2 files changed, 34 insertions, 3 deletions

diff --git a/crates/ra_tools/Cargo.toml b/crates/ra_tools/Cargo.toml
index 02bab8f52..ab9fa5d86 100644
--- a/crates/ra_tools/Cargo.toml
+++ b/crates/ra_tools/Cargo.toml
@@ -12,3 +12,4 @@ itertools = "0.8.0"
 clap = "2.32.0"
 quote = "1.0.2"
 ron = "0.5.1"
+serde = { version = "1.0.0", features = ["derive"] }
diff --git a/crates/ra_tools/src/codegen.rs b/crates/ra_tools/src/codegen.rs
index 405fb623c..f0a54808a 100644
--- a/crates/ra_tools/src/codegen.rs
+++ b/crates/ra_tools/src/codegen.rs
@@ -1,6 +1,8 @@
-use std::{fs, path::Path};
+use std::{collections::BTreeMap, fs, path::Path};
 
+use quote::quote;
 use ron;
+use serde::Deserialize;
 
 use crate::{project_root, Mode, Result, AST, GRAMMAR};
 
@@ -12,10 +14,38 @@ pub fn generate(mode: Mode) -> Result<()> {
 }
 
 fn generate_ast(grammar_src: &Path, dst: &Path, mode: Mode) -> Result<()> {
-    let src: ron::Value = {
+    let src: Grammar = {
         let text = fs::read_to_string(grammar_src)?;
         ron::de::from_str(&text)?
     };
-    eprintln!("{:?}", src);
+    eprintln!("{:#?}", src);
     Ok(())
 }
+
+#[derive(Deserialize, Debug)]
+struct Grammar {
+    single_byte_tokens: Vec<(String, String)>,
+    multi_byte_tokens: Vec<(String, String)>,
+    keywords: Vec<String>,
+    contextual_keywords: Vec<String>,
+    literals: Vec<String>,
+    tokens: Vec<String>,
+    ast: BTreeMap<String, AstNode>,
+}
+
+#[derive(Deserialize, Debug)]
+struct AstNode {
+    #[serde(default)]
+    traits: Vec<String>,
+    #[serde(default)]
+    collections: Vec<Attr>,
+    #[serde(default)]
+    options: Vec<Attr>,
+}
+
+#[derive(Deserialize, Debug)]
+#[serde(untagged)]
+enum Attr {
+    Type(String),
+    NameType(String, String),
+}