From 051f6e781fb8454f094931614aa6680d7f68e954 Mon Sep 17 00:00:00 2001
From: Erin <erin@erindesu.cz>
Date: Sun, 2 May 2021 18:12:51 +0200
Subject: [PATCH] Added tests and loop flow

---
 src/lexer.rs       |  9 ++++++
 src/parser/item.rs | 17 ++++++++--
 src/parser/mod.rs  | 78 ++++++++++++++++++++++++++++++++++++++++++++++
 src/parser/ops.rs  |  1 +
 src/variables.rs   |  2 +-
 5 files changed, 103 insertions(+), 4 deletions(-)

diff --git a/src/lexer.rs b/src/lexer.rs
index 2fcb4bb..8474e8c 100644
--- a/src/lexer.rs
+++ b/src/lexer.rs
@@ -94,6 +94,12 @@ pub enum Token {
     #[token("loop")]
     Loop,
 
+    #[token("break")]
+    Break,
+
+    #[token("hopback")]
+    HopBack,
+
     // Literals
     /// True, False
     #[regex("true|false", get_bool)]
@@ -115,6 +121,9 @@ pub enum Token {
     #[regex(r"[a-zA-Z_][a-zA-Z_0-9]*", get_iden)]
     Identifier(String),
 
+    #[regex("nul")]
+    Nul,
+
     #[token("(")]
     LeftParenthesis,
 
diff --git a/src/parser/item.rs b/src/parser/item.rs
index e9e8a84..2e22968 100644
--- a/src/parser/item.rs
+++ b/src/parser/item.rs
@@ -3,7 +3,7 @@ use crate::variables::Value;
 #[derive(Debug, Clone, Hash, PartialEq, Eq)]
 pub struct Iden(pub String);
 
-#[derive(Debug, Clone)]
+#[derive(Debug, Clone, PartialEq)]
 pub enum Item {
     Expr(Expr),
     Stmt(Stmt),
@@ -15,13 +15,19 @@ impl From<Expr> for Item {
     }
 }
 
+impl From<Iden> for Item {
+    fn from(i: Iden) -> Self {
+        Item::Expr(Expr::Identifier(i))
+    }
+}
+
 impl From<Stmt> for Item {
     fn from(s: Stmt) -> Self {
         Item::Stmt(s)
     }
 }
 
-#[derive(Debug, Clone)]
+#[derive(Debug, Clone, PartialEq)]
 pub enum Expr {
     Add { left: Box<Expr>, right: Box<Expr> },
     Subtract { left: Box<Expr>, right: Box<Expr> },
@@ -43,7 +49,7 @@ impl From<Iden> for Expr {
     }
 }
 
-#[derive(Debug, Clone)]
+#[derive(Debug, Clone, PartialEq)]
 pub enum Stmt {
     VariableDeclaration {
         iden: Iden,
@@ -66,6 +72,11 @@ pub enum Stmt {
         iden: Iden,
         args: Vec<Expr>,
     },
+    Loop {
+        body: Vec<Item>,
+    },
+    Break,
+    HopBack,
     Print(Expr),
     Melo(Iden),
 }
diff --git a/src/parser/mod.rs b/src/parser/mod.rs
index d58ed00..a3393df 100644
--- a/src/parser/mod.rs
+++ b/src/parser/mod.rs
@@ -67,10 +67,21 @@ impl<'a> Parser<'a> {
             | Token::Boolean(_)
             | Token::Integer(_)
             | Token::String(_)
+            | Token::Nul
             | Token::LogNot => self.parse_ops(token),
 
             // Control flow
             Token::If => self.if_cond(),
+            Token::Loop => self.loop_block(),
+
+            Token::HopBack => {
+                self.require(Token::Semicolon)?;
+                Ok(Stmt::HopBack.into())
+            }
+            Token::Break => {
+                self.require(Token::Semicolon)?;
+                Ok(Stmt::Break.into())
+            }
 
             // Declarations
             Token::Variable => self.variable_declaration(),
@@ -194,6 +205,14 @@ impl<'a> Parser<'a> {
         .into())
     }
 
+    /// Parse loop
+    pub fn loop_block(&mut self) -> ParseResult {
+        self.require(Token::LeftBrace)?;
+        let body = self.parse_body()?;
+
+        Ok(Stmt::Loop { body }.into())
+    }
+
     /// T-Dark block parsing
     pub fn tdark_block(&mut self) -> Result<Vec<Item>, Error> {
         self.require(Token::LeftBrace)?;
@@ -221,3 +240,62 @@ impl<'a> Parser<'a> {
         Ok(body)
     }
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use Expr::*;
+    use Stmt::*;
+
+    #[test]
+    fn control_flow() {
+        let code = r#"loop { var a = 3 + 2; if (a == 5) { break; } }"#;
+
+        let expected: &[Item] = &[Item::Stmt(Loop {
+            body: vec![
+                VariableDeclaration {
+                    iden: Iden("a".to_owned()),
+                    init: Some(Box::new(
+                        Add {
+                            left: Box::new(Literal(Value::Int(3))),
+                            right: Box::new(Literal(Value::Int(2))),
+                        }
+                        .into(),
+                    )),
+                }
+                .into(),
+                If {
+                    cond: Box::new(
+                        Eq {
+                            left: Box::new(Iden("a".to_owned()).into()),
+                            right: Box::new(Literal(Value::Int(5)).into()),
+                        }
+                        .into(),
+                    ),
+                    body: vec![Break.into()],
+                }
+                .into(),
+            ],
+        })];
+        let ast = Parser::new(code).init().unwrap();
+
+        assert_eq!(ast, expected)
+    }
+
+    #[test]
+    fn tdark() {
+        let code = r#"T-Dark { var lang = nul; lang print; }"#;
+        let expected: &[Item] = &[
+            VariableDeclaration {
+                iden: Iden("script".to_owned()),
+                init: Some(Box::new(Literal(Value::Nul).into())),
+            }
+            .into(),
+            Print(Iden("script".to_owned()).into()).into(),
+        ];
+
+        let ast = Parser::new(code).init().unwrap();
+
+        assert_eq!(ast, expected)
+    }
+}
diff --git a/src/parser/ops.rs b/src/parser/ops.rs
index c400925..a8104ca 100644
--- a/src/parser/ops.rs
+++ b/src/parser/ops.rs
@@ -83,6 +83,7 @@ impl<'a> Parser<'a> {
             } else {
                 i
             }))),
+            Token::Nul => Ok(Expr::Literal(Value::Nul)),
             Token::LogNot => {
                 let next = self.lexer.next();
                 Ok(Expr::Not(Box::new(self.parse_expr(next)?)))
diff --git a/src/variables.rs b/src/variables.rs
index 10927c1..8c94fba 100644
--- a/src/variables.rs
+++ b/src/variables.rs
@@ -17,7 +17,7 @@ impl From<Abool> for bool {
     }
 }
 
-#[derive(Debug, Clone)]
+#[derive(Debug, Clone, PartialEq)]
 pub enum Value {
     Str(String),
     Int(i32),