diff options
Diffstat (limited to 'dhall_generator/src')
| -rw-r--r-- | dhall_generator/src/dhall_expr.rs | 122 | ||||
| -rw-r--r-- | dhall_generator/src/dhall_type.rs | 46 |
2 files changed, 70 insertions, 98 deletions
diff --git a/dhall_generator/src/dhall_expr.rs b/dhall_generator/src/dhall_expr.rs index 2e3adf7..96201e8 100644 --- a/dhall_generator/src/dhall_expr.rs +++ b/dhall_generator/src/dhall_expr.rs @@ -11,51 +11,56 @@ pub fn dhall_expr(input: proc_macro::TokenStream) -> proc_macro::TokenStream { let no_import = |_: &Import| -> X { panic!("Don't use import in dhall!()") }; let expr = rc(expr.as_ref().map_embed(&no_import)); - let output = dhall_to_tokenstream_bx(&expr, &Context::new()); + let output = quote_subexpr(&expr, &Context::new()); output.into() } -// Returns an expression of type Expr<_, _>. Expects interpolated variables -// to be of type SubExpr<_, _>. -fn dhall_to_tokenstream( - expr: &DhallExpr, - ctx: &Context<Label, ()>, -) -> TokenStream { +// Returns an expression of type ExprF<T, _, _>, where T is the +// type of the subexpressions after interpolation. +pub fn quote_expr<TS>(expr: ExprF<TS, X, X>) -> TokenStream +where + TS: quote::ToTokens + std::fmt::Debug, +{ + let quote_map = |m: BTreeMap<Label, TS>| -> TokenStream { + let (keys, values): (Vec<TokenStream>, Vec<TS>) = + m.into_iter().map(|(k, v)| (quote_label(&k), v)).unzip(); + quote! { { + use std::collections::BTreeMap; + let mut m = BTreeMap::new(); + #( m.insert(#keys, #values); )* + m + } } + }; + + let quote_vec = |e: Vec<TS>| -> TokenStream { + quote! { vec![ #(#e),* ] } + }; + use dhall_core::ExprF::*; - match expr.as_ref() { - Var(_) => { - let v = dhall_to_tokenstream_bx(expr, ctx); - quote! { *#v } - } + match expr { + Var(_) => unreachable!(), Pi(x, t, b) => { - let t = dhall_to_tokenstream_bx(t, ctx); - let b = dhall_to_tokenstream_bx(b, &ctx.insert(x.clone(), ())); - let x = label_to_tokenstream(x); + let x = quote_label(&x); quote! { dhall_core::ExprF::Pi(#x, #t, #b) } } Lam(x, t, b) => { - let t = dhall_to_tokenstream_bx(t, ctx); - let b = dhall_to_tokenstream_bx(b, &ctx.insert(x.clone(), ())); - let x = label_to_tokenstream(x); + let x = quote_label(&x); quote! { dhall_core::ExprF::Lam(#x, #t, #b) } } App(f, a) => { - let f = dhall_to_tokenstream_bx(f, ctx); - let a = vec_to_tokenstream(a, ctx); + let a = quote_vec(a); quote! { dhall_core::ExprF::App(#f, #a) } } Const(c) => { - let c = const_to_tokenstream(*c); + let c = quote_const(c); quote! { dhall_core::ExprF::Const(#c) } } Builtin(b) => { - let b = builtin_to_tokenstream(*b); + let b = quote_builtin(b); quote! { dhall_core::ExprF::Builtin(#b) } } BinOp(o, a, b) => { - let o = binop_to_tokenstream(*o); - let a = dhall_to_tokenstream_bx(a, ctx); - let b = dhall_to_tokenstream_bx(b, ctx); + let o = quote_binop(o); quote! { dhall_core::ExprF::BinOp(#o, #a, #b) } } NaturalLit(n) => { @@ -65,46 +70,51 @@ fn dhall_to_tokenstream( quote! { dhall_core::ExprF::BoolLit(#b) } } EmptyOptionalLit(x) => { - let x = dhall_to_tokenstream_bx(x, ctx); quote! { dhall_core::ExprF::EmptyOptionalLit(#x) } } NEOptionalLit(x) => { - let x = dhall_to_tokenstream_bx(x, ctx); quote! { dhall_core::ExprF::NEOptionalLit(#x) } } EmptyListLit(t) => { - let t = dhall_to_tokenstream_bx(t, ctx); quote! { dhall_core::ExprF::EmptyListLit(#t) } } NEListLit(es) => { - let es = vec_to_tokenstream(es, ctx); + let es = quote_vec(es); quote! { dhall_core::ExprF::NEListLit(#es) } } RecordType(m) => { - let m = map_to_tokenstream(m, ctx); + let m = quote_map(m); quote! { dhall_core::ExprF::RecordType(#m) } } RecordLit(m) => { - let m = map_to_tokenstream(m, ctx); + let m = quote_map(m); quote! { dhall_core::ExprF::RecordLit(#m) } } UnionType(m) => { - let m = map_to_tokenstream(m, ctx); + let m = quote_map(m); quote! { dhall_core::ExprF::UnionType(#m) } } e => unimplemented!("{:?