From 6a392a27de6bf2f289d9f44183daab521a5c83eb Mon Sep 17 00:00:00 2001
From: Yaroslav Bolyukin <iam@lach.pw>
Date: Wed, 06 Jan 2021 04:04:56 +0000
Subject: [PATCH] feat: describe jrsonnet type system


---
--- /dev/null
+++ b/crates/jrsonnet-types/Cargo.toml
@@ -0,0 +1,7 @@
+[package]
+name = "jrsonnet-types"
+version = "0.3.2"
+authors = ["Yaroslav Bolyukin <iam@lach.pw>"]
+edition = "2018"
+
+[dependencies]
--- /dev/null
+++ b/crates/jrsonnet-types/src/lib.rs
@@ -0,0 +1,183 @@
+use std::fmt::Display;
+
+#[macro_export]
+macro_rules! ty {
+	([$inner:tt]) => {{
+		static VAL: &'static ComplexValType = &ty!($inner);
+		match VAL {
+			ComplexValType::Any => ComplexValType::Simple(ValType::Arr),
+			_ => ComplexValType::ArrayRef(&VAL),
+		}
+	}};
+	(bool) => {
+		ComplexValType::Simple(ValType::Bool)
+	};
+	(null) => {
+		ComplexValType::Simple(ValType::Null)
+	};
+	(str) => {
+		ComplexValType::Simple(ValType::Str)
+	};
+	(char) => {
+		ComplexValType::Char
+	};
+	(num) => {
+		ComplexValType::Simple(ValType::Num)
+	};
+	(number(($min:expr)..($max:expr))) => {{
+		ComplexValType::BoundedNumber($min, $max)
+	}};
+	(obj) => {
+		ComplexValType::Simple(ValType::Obj)
+	};
+	(any) => {
+		ComplexValType::Any
+	};
+	(fn.any) => {
+		ComplexValType::Simple(ValType::Func)
+	};
+	(($($a:tt) |+)) => {{
+		static CONTENTS: &'static [ComplexValType] = &[
+			$(ty!($a)),+
+		];
+		ComplexValType::UnionRef(CONTENTS)
+	}};
+	(($($a:tt) &+)) => {{
+		static CONTENTS: &'static [ComplexValType] = &[
+			$(ty!($a)),+
+		];
+		ComplexValType::SumRef(CONTENTS)
+	}};
+}
+
+#[test]
+fn test() {
+	assert_eq!(
+		ty!([num]),
+		ComplexValType::ArrayRef(&ComplexValType::Simple(ValType::Num))
+	);
+	assert_eq!(ty!([any]), ComplexValType::Simple(ValType::Arr));
+	assert_eq!(ty!(any), ComplexValType::Any);
+	assert_eq!(
+		ty!((str | num)),
+		ComplexValType::UnionRef(&[
+			ComplexValType::Simple(ValType::Str),
+			ComplexValType::Simple(ValType::Num)
+		])
+	);
+	assert_eq!(
+		format!("{}", ty!(((str & num) | (obj & null)))),
+		"((str & num) | (obj & null))"
+	);
+	assert_eq!(format!("{}", ty!((str | [any]))), "(str | [any])");
+}
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+pub enum ValType {
+	Bool,
+	Null,
+	Str,
+	Num,
+	Arr,
+	Obj,
+	Func,
+}
+
+impl ValType {
+	pub const fn name(&self) -> &'static str {
+		use ValType::*;
+		match self {
+			Bool => "bool",
+			Null => "null",
+			Str => "str",
+			Num => "num",
+			Arr => "[any]",
+			Obj => "obj",
+			Func => "fn.any",
+		}
+	}
+}
+
+impl Display for ValType {
+	fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+		write!(f, "{}", self.name())
+	}
+}
+
+#[derive(Debug, Clone, PartialEq)]
+pub enum ComplexValType {
+	Any,
+	Char,
+	Simple(ValType),
+	BoundedNumber(Option<f64>, Option<f64>),
+	ArrayRef(&'static ComplexValType),
+	ObjectRef(&'static [(&'static str, ComplexValType)]),
+	UnionRef(&'static [ComplexValType]),
+	SumRef(&'static [ComplexValType]),
+}
+impl From<ValType> for ComplexValType {
+	fn from(s: ValType) -> Self {
+		Self::Simple(s)
+	}
+}
+
+impl ComplexValType {
+	fn needs_brackets(&self) -> bool {
+		matches!(self, ComplexValType::UnionRef(_) | ComplexValType::SumRef(_))
+	}
+}
+
+fn write_union(
+	f: &mut std::fmt::Formatter<'_>,
+	ch: char,
+	union: &[ComplexValType],
+) -> std::fmt::Result {
+	write!(f, "(")?;
+	for (i, v) in union.iter().enumerate() {
+		if i != 0 {
+			write!(f, " {} ", ch)?;
+		}
+		write!(f, "{}", v)?;
+	}
+	write!(f, ")")?;
+	Ok(())
+}
+
+impl Display for ComplexValType {
+	fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+		match self {
+			ComplexValType::Any => write!(f, "any")?,
+			ComplexValType::Simple(s) => write!(f, "{}", s)?,
+			ComplexValType::Char => write!(f, "char")?,
+			ComplexValType::BoundedNumber(a, b) => write!(
+				f,
+				"number({}..{})",
+				a.map(|e| e.to_string()).unwrap_or_else(|| "".into()),
+				b.map(|e| e.to_string()).unwrap_or_else(|| "".into())
+			)?,
+			ComplexValType::ArrayRef(a) => {
+				if a.needs_brackets() {
+					write!(f, "(")?;
+				}
+				write!(f, "{}", a)?;
+				if a.needs_brackets() {
+					write!(f, ")")?;
+				}
+				write!(f, "[]")?;
+			}
+			ComplexValType::ObjectRef(fields) => {
+				write!(f, "{{")?;
+				for (i, (k, v)) in fields.iter().enumerate() {
+					if i != 0 {
+						write!(f, ", ")?;
+					}
+					write!(f, "{}: {}", k, v)?;
+				}
+				write!(f, "}}")?;
+			}
+			ComplexValType::UnionRef(v) => write_union(f, '|', v)?,
+			ComplexValType::SumRef(v) => write_union(f, '&', v)?,
+		};
+		Ok(())
+	}
+}

-- 
gitstuff