Prepare dhall_generator for a new module

2 files changed, 171 insertions, 163 deletions

diff --git a/dhall_generator/src/dhall_expr.rs b/dhall_generator/src/dhall_expr.rs
new file mode 100644
index 0000000..07873bd
--- /dev/null
+++ b/dhall_generator/src/dhall_expr.rs
@@ -0,0 +1,168 @@
+extern crate proc_macro;
+use dhall_core::context::Context;
+use dhall_core::*;
+use proc_macro2::TokenStream;
+use quote::quote;
+use std::collections::BTreeMap;
+use std::rc::Rc;
+
+pub fn dhall_expr(input: proc_macro::TokenStream) -> proc_macro::TokenStream {
+    let input_str = input.to_string();
+    let expr: SubExpr<X, Import> = parse_expr(&input_str).unwrap();
+    let no_import =
+        |_: &Import| -> X { panic!("Don't use import in dhall!()") };
+    let expr = rc(expr.map_embed(&no_import));
+    let output = dhall_to_tokenstream_bx(&expr, &Context::new());
+    output.into()
+}
+
+// Returns an expression of type Expr<_, _>. Expects interpolated variables
+// to be of type Rc<Expr<_, _>>.
+fn dhall_to_tokenstream(
+    expr: &DhallExpr,
+    ctx: &Context<Label, ()>,
+) -> TokenStream {
+    use dhall_core::Expr::*;
+    match expr.as_ref() {
+        Var(_) => {
+            let v = dhall_to_tokenstream_bx(expr, ctx);
+            quote! { *#v }
+        }
+        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);
+            quote! { 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);
+            quote! { Lam(#x, #t, #b) }
+        }
+        App(f, a) => {
+            let f = dhall_to_tokenstream_bx(f, ctx);
+            let a = vec_to_tokenstream(a, ctx);
+            quote! { App(#f, #a) }
+        }
+        Const(c) => {
+            let c = const_to_tokenstream(*c);
+            quote! { Const(#c) }
+        }
+        Builtin(b) => {
+            let b = builtin_to_tokenstream(*b);
+            quote! { 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);
+            quote! { BinOp(#o, #a, #b) }
+        }
+        NaturalLit(n) => {
+            quote! { NaturalLit(#n) }
+        }
+        EmptyOptionalLit(x) => {
+            let x = dhall_to_tokenstream_bx(x, ctx);
+            quote! { EmptyOptionalLit(#x) }
+        }
+        NEOptionalLit(x) => {
+            let x = dhall_to_tokenstream_bx(x, ctx);
+            quote! { NEOptionalLit(#x) }
+        }
+        EmptyListLit(t) => {
+            let t = dhall_to_tokenstream_bx(t, ctx);
+            quote! { EmptyListLit(#t) }
+        }
+        NEListLit(es) => {
+            let es = vec_to_tokenstream(es, ctx);
+            quote! { NEListLit(#es) }
+        }
+        RecordType(m) => {
+            let m = map_to_tokenstream(m, ctx);
+            quote! { RecordType(#m) }
+        }
+        RecordLit(m) => {
+            let m = map_to_tokenstream(m, ctx);
+            quote! { RecordLit(#m) }
+        }
+        e => unimplemented!("{:?}", e),
+    }
+}
+
+// Returns an expression of type Rc<Expr<_, _>>
+fn dhall_to_tokenstream_bx(
+    expr: &DhallExpr,
+    ctx: &Context<Label, ()>,
+) -> TokenStream {
+    use dhall_core::Expr::*;
+    match expr.as_ref() {
+        Var(V(s, n)) => {
+            match ctx.lookup(&s, *n) {
+                // Non-free variable; interpolates as itself
+                Some(()) => {
+                    let s: String = s.into();
+                    quote! { bx(Var(V(#s.into(), #n))) }
+                }
+                // Free variable; interpolates as a rust variable
+                None => {
+                    let s: String = s.into();
+                    // TODO: insert appropriate shifts ?
+                    let v: TokenStream = s.parse().unwrap();
+                    quote! { {
+                        let x: Rc<Expr<_, _>> = #v.clone();
+                        x
+                    } }
+                }
+            }
+        }
+        _ => bx(dhall_to_tokenstream(expr, ctx)),
+    }
+}
+
+fn builtin_to_tokenstream(b: Builtin) -> TokenStream {
+    format!("{:?}", b).parse().unwrap()
+}
+
+fn const_to_tokenstream(c: Const) -> TokenStream {
+    format!("{:?}", c).parse().unwrap()
+}
+
+fn binop_to_tokenstream(b: BinOp) -> TokenStream {
+    format!("{:?}", b).parse().unwrap()
+}
+
+fn label_to_tokenstream(l: &Label) -> TokenStream {
+    let l = String::from(l);
+    quote! { #l.into() }
+}
+
+fn map_to_tokenstream(
+    m: &BTreeMap<Label, Rc<Expr<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! { bx(#x) }
+}
diff --git a/dhall_generator/src/lib.rs b/dhall_generator/src/lib.rs
index ee9af5e..7d3304b 100644
--- a/dhall_generator/src/lib.rs
+++ b/dhall_generator/src/lib.rs
@@ -1,169 +1,9 @@
 extern crate proc_macro;
-use dhall_core::context::Context;
-use dhall_core::*;
-use proc_macro2::TokenStream;
-use quote::quote;
-use std::collections::BTreeMap;
-use std::rc::Rc;
+
+mod dhall_expr;
 
