ -2,3 +2,79 @@
 //!
 //! One of the design goals for this library is, however, to be a simple, generic image processing library.
 //! For now, it's just indev... lets see what comes of it!
+
+use experimental::enum_based::{Instruction, PipelineBuilder};
+
+/// just some experiments, to test whether the architecture i want is even possible (or how to do it). probably temporary.
+/// Gonna first try string processing...
+mod experimental {
+    pub mod enum_based {
+        pub enum Instruction {
+            Uppercase,
+            Lowercase,
+        }
+
+        pub struct Pipeline {
+            pipeline: Vec<fn(String) -> String>,
+        }
+
+        impl Pipeline {
+            pub fn run(&self, val: String) -> String {
+                let mut current = val;
+
+                for instr in &self.pipeline {
+                    current = instr(current);
+                }
+
+                current
+            }
+        }
+
+        pub struct PipelineBuilder {
+            pipeline: Vec<Instruction>,
+        }
+
+        impl PipelineBuilder {
+            pub fn new() -> Self {
+                Self {
+                    pipeline: Vec::new(),
+                }
+            }
+
+            pub fn insert(mut self, instr: Instruction) -> Self {
+                self.pipeline.push(instr);
+                self
+            }
+
+            pub fn build(&self) -> Pipeline {
+                fn uppercase(v: String) -> String {
+                    str::to_uppercase(&v)
+                }
+                fn lowercase(v: String) -> String {
+                    str::to_lowercase(&v)
+                }
+
+                let mut res = Vec::new();
+
+                for item in &self.pipeline {
+                    res.push(match item {
+                        Instruction::Uppercase => uppercase,
+                        Instruction::Lowercase => lowercase,
+                    });
+                }
+
+                Pipeline { pipeline: res }
+            }
+        }
+    }
+}
+
+#[test]
+fn test_enums() {
+    let builder = PipelineBuilder::new().insert(Instruction::Uppercase);
+    let upr = builder.build();
+    let upr_lowr = builder.insert(Instruction::Lowercase).build();
+
+    assert_eq!(upr.run(String::from("Test")), String::from("TEST"));
+    assert_eq!(upr_lowr.run(String::from("Test")), String::from("test"));
+}