Refactor compiler to have a separate typed ast infrastucture

ast/src/lib.rs

@@ -29,29 +29,41 @@ pub(crate) use span::*;
 use from_pest::FromPest;
 use std::{fs, path::PathBuf};
 
-pub struct LeoParser;
+pub struct LeoAst<'ast> {
+    ast: files::File<'ast>,
+}
 
-impl LeoParser {
+impl<'ast> LeoAst<'ast> {
+    /// Creates a new abstract syntax tree given the file path.
+    pub fn new(file_path: &'ast PathBuf, program_string: &'ast str) -> Result<Self, ParserError> {
+        // TODO (howardwu): Turn this check back on after fixing the testing module.
+        // assert_eq!(program_string, fs::read_to_string(file_path).map_err(|_| ParserError::FileReadError(file_path.clone()))?);
+
+        // Parse the file using leo.pest
+        let file = &mut ast::parse(&program_string)
+            .map_err(|error| ParserError::from(error.with_path(file_path.to_str().unwrap())))?;
+
+        // Builds the abstract syntax tree using pest derivation.
+        let ast = files::File::<'ast>::from_pest(file).map_err(|_| ParserError::SyntaxTreeError)?;
+        log::debug!("{:#?}", ast);
+
+        Ok(Self { ast })
+    }
+
+    // TODO (howardwu): Remove this in favor of a dedicated file loader to verify checksums
+    //  and maintain a global cache of program strings during the compilation process.
     /// Loads the Leo code as a string from the given file path.
-    pub fn load_file(file_path: &PathBuf) -> Result<String, ParserError> {
+    pub fn load_file(file_path: &'ast PathBuf) -> Result<String, ParserError> {
         Ok(fs::read_to_string(file_path).map_err(|_| ParserError::FileReadError(file_path.clone()))?)
     }
 
-    /// Parses the Leo program string and constructs an abstract syntax tree.
-    pub fn parse_file<'a>(file_path: &'a PathBuf, program_string: &'a str) -> Result<files::File<'a>, ParserError> {
-        // Parse the file using leo.pest
-        let mut file = ast::parse(program_string)
-            .map_err(|error| ParserError::from(error.with_path(file_path.to_str().unwrap())))?;
-
-        // Build the abstract syntax tree
-        let syntax_tree = files::File::from_pest(&mut file).map_err(|_| ParserError::SyntaxTreeError)?;
-        log::debug!("{:#?}", syntax_tree);
-
-        Ok(syntax_tree)
+    /// Returns a reference to the inner abstract syntax tree representation.
+    pub fn as_repr(&self) -> &files::File<'ast> {
+        &self.ast
     }
 
-    /// Serializes a given abstract syntax tree into a JSON string.
-    pub fn to_json_string(syntax_tree: &files::File) -> Result<String, ParserError> {
-        Ok(serde_json::to_string_pretty(syntax_tree)?)
+    /// Serializes the abstract syntax tree into a JSON string.
+    pub fn to_json_string(&self) -> Result<String, ParserError> {
+        Ok(serde_json::to_string_pretty(&self.ast)?)
     }
 }

ast/src/main.rs

@@ -1,16 +1,16 @@
-use leo_ast::{LeoParser, ParserError};
+use leo_ast::{LeoAst, ParserError};
 use std::{env, fs, path::Path};
 
 fn to_leo_ast(filepath: &Path) -> Result<String, ParserError> {
     // Loads the Leo code as a string from the given file path.
     let program_filepath = filepath.to_path_buf();
-    let program_string = LeoParser::load_file(&program_filepath)?;
+    let program_string = LeoAst::load_file(&program_filepath)?;
 
-    // Parses the Leo program string and constructs an abstract syntax tree.
-    let abstract_syntax_tree = LeoParser::parse_file(&program_filepath, &program_string)?;
+    // Parses the Leo file and constructs an abstract syntax tree.
+    let ast = LeoAst::new(&program_filepath, &program_string)?;
 
