2024-01-23 12:55:01 +00:00
46 changed files with 1857 additions and 445 deletions
--- a/.gitignore
+++ b/.gitignore
@ -3,4 +3,6 @@
 /target
 .pre-commit-config.yaml
 *.pdf
-*.png
+/docs/*.png
 /testfiles/gen/*
 !/testfiles/gen/.gitkeep
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@ -14,7 +14,7 @@ Before we get started, thank you for thinking about doing so!
  - How did you install iOwO?
  - What version of iOwO are you running?
  - What operating system are you running?
-    In the case of a Linux distro, mention the specific distro and when you last update as well.
+    In the case of a Linux distro, mention the specific distro and when you last updated as well.
 - If the bug causes a crash, try to get a backtrace or in worse cases, a coredump.
 ### Feature requests
--- a/Cargo.lock
+++ b/Cargo.lock
@ -63,6 +63,8 @@ dependencies = [
 "ariadne",
 "clap",
 "dirs",
 "eval",
 "ir",
 "owo-colors",
 "ron",
 "serde",
@ -266,12 +268,13 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "a26ae43d7bcc3b814de94796a5e736d4029efb0ee900c12e2d54c993ad1a1e07"
 [[package]]
-name = "executor"
+name = "eval"
 version = "0.1.0"
 dependencies = [
 "clap",
 "image",
- "rpl",
+ "ir",
 "serde",
 ]
 [[package]]
@ -373,6 +376,15 @@ dependencies = [
 "tiff",
 ]
 [[package]]
 name = "ir"
 version = "0.1.0"
 dependencies = [
 "either",
 "ron",
 "serde",
 ]
 [[package]]
 name = "itoa"
 version = "1.0.10"
@ -482,15 +494,6 @@ version = "4.0.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "caff54706df99d2a78a5a4e3455ff45448d81ef1bb63c22cd14052ca0e993a3f"
 [[package]]
 name = "pl-cli"
 version = "0.1.0"
 dependencies = [
 "clap",
 "executor",
 "rpl",
 ]
 [[package]]
 name = "png"
 version = "0.17.10"
@ -589,14 +592,6 @@ dependencies = [
 "serde_derive",
 ]
 [[package]]
 name = "rpl"
 version = "0.1.0"
 dependencies = [
 "ron",
 "serde",
 ]
 [[package]]
 name = "ryu"
 version = "1.0.16"
--- a/Cargo.toml
+++ b/Cargo.toml
@ -1,20 +1,24 @@
 [workspace]
 members = [
  "crates/app",
-  "crates/executor", 
+  "crates/eval",
-  "crates/rpl"
+  "crates/ir",
 ]
 resolver = "2"
 [workspace.dependencies]
-clap = { version = "4", features = [ "derive" ] }
+clap = { version = "4", features = ["derive"] }
-serde = { version = "1.0", features = [ "derive" ] }
+serde = { version = "1.0", features = ["derive"] }
-[lints.rust]
+# to enable all the lints below, this must be present in a workspace member's Cargo.toml:
 # [lints]
 # workspace = true
 [workspace.lints.rust]
 unsafe_code = "deny"
 variant_size_differences = "warn"
-[lints.clippy]
+[workspace.lints.clippy]
 branches_sharing_code = "warn"
 clone_on_ref_ptr = "warn"
 cognitive_complexity = "warn"
--- a/676
+++ b/676
@ -0,0 +1,676 @@
 The main program and its libraries are licensed under the AGPL 3.0
 as listed below the separator line.
 Media samples in the testfiles folder are licensed under CC BY-SA 4.0.
 To view a copy of this license, visit http://creativecommons.org/licenses/by-sa/4.0/
 The appropiate authors are given below, in the format of
 `- file/path: author (link to author)`
 - testfiles/rails.png: Schrottkatze (https://forge.katzen.cafe/schrottkatze)
 ===============================================================================
 iOwO: media pipeline toolset
 Copyright (C) 2024  Schrottkatze, MultisampledNight and iOwO contributors
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  Each version is given a distinguishing version number.  If the
 Program specifies that a certain numbered version of the GNU Affero General
 Public License "or any later version" applies to it, you have the
 option of following the terms and conditions either of that numbered
 version or of any later version published by the Free Software
 Foundation.  If the Program does not specify a version number of the
 GNU Affero General Public License, you may choose any version ever published
 by the Free Software Foundation.
  If the Program specifies that a proxy can decide which future
 versions of the GNU Affero General Public License can be used, that proxy's
 public statement of acceptance of a version permanently authorizes you
 to choose that version for the Program.
  Later license versions may give you additional or different
 permissions.  However, no additional obligations are imposed on any
 author or copyright holder as a result of your choosing to follow a
 later version.
  15. Disclaimer of Warranty.
  THERE IS NO WARRANTY FOR THE PROGRAM, TO THE EXTENT PERMITTED BY
 APPLICABLE LAW.  EXCEPT WHEN OTHERWISE STATED IN WRITING THE COPYRIGHT
 HOLDERS AND/OR OTHER PARTIES PROVIDE THE PROGRAM "AS IS" WITHOUT WARRANTY
 OF ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING, BUT NOT LIMITED TO,
 THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
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 IS WITH YOU.  SHOULD THE PROGRAM PROVE DEFECTIVE, YOU ASSUME THE COST OF
 ALL NECESSARY SERVICING, REPAIR OR CORRECTION.
  16. Limitation of Liability.
  IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN WRITING
 WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MODIFIES AND/OR CONVEYS
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 USE OR INABILITY TO USE THE PROGRAM (INCLUDING BUT NOT LIMITED TO LOSS OF
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 PARTIES OR A FAILURE OF THE PROGRAM TO OPERATE WITH ANY OTHER PROGRAMS),
 EVEN IF SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF THE POSSIBILITY OF
 SUCH DAMAGES.
  17. Interpretation of Sections 15 and 16.
  If the disclaimer of warranty and limitation of liability provided
 above cannot be given local legal effect according to their terms,
 reviewing courts shall apply local law that most closely approximates
 an absolute waiver of all civil liability in connection with the
 Program, unless a warranty or assumption of liability accompanies a
 copy of the Program in return for a fee.
                     END OF TERMS AND CONDITIONS
            How to Apply These Terms to Your New Programs
  If you develop a new program, and you want it to be of the greatest
 possible use to the public, the best way to achieve this is to make it
 free software which everyone can redistribute and change under these terms.
  To do so, attach the following notices to the program.  It is safest
 to attach them to the start of each source file to most effectively
 state the exclusion of warranty; and each file should have at least
 the "copyright" line and a pointer to where the full notice is found.
    <one line to give the program's name and a brief idea of what it does.>
    Copyright (C) <year>  <name of author>
    This program is free software: you can redistribute it and/or modify
    it under the terms of the GNU Affero General Public License as published by
    the Free Software Foundation, either version 3 of the License, or
    (at your option) any later version.
    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU Affero General Public License for more details.
    You should have received a copy of the GNU Affero General Public License
    along with this program.  If not, see <https://www.gnu.org/licenses/>.
 Also add information on how to contact you by electronic and paper mail.
  If your software can interact with users remotely through a computer
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  You should also get your employer (if you work as a programmer) or school,
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 <https://www.gnu.org/licenses/>.
