From cfa199e81e382b4e1cf2d7a2eab2e996617b9ea3 Mon Sep 17 00:00:00 2001
From: Ryan Chandler <ryangjchandler@gmail.com>
Date: Tue, 19 Jul 2022 12:04:40 +0100
Subject: [PATCH] parser: class methods with visibility

---
 trunk_lexer/src/lexer.rs   |  4 ++-
 trunk_lexer/src/token.rs   |  1 +
 trunk_parser/src/ast.rs    |  4 +--
 trunk_parser/src/parser.rs | 66 ++++++++++++++++++++++++++++++++++++--
 4 files changed, 69 insertions(+), 6 deletions(-)

diff --git a/trunk_lexer/src/lexer.rs b/trunk_lexer/src/lexer.rs
index 725e2bd..e1b87c9 100644
--- a/trunk_lexer/src/lexer.rs
+++ b/trunk_lexer/src/lexer.rs
@@ -238,6 +238,7 @@ fn identifier_to_keyword(ident: &str) -> Option<TokenKind> {
         "public" => TokenKind::Public,
         "protected" => TokenKind::Protected,
         "private" => TokenKind::Private,
+        "static" => TokenKind::Static,
         _ => return None,
     })
 }
@@ -290,7 +291,7 @@ mod tests {
 
     #[test]
     fn keywords() {
-        assert_tokens("<?php function if echo return class public protected private", &[
+        assert_tokens("<?php function if echo return class public protected private static", &[
             open!(),
             TokenKind::Function,
             TokenKind::If,
@@ -300,6 +301,7 @@ mod tests {
             TokenKind::Public,
             TokenKind::Protected,
             TokenKind::Private,
+            TokenKind::Static,
         ]);
     }
 
diff --git a/trunk_lexer/src/token.rs b/trunk_lexer/src/token.rs
index e299a41..f70b35f 100644
--- a/trunk_lexer/src/token.rs
+++ b/trunk_lexer/src/token.rs
@@ -14,6 +14,7 @@ pub enum TokenKind {
     Public,
     Protected,
     Private,
+    Static,
     If,
     Return,
     Echo,
diff --git a/trunk_parser/src/ast.rs b/trunk_parser/src/ast.rs
index 8525512..efcabd8 100644
--- a/trunk_parser/src/ast.rs
+++ b/trunk_parser/src/ast.rs
@@ -32,7 +32,7 @@ impl From<&str> for Param {
 }
 
 #[derive(Debug, Clone, PartialEq)]
-pub enum MethodFlags {
+pub enum MethodFlag {
     Public,
     Protected,
     Private,
@@ -55,7 +55,7 @@ pub enum Statement {
         name: Identifier,
         params: Vec<Param>,
         body: Block,
-        flags: Vec<MethodFlags>,
+        flags: Vec<MethodFlag>,
     },
     If {
         condition: Expression,
diff --git a/trunk_parser/src/parser.rs b/trunk_parser/src/parser.rs
index 9326dd5..49479e9 100644
--- a/trunk_parser/src/parser.rs
+++ b/trunk_parser/src/parser.rs
@@ -1,7 +1,7 @@
-use std::vec::IntoIter;
+use std::{vec::IntoIter};
 use std::iter::Peekable;
 use trunk_lexer::{Token, TokenKind};
-use crate::{Program, Statement, Block, Expression};
+use crate::{Program, Statement, Block, Expression, ast::MethodFlag};
 
 macro_rules! expect {
     ($actual:expr, $expected:pat, $out:expr, $message:literal) => {
@@ -81,6 +81,7 @@ impl Parser {
                         Statement::Function { name, params, body } => {
                             Statement::Method { name, params, body, flags: vec![] }
                         },
+                        s @ Statement::Method { .. } => s,
                         _ => return Err(ParseError::InvalidClassStatement(format!("Classes can only contain properties, constants and methods.")))
                     };
 
@@ -148,6 +149,22 @@ impl Parser {
 
                 Statement::Function { name: name.into(), params, body }
             },
+            _ if is_method_visibility_modifier(&t.kind) => {
+                let mut flags = vec![visibility_token_to_flag(&t.kind)];
+
+                while let Some(t) = tokens.peek() && is_method_visibility_modifier(&t.kind) {
+                    let next = tokens.next().unwrap();
+
+                    flags.push(visibility_token_to_flag(&next.kind));
+                }
+
+                match self.statement(tokens.next().unwrap(), tokens)? {
+                    Statement::Function { name, params, body } => {
+                        Statement::Method { name, params, body, flags }
+                    },
+                    _ => return Err(ParseError::InvalidClassStatement("Classes can only contain properties, constants and methods.".into()))
+                }
+            },
             _ => todo!("unhandled token: {:?}", t)
         })
     }
@@ -226,6 +243,20 @@ impl Parser {
     }
 }
 
+fn is_method_visibility_modifier(kind: &TokenKind) -> bool {
+    [TokenKind::Public, TokenKind::Protected, TokenKind::Private, TokenKind::Static].contains(kind)
+}
+
+fn visibility_token_to_flag(kind: &TokenKind) -> MethodFlag {
+    match kind {
+        TokenKind::Public => MethodFlag::Public,
+        TokenKind::Protected => MethodFlag::Protected,
+        TokenKind::Private => MethodFlag::Private,
+        TokenKind::Static => MethodFlag::Static,
+        _ => unreachable!()
+    }
+}
+
 fn infix(lhs: Expression, op: TokenKind, rhs: Expression) -> Expression {
     Expression::Infix(Box::new(lhs), op.into(), Box::new(rhs))
 }
@@ -255,7 +286,7 @@ pub enum ParseError {
 #[cfg(test)]
 mod tests {
     use trunk_lexer::Lexer;
-    use crate::{Statement, Block, Param, Expression, ast::InfixOp};
+    use crate::{Statement, Block, Param, Expression, ast::{InfixOp, MethodFlag}};
     use super::Parser;
 
     macro_rules! function {
@@ -403,6 +434,35 @@ mod tests {
         ]);
     }
 
+    #[test]
+    fn class_with_method_visibility() {
+        assert_ast("\
+        <?php
+        
+        class Foo {
+            public function bar() {
+                echo 1;
+            }
+
+            private static function baz() {}
+        }
+        ", &[
+            class!("Foo", &[
+                method!("bar", &[], &[
+                    MethodFlag::Public,
+                ], &[
+                    Statement::Echo { values: vec![
+                        Expression::Int(1),
+                    ] }
+                ]),
+                method!("baz", &[], &[
+                    MethodFlag::Private,
+                    MethodFlag::Static,
+                ], &[])
+            ])
+        ]);
+    }
+
     fn assert_ast(source: &str, expected: &[Statement]) {
         let mut lexer = Lexer::new(None);
         let tokens = lexer.tokenize(source).unwrap();