From 9353c8fab1bab18e22ddcdfac9959304d885efd0 Mon Sep 17 00:00:00 2001
From: Ryan Chandler <ryangjchandler@gmail.com>
Date: Fri, 16 Sep 2022 10:09:29 +0100
Subject: [PATCH 1/3] lexer: produce single dollar tokens

---
 trunk_lexer/src/lexer.rs | 8 ++++++--
 trunk_lexer/src/token.rs | 2 ++
 2 files changed, 8 insertions(+), 2 deletions(-)

diff --git a/trunk_lexer/src/lexer.rs b/trunk_lexer/src/lexer.rs
index 5bba1c4..23f4b95 100644
--- a/trunk_lexer/src/lexer.rs
+++ b/trunk_lexer/src/lexer.rs
@@ -663,7 +663,11 @@ impl Lexer {
             }
         }
 
-        TokenKind::Variable(buffer.into())
+        if buffer.is_empty() {
+            TokenKind::Dollar
+        } else {
+            TokenKind::Variable(buffer.into())
+        }
     }
 
     fn tokenize_number(
@@ -1066,7 +1070,7 @@ function"#,
 
     #[test]
     fn sigils() {
-        assert_tokens("<?php ->", &[open!(), TokenKind::Arrow]);
+        assert_tokens("<?php -> $", &[open!(), TokenKind::Arrow, TokenKind::Dollar]);
     }
 
     #[test]
diff --git a/trunk_lexer/src/token.rs b/trunk_lexer/src/token.rs
index 3fc7b0c..47ca78c 100644
--- a/trunk_lexer/src/token.rs
+++ b/trunk_lexer/src/token.rs
@@ -11,6 +11,7 @@ pub enum OpenTagKind {
 
 #[derive(Debug, PartialEq, Clone)]
 pub enum TokenKind {
+    Dollar,
     HaltCompiler,
     Readonly,
     Global,
@@ -174,6 +175,7 @@ impl Default for Token {
 impl Display for TokenKind {
     fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         let s = match self {
+            Self::Dollar => "$",
             Self::HaltCompiler => "__halt_compiler",
             Self::Readonly => "readonly",
             Self::AsteriskEqual => "*=",

From 5cc76b4f3d8f5ff46a9cf38ea3fec48d1d498f9a Mon Sep 17 00:00:00 2001
From: Ryan Chandler <ryangjchandler@gmail.com>
Date: Fri, 16 Sep 2022 10:20:38 +0100
Subject: [PATCH 2/3] parser: support braced variables

---
 trunk_parser/src/ast.rs        |  3 +++
 trunk_parser/src/parser/mod.rs | 27 ++++++++++++++++++++++++++-
 2 files changed, 29 insertions(+), 1 deletion(-)

diff --git a/trunk_parser/src/ast.rs b/trunk_parser/src/ast.rs
index ab3506a..3e18ca5 100644
--- a/trunk_parser/src/ast.rs
+++ b/trunk_parser/src/ast.rs
@@ -442,6 +442,9 @@ pub enum Expression {
     Variable {
         name: ByteString,
     },
+    DynamicVariable {
+        name: Box<Self>,
+    },
     Infix {
         lhs: Box<Self>,
         op: InfixOp,
diff --git a/trunk_parser/src/parser/mod.rs b/trunk_parser/src/parser/mod.rs
index 016a086..14c1bf2 100644
--- a/trunk_parser/src/parser/mod.rs
+++ b/trunk_parser/src/parser/mod.rs
@@ -1929,7 +1929,23 @@ impl Parser {
                 let rhs = self.expression(rpred)?;
 
                 prefix(&op, rhs)
-            }
+            },
+            TokenKind::Dollar => {
+                self.next();
+
+                match self.current.kind {
+                    TokenKind::LeftBrace => {
+                        self.next();
+
+                        let name = self.expression(Precedence::Lowest)?;
+
+                        self.rbrace()?;
+
+                        Expression::DynamicVariable { name: Box::new(name) }
+                    },
+                    _ => todo!(),
+                }
+            },
             _ => todo!(
                 "expr lhs: {:?}, line {} col {}",
                 self.current.kind,
@@ -4200,6 +4216,15 @@ mod tests {
         );
     }
 
+    #[test]
+    fn braced_variables() {
+        assert_ast("<?php ${'foo'};", &[
+            expr!(Expression::DynamicVariable {
+                name: Box::new(Expression::ConstantString { value: "foo".into() })
+            })
+        ]);
+    }
+
     fn assert_ast(source: &str, expected: &[Statement]) {
         let mut lexer = Lexer::new(None);
         let tokens = lexer.tokenize(source).unwrap();

From 59ebb1ed2dd8fc2ef53302fb8974dbb6a7e1dcf7 Mon Sep 17 00:00:00 2001
From: Ryan Chandler <ryangjchandler@gmail.com>
Date: Fri, 16 Sep 2022 10:21:37 +0100
Subject: [PATCH 3/3] parser: add test case for call inside braced var

---
 trunk_lexer/src/lexer.rs       |  5 ++++-
 trunk_parser/src/parser/mod.rs | 33 ++++++++++++++++++++++++---------
 2 files changed, 28 insertions(+), 10 deletions(-)

diff --git a/trunk_lexer/src/lexer.rs b/trunk_lexer/src/lexer.rs
index 23f4b95..069a0c2 100644
--- a/trunk_lexer/src/lexer.rs
+++ b/trunk_lexer/src/lexer.rs
@@ -1070,7 +1070,10 @@ function"#,
 
     #[test]
     fn sigils() {
-        assert_tokens("<?php -> $", &[open!(), TokenKind::Arrow, TokenKind::Dollar]);
+        assert_tokens(
+            "<?php -> $",
+            &[open!(), TokenKind::Arrow, TokenKind::Dollar],
+        );
     }
 
     #[test]
diff --git a/trunk_parser/src/parser/mod.rs b/trunk_parser/src/parser/mod.rs
index 14c1bf2..5200fa1 100644
--- a/trunk_parser/src/parser/mod.rs
+++ b/trunk_parser/src/parser/mod.rs
@@ -1929,7 +1929,7 @@ impl Parser {
                 let rhs = self.expression(rpred)?;
 
                 prefix(&op, rhs)
-            },
+            }
             TokenKind::Dollar => {
                 self.next();
 
@@ -1941,11 +1941,13 @@ impl Parser {
 
                         self.rbrace()?;
 
-                        Expression::DynamicVariable { name: Box::new(name) }
-                    },
+                        Expression::DynamicVariable {
+                            name: Box::new(name),
+                        }
+                    }
                     _ => todo!(),
                 }
-            },
+            }
             _ => todo!(
                 "expr lhs: {:?}, line {} col {}",
                 self.current.kind,
@@ -4218,11 +4220,24 @@ mod tests {
 
     #[test]
     fn braced_variables() {
-        assert_ast("<?php ${'foo'};", &[
-            expr!(Expression::DynamicVariable {
-                name: Box::new(Expression::ConstantString { value: "foo".into() })
-            })
-        ]);
+        assert_ast(
+            "<?php ${'foo'};",
+            &[expr!(Expression::DynamicVariable {
+                name: Box::new(Expression::ConstantString {
+                    value: "foo".into()
+                })
+            })],
+        );
+
+        assert_ast(
+            "<?php ${foo()};",
+            &[expr!(Expression::DynamicVariable {
+                name: Box::new(Expression::Call {
+                    target: Box::new(Expression::Identifier { name: "foo".into() }),
+                    args: vec![]
+                })
+            })],
+        );
     }
 
     fn assert_ast(source: &str, expected: &[Statement]) {