--- a/crates/app/Cargo.toml
+++ b/crates/app/Cargo.toml
@ -6,11 +6,16 @@ edition = "2021"
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
 [dependencies]
 clap = { workspace = true, features = [ "derive", "env" ] }
 serde = { workspace = true, features = [ "derive" ] }
 ron = "0.8"
 serde_json = "1.0"
 ariadne = "0.4"
-time = { version = "0.3", features = [ "local-offset" ] }
+clap = { workspace = true, features = [ "derive", "env" ] }
 dirs = "5"
 eval = { path = "../eval" }
 ir = { path = "../ir" }
 owo-colors = "4"
 ron = "0.8"
 serde = { workspace = true, features = [ "derive" ] }
 serde_json = "1.0"
 time = { version = "0.3", features = [ "local-offset" ] }
 [lints]
 workspace = true
--- a/crates/app/src/config.rs
+++ b/crates/app/src/config.rs
@ -1,3 +1,5 @@
 use std::path::PathBuf;
 use clap::Parser;
 use self::{
@ -10,6 +12,9 @@ mod config_file;
 /// this struct may hold all configuration
 pub struct Config {
    pub source: PathBuf,
    pub evaluator: eval::Available,
    pub startup_msg: bool,
 }
@ -17,37 +22,37 @@ impl Config {
    /// Get the configs from all possible places (args, file, env...)
    pub fn read() -> Self {
        let args = Args::parse();
-        let config_path = if let Some(config_path) = args.config_path {
+        let config = if let Some(config) = args.config_path {
-            Ok(config_path)
+            Ok(config)
        } else {
            find_config_file()
        };
        // try to read a maybe existing config file
-        let file_config = if let Ok(config_path) = config_path {
+        let config = config.ok().and_then(|path| {
-            let file_config = Configs::read(config_path);
+            Configs::read(path).map_or_else(
-
+                |e| {
            match file_config {
                Ok(c) => Some(c),
                Err(e) => {
                    eprintln!("Config error: {e:?}");
                    eprintln!("Proceeding with defaults or cli args...");
                    None
-                }
+                },
-            }
+                Some,
-        } else {
+            )
-            None
+        });
        };
-        if let Some(file_config) = file_config {
+        if let Some(file) = config {
            Self {
                source: args.source,
                evaluator: args.evaluator.and(file.evaluator).unwrap_or_default(),
                // this is negated because to an outward api, the negative is more intuitive,
                // while in the source the other way around is more intuitive
-                startup_msg: !(args.no_startup_message || file_config.no_startup_message),
+                startup_msg: !(args.no_startup_message || file.no_startup_message),
            }
        } else {
            Self {
                source: args.source,
                startup_msg: !args.no_startup_message,
                evaluator: args.evaluator.unwrap_or_default(),
            }
        }
    }
@ -56,7 +61,7 @@ impl Config {
 pub mod error {
    /// Errors that can occur when reading configs
    #[derive(Debug)]
-    pub enum ConfigError {
+    pub enum Config {
        /// The config dir doesn't exist
        NoConfigDir,
        /// We didn't find a config file in the config dir
@ -73,19 +78,19 @@ pub mod error {
        SerdeRonError(ron::error::SpannedError),
    }
-    impl From<std::io::Error> for ConfigError {
+    impl From<std::io::Error> for Config {
        fn from(value: std::io::Error) -> Self {
            Self::IoError(value)
        }
    }
-    impl From<serde_json::Error> for ConfigError {
+    impl From<serde_json::Error> for Config {
        fn from(value: serde_json::Error) -> Self {
            Self::SerdeJsonError(value)
        }
    }
-    impl From<ron::error::SpannedError> for ConfigError {
+    impl From<ron::error::SpannedError> for Config {
        fn from(value: ron::error::SpannedError) -> Self {
            Self::SerdeRonError(value)
        }
--- a/crates/app/src/config/cli.rs
+++ b/crates/app/src/config/cli.rs
@ -4,6 +4,14 @@ use clap::{builder::BoolishValueParser, ArgAction, Parser};
 #[derive(Parser)]
 pub(crate) struct Args {
    /// What file contains the pipeline to evaluate.
    pub source: PathBuf,
    /// How to actually run the pipeline.
    /// Overrides the config file. Defaults to the debug evaluator.
    #[arg(short, long)]
    pub evaluator: Option<eval::Available>,
    /// Read this config file.
    #[arg(short, long)]
    pub config_path: Option<PathBuf>,
--- a/crates/app/src/config/config_file.rs
+++ b/crates/app/src/config/config_file.rs
@ -5,7 +5,7 @@ use std::{
 use serde::{Deserialize, Serialize};
-use super::error::ConfigError;
+use super::error::Config;
 #[derive(Debug, Serialize, Deserialize)]
 pub struct Configs {
@ -13,6 +13,7 @@ pub struct Configs {
    pub example_value: i32,
    #[serde(default)]
    pub no_startup_message: bool,
    pub evaluator: Option<eval::Available>,
 }
 /// what the fuck serde why do i need this
@ -21,9 +22,9 @@ fn default_example_value() -> i32 {
 }
 /// Find the location of a config file and check if there is, in fact, a file
-pub(super) fn find_config_file() -> Result<PathBuf, ConfigError> {
+pub(super) fn find_config_file() -> Result<PathBuf, Config> {
    let Some(config_path) = dirs::config_dir() else {
-        return Err(ConfigError::NoConfigDir);
+        return Err(Config::NoConfigDir);
    };
    let ron_path = config_path.with_file_name("config.ron");
@ -34,16 +35,19 @@ pub(super) fn find_config_file() -> Result<PathBuf, ConfigError> {
    } else if Path::new(&json_path).exists() {
        Ok(json_path)
    } else {
-        Err(ConfigError::NoConfigFileFound)
+        Err(Config::NoConfigFileFound)
    }
 }
 impl Configs {
-    pub fn read(p: PathBuf) -> Result<Self, ConfigError> {
+    pub fn read(p: PathBuf) -> Result<Self, Config> {
-        match p.extension().map(|v| v.to_str().unwrap()) {
+        match p
            .extension()
            .map(|v| v.to_str().expect("config path to be UTF-8"))
        {
            Some("ron") => Ok(serde_json::from_str(&fs::read_to_string(p)?)?),
            Some("json") => Ok(ron::from_str(&fs::read_to_string(p)?)?),
-            e => Err(ConfigError::UnknownExtension(e.map(|v| v.to_owned()))),
+            e => Err(Config::UnknownExtension(e.map(str::to_owned))),
        }
    }
 }
--- a/crates/app/src/error_reporting.rs
+++ b/crates/app/src/error_reporting.rs
@ -3,12 +3,12 @@ use std::process;
 use ron::error::Position;
 /// Report an `Error` from the `serde_json` crate
-pub fn report_serde_json_err(src: &str, err: serde_json::Error) -> ! {
+pub fn report_serde_json_err(src: &str, err: &serde_json::Error) -> ! {
    report_serde_err(src, err.line(), err.column(), err.to_string())
 }
 /// Report a `SpannedError` from the `ron` crate
-pub fn report_serde_ron_err(src: &str, err: ron::error::SpannedError) -> ! {
+pub fn report_serde_ron_err(src: &str, err: &ron::error::SpannedError) -> ! {
    let Position { line, col } = err.position;
    report_serde_err(src, line, col, err.to_string())
 }
@ -23,8 +23,8 @@ fn report_serde_err(src: &str, line: usize, col: usize, msg: String) -> ! {
        .with_message(msg)
        .with_note("We'd like to give better errors, but serde errors are horrible to work with...")
        .finish()
-        .print(("test", Source::from(src)))
+        .eprint(("test", Source::from(src)))
-        .unwrap();
+        .expect("writing error to stderr failed");
    process::exit(1);
 }
--- a/crates/app/src/main.rs
+++ b/crates/app/src/main.rs
@ -1,3 +1,5 @@
 use std::fs;
 use config::Config;
 use welcome_msg::print_startup_msg;
@ -8,10 +10,18 @@ mod error_reporting;
 mod welcome_msg;
 fn main() {
-    // TODO: proper error handling
+    // TODO: proper error handling across the whole function
    //       don't forget to also look inside `Config`
    let cfg = Config::read();
    if cfg.startup_msg {
        print_startup_msg();
    }
    let source = fs::read_to_string(cfg.source).expect("can't find source file");
    let ir = ir::from_ron(&source).expect("failed to parse source to graph ir");
    let mut machine = cfg.evaluator.pick();
    machine.feed(ir);
    machine.eval_full();
 }
--- a/crates/executor/Cargo.toml
+++ b/crates/executor/Cargo.toml
@ -1,5 +1,5 @@
 [package]
-name = "executor"
+name = "eval"
 version = "0.1.0"
 edition = "2021"
@ -8,4 +8,8 @@ edition = "2021"
 [dependencies]
 clap = { workspace = true, features = [ "derive" ] }
 image = "0.24"
-rpl = { path = "../rpl" }
+ir = { path = "../ir" }
 serde = { workspace = true }
 [lints]
 workspace = true
--- a/crates/eval/src/kind/debug/instr/mod.rs
+++ b/crates/eval/src/kind/debug/instr/mod.rs
@ -0,0 +1,45 @@
 pub mod read {
    use image::{io::Reader as ImageReader, DynamicImage};
    use ir::instruction::read::{Read, SourceType};
    pub fn read(Read { source }: Read) -> DynamicImage {
        // TODO: actual error handling
        let img = ImageReader::open(match source {
            SourceType::File(path) => path,
        })
        .expect("something went wrong :(((");
        img.decode().expect("couldn't decode image")
    }
 }
 pub mod write {
    use image::{DynamicImage, ImageFormat};
    use ir::instruction::write::{TargetFormat, TargetType, Write};
    pub fn write(Write { target, format }: Write, input_data: &DynamicImage) {
        // TODO: actual error handling
        input_data
            .save_with_format(
                match target {
                    TargetType::File(path) => path,
                },
                match format {
                    TargetFormat::Jpeg => ImageFormat::Jpeg,
                    TargetFormat::Png => ImageFormat::Png,
                },
            )
            .expect("couldn't save file");
    }
 }
 pub mod filters {
    pub mod invert {
        use image::DynamicImage;
        pub fn invert(mut input_data: DynamicImage) -> DynamicImage {
            input_data.invert();
            input_data
        }
    }
 }
--- a/crates/eval/src/kind/debug/mod.rs
+++ b/crates/eval/src/kind/debug/mod.rs
@ -0,0 +1,105 @@
 use ir::{
    id,
    instruction::{Filter, Kind},
    GraphIr, Instruction, Map,
 };
 use crate::value::Variant;
 mod instr;
 #[derive(Debug, Default)]
 pub struct Evaluator {
    ir: GraphIr,
    /// What the output of each individual streamer, and as result its output sockets, is.
