fix: statement branch

mist-test/src/main.mist

@@ -1,4 +1,15 @@
+pub mod app;
+pub mod task;
+pub mod plugin;
+pub mod logger;
+pub mod event;
+
 void main() {
+    var mut app_instance = new app::Application("mist-app");
+
+    // greeting::register(&mut app_instance);
+    // statistics::register(&mut app_instance);
+
     app_instance.boot();
     app_instance.run();
 }

parser/src/grammar.pest

@@ -357,8 +357,10 @@ assign_statement = {
 // CONDITIONALS
 // ------------------------------------------------------
 
+statement_branch = { "(" ~ expr ~ ")" ~ statement }
+
 else_if = {
-    "else" ~ "if" ~ "(" ~ expr ~ ")" ~ statement
+    "else" ~ "if" ~ statement_branch
 }
 
 else_if_list = {
@@ -366,7 +368,7 @@ else_if_list = {
 }
 
 if_stmt = {
-    "if" ~ "(" ~ expr ~ ")" ~ statement ~ else_if_list ~ ("else" ~ statement)?
+    "if" ~ "(" ~ statement_branch ~ else_if_list ~ ("else" ~ statement)?
 }
 
 // ------------------------------------------------------
@@ -374,7 +376,7 @@ if_stmt = {
 // ------------------------------------------------------
 
 while_stmt = {
-    "while" ~ "(" ~ expr ~ ")" ~ statement
+    "while" ~ statement_branch
 }
 
 c_for_stmt = {

parser/src/parser/common/statement.rs

@@ -20,12 +20,14 @@ impl<'a> TryFrom<pest::iterators::Pair<'a, Rule>> for StatementBranch {
     type Error = AstError<'a, Self>;
 
     fn try_from(pair: pest::iterators::Pair<'a, Rule>) -> Result<Self, Self::Error> {
-        let mut inner = pair.into_inner();
+        let mut inner = pair.clone().into_inner();
 
+        ast_ensure!(pair, Rule::statement_branch => {
             ast_expr!(StatementBranch {
                 condition: inner.next().unwrap().try_into(),
                 body: inner.next().unwrap().try_into().map(Box::new),
             })
+        })
     }
 }
 
@@ -74,7 +76,7 @@ impl<'a> TryFrom<pest::iterators::Pair<'a, Rule>> for Statement {
                 })
             }
 
-            Rule::while_stmt => ast_expr!(Statement::While(pair.try_into())),
+            Rule::while_stmt => ast_expr!(Statement::While(inner.next().unwrap().try_into())),
 
             Rule::c_for_stmt => ast_expr!(Statement::CStyleFor {
                 init: inner.next().unwrap().try_into().map(Box::new),