Try generating types.

.github/workflows/builder.yml

@@ -1,26 +1,64 @@
 name: Matrix
 on:
-  - pull_request
-  - push
+  push:
+    branches:
+      - main
+  pull_request:
+
 jobs:
-  main:
+  format:
+    name: Format
+    runs-on: native
+    steps:
+      - uses: actions/checkout@v6
+      - uses: dtolnay/rust-toolchain@stable
+        with:
+          components: rustfmt, clippy
+      - run: cargo fmt --all -- --check
+
+  clippy:
+    name: Clippy check
+    runs-on: native
+    steps:
+      - uses: actions/checkout@v6
+      - uses: dtolnay/rust-toolchain@stable
+        with:
+          components: rustfmt, clippy
+      - run: cargo clippy --all-targets -- -D warnings
+
+  build:
     strategy:
       matrix:
         rust:
           - stable
           - beta
           - nightly
-    name: ${{matrix.rust}}
-    runs-on: x86_64-linux
+
+    name: Build - ${{matrix.rust}}
+    runs-on: native
     steps:
-      - uses: actions/checkout@v4
-      - uses: dtolnay/rust-toolchain@v1
+      - uses: actions/checkout@v6
+      - uses: dtolnay/rust-toolchain@master
         with:
           toolchain: ${{matrix.rust}}
           components: rustfmt, clippy
-      - run: rustup --version
-      - run: rustc -vV
+      - run: cargo build
+
+  test:
+    strategy:
+      matrix:
+        rust:
+          - stable
+          - beta
+          - nightly
+
+    name: Test - ${{matrix.rust}}
+    runs-on: native
+    steps:
+      - uses: actions/checkout@v6
+      - uses: dtolnay/rust-toolchain@master
+        with:
+          toolchain: ${{matrix.rust}}
+          components: rustfmt, clippy
+      - run: cargo build
 
-      - run: cargo clippy -- --deny clippy::pedantic
-      - run: cargo fmt --all -- --check
-      - run: cargo test

src/syntax/arbitrary.rs

@@ -1,12 +1,9 @@
-use std::fmt::Arguments;
-
 use crate::syntax::ast::{ConstantValue, IntegerWithBase, Type};
 use crate::syntax::location::Location;
 use crate::syntax::name::Name;
 use itertools::Itertools;
 use proptest::arbitrary::Arbitrary;
 use proptest::prelude::{BoxedStrategy, Rng};
-use proptest::prop_oneof;
 use proptest::strategy::{NewTree, Strategy, ValueTree};
 use proptest::test_runner::TestRunner;
 
@@ -24,39 +21,53 @@ pub struct TypeGenerationContext {
 }
 
 impl TypeGenerationContext {
-    fn generate_type(&mut self, runner: &mut TestRunner, depth: usize) -> Type {
+    fn generate_type(&self, runner: &mut TestRunner, depth: usize) -> Type {
         let mut leaf_options = vec![];
 
         if !self.available_constructors.is_empty() {
             for name in self.available_constructors.iter() {
-                leaf_options.push(Type::Constructor(
-                    Location::manufactured(),
-                    name.clone(),
-                ));
+                leaf_options.push(Type::Constructor(Location::manufactured(), name.clone()));
             }
         }
 
         if !self.available_variables.is_empty() {
             for name in self.available_variables.iter() {
-                leaf_options.push(Type::Variable(
-                    Location::manufactured(),
-                    name.clone(),
-                ));
+                leaf_options.push(Type::Variable(Location::manufactured(), name.clone()));
             }
         }
 
         for prim in PRIMITIVE_TYPES.iter() {
             leaf_options.push(Type::Primitive(
-               Location::manufactured(),
-               Name::new(Location::manufactured(), prim.to_string()),
+                Location::manufactured(),
+                Name::new(Location::manufactured(), prim.to_string()),
             ));
         }
 
+        let mut possibilities = leaf_options.len();
+
         if depth < MAXIMUM_TYPE_DEPTH && runner.rng().random_bool(0.5) {
+            possibilities += 2;
         }
 
-        let index = runner.rng().random_range(0..leaf_options.len());
-        leaf_options.remove(index)
+        let index = runner.rng().random_range(0..possibilities);
+
+        if index >= leaf_options.len() {
+            let argument_count = runner.rng().random_range(0..MAXIMUM_TYPE_WIDTH);
+            let final_type = self.generate_type(runner, depth + 1);
+            let mut args = vec![];
+
+            for _ in 0..argument_count {
+                args.push(self.generate_type(runner, depth + 1));
+            }
+
+            if index - leaf_options.len() == 0 {
+                Type::Function(args, Box::new(final_type))
+            } else {
+                Type::Application(Box::new(final_type), args)
+            }
+        } else {
+            leaf_options.remove(index)
+        }
     }
 }
 
@@ -79,10 +90,6 @@ impl TypeGenerationTree {
     }
 }
 
-fn generate_powerset(_: &[Type]) -> Vec<Vec<Type>> {
-    vec![]
-}
-
 fn simplify_type(incoming: &Type) -> Vec<Type> {
     match incoming {
         Type::Primitive(_, _) => vec![],
@@ -282,8 +289,14 @@ impl Strategy for TypeGenerationContext {
     type Tree = TypeGenerationTree;
     type Value = Type;
 
-    fn new_tree(&self, _runner: &mut TestRunner) -> NewTree<Self> {
-        unimplemented!()
+    fn new_tree(&self, runner: &mut TestRunner) -> NewTree<Self> {
+        let initial_type = self.generate_type(runner, 0);
+
+        Ok(TypeGenerationTree {
+            current_value: initial_type,
+            parent: None,
+            untried_simplified_items: None,
+        })
     }
 }