Split yunq compliation to library and use it in build process.

yunq/rust/src/lib.rs

@@ -0,0 +1,15 @@
+mod codegen;
+mod lexer;
+mod parser;
+
+use std::error::Error;
+
+pub fn codegen(input: &str) -> Result<String, Box<dyn Error>> {
+    let tokens = lexer::lex_input(input)?;
+
+    let mut ast_parser = parser::Parser::new(&tokens);
+    ast_parser.parse_ast()?;
+    ast_parser.type_check()?;
+
+    Ok(codegen::generate_code(ast_parser.ast()))
+}