     // Serializes the abstract syntax tree into JSON format.
-    let serialized_ast = LeoParser::to_json_string(&abstract_syntax_tree)?;
+    let serialized_ast = LeoAst::to_json_string(&ast)?;
 
     Ok(serialized_ast)
 }

compiler/src/compiler.rs

@@ -7,9 +7,9 @@ use crate::{
     GroupType,
     ImportParser,
 };
-use leo_ast::LeoParser;
+use leo_ast::LeoAst;
 use leo_inputs::LeoInputsParser;
-use leo_types::{InputValue, Inputs, Program};
+use leo_types::{InputValue, Inputs, LeoTypedAst, Program};
 
 use snarkos_errors::gadgets::SynthesisError;
 use snarkos_models::{
@@ -48,9 +48,8 @@ impl<F: Field + PrimeField, G: GroupType<F>> Compiler<F, G> {
         let mut compiler = Self::new(package_name);
         compiler.set_path(main_file_path);
 
-        // Generate the abstract syntax tree and assemble the program
-        let program_string = compiler.load_program()?;
-        compiler.parse_program(&program_string)?;
+        // Generate the abstract syntax tree and assemble the program.
+        compiler.parse_program()?;
 
         Ok(compiler)
     }
@@ -94,20 +93,40 @@ impl<F: Field + PrimeField, G: GroupType<F>> Compiler<F, G> {
         generate_test_constraints::<F, G>(cs, self.program, &self.imported_programs)
     }
 
-    /// Loads the Leo code as a string from the given file path.
-    fn load_program(&mut self) -> Result<String, CompilerError> {
-        Ok(LeoParser::load_file(&self.main_file_path)?)
+    /// Parses the Leo program file, constructs a syntax tree, and generates a program.
+    pub fn parse_program(&mut self) -> Result<(), CompilerError> {
+        // Use the parser to construct the abstract syntax tree.
+        let program_string = LeoAst::load_file(&self.main_file_path)?;
+        let ast = LeoAst::new(&self.main_file_path, &program_string)?;
+
+        // Derive the package name.
+        let package_name = self.package_name.clone();
+
+        // Use the typed parser to construct the typed syntax tree.
+        let typed_tree = LeoTypedAst::new(&package_name, &ast);
+
+        self.program = typed_tree.into_repr();
+        self.program_inputs.set_inputs_size(self.program.expected_inputs.len());
+        self.imported_programs = ImportParser::parse(&self.program)?;
+
+        log::debug!("Program parsing complete\n{:#?}", self.program);
+
+        Ok(())
     }
 
     /// Parses the Leo program string, constructs a syntax tree, and generates a program.
-    pub fn parse_program(&mut self, program_string: &str) -> Result<(), CompilerError> {
-        // Parse the program syntax tree
-        let syntax_tree = LeoParser::parse_file(&self.main_file_path, program_string)?;
+    /// Used for testing only.
+    pub fn parse_program_from_string(&mut self, program_string: &str) -> Result<(), CompilerError> {
+        // Use the given bytes to construct the abstract syntax tree.
+        let ast = LeoAst::new(&self.main_file_path, &program_string)?;
 
-        // Build program from syntax tree
+        // Derive the package name.
         let package_name = self.package_name.clone();
 
-        self.program = Program::from(syntax_tree, package_name);
+        // Use the typed parser to construct the typed syntax tree.
+        let typed_tree = LeoTypedAst::new(&package_name, &ast);
+
+        self.program = typed_tree.into_repr();
         self.program_inputs.set_inputs_size(self.program.expected_inputs.len());
         self.imported_programs = ImportParser::parse(&self.program)?;
 

compiler/src/import/parser/parse_symbol.rs

@@ -1,5 +1,5 @@
 use crate::{errors::ImportError, ImportParser};
-use leo_ast::LeoParser;
+use leo_ast::LeoAst;
 use leo_types::{ImportSymbol, Program, Span};
 
 use std::{ffi::OsString, fs::DirEntry, path::PathBuf};
@@ -30,12 +30,12 @@ fn parse_import_file(entry: &DirEntry, span: &Span) -> Result<Program, ImportErr
         }
     }
 
