parser

src/ast/mod.rs

@@ -1,3 +1,5 @@
+use crate::token;
+
 trait NodeTrait {
     fn token_literal(&self) -> String;
 }
@@ -9,6 +11,14 @@ trait StatementTrait: NodeTrait {
 trait ExpressionTrait: NodeTrait {
     fn expression_node(&self);
 }
+struct Expression {
+    //
+}
+impl NodeTrait for Expression {
+    fn token_literal(&self) -> String {
+        todo!()
+    }
+}
 
 struct Statement {
     //
@@ -23,7 +33,7 @@ impl StatementTrait for Statement {
     fn statement_node(&self) {}
 }
 
-struct Program {
+pub struct Program {
     statements: Vec<Statement>,
 }
 
@@ -36,3 +46,38 @@ impl NodeTrait for Program {
         }
     }
 }
+
+struct LetStatement {
+    token: token::Token,
+    name: Identifier,
+    value: Expression,
+}
+
+impl NodeTrait for LetStatement {
+    fn token_literal(&self) -> String {
+        String::from(&self.token.literal)
+    }
+}
+
+impl StatementTrait for LetStatement {
+    fn statement_node(&self) {
+        todo!()
+    }
+}
+
+struct Identifier {
+    token: token::Token,
+    value: String,
+}
+
+impl NodeTrait for Identifier {
+    fn token_literal(&self) -> String {
+        String::from(&self.token.literal)
+    }
+}
+
+impl ExpressionTrait for Identifier {
+    fn expression_node(&self) {
+        todo!()
+    }
+}

src/main.rs

@@ -1,5 +1,6 @@
 mod ast;
 mod lexer;
+mod parser;
 mod repl;
 mod token;
 

src/parser/mod.rs

@@ -0,0 +1,47 @@
+use crate::{
+    ast,
+    lexer::{self, LexerTraits},
+    token,
+};
+
+pub struct Parser {
+    lexer: lexer::Lexer,
+    cur_token: token::Token,
+    peek_token: token::Token,
+}
+
+trait PaserTrait {
+    fn next_token(&mut self);
+    fn parse_program(&self) -> ast::Program;
+}
+
+pub fn new(l: lexer::Lexer) -> Parser {
+    let mut p: Parser = Parser {
+        lexer: l,
+        cur_token: token::Token {
+            literal: String::new(),
+            type_: String::new(),
+        },
+        peek_token: token::Token {
+            literal: String::new(),
+            type_: String::new(),
+        },
+    };
+    p.next_token();
+    p.next_token();
+    p
+}
+
+impl PaserTrait for Parser {
+    fn next_token(&mut self) {
+        self.cur_token = token::Token {
+            literal: String::from(&self.peek_token.literal),
+            type_: String::from(&self.peek_token.type_),
+        };
+        self.peek_token = self.lexer.next_token();
+    }
+
+    fn parse_program(&self) -> ast::Program {
+        todo!()
+    }
+}