chore: rename executor -> evaluator and integrate into app

crates/eval/Cargo.toml

@@ -9,6 +9,7 @@ edition = "2021"
 clap = { workspace = true, features = [ "derive" ] }
 image = "0.24"
 ir = { path = "../ir" }
+serde = { workspace = true }
 
 [lints]
 workspace = true

crates/eval/src/cpu/mod.rs

@@ -1 +0,0 @@
-pub(crate) struct CpuExecutor;

crates/eval/src/debug/mod.rs

@@ -1,37 +0,0 @@
-use ir::instruction::{Filter, Kind};
-
-use crate::value::Dynamic;
-mod instructions;
-
-pub struct Executor;
-
-impl crate::Executor for Executor {
-    fn execute(instruction: Kind, input: Option<Dynamic>) -> Option<Dynamic> {
-        match instruction {
-            Kind::Read(read_instruction) => {
-                Some(Dynamic::Image(instructions::read::read(read_instruction)))
-            }
-            Kind::Write(write_instruction) => {
-                instructions::write::write(
-                    write_instruction,
-                    match input {
-                        Some(Dynamic::Image(ref img)) => img,
-                        _ => panic!("awawwawwa"),
-                    },
-                );
-                None
-            }
-            Kind::Math(_) => todo!(),
-            Kind::Blend(_) => todo!(),
-            Kind::Noise(_) => todo!(),
-            Kind::Filter(filter_instruction) => match filter_instruction {
-                Filter::Invert => Some(Dynamic::Image(instructions::filters::invert::invert(
-                    match input {
-                        Some(Dynamic::Image(img)) => img,
-                        _ => panic!("invalid value type for invert"),
-                    },
-                ))),
-            },
-        }
-    }
-}

crates/eval/src/kind/debug/mod.rs

@@ -0,0 +1,57 @@
+use std::mem;
+
+use ir::{
+    instruction::{Filter, Kind},
+    GraphIr, Instruction, InstructionRef,
+};
+
+use crate::value::Dynamic;
+mod instr;
+
+#[derive(Debug, Default)]
+pub struct Evaluator {
+    ir: GraphIr,
+}
+
+impl crate::Evaluator for Evaluator {
+    fn feed(&mut self, ir: GraphIr) {
+        // TODO: should add instead of replace, see note in Evaluator trait above this method
+        self.ir = ir;
+    }
+
+    fn eval_full(&mut self) {
+        let queue: Vec<Instruction> = self
+            .ir
+            .topological_sort()
+            .into_iter()
+            .map(Into::into)
+            .collect();
+        for instr in queue {
+            self.step(instr);
+        }
+    }
+}
+
+impl Evaluator {
+    #[allow(clippy::needless_pass_by_value)]
+    fn step(&mut self, instr: Instruction) {
+        let _ = match instr.kind {
+            Kind::Read(details) => Some(Dynamic::Image(instr::read::read(details))),
+            Kind::Write(details) => {
+                instr::write::write(details, todo!());
+                None
+            }
+            Kind::Math(_) => todo!(),
+            Kind::Blend(_) => todo!(),
+            Kind::Noise(_) => todo!(),
+            Kind::Filter(filter_instruction) => match filter_instruction {
+                Filter::Invert => Some(Dynamic::Image(instr::filters::invert::invert(
+                    match todo!() {
+                        Some(Dynamic::Image(img)) => img,
+                        _ => panic!("invalid value type for invert"),
+                    },
+                ))),
+            },
+        };
+    }
+}

crates/eval/src/kind/mod.rs

@@ -0,0 +1 @@
+pub mod debug;

crates/eval/src/lib.rs

@@ -1,34 +1,43 @@
-use ir::instruction::Kind;
-use value::Dynamic;
+use ir::GraphIr;
 
-mod debug;
+mod kind;
 mod value;
 
-/// The available executors
-/// unused in early dev.
-#[derive(Debug, Clone, Copy, clap::ValueEnum)]
-pub enum RegisteredExecutor {
-    /// the debug executor is single threaded and really, *really* slow. And unstable. Don't use. Unless you're a dev working on this.
+/// Can collapse a [`GraphIr`] in meaningful ways and do interesting work on it.
+///
+/// It's surprisingly difficult to find a fitting description for this.
+pub trait Evaluator {
+    /// Take some [`GraphIr`] which will then be processed later.
+    /// May be called multiple times, in which the [`GraphIr`]s should add up.
+    // TODO: atm they definitely don't add up -- add some functionality to GraphIr to
+    //       make it combine two graphs into one
+    fn feed(&mut self, ir: GraphIr);
+
+    /// Walk through the _whole_ [`GraphIr`] and run through each instruction.
+    fn eval_full(&mut self);
+
+    // TODO: for an LSP or the like, eval_single which starts at a given instr
+}
+
+/// The available [`Evaluator`]s.
+///
+/// Checklist for adding new ones:
+///
+/// 1. Create a new module under the [`kind`] module.
+/// 2. Add a struct and implement [`Evaluator`] for it.
+#[derive(Clone, Copy, Debug, Default, clap::ValueEnum, serde::Deserialize, serde::Serialize)]
+pub enum Available {
+    /// Runs fully on the CPU. Single-threaded, debug-friendly and quick to implement.
+    #[default]
     Debug,
 }
 
-trait Executor {
-    fn execute(instruction: Kind, input: Option<Dynamic>) -> Option<Dynamic>;
-}
-
-pub fn execute_all(instructions: Vec<Kind>) {
-    let mut tmp = None;
-
-    for instruction in instructions {
-        tmp = debug::Executor::execute(instruction, tmp);
+impl Available {
+    /// Selects the [`Evaluator`] corresponding to this label.
+    #[must_use]
+    pub fn pick(&self) -> Box<dyn Evaluator> {
+        match self {
+            Self::Debug => Box::new(kind::debug::Evaluator::default()),
+        }
     }
 }
-
-// scratchpad lol:
-// execution structure:
-// 1. take in rpl
-// 2. analyse/validate structure against allowed executors
-// 3. assign executors to instructions
-// 4. optimize
-// 5. prepare memory management patterns
-// 6. run