From ba3ae0ee069866b119646ca0bfc771ef377ebc5c Mon Sep 17 00:00:00 2001
From: Domantas <domantas.mauruca@gmail.com>
Date: Tue, 26 Jul 2022 14:39:22 +0200
Subject: [PATCH 1/2] parser: support else if statements

---
 phpast/samples/if.php          |  4 ++++
 trunk_parser/src/ast.rs        |  7 +++++++
 trunk_parser/src/parser/mod.rs | 35 +++++++++++++++++++++++++++++++---
 3 files changed, 43 insertions(+), 3 deletions(-)

diff --git a/phpast/samples/if.php b/phpast/samples/if.php
index 7c55694..bdee8d8 100644
--- a/phpast/samples/if.php
+++ b/phpast/samples/if.php
@@ -2,6 +2,10 @@
 
 if($foo) {
     return $foo;
+} elseif($foo) {
+    return $foo;
+} elseif($foo) {
+    return $foo;
 } else {
     return $foo;
 }
\ No newline at end of file
diff --git a/trunk_parser/src/ast.rs b/trunk_parser/src/ast.rs
index 765cc1b..4ad0a5a 100644
--- a/trunk_parser/src/ast.rs
+++ b/trunk_parser/src/ast.rs
@@ -176,6 +176,7 @@ pub enum Statement {
     If {
         condition: Expression,
         then: Block,
+        else_ifs: Vec<ElseIf>,
         r#else: Option<Block>
     },
     Return {
@@ -271,4 +272,10 @@ impl From<TokenKind> for InfixOp {
             _ => unreachable!()
         }
     }
+}
+
+#[derive(Debug, Clone, PartialEq, Serialize)]
+pub struct ElseIf {
+    pub condition: Expression,
+    pub body: Block,
 }
\ No newline at end of file
diff --git a/trunk_parser/src/parser/mod.rs b/trunk_parser/src/parser/mod.rs
index ed5984b..e89b7ee 100644
--- a/trunk_parser/src/parser/mod.rs
+++ b/trunk_parser/src/parser/mod.rs
@@ -1,6 +1,6 @@
 use std::{vec::IntoIter, fmt::{Display}};
 use trunk_lexer::{Token, TokenKind, Span};
-use crate::{Program, Statement, Block, Expression, ast::{ArrayItem, Use, MethodFlag, ClassFlag}, Identifier, Type, Param};
+use crate::{Program, Statement, Block, Expression, ast::{ArrayItem, Use, MethodFlag, ClassFlag, ElseIf}, Identifier, Type, Param};
 
 type ParseResult<T> = Result<T, ParseError>;
 
@@ -354,8 +354,34 @@ impl Parser {
                     expect!(self, TokenKind::RightBrace, "expected }");
                 }
 
+                let mut else_ifs: Vec<ElseIf> = Vec::new();
+                loop {
+                    if self.current.kind == TokenKind::ElseIf {
+                        self.next();
+
+                        expect!(self, TokenKind::LeftParen, "expected (");
+
+                        let condition = self.expression(0)?;
+
+                        expect!(self, TokenKind::RightParen, "expected )");
+
+                        expect!(self, TokenKind::LeftBrace, "expected {");
+
+                        let mut body = Block::new();
+                        while ! self.is_eof() && self.current.kind != TokenKind::RightBrace {
+                            body.push(self.statement()?);
+                        }
+
+                        expect!(self, TokenKind::RightBrace, "expected }");
+
+                        else_ifs.push(ElseIf { condition, body });
+                    } else {
+                        break;
+                    }
+                }
+
                 if self.current.kind != TokenKind::Else {
-                    return Ok(Statement::If { condition, then, r#else: None });
+                    return Ok(Statement::If { condition, then, else_ifs, r#else: None });
                 }
 
                 expect!(self, TokenKind::Else, "expected else");
@@ -369,7 +395,7 @@ impl Parser {
 
                 expect!(self, TokenKind::RightBrace, "expected }");
 
-                Statement::If { condition, then, r#else: Some(r#else) }
+                Statement::If { condition, then, else_ifs, r#else: Some(r#else) }
             },
             TokenKind::Class => self.class()?,
             TokenKind::Echo => {
@@ -1209,6 +1235,7 @@ mod tests {
                     then: vec![
                         Statement::Return { value: Some(Expression::Variable("n".into())) }
                     ],
+                    else_ifs: vec![],
                     r#else: None
                 },
                 Statement::Return {
@@ -1248,6 +1275,7 @@ mod tests {
                     then: vec![
                         Statement::Return { value: Some(Expression::Variable("foo".into())) }
                     ],
+                    else_ifs: vec![],
                     r#else: None
                 },
         ]);
@@ -1261,6 +1289,7 @@ mod tests {
                     then: vec![
                         Statement::Return { value: Some(Expression::Variable("foo".into())) }
                     ],
+                    else_ifs: vec![],
                     r#else: Some(vec![
                         Statement::Return { value: Some(Expression::Variable("foo".into())) }
                     ])

From 72ff4cdcc244421102fa57bf4c574ffdf72ae69d Mon Sep 17 00:00:00 2001
From: Domantas <domantas.mauruca@gmail.com>
Date: Tue, 26 Jul 2022 14:44:06 +0200
Subject: [PATCH 2/2] parser: add elseif test

---
 trunk_parser/src/parser/mod.rs | 25 ++++++++++++++++++++++++-
 1 file changed, 24 insertions(+), 1 deletion(-)

diff --git a/trunk_parser/src/parser/mod.rs b/trunk_parser/src/parser/mod.rs
index e89b7ee..b27b80d 100644
--- a/trunk_parser/src/parser/mod.rs
+++ b/trunk_parser/src/parser/mod.rs
@@ -1031,7 +1031,7 @@ impl Display for ParseError {
 #[cfg(test)]
 mod tests {
     use trunk_lexer::Lexer;
-    use crate::{Statement, Param, Expression, ast::{InfixOp}, Type, Identifier};
+    use crate::{Statement, Param, Expression, ast::{InfixOp, ElseIf}, Type, Identifier};
     use super::Parser;
 
     macro_rules! function {
@@ -1297,6 +1297,29 @@ mod tests {
         ]);
     }
 
+    #[test]
+    fn if_elseif_else_statement() {
+        assert_ast("<?php if($foo) { return $foo; } elseif($foo) { return $foo; } else { return $foo; }", &[
+                Statement::If {
+                    condition: Expression::Variable("foo".into()),
+                    then: vec![
+                        Statement::Return { value: Some(Expression::Variable("foo".into())) }
+                    ],
+                    else_ifs: vec![
+                        ElseIf {
+                            condition: Expression::Variable("foo".into()),
+                            body: vec![
+                                Statement::Return { value: Some(Expression::Variable("foo".into())) }
+                            ]
+                        }
+                    ],
+                    r#else: Some(vec![
+                        Statement::Return { value: Some(Expression::Variable("foo".into())) }
+                    ])
+                },
+        ]);
+    }
+
     #[test]
     fn echo() {
         assert_ast("<?php echo 1;", &[