    /// Grows larger as evaluation continues,
    /// as there's no mechanism for purging never-to-be-used-anymore instructions yet.
    evaluated: Map<id::Output, Variant>,
 }
 impl crate::Evaluator for Evaluator {
    fn feed(&mut self, ir: GraphIr) {
        self.ir = ir;
        self.evaluated.clear();
    }
    fn eval_full(&mut self) {
        // GraphIr::topological_sort returns InstructionRefs, which are mostly cool
        // but we'd like to have them owned, so we can call Self::step without lifetime hassle
        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) {
        // what inputs does this instr need? fetch them
        let inputs: Vec<_> = instr
            .input_sources()
            .iter()
            .map(|source| {
                let source_socket = source
                    .as_ref()
                    .expect("all inputs to be connected when an instruction is ran");
                self.evaluated
                    .get(source_socket)
                    .expect("toposort to yield later instrs only after previous ones")
            })
            .collect();
        // then actually do whatever the instruction should do
        // NOTE: makes heavy use of index slicing,
        // on the basis that ir::instruction::Kind::socket_count is correct
        // TODO: make this a more flexible dispatch-ish arch
        let output = match instr.kind {
            Kind::Read(details) => Some(Variant::Image(instr::read::read(details))),
            Kind::Write(details) => {
                #[allow(irrefutable_let_patterns)] // will necessarily change
                let Variant::Image(input) = inputs[0] else {
                    panic!("cannot only write images, but received: `{:?}`", inputs[0]);
                };
                instr::write::write(details, input);
                None
            }
            Kind::Math(_) => todo!(),
            Kind::Blend(_) => todo!(),
            Kind::Noise(_) => todo!(),
            Kind::Filter(filter_instruction) => match filter_instruction {
                Filter::Invert => {
                    #[allow(irrefutable_let_patterns)]
                    let Variant::Image(input) = inputs[0] else {
                        panic!(
                            "cannot only filter invert images, but received: `{:?}`",
                            inputs[0]
                        );
                    };
                    Some(Variant::Image(instr::filters::invert::invert(
                        input.clone(),
                    )))
                }
            },
        };
        if let Some(output) = output {
            // TODO: very inaccurate, actually respect individual instructions.
            //       should be implied by a different arch
            // TODO: all of those should not be public, offer some methods to get this on
            //       `Instruction` instead (can infer short-term based on Kind::socket_count)
            let socket = id::Output(id::Socket {
                belongs_to: instr.id,
                idx: id::SocketIdx(0),
            });
            self.evaluated.insert(socket, output);
        }
    }
 }
--- a/crates/eval/src/kind/mod.rs
+++ b/crates/eval/src/kind/mod.rs
@ -0,0 +1 @@
 pub mod debug;
--- a/crates/eval/src/lib.rs
+++ b/crates/eval/src/lib.rs
@ -0,0 +1,43 @@
 use ir::GraphIr;
 mod kind;
 mod value;
 /// 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,
 }
 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()),
        }
    }
 }
--- a/crates/eval/src/value/mod.rs
+++ b/crates/eval/src/value/mod.rs
@ -0,0 +1,12 @@
 use image::DynamicImage;
 /// Any runtime value that an instruction can input or output.
 ///
 /// The name is taken from [Godot's `Variant` type],
 /// which is very similar to this one.
 ///
 /// [Godot's `Variant` type]: https://docs.godotengine.org/en/stable/classes/class_variant.html
 #[derive(Clone, Debug)]
 pub enum Variant {
    Image(DynamicImage),
 }
--- a/crates/executor/src/cpu/mod.rs
+++ b/crates/executor/src/cpu/mod.rs
@ -1 +0,0 @@
 pub(crate) struct CpuExecutor;
--- a/crates/executor/src/debug/instructions/mod.rs
+++ b/crates/executor/src/debug/instructions/mod.rs
@ -1,41 +0,0 @@
 pub mod read {
    use image::{io::Reader as ImageReader, DynamicImage};
    use rpl::instructions::read::{Read, SourceType};
    pub fn read(Read { source, format }: Read) -> DynamicImage {
        let mut img = ImageReader::open(match source {
            SourceType::File(path) => path,
        })
        .expect("something went wrong :(((");
        img.decode().expect("couldn't decode image")
    }
 }
 pub mod write {
    use image::{io::Reader as ImageReader, DynamicImage, ImageFormat};
    use rpl::instructions::write::{TargetFormat, TargetType, Write};
    pub fn write(Write { target, format }: Write, input_data: DynamicImage) {
        input_data.save_with_format(
            match target {
                TargetType::File(path) => path,
            },
            match format {
                TargetFormat::Jpeg => ImageFormat::Jpeg,
                TargetFormat::Png => ImageFormat::Png,
            },
        );
    }
 }
 pub mod filters {
    pub mod invert {
        use image::DynamicImage;
        pub fn invert(mut input_data: DynamicImage) -> DynamicImage {
            input_data.invert();
            input_data
        }
    }
 }
--- a/crates/executor/src/debug/mod.rs
+++ b/crates/executor/src/debug/mod.rs
@ -1,37 +0,0 @@
 use rpl::instructions::{FilterInstruction, Instruction};
 use crate::{value::DynamicValue, Executor};
 mod instructions;
 pub struct DebugExecutor;
 impl Executor for DebugExecutor {
    fn execute(instruction: Instruction, input: Option<DynamicValue>) -> Option<DynamicValue> {
        match instruction {
            Instruction::Read(read_instruction) => Some(DynamicValue::Image(
                instructions::read::read(read_instruction),
            )),
            Instruction::Write(write_instruction) => {
                instructions::write::write(
                    write_instruction,
                    match input {
                        Some(DynamicValue::Image(img)) => img,
                        _ => panic!("awawwawwa"),
                    },
                );
                None
            }
            Instruction::Math(_) => todo!(),
            Instruction::Blend(_) => todo!(),
            Instruction::Noise(_) => todo!(),
            Instruction::Filter(filter_instruction) => match filter_instruction {
                FilterInstruction::Invert => Some(DynamicValue::Image(
                    instructions::filters::invert::invert(match input {
                        Some(DynamicValue::Image(img)) => img,
                        _ => panic!("invalid value type for invert"),
                    }),
                )),
            },
        }
    }
 }
--- a/crates/executor/src/lib.rs
+++ b/crates/executor/src/lib.rs
@ -1,38 +0,0 @@
 use rpl::instructions::Instruction;
 use value::DynamicValue;
 mod debug;
 mod value;
 /// The available executors
 /// unused in early dev.
 #[derive(Debug, Clone, Copy, clap::ValueEnum)]
 pub enum Executors {
    /// the debug executor is single threaded and really, *really* slow. And unstable. Don't use. Unless you're a dev working on this.
    Debug,
    /// the CPU executor primarily uses the CPU. Most likely most feature complete, and the fallback.
    Cpu,
    /// the Vulkan executor (obviously) uses vulkan. there's a good chance this isn't implemented yet as you're reading this.
