added struct def for variable decl

src/language_frontend/abstract_syntax_tree/ast.rs

@@ -24,21 +24,13 @@ pub enum Expr {
 
     Call(Call),
 
-    Unary {
-        operator: UnaryOp,
-        operand: Box<Expr>,
-    },
+    Unary(Unary),
 
-    Binary {
-        lhs: Box<Expr>,
-        operator: BinaryOp,
-        rhs: Box<Expr>,
-    },
+    Binary(Binary),
 
-    Assignment {
-        target: Box<Expr>,
-        value: Box<Expr>,
-    },
+    Assignment(Assignment),
+
+    Var(Var),
 
     Function(Function),
 

src/language_frontend/abstract_syntax_tree/definitions.rs

@@ -99,6 +99,37 @@ pub struct Condition {
     pub else_body: Option<BlockStatement>,
 }
 
+
+/// Example: `x = 5` 
+#[derive(Clone, Debug, PartialEq)]
+pub struct Assignment {
+    pub target: Box<Expr>,
+    pub value: Box<Expr>,
+}
+
+/// Example: `var String: foo = "Test"`
+#[derive(Clone, Debug, PartialEq)]
+pub struct Var {
+    pub ty: Option<Type>,
+    pub ident: String,
+    pub value: Box<Expr>
+}
+
+/// Example: `x++`
+#[derive(Clone, Debug, PartialEq)]
+pub struct Unary {
+    pub operand: Box<Expr>,
+    pub operator: UnaryOp,
+}
+
+/// Example: `x++`
+#[derive(Clone, Debug, PartialEq)]
+pub struct Binary {
+    pub lhs: Box<Expr>,
+    pub operator: BinaryOp,
+    pub rhs: Box<Expr>,
+}
+
 /// Represents the Structure of a `Function` in AkaiLang
 /// 
 /// Examples:
@@ -110,7 +141,7 @@ pub struct Condition {
 /// <br>
 /// 
 ///```AkaiLang
-///fun returnsIntPlusOne(i: i32): i32 {
+///fun returnsIntPlusOne(i: int): int {
 ///    -> i + 1
 ///}
 ///``` 
@@ -126,6 +157,6 @@ pub struct Function {
 
 #[derive(Clone, Debug, PartialEq)]
 pub struct Call {
-    callee: Box<Expr>,
-    arguments: Vec<Expr>,
+    pub callee: Box<Expr>,
+    pub arguments: Vec<Expr>,
 }

src/language_frontend/abstract_syntax_tree/parser.rs

@@ -7,6 +7,8 @@ use crate::language_frontend::{abstract_syntax_tree::{ast::Expr, definitions::*}
 
 // goal of parsing is to construct an abstract syntax tree
 
+// todo: improve test-ability of parser
+
 pub fn parse(source: &str) ->Result<Vec<Expr>, Vec<Rich<'_, Token>>> {
     let token_iter = Token::lexer(source).spanned().map(|(token, span)| (token.unwrap_or(Token::Error), span.into()));
     let end_of_input: SimpleSpan = (0..source.len()).into();
@@ -51,12 +53,12 @@ where
             .then(atom)
             .then_ignore(just(Token::NewLine).or_not())
             .repeated(),
-            |lhs, (op, rhs)| Expr::Binary {
+            |lhs, (op, rhs)| Expr::Binary ( Binary {
                 lhs: Box::new(lhs),
                 operator: op,
                 rhs: Box::new(rhs),
             },
-        );
+        ));
 
         let add_sub = mul_div.clone().foldl(
             choice((
@@ -66,12 +68,12 @@ where
             .then(mul_div)
             .then_ignore(just(Token::NewLine).or_not())
             .repeated(),
-            |lhs, (op, rhs)| Expr::Binary {
+            |lhs, (op, rhs)| Expr::Binary ( Binary {
                 lhs: Box::new(lhs),
                 operator: op,
                 rhs: Box::new(rhs),
             },
-        );
+        ));
 
         add_sub
     });
@@ -81,10 +83,12 @@ where
             .then_ignore(just(Token::Assign))
             .then(expr.clone())
             .then_ignore(just(Token::NewLine))
-            .map(|(name, rhs)| Expr::Assignment {
-                target: Box::new(Expr::Ident(name)), 
-                value: Box::new(rhs), 
-            });
+            .map(|(name, rhs)| Expr::Var ( Var {
+                ty: None,
+                ident: name, 
+                value: Box::new(rhs),
+            }
+        ));
         /*
         let fun = just(Token::Fun)
             .ignore_then(ident.clone())