Improvements to types and subtyping (#68)

CONTRIBUTING.md

@@ -2,7 +2,7 @@
 
 Consider checking out [current standing issues](https://github.com/kaleidawave/ezno/issues) before contributing. In general, leave an issue before putting in a PR.
 
-*If any problems come up following the steps. Leave an issue*
+If any problems come up in the following steps, please leave an issue :)
 
 #### Setting up
 
@@ -14,21 +14,28 @@ then clone the repo with `git`:
 
 ```shell
 git clone https://github.com/kaleidawave/ezno.git
+# or using the GH CLI
+gh repo clone kaleidawave/ezno
 ```
 
-or using the GH CLI
+Now in the `ezno` directory, `cargo run` should show the CLI.
+
+## Development
+
+If you don't want to run the whole Ezno CLI. You can run just the checker with
 
 ```shell
-gh repo clone kaleidawave/ezno
+cargo run -p ezno-checker -F ezno-parser --example check path/to/file.ts
 ```
 
-Now in the `ezno` directory, `cargo run` should show the CLI
-
-### Rules
+If you want to test the lexing and parsing in Ezno's parser
 
-- Won't merge PRs that introduce new errors. However will merge PRs which pick up or find existing issues
-- Code **must** be formatted with `cargo format` inline with the current format configuration
-- Use `cargo clippy` as guidance but lints are not a blocker
+```shell
+# Parsing, prints parse errors or the debug view of the AST
+cargo run -p ezno-parser --example parse path/to/file.ts
+# Lexing, prints lex errors or the tokens
+cargo run -p ezno-parser --example lex path/to/file.ts
+```
 
 ### Useful commands
 
@@ -39,7 +46,12 @@ Now in the `ezno` directory, `cargo run` should show the CLI
 ### The notify! macro
 
 The checker crate has the `crate::utils::notify!` macro, which can be used to trace information when the `EZNO_DEBUG` environment variable is set.
+## *Rules* for contributions
+
+- Won't merge PRs that introduce new errors. However will merge PRs which pick up or find existing issues
+- Code **must** be formatted with `cargo format` inline with the current format configuration
+- Use `cargo clippy` as guidance for design but warning lints are not a blocker
 
-### Oxc
+## Oxc
 
-If working on [oxc_type_synthesis](https://github.com/web-infra-dev/oxc/tree/main/crates/oxc_type_synthesis). You can (git) clone [oxc](https://github.com/web-infra-dev/oxc) alongside Ezno and then use path dependencies to work on them simultaneously.
+If working on [oxc_type_synthesis](https://github.com/web-infra-dev/oxc/tree/main/crates/oxc_type_synthesis) **and Ezno simultaneously**. You can (git) clone [oxc](https://github.com/web-infra-dev/oxc) alongside Ezno and then use path dependencies to work on them simultaneously.

checker/definitions/internal.d.ts

@@ -1,3 +1,4 @@
+// ↓↓ Ezno Functions ↓↓
 declare function debug_context(): void performs const debug_context;
 declare function print_type(t: any): void performs const print_type;
 declare function debug_type(t: any): void performs const debug_type;
@@ -11,17 +12,30 @@ declare function context_id_chain(): void performs const context_id_chain;
 declare function satisfies<T>(t: T): T performs const satisfies;
 
 declare function compile_type_to_object<T>(): any performs const compile_type_to_object;
+// ↑↑ Ezno Functions ↑↑
 
-interface Array<T> {
-    length: number;
+declare var undefined: undefined;
 
+interface nominal Array<T> {
     [index: number]: T;
+
+    length: number;
 
-    push(item: any) performs {
+    push(item: T) performs {
         this[this.length] = item;
         return ++this.length
     }
 
+    pop(): T | undefined performs {
+        if (this.length === 0) {
+            return undefined
+        } else {
+            const value = this[--this.length];
+            delete this[this.length];
+            return value
+        }
+    }
+
     last() performs {
         return this[this.length - 1]
     }
@@ -36,9 +50,11 @@ interface Math {
     cbrt(x: number): number performs const cbrt;
 }
 
