diff --git a/src/parser/grammar.pest b/src/parser/grammar.pest
index 23f246c..53e39ea 100644
--- a/src/parser/grammar.pest
+++ b/src/parser/grammar.pest
@@ -14,12 +14,14 @@ inner_str  = @{ (!"\"" ~ ANY)* }
 
 // ================= TOP LEVEL =================
 
+export = { "export"? }
+
 import_decl = { "import" ~ string_lit ~ ";" }
 
 param_list    = { param ~ ("," ~ param)* ~ ","? }
 param         = { identifier ~ ":" ~ type_expr }
 function_decl = {
-    "function" ~ identifier ~ "(" ~ param_list? ~ ")" ~ (":" ~ type_expr)? ~ block
+    export ~ "function" ~ identifier ~ "(" ~ param_list? ~ ")" ~ (":" ~ type_expr)? ~ block
 }
 
 // ================= STATEMENTS =================
@@ -30,3 +32,5 @@ statement = _{ "idk" }
 
 // ================= EXPRESSIONS =================
 type_expr = _{ identifier }
+
+expr = { identifier | integer | float | boolean | string_lit }
diff --git a/src/parser/mod.rs b/src/parser/mod.rs
index faaa5e7..0aa6a79 100644
--- a/src/parser/mod.rs
+++ b/src/parser/mod.rs
@@ -39,3 +39,32 @@ pub fn parse(source: &str) -> Result<Vec<TopLevel>, ParseError> {
 
     Ok(statements)
 }
+
+impl Expression {
+    pub fn from_pair(pair: pest::iterators::Pair<Rule>) -> Self {
+        match pair.as_rule() {
+            Rule::expr => {
+                let inner = pair.into_inner().next().unwrap();
+                Expression::from_pair(inner)
+            }
+            Rule::identifier => Expression::Identifier(pair.as_str().to_string()),
+            Rule::integer => {
+                let value = pair.as_str().parse::<i64>().unwrap();
+                Expression::IntLiteral(value)
+            }
+            Rule::float => {
+                let value = pair.as_str().parse::<f64>().unwrap();
+                Expression::FloatLiteral(value)
+            }
+            Rule::boolean => {
+                let value = pair.as_str().parse::<bool>().unwrap();
+                Expression::BoolLiteral(value)
+            }
+            Rule::string_lit => {
+                let inner_str = pair.into_inner().next().unwrap().as_str();
+                Expression::StringLiteral(inner_str.to_string())
+            }
+            _ => unimplemented!("Expression parsing not implemented yet"),
+        }
+    }
+}