[lang] Add initial implementation of JSON api generation

lang/Cargo.toml

@@ -28,6 +28,8 @@ proc-macro2 = "0.4"
 heck = "0.3"
 itertools = "0.7"
 either = "1.5"
+serde = { version = "1.0.89", features = ["derive"] }
+serde_json = "1.0.39"
 
 [lib]
 name = "pdsl_lang"

lang/src/api.rs

+use crate::{
+    ast,
+    errors::Result,
+    hir,
+    ident_ext::IdentExt,
+};
+use serde::{
+    Deserialize,
+    Serialize,
+};
+use serde_json::{
+    json,
+    Value as JsonValue,
+};
+
+/// Describes a message parameter or return type.
+#[derive(Debug, PartialEq, Eq, Deserialize, Serialize)]
+pub enum TypeDescription {
+    /// The `bool` primitive type.
+    Bool,
+    /// The `u8` primitive unsigned integer.
+    U8,
+    /// The `u16` primitive unsigned integer.
+    U16,
+    /// The `u32` primitive unsigned integer.
+    U32,
+    /// The `u64` primitive unsigned integer.
+    U64,
+    /// The `u128` primitive unsigned integer.
+    U128,
+    /// The `i8` primitive signed integer.
+    I8,
+    /// The `i16` primitive signed integer.
+    I16,
+    /// The `i32` primitive signed integer.
+    I32,
+    /// The `i64` primitive signed integer.
+    I64,
+    /// The `i128` primitive signed integer.
+    I128,
+    /// The SRML address type.
+    Address,
+    /// The SRML balance type.
+    Balance,
+    /// Custom type.
+    Custom(String),
+}
+
+impl From<&syn::Type> for TypeDescription {
+    fn from(ty: &syn::Type) -> Self {
+        use quote::ToTokens;
+        match ty.into_token_stream().to_string().as_str() {
+            "bool" => TypeDescription::Bool,
+            "u8" => TypeDescription::U8,
+            "u16" => TypeDescription::U16,
+            "u32" => TypeDescription::U32,
+            "u64" => TypeDescription::U64,
+            "u128" => TypeDescription::U128,
+            "i8" => TypeDescription::I8,
+            "i16" => TypeDescription::I16,
+            "i32" => TypeDescription::I32,
+            "i64" => TypeDescription::I64,
+            "i128" => TypeDescription::I128,
+            "Address" => TypeDescription::Address,
+            "Balance" => TypeDescription::Balance,
+            custom => TypeDescription::Custom(custom.to_owned()),
+        }
+    }
+}
+
+/// Describes a pair of parameter name and type.
+#[derive(Debug, PartialEq, Eq, Deserialize, Serialize)]
+pub struct ParamDescription {
+    /// The name of the parameter.
+    name: String,
+    /// The type of the parameter.
+    ty: TypeDescription,
+}
+
+impl From<&syn::ArgCaptured> for ParamDescription {
+    fn from(arg: &syn::ArgCaptured) -> Self {
+        let name = match &arg.pat {
+            syn::Pat::Ident(ident) => ident.ident.to_owned_string(),
+            _ => panic!("cannot handle non-ident function arguments"),
+        };
+        Self {
+            name,
+            ty: TypeDescription::from(&arg.ty),
+        }
+    }
+}
+
+/// Describes the deploy handler of a contract.
+#[derive(Debug, PartialEq, Eq, Deserialize, Serialize)]
+pub struct DeployDescription {
+    /// The parameters of the deploy handler.
+    params: Vec<ParamDescription>,
+}
+
+impl From<&hir::DeployHandler> for DeployDescription {
+    fn from(deploy_handler: &hir::DeployHandler) -> Self {
+        Self {
+            params: {
+                deploy_handler
+                    .decl
+                    .inputs
+                    .iter()
+                    .filter_map(|arg| {
+                        match arg {
+                            ast::FnArg::Captured(captured) => {
+                                Some(ParamDescription::from(captured))
+                            }
+                            _ => None,
+                        }
+                    })
+                    .collect::<Vec<_>>()
+            },
+        }
+    }
+}
+
+/// Describes the return type of a contract message.
+#[derive(Debug, PartialEq, Eq, Deserialize, Serialize)]
+pub struct ReturnTypeDescription {
+    /// The optional return type.
+    ret_ty: Option<TypeDescription>,
+}
+
+impl ReturnTypeDescription {
+    /// Creates a new return type description from the given optional type.