-interface string {
+interface nominal string {
     toUpperCase(): string performs const uppercase;
     toLowerCase(): string performs const lowercase;
+
+    get length(): number performs const string_length;
 }
 
 interface Console {

checker/examples/check.rs

@@ -0,0 +1,55 @@
+#[cfg(feature = "ezno-parser")]
+fn main() {
+	use ezno_checker::{check_project, synthesis};
+	use std::{
+		collections::HashSet,
+		env, fs,
+		path::{Path, PathBuf},
+	};
+
+	let name = env::args().nth(1).unwrap_or_else(|| "examples/test.ts".to_string());
+	let path = Path::new(&name);
+
+	let (diagnostics, post_check_data) = check_project::<_, synthesis::EznoParser>(
+		path.to_path_buf(),
+		HashSet::from_iter(std::iter::once(ezno_checker::INTERNAL_DEFINITION_FILE_PATH.into())),
+		|path: &std::path::Path| {
+			if path == &PathBuf::from(ezno_checker::INTERNAL_DEFINITION_FILE_PATH) {
+				Some(ezno_checker::INTERNAL_DEFINITION_FILE.to_owned())
+			} else {
+				Some(fs::read_to_string(path).unwrap())
+			}
+		},
+		None,
+		Default::default(),
+	);
+
+	let args: Vec<_> = env::args().collect();
+
+	if let Ok(mut post_check_data) = post_check_data {
+		if args.iter().any(|arg| arg == "--types") {
+			eprintln!("Types:");
+			for item in post_check_data.types.into_vec_temp() {
+				eprintln!("\t{:?}", item);
+			}
+		}
+		if args.iter().any(|arg| arg == "--events") {
+			eprintln!("Events on entry:");
+			let entry_module =
+				post_check_data.modules.remove(&post_check_data.entry_source).unwrap();
+			for item in entry_module.facts.get_events() {
+				eprintln!("\t{:?}", item);
+			}
+		}
+	}
+
+	eprintln!("Diagnostics:");
+	for diagnostic in diagnostics.into_iter() {
+		eprintln!("\t{}", diagnostic.reason())
+	}
+}
+
+#[cfg(not(feature = "ezno-parser"))]
+fn main() {
+	println!("Requires 'ezno-parser'")
+}

checker/specification/Cargo.toml

@@ -10,6 +10,9 @@ publish = false
 [workspace]
 members = ["."]
 
+[features]
+all = []
+
 [[test]]
 name = "specification_test"
 path = "test.rs"

checker/specification/build.rs

@@ -4,6 +4,9 @@ use std::io::Write;
 use std::path::Path;
 
 fn main() -> Result<(), Box<dyn Error>> {
+	println!("cargo:rerun-if-changed=specification.md");
+	println!("cargo:rerun-if-changed=TODO.md");
+
 	let out_path = Path::new(&std::env::var("OUT_DIR")?).join("specification.rs");
 	let mut out = File::create(out_path)?;
 
@@ -19,14 +22,8 @@ fn main() -> Result<(), Box<dyn Error>> {
 	markdown_lines_append_test_to_rust(lines, &mut out)?;
 
 	if cfg!(feature = "all") {
-		let not_yet_implemented = read_to_string("./not_yet_implemented.md")?;
-		let mut lines = not_yet_implemented.lines().enumerate();
-
-		while let Some((_, line)) = lines.next() {
-			if line == "## TODO" {
-				break;
-			}
-		}
+		let not_yet_implemented = read_to_string("./to_implement.md")?;
+		let lines = not_yet_implemented.lines().enumerate();
 
 		writeln!(&mut out, "mod todo {{ use super::check_errors; ").unwrap();
 		markdown_lines_append_test_to_rust(lines, &mut out)?;