    Vulkan,
 }
 trait Executor {
    fn execute(instruction: Instruction, input: Option<DynamicValue>) -> Option<DynamicValue>;
 }
 pub fn execute_all(instructions: Vec<Instruction>) {
    let mut tmp = None;
    for instruction in instructions {
        tmp = debug::DebugExecutor::execute(instruction, tmp);
    }
 }
 // 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
--- a/crates/executor/src/value/mod.rs
+++ b/crates/executor/src/value/mod.rs
@ -1,5 +0,0 @@
 use image::DynamicImage;
 pub enum DynamicValue {
    Image(DynamicImage),
 }
--- a/crates/rpl/Cargo.toml
+++ b/crates/rpl/Cargo.toml
@ -1,10 +1,14 @@
 [package]
-name = "rpl"
+name = "ir"
 version = "0.1.0"
 edition = "2021"
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
 [dependencies]
-serde = { workspace = true, features = [ "derive" ] }
+either = "1.9"
 ron = "0.8"
 serde = { version = "1.0.193", features = ["derive"] }
 [lints]
 workspace = true
--- a/crates/ir/src/id.rs
+++ b/crates/ir/src/id.rs
@ -0,0 +1,84 @@
 //! Instance identification for instructions and their glue.
 //!
 //! Instructions as defined in [`crate::instruction::Kind`] and descendants are very useful,
 //! but they cannot be directly used as vertices in the graph IR,
 //! as there may easily be multiple instructions of the same kind in the same program.
 //!
 //! Instead, this module offers an alternative way to refer to specific instances:
 //!
 //! - [`Instruction`]s are effectively just a number floating in space,
 //!   incremented each time a new instruction is referred to.
 //! - [`Socket`]s contain
 //!   - what [`Instruction`] they belong to
 //!   - which index they occupy on it
 //!
 //!   The distinction between [`Input`] and [`Output`] is implemented
 //!   as them being different types.
 use std::fmt;
 use serde::{Deserialize, Serialize};
 /// One specific instruction.
 ///
 /// It does **not** contain what kind of instruction this is.
 /// Refer to [`crate::instruction::Kind`] for this instead.
 #[derive(Clone, PartialEq, Eq, PartialOrd, Ord, Hash, Serialize, Deserialize)]
 pub struct Instruction(pub(super) u64);
 impl fmt::Debug for Instruction {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        write!(f, "InstrId {}", self.0)
    }
 }
 /// On an **instruction**, accepts incoming data.
 ///
 /// An **instruction** cannot run if any of these are not connected.
 #[derive(Clone, Debug, PartialEq, Eq, PartialOrd, Ord, Hash, Serialize, Deserialize)]
 pub struct Input(pub(super) Socket);
 impl Input {
    #[must_use]
    pub fn socket(&self) -> &Socket {
        &self.0
    }
 }
 /// On an **instruction**, returns outgoing data to be fed to [`Input`]s.
 ///
 /// In contrast to [`Input`]s, [`Output`]s may be used or unused.
 #[derive(Clone, Debug, PartialEq, Eq, PartialOrd, Ord, Hash, Serialize, Deserialize)]
 pub struct Output(pub Socket); // TODO: Restrict publicness to super
 impl Output {
    #[must_use]
    pub fn socket(&self) -> &Socket {
        &self.0
    }
 }
 /// An unspecified socket on a specific **instruction**,
 /// and where it is on that **instruction**.
 #[derive(Clone, Debug, PartialEq, Eq, PartialOrd, Ord, Hash, Serialize, Deserialize)]
 pub struct Socket {
    pub belongs_to: Instruction,
    pub idx: SocketIdx,
 }
 /// Where a [`Socket`] is on one **instruction**.
 ///
 /// Note that this does **not** identify a [`Socket`] globally.
 /// There may be multiple [`Socket`]s sharing the same [`SocketIdx`],
 /// but on different [`Instruction`]s.
 ///
 /// This really only serves for denoting where a socket is,
 /// when it's already clear which instruction is referred to.
 #[derive(Clone, PartialEq, Eq, PartialOrd, Ord, Hash, Serialize, Deserialize)]
 pub struct SocketIdx(pub u16); // TODO: Restrict publicness to super
 impl fmt::Debug for SocketIdx {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        self.0.fmt(f)
    }
 }
--- a/crates/ir/src/instruction/mod.rs
+++ b/crates/ir/src/instruction/mod.rs
@ -0,0 +1,81 @@
 use serde::{Deserialize, Serialize};
 pub mod read;
 pub mod write;
 #[derive(Clone, Debug, PartialEq, Eq, PartialOrd, Ord, Hash, Serialize, Deserialize)]
 pub enum Kind {
    // TODO: `read::Read` and `write::Write` hold real values atm -- they should actually
    //       point to `Const` instructions instead (which are... yet to be done...)
    Read(read::Read),
    Write(write::Write),
    Math(Math),
    Blend(Blend),
    Noise(Noise),
    Filter(Filter),
 }
 #[derive(Clone, Debug, PartialEq, Eq, PartialOrd, Ord, Hash, Serialize, Deserialize)]
 pub enum Math {
    Add,
    Subtract,
    Multiply,
    Divide,
 }
 #[derive(Clone, Debug, PartialEq, Eq, PartialOrd, Ord, Hash, Serialize, Deserialize)]
 pub enum Blend {
    Normal,
    Multiply,
    Additive,
    Overlay,
    Screen,
    Subtractive,
    Difference,
    Darken,
    Lighten,
 }
 #[derive(Clone, Debug, PartialEq, Eq, PartialOrd, Ord, Hash, Serialize, Deserialize)]
 pub enum Noise {
    Perlin,
    Simplex,
    Voronoi,
 }
 #[derive(Clone, Debug, PartialEq, Eq, PartialOrd, Ord, Hash, Serialize, Deserialize)]
 pub enum Filter {
    Invert,
 }
 // TODO: given that this basically matches on all instructions, we may need to use
 //       the visitor pattern in future here, or at least get them behind traits
 //       which should allow far more nuanced description
 impl Kind {
    /// Returns how many sockets this kind of instruction has.
    #[must_use]
    pub fn socket_count(&self) -> SocketCount {
        match self {
            Self::Read(_) => (0, 1),
            Self::Write(_) => (1, 0),
            Self::Math(_) | Self::Blend(_) => (2, 1),
            Self::Noise(_) => {
                todo!("how many arguments does noise take? how many outputs does it have?")
            }
            Self::Filter(Filter::Invert) => (1, 1),
        }
        .into()
    }
 }
 /// How many sockets are on an instruction?
 pub struct SocketCount {
    pub inputs: u16,
    pub outputs: u16,
 }
 impl From<(u16, u16)> for SocketCount {
    fn from((inputs, outputs): (u16, u16)) -> Self {
        Self { inputs, outputs }
    }
 }
--- a/crates/ir/src/instruction/read.rs
+++ b/crates/ir/src/instruction/read.rs
@ -0,0 +1,12 @@
 use serde::{Deserialize, Serialize};
 use std::path::PathBuf;
 #[derive(Clone, Debug, PartialEq, Eq, PartialOrd, Ord, Hash, Serialize, Deserialize)]
 pub struct Read {
    pub source: SourceType,
 }
 #[derive(Clone, Debug, PartialEq, Eq, PartialOrd, Ord, Hash, Serialize, Deserialize)]
 pub enum SourceType {
    File(PathBuf),
 }
--- a/crates/ir/src/instruction/write.rs
+++ b/crates/ir/src/instruction/write.rs
@ -0,0 +1,19 @@
 use serde::{Deserialize, Serialize};
 use std::path::PathBuf;
 #[derive(Clone, Debug, PartialEq, Eq, PartialOrd, Ord, Hash, Serialize, Deserialize)]
 pub struct Write {
    pub target: TargetType,
    pub format: TargetFormat,
 }
 #[derive(Clone, Debug, PartialEq, Eq, PartialOrd, Ord, Hash, Serialize, Deserialize)]
 pub enum TargetType {
    File(PathBuf),
 }
 #[derive(Clone, Debug, PartialEq, Eq, PartialOrd, Ord, Hash, Serialize, Deserialize)]
 pub enum TargetFormat {
    Jpeg,
    Png,
 }
--- a/crates/ir/src/lib.rs
+++ b/crates/ir/src/lib.rs
@ -0,0 +1,353 @@
 use std::num::NonZeroUsize;
 use instruction::SocketCount;
 use serde::{Deserialize, Serialize};
 pub mod id;
 pub mod instruction;
 pub mod semi_human;
 pub type Map<K, V> = std::collections::BTreeMap<K, V>;
 pub type Set<T> = std::collections::BTreeSet<T>;
 /// Gives you a super well typed graph IR for a given human-readable repr.
