Add walk impl.

ast-generator/src/lib.rs

@@ -4,6 +4,7 @@ mod deserialize;
 mod pretty_print;
 mod spec;
 mod type_gen;
+mod walk;
 
 use crate::ast_node::{make_ast_enum_member, make_ast_node_impl};
 use crate::build_fn::make_build_fn;
@@ -14,6 +15,7 @@ use proc_macro2::TokenStream;
 use quote::quote;
 use spec::BuildSpec;
 use syn::File;
+use crate::walk::make_walk_fn;
 
 fn debug_built_spec(build_spec: &BuildSpec, token_stream: &TokenStream) {
     println!("*** BuildSpec ***");
@@ -184,6 +186,14 @@ fn generate_ast_node_file(build_specs: &[BuildSpec]) -> AstGeneratedFile {
     }
 }
 
+fn generate_walk_file(build_specs: &[BuildSpec]) -> AstGeneratedFile {
+    let stream = make_walk_fn(build_specs);
+    AstGeneratedFile {
+        name: String::from("walk.rs"),
+        contents: token_stream_to_string(stream),
+    }
+}
+
 pub fn get_build_specs(yaml: &str) -> Vec<BuildSpec> {
     deserialize_yaml_spec(yaml)
 }
@@ -194,5 +204,6 @@ pub fn generate_files(build_specs: &[BuildSpec]) -> Vec<AstGeneratedFile> {
         generate_node_file(build_specs),
         generate_pretty_print_file(build_specs),
         generate_ast_node_file(build_specs),
+        generate_walk_file(build_specs),
     ]
 }

ast-generator/src/walk.rs

@@ -0,0 +1,60 @@
+use crate::spec::BuildSpec;
+use convert_case::{Case, Casing};
+use proc_macro2::TokenStream;
+use quote::{format_ident, quote};
+
+pub fn make_walk_fn(specs: &[BuildSpec]) -> TokenStream {
+    let child_match_arms = specs
+        .iter()
+        .map(|spec| match spec {
+            BuildSpec::Enum(enum_spec) => Some((
+                format_ident!("{}", enum_spec.build()),
+                format_ident!("{}", enum_spec.build().to_case(Case::Snake)),
+            )),
+            BuildSpec::LeafEnum(leaf_enum) => Some((
+                format_ident!("{}", leaf_enum.build()),
+                format_ident!("{}", leaf_enum.build().to_case(Case::Snake)),
+            )),
+            BuildSpec::Struct(struct_spec) => Some((
+                format_ident!("{}", struct_spec.build()),
+                format_ident!("{}", struct_spec.build().to_case(Case::Snake)),
+            )),
+            BuildSpec::LeafStruct(leaf_struct) => Some((
+                format_ident!("{}", leaf_struct.build()),
+                format_ident!("{}", leaf_struct.build().to_case(Case::Snake)),
+            )),
+            BuildSpec::Production(_) => None,
+            BuildSpec::NodeProduction(_) => None,
+            BuildSpec::PolymorphicType(polymorphic_type) => Some((
+                format_ident!("{}", polymorphic_type.name()),
+                format_ident!("{}", polymorphic_type.name().to_case(Case::Snake)),
+            )),
+            BuildSpec::PolymorphicEnumLoop(polymorphic_enum_loop) => Some((
+                format_ident!("{}", polymorphic_enum_loop.name()),
+                format_ident!("{}", polymorphic_enum_loop.name().to_case(Case::Snake)),
+            )),
+            BuildSpec::PolymorphicPassThrough(_) => None,
+        })
+        .filter(Option::is_some)
+        .map(Option::unwrap)
+        .map(|(type_ident, inner_ident)| {
+            quote! {
+                #type_ident(#inner_ident) => walk_depth_first(#inner_ident, f)
+            }
+        })
+        .collect::<Vec<_>>();
+
+    quote! {
+        use crate::ast::node::*;
+        use crate::ast::ast_node::*;
+
+        pub fn walk_depth_first(node: &impl AstNode, f: &mut impl FnMut(AstNodeRef)) {
+            use AstNodeRef::*;
+            for child in node.children() {
+                match child {
+                    #(#child_match_arms,)*
+                }
+            }
+        }
+    }
+}

src/ast/mod.rs

@@ -161,3 +161,7 @@ pub mod ast_node {
         }
     }
 }
+
+pub mod walk {
+    include!(concat!(env!("OUT_DIR"), "/src/ast/walk.rs"));
+}