}", e), } } -// Returns an expression of type SubExpr<_, _> -fn dhall_to_tokenstream_bx( - expr: &DhallExpr, +// Returns an expression of type SubExpr<_, _>. Expects interpolated variables +// to be of type SubExpr<_, _>. +fn quote_subexpr( + expr: &SubExpr<X, X>, ctx: &Context<Label, ()>, ) -> TokenStream { use dhall_core::ExprF::*; - match expr.as_ref() { - Var(V(s, n)) => { - match ctx.lookup(&s, *n) { + match map_subexpr( + expr.as_ref(), + |e| quote_subexpr(e, ctx), + |_| unreachable!(), + |_| unreachable!(), + |l| l.clone(), + |l, e| quote_subexpr(e, &ctx.insert(l.clone(), ())), + ) { + Var(V(ref s, n)) => { + match ctx.lookup(s, n) { // Non-free variable; interpolates as itself Some(()) => { let s: String = s.into(); @@ -123,53 +133,27 @@ fn dhall_to_tokenstream_bx( } } } - _ => bx(dhall_to_tokenstream(expr, ctx)), + e => bx(quote_expr(e)), } } -fn builtin_to_tokenstream(b: Builtin) -> TokenStream { +fn quote_builtin(b: Builtin) -> TokenStream { format!("dhall_core::Builtin::{:?}", b).parse().unwrap() } -fn const_to_tokenstream(c: Const) -> TokenStream { +fn quote_const(c: Const) -> TokenStream { format!("dhall_core::Const::{:?}", c).parse().unwrap() } -fn binop_to_tokenstream(b: BinOp) -> TokenStream { +fn quote_binop(b: BinOp) -> TokenStream { format!("dhall_core::BinOp::{:?}", b).parse().unwrap() } -fn label_to_tokenstream(l: &Label) -> TokenStream { +fn quote_label(l: &Label) -> TokenStream { let l = String::from(l); quote! { #l.into() } } -fn map_to_tokenstream( - m: &BTreeMap<Label, SubExpr<X, X>>, - ctx: &Context<Label, ()>, -) -> TokenStream { - let (keys, values): (Vec<TokenStream>, Vec<TokenStream>) = m - .iter() - .map(|(k, v)| { - (label_to_tokenstream(k), dhall_to_tokenstream_bx(&*v, ctx)) - }) - .unzip(); - quote! { { - use std::collections::BTreeMap; - let mut m = BTreeMap::new(); - #( m.insert(#keys, #values); )* - m - } } -} - -fn vec_to_tokenstream( - e: &Vec<DhallExpr>, - ctx: &Context<Label, ()>, -) -> TokenStream { - let e = e.iter().map(|x| dhall_to_tokenstream_bx(x, ctx)); - quote! { vec![ #(#e),* ] } -} - fn bx(x: TokenStream) -> TokenStream { quote! { dhall_core::bx(#x) } } diff --git a/dhall_generator/src/dhall_type.rs b/dhall_generator/src/dhall_type.rs index 876d261..ec023bc 100644 --- a/dhall_generator/src/dhall_type.rs +++ b/dhall_generator/src/dhall_type.rs @@ -39,21 +39,17 @@ pub fn derive_for_struct( .collect(), syn::Fields::Unit => vec![], }; - let fields = fields.into_iter().map(|(name, ty)| { - constraints.push(ty.clone()); - quote! { - m.insert( - dhall_core::Label::from(#name), - <#ty as dhall::Type>::get_type() - ); - } - }); - Ok(quote! { dhall_core::rc(dhall_core::ExprF::RecordType({ - use std::collections::BTreeMap; - let mut m = BTreeMap::new(); - #(#fields)* - m - })) }) + let fields = fields + .into_iter() + .map(|(name, ty)| { + let name = dhall_core::Label::from(name); + constraints.push(ty.clone()); + (name, quote!(<#ty as dhall::Type>::get_type())) + }) + .collect(); + let record = + crate::dhall_expr::quote_expr(dhall_core::ExprF::RecordType(fields)); + Ok(quote! { dhall_core::rc(#record) }) } pub fn derive_for_enum( @@ -64,7 +60,7 @@ pub fn derive_for_enum( .variants .iter() .map(|v| { - let name = v.ident.to_string(); + let name = dhall_core::Label::from(v.ident.to_string()); let ty = match &v.fields { syn::Fields::Unnamed(fields) if fields.unnamed.is_empty() => { Err(Error::new( @@ -92,21 +88,13 @@ pub fn derive_for_enum( }; let ty = ty?; constraints.push(ty.clone()); - Ok(quote! { - m.insert( - dhall_core::Label::from(#name), - <#ty as dhall::Type>::get_type() - ); - }) + Ok((name, quote!(<#ty as dhall::Type>::get_type()))) }) - .collect::<Result<Vec<_>, Error>>()?; + .collect::<Result<_, Error>>()?; - Ok(quote! { dhall_core::rc(dhall_core::ExprF::UnionType({ - use std::collections::BTreeMap; - let mut m = BTreeMap::new(); - #(#variants)* - m - })) }) + let union = + crate::dhall_expr::quote_expr(dhall_core::ExprF::UnionType(variants)); + Ok(quote! { dhall_core::rc(#union) }) } pub fn derive_type_inner( |