 ///
 /// Look at [`semi_human::GraphIr`] and the test files in the repo at `testfiles/`
 /// to see what the RON should look like.
 /// No, we don't want you to write out [`GraphIr`] in full by hand.
 /// That's something for the machines to do.
 ///
 /// # Errors
 ///
 /// Returns an error if the parsed source is not a valid human-readable graph IR.
 pub fn from_ron(source: &str) -> ron::error::SpannedResult<GraphIr> {
    let human_repr: semi_human::GraphIr = ron::from_str(source)?;
    Ok(human_repr.into())
 }
 /// The toplevel representation of a whole pipeline.
 ///
 /// # DAGs
 ///
 /// Pipelines may not be fully linear. They may branch out and recombine later on.
 /// As such, the representation for them which is currently used is a
 /// [**D**irected **A**cyclic **G**raph](https://en.wikipedia.org/wiki/Directed_acyclic_graph).
 ///
 /// For those who are already familiar with graphs, a DAG is one, except that:
 ///
 /// - It is **directed**: Edges have a direction they point to.
 ///   In this case, edges point from the outputs of streamers to inputs of consumers.
 /// - It is **acyclic**: Those directed edges may not form loops.
 ///   In other words, if one follows edges only in their direction, it must be impossible
 ///   to come back to an already visited node.
 ///
 /// Here, if an edge points from _A_ to _B_ (`A --> B`),
 /// then _A_ is called a **dependency** or an **input source** of _B_,
 /// and _B_ is called a **dependent** or an **output target** of _A_.
 ///
 /// The DAG also enables another neat operation:
 /// [Topological sorting](https://en.wikipedia.org/wiki/Topological_sorting).
 /// This allows to put the entire graph into a linear list,
 /// where it's guaranteed that once a vertex is visited,
 /// all dependencies of it will have been visited already as well.
 ///
 /// The representation used here in specific is a bit more complicated,
 /// since **instructions** directly aren't just connected to one another,
 /// but their **sockets** are instead.
 ///
 /// So the vertices of the DAG are the **sockets**
 /// (which are either [`id::Input`] or [`id::Output`] depending on the direction),
 /// and each **socket** in turn belongs to an **instruction**.
 ///
 /// # Usage
 ///
 /// - If you want to build one from scratch,
 ///   add a few helper methods like
 ///     constructing an empty one,
 ///     adding instructions and
 ///     adding edges
 /// - If you want to construct one from an existing repr,
 ///   maybe you want to use [`semi_human::GraphIr`].
 ///
 /// # Storing additional data
 ///
 /// Chances are the graph IR seems somewhat fit to put metadata in it.
 /// However, most likely you're interacting in context of some other system,
 /// and also want to manage and index that data on your own.
 ///
 /// As such, consider using _secondary_ maps instead.
 /// That is, store in a data structure _you_ own a mapping
 /// from [`id`]s
 /// to whatever data you need.
 #[derive(Clone, Debug, Default, PartialEq, Eq, Deserialize, Serialize)]
 pub struct GraphIr {
    /// "Backbone" storage of all **instruction** IDs to
    /// what **kind of instruction** they are.
    instructions: Map<id::Instruction, instruction::Kind>,
    /// How the data flows forward. **Dependencies** map to **dependents** here.
    edges: Map<id::Output, Set<id::Input>>,
    /// How the data flows backward. **Dependents** map to **dependencies** here.
    rev_edges: Map<id::Input, id::Output>,
 }
 // TODO: this impl block, but actually the whole module, screams for tests
 impl GraphIr {
    /// Look "backwards" in the graph,
    /// and find out what instructions need to be done before this one.
    /// The input slots are visited in order.
    ///
    /// - The iterator returns individually [`Some`]`(`[`None`]`)` if the corresponding slot is
    ///   not connected.
    ///
    /// The same caveats as for [`GraphIr::resolve`] apply.
    #[must_use]
    pub fn input_sources(
        &self,
        subject: &id::Instruction,
    ) -> Option<impl Iterator<Item = Option<&id::Output>> + '_> {
        let (subject, kind) = self.instructions.get_key_value(subject)?;
        let SocketCount { inputs, .. } = kind.socket_count();
        Some((0..inputs).map(|idx| {
            let input = id::Input(socket(subject, idx));
            self.rev_edges.get(&input)
        }))
    }
    /// Look "forwards" in the graph to see what other instructions this instruction feeds into.
    ///
    /// The output slots represent the top-level iterator,
    /// and each one's connections are emitted one level below.
    ///
    /// Just [`Iterator::flatten`] if you are not interested in the slots.
    ///
    /// The same caveats as for [`GraphIr::resolve`] apply.
    #[must_use]
    pub fn output_targets(
        &self,
        subject: &id::Instruction,
    ) -> Option<impl Iterator<Item = Option<&Set<id::Input>>> + '_> {
        let (subject, kind) = self.instructions.get_key_value(subject)?;
        let SocketCount { outputs, .. } = kind.socket_count();
        Some((0..outputs).map(|idx| {
            let output = id::Output(socket(subject, idx));
            self.edges.get(&output)
        }))
    }
    /// Returns the instruction corresponding to the given ID.
    /// Returns [`None`] if there is no such instruction in this graph IR.
    ///
    /// Theoretically this could be fixed easily at the expense of some memory
    /// by just incrementing and storing some global counter,
    /// however, at the moment there's no compelling reason
    /// to actually have multiple [`GraphIr`]s at one point in time.
    /// Open an issue if that poses a problem for you.
    #[must_use]
    pub fn resolve<'ir>(&'ir self, subject: &id::Instruction) -> Option<InstructionRef<'ir>> {
        let (id, kind) = self.instructions.get_key_value(subject)?;
        let input_sources = self.input_sources(subject)?.collect();
        let output_targets = self.output_targets(subject)?.collect();
        Some(InstructionRef {
            id,
            kind,
            input_sources,
            output_targets,
        })
    }
    /// Returns the instruction this input belongs to.
    ///
    /// The same caveats as for [`GraphIr::resolve`] apply.
    #[must_use]
    pub fn owner_of_input<'ir>(&'ir self, input: &id::Input) -> Option<InstructionRef<'ir>> {
        self.resolve(&input.socket().belongs_to)
    }
    /// Returns the instruction this output belongs to.
    ///
    /// The same caveats as for [`GraphIr::resolve`] apply.
    #[must_use]
    pub fn owner_of_output<'ir>(&'ir self, output: &id::Output) -> Option<InstructionRef<'ir>> {
        self.resolve(&output.socket().belongs_to)
    }
    /// Returns the order in which the instructions could be visited
    /// in order to ensure that all dependencies are resolved
    /// before a vertex is visited.
    ///
    /// # Panics
    ///
    /// Panics if there are any cycles in the IR, as it needs to be a DAG.
    #[must_use]
    // yes, this function could probably return an iterator and be lazy
    // no, not today
    pub fn topological_sort(&self) -> Vec<InstructionRef> {
        // count how many incoming edges each vertex has
        let mut nonzero_input_counts: Map<_, NonZeroUsize> =
            self.rev_edges
                .iter()
                .fold(Map::new(), |mut count, (input, _)| {
                    let _ = *count
                        .entry(input.socket().belongs_to.clone())
                        .and_modify(|count| *count = count.saturating_add(1))
                        .or_insert(NonZeroUsize::MIN);
                    count
                });
        // are there any unconnected ones we could start with?