 #[proc_macro]
 pub fn dhall_expr(input: proc_macro::TokenStream) -> proc_macro::TokenStream {
-    let input_str = input.to_string();
-    let expr: Rc<Expr<X, Import>> = parse_expr(&input_str).unwrap();
-    let no_import =
-        |_: &Import| -> X { panic!("Don't use import in dhall!()") };
-    let expr = rc(expr.map_embed(&no_import));
-    let output = dhall_to_tokenstream_bx(&expr, &Context::new());
-    output.into()
-}
-
-// Returns an expression of type Expr<_, _>. Expects interpolated variables
-// to be of type Rc<Expr<_, _>>.
-fn dhall_to_tokenstream(
-    expr: &DhallExpr,
-    ctx: &Context<Label, ()>,
-) -> TokenStream {
-    use dhall_core::Expr::*;
-    match expr.as_ref() {
-        Var(_) => {
-            let v = dhall_to_tokenstream_bx(expr, ctx);
-            quote! { *#v }
-        }
-        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);
-            quote! { 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);
-            quote! { Lam(#x, #t, #b) }
-        }
-        App(f, a) => {
-            let f = dhall_to_tokenstream_bx(f, ctx);
-            let a = vec_to_tokenstream(a, ctx);
-            quote! { App(#f, #a) }
-        }
-        Const(c) => {
-            let c = const_to_tokenstream(*c);
-            quote! { Const(#c) }
-        }
-        Builtin(b) => {
-            let b = builtin_to_tokenstream(*b);
-            quote! { 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);
-            quote! { BinOp(#o, #a, #b) }
-        }
-        NaturalLit(n) => {
-            quote! { NaturalLit(#n) }
-        }
-        EmptyOptionalLit(x) => {
-            let x = dhall_to_tokenstream_bx(x, ctx);
-            quote! { EmptyOptionalLit(#x) }
-        }
-        NEOptionalLit(x) => {
-            let x = dhall_to_tokenstream_bx(x, ctx);
-            quote! { NEOptionalLit(#x) }
-        }
-        EmptyListLit(t) => {
-            let t = dhall_to_tokenstream_bx(t, ctx);
-            quote! { EmptyListLit(#t) }
-        }
-        NEListLit(es) => {
-            let es = vec_to_tokenstream(es, ctx);
-            quote! { NEListLit(#es) }
-        }
-        RecordType(m) => {
-            let m = map_to_tokenstream(m, ctx);
-            quote! { RecordType(#m) }
-        }
-        RecordLit(m) => {
-            let m = map_to_tokenstream(m, ctx);
-            quote! { RecordLit(#m) }
-        }
-        e => unimplemented!("{:?}", e),
-    }
-}
-
-// Returns an expression of type Rc<Expr<_, _>>
-fn dhall_to_tokenstream_bx(
-    expr: &DhallExpr,
-    ctx: &Context<Label, ()>,
-) -> TokenStream {
-    use dhall_core::Expr::*;
-    match expr.as_ref() {
-        Var(V(s, n)) => {
-            match ctx.lookup(&s, *n) {
-                // Non-free variable; interpolates as itself
-                Some(()) => {
-                    let s: String = s.into();
-                    quote! { bx(Var(V(#s.into(), #n))) }
-                }
-                // Free variable; interpolates as a rust variable
-                None => {
-                    let s: String = s.into();
-                    // TODO: insert appropriate shifts ?
-                    let v: TokenStream = s.parse().unwrap();
-                    quote! { {
-                        let x: Rc<Expr<_, _>> = #v.clone();
-                        x
-                    } }
-                }
-            }
-        }
-        _ => bx(dhall_to_tokenstream(expr, ctx)),
-    }
-}
-
-fn builtin_to_tokenstream(b: Builtin) -> TokenStream {
-    format!("{:?}", b).parse().unwrap()
-}
-
-fn const_to_tokenstream(c: Const) -> TokenStream {
-    format!("{:?}", c).parse().unwrap()
+    dhall_expr::dhall_expr(input)
 }
 
-fn binop_to_tokenstream(b: BinOp) -> TokenStream {
-    format!("{:?}", b).parse().unwrap()
-}
-
-fn label_to_tokenstream(l: &Label) -> TokenStream {
-    let l = String::from(l);
-    quote! { #l.into() }
-}
-
-fn map_to_tokenstream(
-    m: &BTreeMap<Label, Rc<Expr<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! { bx(#x) }
-}