-    // Build the abstract syntax tree
-    let input_file = &LeoParser::load_file(&file_path)?;
-    let syntax_tree = LeoParser::parse_file(&file_path, input_file)?;
+    // Builds the abstract syntax tree.
+    let program_string = &LeoAst::load_file(&file_path)?;
+    let ast = &LeoAst::new(&file_path, &program_string)?;
 
-    // Generate aleo program from file
-    Ok(Program::from(syntax_tree, file_name.clone()))
+    // Generates the Leo program from file.
+    Ok(Program::from(&file_name, ast.as_repr()))
 }
 
 impl ImportParser {

compiler/tests/mod.rs

@@ -59,7 +59,7 @@ pub(crate) fn parse_program(bytes: &[u8]) -> Result<EdwardsTestCompiler, Compile
     let mut compiler = new_compiler();
     let program_string = String::from_utf8_lossy(bytes);
 
-    compiler.parse_program(&program_string)?;
+    compiler.parse_program_from_string(&program_string)?;
 
     Ok(compiler)
 }

types/src/lib.rs

@@ -1,3 +1,6 @@
+//! A typed syntax tree is represented as a `Program` and consists of import, circuit, and function definitions.
+//! Each defined type consists of typed statements and expressions.
+
 pub mod circuits;
 pub use self::circuits::*;
 
@@ -30,3 +33,22 @@ pub use self::statements::*;
 
 pub mod types;
 pub use self::types::*;
+
+use leo_ast::LeoAst;
+
+pub struct LeoTypedAst {
+    typed_ast: Program,
+}
+
+impl LeoTypedAst {
+    /// Creates a new typed syntax tree from a given program name and abstract syntax tree.
+    pub fn new<'ast>(program_name: &str, ast: &LeoAst<'ast>) -> Self {
+        Self {
+            typed_ast: Program::from(program_name, ast.as_repr()),
+        }
+    }
+
+    pub fn into_repr(self) -> Program {
+        self.typed_ast
+    }
+}

types/src/program.rs

@@ -20,10 +20,11 @@ pub struct Program {
 
 impl<'ast> Program {
     //! Logic to convert from an abstract syntax tree (ast) representation to a Leo program.
-    pub fn from(file: File<'ast>, name: String) -> Self {
+    pub fn from(program_name: &str, program_ast: &File<'ast>) -> Self {
         // Compiled ast -> aleo program representation
-        let imports = file
+        let imports = program_ast
             .imports
+            .to_owned()
             .into_iter()
             .map(|import| Import::from(import))
             .collect::<Vec<Import>>();
@@ -33,23 +34,23 @@ impl<'ast> Program {
         let mut tests = HashMap::new();
         let mut expected_inputs = vec![];
 
-        file.circuits.into_iter().for_each(|circuit| {
+        program_ast.circuits.to_owned().into_iter().for_each(|circuit| {
             circuits.insert(Identifier::from(circuit.identifier.clone()), Circuit::from(circuit));
         });
-        file.functions.into_iter().for_each(|function_def| {
+        program_ast.functions.to_owned().into_iter().for_each(|function_def| {
             let function = Function::from(function_def);
             if function.function_name.name.eq("main") {
                 expected_inputs = function.inputs.clone();
             }
             functions.insert(function.function_name.clone(), function);
         });
-        file.tests.into_iter().for_each(|test_def| {
+        program_ast.tests.to_owned().into_iter().for_each(|test_def| {
             let test = TestFunction::from(test_def);
             tests.insert(test.0.function_name.clone(), test);
         });
 
         Self {
-            name,
+            name: program_name.to_string(),
             expected_inputs,
             imports,
             circuits,