        // TODO: experiment if a VecDeque with some ordering fun is digested better by the executor
        let no_inputs: Vec<_> = {
            let nonzero: Set<_> = nonzero_input_counts.keys().collect();
            let all: Set<_> = self.instructions.keys().collect();
            all.difference(&nonzero).copied().cloned().collect()
        };
        // then let's find the order!
        let mut order = Vec::new();
        let mut active_queue = no_inputs;
        while let Some(current) = active_queue.pop() {
            // now that this vertex is visited and resolved,
            // make sure all dependents notice that
            let dependents = self
                .output_targets(&current)
                .expect("graph to be consistent")
                .flatten()
                .flatten();
            for dependent_input in dependents {
                let dependent = &dependent_input.socket().belongs_to;
                // how many inputs are connected to this dependent without us?
                let count = nonzero_input_counts
                    .get_mut(dependent)
                    .expect("connected output must refer to non-zero input");
                let new = NonZeroUsize::new(count.get() - 1);
                if let Some(new) = new {
                    // aww, still some
                    *count = new;
                    continue;
                }
                // none, that means this one is free now! let's throw it onto the active queue then
                let (now_active, _) = nonzero_input_counts
                    .remove_entry(dependent)
                    .expect("connected output must refer to non-zero input");
                active_queue.push(now_active);
            }
            // TODO: check if this instruction is "well-fed", that is, has all the inputs it needs,
            //       and if not, panic
            order.push(self.resolve(&current).expect("graph to be consistent"));
        }
        assert!(
            nonzero_input_counts.is_empty(),
            concat!(
                "topological sort didn't cover all instructions\n",
                "either there are unconnected inputs, or there is a cycle\n",
                "unresolved instructions:\n",
                "{:#?}"
            ),
            nonzero_input_counts,
        );
        order
    }
 }
 /// Constructs an [`id::Socket`] a bit more tersely.
 fn socket(id: &id::Instruction, idx: u16) -> id::Socket {
    id::Socket {
        belongs_to: id.clone(),
        idx: id::SocketIdx(idx),
    }
 }
 /// A full instruction bundeled in context, with its inputs and outputs.
 #[derive(Clone, Debug, PartialEq, Eq, PartialOrd, Ord)]
 pub struct Instruction {
    pub id: id::Instruction,
    pub kind: instruction::Kind,
    // can't have these two public since then a user might corrupt their length
    input_sources: Vec<Option<id::Output>>,
    output_targets: Vec<Set<id::Input>>,
 }
 impl Instruction {
    /// Where this instruction gets its inputs from.
    ///
    /// [`None`] means that this input is unfilled,
    /// and must be filled before the instruction can be ran.
    #[must_use]
    pub fn input_sources(&self) -> &[Option<id::Output>] {
        &self.input_sources
    }
    /// To whom outputs are sent.
    #[must_use]
    pub fn output_targets(&self) -> &[Set<id::Input>] {
        &self.output_targets
    }
 }
 /// [`Instruction`], but every single field is borrowed instead.
 /// See its docs.
 ///
 /// Use the [`From`] impl to handily convert into an [`Instruction`].
 /// The other way around is unlikely to be wanted — since you already have an [`Instruction`],
 /// chances are you just want to take a reference (`&`) of it.
 #[derive(Clone, Debug, PartialEq, Eq, PartialOrd, Ord)]
 pub struct InstructionRef<'ir> {
    pub id: &'ir id::Instruction,
    pub kind: &'ir instruction::Kind,
    input_sources: Vec<Option<&'ir id::Output>>,
    output_targets: Vec<Option<&'ir Set<id::Input>>>,
 }
 impl<'ir> InstructionRef<'ir> {
    /// Where this instruction gets its inputs from.
    ///
    /// [`None`] means that this input is unfilled,
    /// and must be filled before the instruction can be ran.
    #[must_use]
    pub fn input_sources(&self) -> &[Option<&'ir id::Output>] {
        &self.input_sources
    }
    /// To whom outputs are sent.
    #[must_use]
    pub fn output_targets(&self) -> &[Option<&'ir Set<id::Input>>] {
        &self.output_targets
    }
 }
 // would love to use ToOwned but Rust has no specialization yet
 // and it'd hurt a blanket impl of ToOwned otherwise
 impl From<InstructionRef<'_>> for Instruction {
    fn from(source: InstructionRef<'_>) -> Self {
        Self {
            id: source.id.clone(),
            kind: source.kind.clone(),
            input_sources: source
                .input_sources
                .into_iter()
                .map(Option::<&_>::cloned)
                .collect(),
            output_targets: source
                .output_targets
                .into_iter()
                .map(|outputs| outputs.map(Clone::clone).unwrap_or_default())
                .collect(),
        }
    }
 }
--- a/crates/ir/src/semi_human.rs
+++ b/crates/ir/src/semi_human.rs
@ -0,0 +1,87 @@
 //! The midterm solution for source representation, until we've got a nice source frontend.
 //!
 //! Sacrifices type expressivity for the sake of typability in [RON] files.
 //!
 //! **If you want to construct a graph IR programmatically,
 //! use [`crate::GraphIr`] directly instead,
 //! as it gives you more control to specify where your instructions came from.**
 //!
 //! [RON]: https://docs.rs/ron/latest/ron/
 use serde::{Deserialize, Serialize};
 use crate::{id, instruction, Map, Set};
 /// Semi-human-{read,writ}able [`crate::GraphIr`] with far less useful types.
 ///
 /// **Do not use this if you want to programatically construct IR.**
 /// Instead, directly use [`crate::GraphIr`].
 #[derive(Clone, Debug, PartialEq, Eq, Deserialize, Serialize)]
 pub struct GraphIr {
    /// See [`crate::GraphIr::instructions`], just that a simple number is used for the ID instead
    pub(crate) instructions: Map<u64, instruction::Kind>,
    /// See [`crate::GraphIr::edges`], the forward edges.
    /// RON wants you to type the set as if it were a list.
    pub(crate) edges: Map<Socket, Set<Socket>>,
 }
 #[derive(Clone, Debug, PartialEq, Eq, PartialOrd, Ord, Hash, Deserialize, Serialize)]
 pub struct Socket {
    /// ID of the instruction this socket is on.
    pub(crate) on: u64,
    pub(crate) idx: u16,
 }
 impl From<Socket> for id::Socket {
    fn from(source: Socket) -> Self {
        Self {
            belongs_to: id::Instruction(source.on),
            idx: id::SocketIdx(source.idx),
        }
    }
 }
 impl From<GraphIr> for crate::GraphIr {
    fn from(source: GraphIr) -> Self {
        let edges = source.edges.clone();
        Self {
            instructions: source
                .instructions
                .into_iter()
                .map(|(id, kind)| (id::Instruction(id), kind))
                .collect(),
            edges: type_edges(source.edges),
            rev_edges: reverse_and_type_edges(edges),
        }
    }
 }
 fn type_edges(edges: Map<Socket, Set<Socket>>) -> Map<id::Output, Set<id::Input>> {
    edges
        .into_iter()
        .map(|(output, inputs)| {
            let output = id::Output(output.into());
            let inputs = inputs.into_iter().map(Into::into).map(id::Input).collect();
            (output, inputs)
        })
        .collect()
 }
 fn reverse_and_type_edges(edges: Map<Socket, Set<Socket>>) -> Map<id::Input, id::Output> {
    edges
        .into_iter()
        .fold(Map::new(), |mut rev_edges, (output, inputs)| {
            let output = id::Output(output.into());
            for input in inputs {
                let input = id::Input(input.into());
                let previous = rev_edges.insert(input, output.clone());
                if let Some(previous) = previous {
                    // TODO: handle this with a TryFrom impl
                    panic!("two or more outputs referred to the same input {previous:#?}");
                }
            }
            rev_edges
        })
 }
--- a/crates/rpl/src/instructions/mod.rs
+++ b/crates/rpl/src/instructions/mod.rs
@ -1,47 +0,0 @@
 use serde::{Deserialize, Serialize};
 pub mod read;
 pub mod write;
 #[derive(Serialize, Deserialize, PartialEq, Eq, Debug)]
 pub enum Instruction {
    Read(read::Read),
    Write(write::Write),
    Math(MathInstruction),
    Blend(BlendInstruction),
    Noise(NoiseInstruction),
    Filter(FilterInstruction),
 }
 #[derive(Serialize, Deserialize, PartialEq, Eq, Debug)]
 pub enum MathInstruction {
    Add,
    Subtract,
    Multiply,
    Divide,
 }
 #[derive(Serialize, Deserialize, PartialEq, Eq, Debug)]
