Replaced var with let

crates/parser/src/grammar.pest

@@ -75,7 +75,7 @@ program = {
 
 visibility = { "pub" ~ ("(" ~ static_path ~ ")")? }
 mutable    = { "mut" }
-var        = { "var" }
+let_kw     = { "let" }
 
 // ======================================================
 // GENERICS
@@ -190,7 +190,7 @@ attributes = {
 // DECLARATION HELPERS
 // ======================================================
 var_decl = {
-    (var | type_expr) ~ pattern
+    (let_kw | type_expr) ~ pattern
 }
 
 field = {

crates/parser/src/parser/common/decl.rs

@@ -54,7 +54,7 @@ impl<'a> TryFrom<pest::iterators::Pair<'a, Rule>> for VarDecl {
                 let type_ = inner
                     .next()
                     .and_then(|pair| {
-                        if pair.as_str().trim() == "var" {
+                        if pair.as_rule() == Rule::let_kw {
                             None
                         } else {
                             Some(TypeExpr::try_from(pair))