+    pub fn new<T>(opt_type: T) -> Self
+    where
+        T: Into<Option<TypeDescription>>,
+    {
+        Self {
+            ret_ty: opt_type.into(),
+        }
+    }
+}
+
+impl From<&syn::ReturnType> for ReturnTypeDescription {
+    fn from(ret_ty: &syn::ReturnType) -> Self {
+        match ret_ty {
+            syn::ReturnType::Default => ReturnTypeDescription::new(None),
+            syn::ReturnType::Type(_, ty) => {
+                ReturnTypeDescription::new(Some(TypeDescription::from(&**ty)))
+            }
+        }
+    }
+}
+
+/// Describes a contract message.
+#[derive(Debug, PartialEq, Eq, Deserialize, Serialize)]
+pub struct MessageDescription {
+    /// The name of the message.
+    name: String,
+    /// The selector hash of the message.
+    selector: u64,
+    /// If the message is allowed to mutate the contract state.
+    mutates: bool,
+    /// The parameters of the message.
+    params: Vec<ParamDescription>,
+    /// The return type of the message.
+    ret_ty: ReturnTypeDescription,
+}
+
+impl From<&hir::Message> for MessageDescription {
+    fn from(message: &hir::Message) -> Self {
+        Self {
+            name: message.sig.ident.to_owned_string(),
+            selector: message.selector().into(),
+            mutates: message.is_mut(),
+            params: {
+                message
+                    .sig
+                    .decl
+                    .inputs
+                    .iter()
+                    .filter_map(|arg| {
+                        match arg {
+                            ast::FnArg::Captured(captured) => {
+                                Some(ParamDescription::from(captured))
+                            }
+                            _ => None,
+                        }
+                    })
+                    .collect::<Vec<_>>()
+            },
+            ret_ty: ReturnTypeDescription::from(&message.sig.decl.output),
+        }
+    }
+}
+
+/// Describes a contract.
+#[derive(Debug, PartialEq, Eq, Deserialize, Serialize)]
+pub struct ContractDescription {
+    /// The name of the contract.
+    name: String,
+    /// The deploy handler of the contract.
+    deploy: DeployDescription,
+    /// The external messages of the contract.
+    messages: Vec<MessageDescription>,
+}
+
+impl ContractDescription {
+    /// Returns the name of the contract.
+    pub fn name(&self) -> &str {
+        &self.name
+    }
+}
+
+impl From<&hir::Contract> for ContractDescription {
+    fn from(contract: &hir::Contract) -> Self {
+        ContractDescription {
+            name: contract.name.to_owned_string(),
+            deploy: DeployDescription::from(&contract.on_deploy),
+            messages: {
+                contract
+                    .messages
+                    .iter()
+                    .map(MessageDescription::from)
+                    .collect::<Vec<_>>()
+            },
+        }
+    }
+}
+
+pub fn generate_api_description(contract: &hir::Contract) {
+    let description = ContractDescription::from(contract);
+    let contents = serde_json::to_string(&description).unwrap();
+    let mut path_buf = String::from("target/");
+    path_buf.push_str(description.name());
+    path_buf.push_str(".json");
+    std::fs::write(path_buf, contents);
+}

lang/src/hir.rs

@@ -373,6 +373,11 @@ impl Message {
             _ => panic!(),
         }
     }
+
+    /// Returns the message selector for this message.
+    pub fn selector(&self) -> u32 {
+        0
+    }
 }
 
 impl From<&ast::ItemImplMethod> for Message {

lang/src/lib.rs

@@ -31,6 +31,7 @@ pub fn contract(input: proc_macro::TokenStream) -> proc_macro::TokenStream {
 #[macro_use]
 mod errors;
 
+mod api;
 mod ast;
 mod gen;
 mod hir;
@@ -60,6 +61,7 @@ pub(crate) fn contract_gen_impl2(
 ) -> Result<proc_macro2::TokenStream> {
     let ast_contract = parser::parse_contract(input.clone())?;
     let hir_contract = hir::Contract::from_ast(&ast_contract)?;
+    api::generate_api_description(&hir_contract);
     // gen::gir::generate(&hir_program)?;
     let tokens = gen::codegen(&hir_contract);
     Ok(tokens.into())