 pub enum BlendInstruction {
    Normal,
    Multiply,
    Additive,
    Overlay,
    Screen,
    Subtractive,
    Difference,
    Darken,
    Lighten,
 }
 #[derive(Serialize, Deserialize, PartialEq, Eq, Debug)]
 pub enum NoiseInstruction {
    Perlin,
    Simplex,
    Voronoi,
 }
 #[derive(Serialize, Deserialize, PartialEq, Eq, Debug)]
 pub enum FilterInstruction {
    Invert,
 }
--- a/crates/rpl/src/instructions/read.rs
+++ b/crates/rpl/src/instructions/read.rs
@ -1,19 +0,0 @@
 use serde::{Deserialize, Serialize};
 use std::path::PathBuf;
 #[derive(Serialize, Deserialize, PartialEq, Eq, Debug)]
 pub struct Read {
    pub source: SourceType,
    pub format: SourceFormat,
 }
 #[derive(Serialize, Deserialize, PartialEq, Eq, Debug)]
 pub enum SourceType {
    File(PathBuf),
 }
 #[derive(Serialize, Deserialize, PartialEq, Eq, Debug)]
 pub enum SourceFormat {
    Jpeg,
    Png,
 }
--- a/crates/rpl/src/instructions/write.rs
+++ b/crates/rpl/src/instructions/write.rs
@ -1,19 +0,0 @@
 use serde::{Deserialize, Serialize};
 use std::path::PathBuf;
 #[derive(Serialize, Deserialize, PartialEq, Eq, Debug)]
 pub struct Write {
    pub target: TargetType,
    pub format: TargetFormat,
 }
 #[derive(Serialize, Deserialize, PartialEq, Eq, Debug)]
 pub enum TargetType {
    File(PathBuf),
 }
 #[derive(Serialize, Deserialize, PartialEq, Eq, Debug)]
 pub enum TargetFormat {
    Jpeg,
    Png,
 }
--- a/crates/rpl/src/lib.rs
+++ b/crates/rpl/src/lib.rs
@ -1,38 +0,0 @@
 use instructions::Instruction;
 use serde::{Deserialize, Serialize};
 use crate::instructions::{
    read::{SourceFormat, SourceType},
    write::{TargetFormat, TargetType},
    MathInstruction,
 };
 pub mod instructions;
 pub fn from_ron(raw: &str) -> Rpl {
    ron::from_str(raw).unwrap()
 }
 #[derive(Serialize, Deserialize, PartialEq, Eq, Debug)]
 pub struct Rpl(pub Vec<Instruction>);
 #[test]
 fn test_simple_deserialize() {
    const TEST_DATA: &str =
        "([Read( (source: File(\"~/example/file.png\"), format: Png) ),Math(Add),Write(( target: File(\"~/example/out.jpg\"), format: Jpeg))])";
    assert_eq!(
        from_ron(TEST_DATA),
        Rpl(vec![
            Instruction::Read(instructions::read::Read {
                source: SourceType::File("~/example/file.png".into()),
                format: SourceFormat::Png
            }),
            Instruction::Math(MathInstruction::Add),
            Instruction::Write(instructions::write::Write {
                target: TargetType::File("~/example/out.jpg".into()),
                format: TargetFormat::Jpeg
            })
        ])
    );
 }
--- a/crates/rpl/src/value/mod.rs
+++ b/crates/rpl/src/value/mod.rs
@ -1,3 +0,0 @@
 pub enum DynamicValue {
    Image(DynamicImage),
 }
--- a/docs/design/iowo-design.typ
+++ b/docs/design/iowo-design.typ
@ -7,7 +7,75 @@
  subtitle: [don't worry, we're just dreaming],
 )
-= Evaluation stages
+= Term overview
 / Processing stages:
  Whole workflow of iOwO,
  from the source to evaluation.
 / Source:
  Nice textual representation of what iOwO is supposed to do.
  Consists of instructions and pipelines.
 / Graph IR:
  Intermediate machine-readable representation of the source.
  Can be modified by the optimizer
  and is evaluated or "ran" by the runtime.
 / Optimizer:
  Simplifies the graph IR and makes it faster to run.
 / Runtime:
  All-encompassing term for what's done
  after a graph IR is optimized and fully ready to go.
 / Scheduler:
  Looks at the graph IR
  and decides which evaluator gets to run which part of it.
 / Evaluator:
  One specific implementation of how to run
  through the whole graph IR to get its results.
 / Function:
  On the source level and before the graph IR,
  anything that can be run with inputs,
  possibly receiving outputs.
 / Instruction:
  Function, but in the graph IR and at runtime.
  Ask schrottkatze on why the differentiation is important.
 / Input:
  Received by a function or instruction.
  Different inputs may result in different behavior
  and/or in different outputs.
 / Argument:
  On the source level,
  an input which is given ad-hoc
  instead of provided through a pipeline.
 / Output:
  Returned by a function or instruction,
  and can be fed into other functions or instructions.
 / Consumer:
  Function or instruction that takes at least 1 input.
 / Streamer:
  Function or instruction that returns at least 1 output.
 / Modifier:
  Function or instruction that is _both_ a consumer and a streamer.
 / Pipeline:
  Any chain of streamers and consumers,
  possibly with modifiers in-between,
  that may branch out
  and recombine arbitrarily.
 = Processing stages
 #graphics.stages-overview
@ -18,7 +86,7 @@ This has a number of benefits and implications:
 - Bugs are easier to trace down to one stage.
 - Stages are also replacable, pluggable and usable somewhere else.
  - For example,
-    one could write a Just-In-Time compiler as a new executor to replace the runtime stage,
+    one could write a Just-In-Time compiler as a new evaluator to replace the runtime stage,
    while preserving the source #arrow() graph IR step.
 However, this also makes the architecture somewhat more complicated. So here we try our best to describe how each stage looks like. If you have any feedback, feel free to drop it on #link("https://forge.katzen.cafe/katzen-cafe/iowo/issues")[the issues in the repository]!
@ -152,17 +220,17 @@ Merges and simplifies functions in the graph IR.
 == Runtime <runtime>
 Runs through all functions in the graph IR.
-It does not have any significantly other representation,
+It does not have any significantly different representation,
 and despite its name there's _no_ bytecode involved.
 Different runtimes are called executors.
 Executors operate on instructions instead of functions.
 === Scheduler
-Looks at the graph IR and decides when the VM should execute what.
+Looks at the graph IR and decides when which evaluator gets to evaluate what.
-=== VM <vm>
+=== Evaluator
 Runs instructions given to it in a specific way,
 such as for example on the GPU using OpenCL.
 = Open questions
--- a/docs/design/util/graphics.typ
+++ b/docs/design/util/graphics.typ
@ -7,69 +7,69 @@
 // - `group` can be used in either of ^, but not standalone
 #let graphic(what) = box({
-	cetz.canvas({
+  cetz.canvas({
-		// any preamble-ish stuff can go here
+    // any preamble-ish stuff can go here
-		set-style(
+    set-style(
-			mark: (angle: 90deg),
+      mark: (angle: 90deg),
      stroke: (cap: "round", join: "round"),
-		)
+    )
-		what
+    what
-	})
+  })
 })
 #let canvas(what) = {
-	align(center, graphic(what))
+  align(center, graphic(what))
 }
 // smaller stuff
 #let arrow(length: 0.4cm, lift: 3pt, stroke: 1pt) = graphic({
-	line((0, lift), (rel: (length, 0)), mark: (end: ">", stroke: stroke))
+  line((0, lift), (rel: (length, 0)), mark: (end: ">", stroke: stroke))
-	// hack for the bounding box bottom
+  // hack for the bounding box bottom
-	// so that `lift` even has any effect
+  // so that `lift` even has any effect
-	line((0, 0), (0, 0), stroke: none)
+  line((0, 0), (0, 0), stroke: none)
 })
 // larger stuff
 #let sequence(
-	distance: 3cm,
+  distance: 3cm,
-	arrow-spacing: 0.15cm,
+  arrow-spacing: 0.15cm,
-	// cetz will support rounded rects in 0.2.0
+  // cetz will support rounded rects in 0.2.0
-	style: (frame: "rect", padding: 0.1cm),
+  style: (frame: "rect", padding: 0.1cm),
-	..labels,
+  ..labels,
 ) = group({
-	let labels = labels.pos()
+  let labels = labels.pos()
-	// draw each label itself
+  // draw each label itself
-	for (i, label) in labels.enumerate() {
+  for (i, label) in labels.enumerate() {
-		if i != 0 {
+    if i != 0 {
-			set-origin((distance, 0))
+      set-origin((distance, 0))
-		}
+    }
-		content((0, 0), name: "label-" + str(i), label, ..style)
+    content((0, 0), name: "label-" + str(i), label, ..style)
-	}
+  }
-	// then draw an arrow from each to each
+  // then draw an arrow from each to each
-	// since an arrow is between two, the last one can't be connected with the "next-to-last" one
+  // since an arrow is between two, the last one can't be connected with the "next-to-last" one
-	// so we leave it out
+  // so we leave it out
-	for i in range(labels.len() - 1) {
+  for i in range(labels.len() - 1) {
-		line(
+    line(
-			(rel: (arrow-spacing, 0), to: "label-" + str(i) + ".right"),
+      (rel: (arrow-spacing, 0), to: "label-" + str(i) + ".right"),
-			(rel: (-arrow-spacing, 0), to: "label-" + str(i + 1) + ".left"),
+      (rel: (-arrow-spacing, 0), to: "label-" + str(i + 1) + ".left"),
-			mark: (end: ">"),
+      mark: (end: ">"),
-		)
+    )
-	}
+  }
 })
 #let stages-overview = canvas({
-	sequence(
+  sequence(
-		[Source],
+    [Source],
-		[Graph IR],
+    [Graph IR],
-		[Runtime],
+    [Runtime],
-	)
+  )
 })
 // A few commands to help demonstration in the docs.
