Prefix parsing

parser/src/ast.rs

@@ -72,6 +72,13 @@ pub enum Postfix {
     Binary(BinaryOp, Expression),
 }
 
+#[derive(Debug, Clone, Serialize)]
+pub enum PreFix {
+    Ref,
+    RefMut,
+    Deref,
+}
+
 #[derive(Debug, Clone, Serialize)]
 pub enum Statement {
     Expression(Expression),
@@ -135,8 +142,9 @@ pub enum Expression {
     FloatLiteral(f64),
     BoolLiteral(bool),
     StringLiteral(String),
-    Postfix {
+    Fix {
         initial: Box<Expression>,
+        prefixes: Vec<PreFix>,
         postfixes: Vec<Postfix>,
     },
 }

parser/src/grammar.pest

@@ -110,6 +110,16 @@ binary_px         = { bin_op ~ expr }
 bin_op            = { "+" | "-" | "*" | "/" | "%" | "==" | "!=" | "<" | ">" | "<=" | ">=" }
 struct_field_decl = { identifier ~ ":" ~ expr }
 
+prefix = {
+    deref_px
+  | mut_ref_px
+  | ref_px
+}
+
+deref_px   = { "*" }
+mut_ref_px = { "&" ~ mutable }
+ref_px     = { "&" }
+
 expr = {
-    primary ~ postfix*
+    prefix* ~ primary ~ postfix*
 }

parser/src/lib.rs

@@ -275,11 +275,24 @@ impl From<pest::iterators::Pair<'_, Rule>> for Expression {
         match pair.as_rule() {
             Rule::expr => {
                 let mut inner = pair.into_inner();
+                let mut prefixes = Vec::new();
+
+                while inner
+                    .peek()
+                    .map(|v| v.as_rule() == Rule::prefix)
+                    .unwrap_or_default()
+                {
+                    prefixes.push(PreFix::from(inner.next().unwrap()));
+                }
+
+                println!("{:#?}", prefixes);
+
                 let exp = Expression::from(inner.next().unwrap());
 
                 if inner.len() > 0 {
-                    Expression::Postfix {
+                    Expression::Fix {
                         initial: Box::new(exp),
+                        prefixes,
                         postfixes: inner.map(|p| Postfix::from(p)).collect(),
                     }
                 } else {
@@ -313,6 +326,18 @@ impl From<pest::iterators::Pair<'_, Rule>> for Expression {
     }
 }
 
+impl From<pest::iterators::Pair<'_, Rule>> for PreFix {
+    fn from(pair: pest::iterators::Pair<Rule>) -> Self {
+        match pair.as_rule() {
+            Rule::prefix => Self::from(pair.into_inner().next().unwrap()),
+            Rule::deref_px => Self::Deref,
+            Rule::mut_ref_px => Self::RefMut,
+            Rule::ref_px => Self::Ref,
+            _ => unimplemented!("{pair:#?}"),
+        }
+    }
+}
+
 impl From<pest::iterators::Pair<'_, Rule>> for Postfix {
     fn from(pair: pest::iterators::Pair<Rule>) -> Self {
         match pair.as_rule() {