@ -219,8 +219,11 @@
  )
 }
 // i wonder if layouting could be automatized
 // if the graph is guaranteed to be acyclic,
 // then we could just lay them out in "columns"
 #let graph-example = canvas({
-  let x = 3
+  let x = 2.25
  let y = -3
  node((-x, -0.75 * y), ty: "const", body: "\"base.png\"", name: "base")
  node((x, -0.75 * y), ty: "const", body: "\"stencil.png\"", name: "stencil")
@ -245,7 +248,7 @@
 // literally just for standalone display of the graphics alone
 #import "../../template.typ": conf
-#show: conf
+#show: conf.with(render-outline: false)
 #set page(width: auto, height: auto)
 #graph-example
--- a/docs/template.typ
+++ b/docs/template.typ
@ -1,11 +1,11 @@
 // would also be interesting to try out IBM Plex Mono/Sans sometime
 #let atk = "Atkinson Hyperlegible"
 #let fonts = (
-	main: (font: atk, size: 12pt),
+  main: (font: atk, size: 12pt),
-	title: (font: atk, size: 20pt),
+  title: (font: atk, size: 20pt),
-	subtitle: (font: atk, size: 10pt),
+  subtitle: (font: atk, size: 10pt),
-	heading: (font: "Montserrat", weight: "regular"),
+  heading: (font: "Montserrat", weight: "regular"),
 )
 #let expand(it) = {
@ -33,49 +33,51 @@
 // this'd require wrapping the whole document in a show rule
 // at which point `query` doesn't find anything anymore
 #let terms = (
  "processing stage",
  "source",
  "AST",
  "graph IR",
  "runtime",
  "executor",
  "optimizer",
  "scheduler",
-  "VM",
+  "evaluator",
  "evaluation",
  "function",
  "instruction",
  "pipeline",
  "input", "argument", "consumer",
  "output", "streamer",
  "modifier",
  "pipeline",
 )
 // yes, the shadowing is intentional to avoid accidentally using the list
 #let terms = regex("\\b(" + terms.map(expand).join("|") + ")\\b")
 #let conf(
-	title: none,
+  title: none,
-	subtitle: none,
+  subtitle: none,
-	doc,
+  render-outline: true,
  doc,
 ) = {
-	set page(
+  set page(
-		numbering: "1 / 1",
+      numbering: "1 / 1",
-    margin: 3.25cm,
+        margin: 3.25cm,
-		header: locate(loc => {
+          header: locate(loc => {
-			datetime.today().display()
+      datetime.today().display()
-			if counter(page).at(loc).first() > 1 {
+      if counter(page).at(loc).first() > 1 {
-				// on all pages other than the first, the title is useful to have at hand
+        // on all pages other than the first, the title is useful to have at hand
-				h(1fr)
+        h(1fr)
-				title
+        title
-			}
+      }
-		}),
+    }),
-	)
+  )
  set par(justify: true)
-	set text(..fonts.main)
+  set text(..fonts.main)
-	set heading(numbering: "A.1")
+  set heading(numbering: "A.1")
-	show heading: it => text(..fonts.heading, it)
+  show heading: it => text(..fonts.heading, it)
  // color links
  show link: text.with(fill: blue)
  // prettify codeblocks
@ -121,32 +123,34 @@
    raw(it.text, lang: "haskell", block: true)
  }
-	// document title
+  // document title
-	if title != none {
+  if title != none {
-		align(
+    align(
-			right,
+      right,
-			text(..fonts.title, title)
+      text(..fonts.title, title)
-			+ v(-12pt)
+      + v(-12pt)
-			+ text(..fonts.subtitle, subtitle)
+      + text(..fonts.subtitle, subtitle)
-		)
+    )
-		v(0.25cm)
+    v(0.25cm)
-	}
+  }
  // outline and other prelude info
-  outline(
+  if render-outline {
-    indent: auto,
+    outline(
-    fill: line(
+      indent: auto,
-      length: 100%,
+      fill: line(
-      stroke: (
+        length: 100%,
-        cap: "round",
+        stroke: (
-        join: "round",
+          cap: "round",
-        thickness: 0.5pt,
+          join: "round",
-        paint: luma(75%),
+          thickness: 0.5pt,
          paint: luma(75%),
        ),
      ),
-    ),
+    )
-  )
+  }
-	// content itself
+  // content itself
-	doc
+  doc
 }
--- a/flake.nix
+++ b/flake.nix
@ -36,7 +36,13 @@
                    rustfmt.enable = true;
                  };
-                  packages = with pkgs; [just nushell typst];
+                  packages = with pkgs; [
                    just nushell
                    ripgrep
                    typst typst-lsp
                    mold
                    cargo-nextest cargo-watch
                  ];
                })
              ];
            };
--- a/12
+++ b/12
@ -1,3 +1,9 @@
 all: test docs
 test:
  #!/usr/bin/env nu
  cargo nextest run
 # Compile all documentation as in proposals and design documents, placing them under `docs/compiled`.
 docs:
  #!/usr/bin/env nu
@ -9,3 +15,9 @@ docs:
    )
    mv $pdf docs/compiled
  } | ignore
 fmt:
  #!/usr/bin/env nu
  cargo fmt
  echo "Places where whitespace is at the end of a line:"
  rg '\s$'
--- a/testfiles/bare.ron
+++ b/testfiles/bare.ron
@ -0,0 +1,16 @@
 (
 	instructions: {
 		0: Read((
 			source: File("testfiles/rails.png"),
 		)),
 		1: Write((
 			target: File("testfiles/gen/out.jpg"),
 			format: Jpeg,
 		)),
 	},
 	edges: {
 		(on: 0, idx: 0): [
 			(on: 1, idx: 0),
 		],
 	},
 )
--- a/testfiles/bare.rpl
+++ b/testfiles/bare.rpl
@ -1,12 +0,0 @@
 (
 	[
 		Read((
 			source: File("/home/jade/example/file.png"), 
 			format: Png
 		)),
 		Write(( 
 			target: File("/home/jade/example/out.jpg"), 
 			format: Jpeg
 		))
 	]
 )
--- a/testfiles/gen/.gitkeep
+++ b/testfiles/gen/.gitkeep
@ -0,0 +1 @@
 the testfile scripts will place generated images and media here. thank you for your understanding.
--- a/testfiles/invert.ron
+++ b/testfiles/invert.ron
@ -0,0 +1,16 @@
 (
 	instructions: {
 		0: Read((
 			source: File("testfiles/rails.png"),
 		)),
 		1: Filter(Invert),
 		2: Write((
 			target: File("testfiles/gen/inverted.png"),
 			format: Png,
 		)),
 	},
 	edges: {
 		(on: 0, idx: 0): [(on: 1, idx: 0)],
 		(on: 1, idx: 0): [(on: 2, idx: 0)],
 	},
 )
--- a/testfiles/invert.rpl
+++ b/testfiles/invert.rpl
@ -1,13 +0,0 @@
 (
 	[
 		Read((
 			source: File("/home/jade/example/file.png"),
 			format: Png
 		)),
 		Filter(Invert),
 		Write((
 			target: File("/home/jade/example/inverted.jpg"),
 			format: Jpeg
 		))
 	]
 )
--- a/testfiles/rails.png
+++ b/testfiles/rails.png
		`@ -0,0 +1 @@`
							`the testfile scripts will place generated images and media here. thank you for your understanding.`