Implemented boolean expressions

src/error/mod.rs

@@ -1,4 +1,5 @@
 use crate::value::Value;
+use token::PartialToken;
 
 #[derive(Debug, PartialEq)]
 pub enum Error {
@@ -9,6 +10,9 @@ pub enum Error {
     ExpectedNumber {
         actual: Value,
     },
+    ExpectedBoolean {
+        actual: Value,
+    },
 
     /// The given expression is empty
     EmptyExpression,
@@ -35,6 +39,11 @@ pub enum Error {
 
     /// A closing brace without a matching opening brace was found.
     UnmatchedRBrace,
+
+    UnmatchedPartialToken {
+        first: PartialToken,
+        second: Option<PartialToken>,
+    },
 }
 
 impl Error {
@@ -45,6 +54,14 @@ impl Error {
     pub fn expected_number(actual: Value) -> Self {
         Error::ExpectedNumber { actual }
     }
+
+    pub fn expected_boolean(actual: Value) -> Self {
+        Error::ExpectedBoolean { actual }
+    }
+
+    pub fn unmatched_partial_token(first: PartialToken, second: Option<PartialToken>) -> Self {
+        Error::UnmatchedPartialToken {first, second}
+    }
 }
 
 pub fn expect_argument_amount(actual: usize, expected: usize) -> Result<(), Error> {
@@ -61,3 +78,10 @@ pub fn expect_number(actual: &Value) -> Result<(), Error> {
         _ => Err(Error::expected_number(actual.clone())),
     }
 }
+
+pub fn expect_boolean(actual: &Value) -> Result<bool, Error> {
+    match actual {
+        Value::Boolean(boolean) => Ok(*boolean),
+        _ => Err(Error::expected_boolean(actual.clone())),
+    }
+}

src/lib.rs

@@ -10,7 +10,7 @@ mod tree;
 mod value;
 
 pub fn eval(string: &str) -> Result<Value, Error> {
-    tree::tokens_to_operator_tree(token::tokenize(string))?.eval(&EmptyConfiguration)
+    tree::tokens_to_operator_tree(token::tokenize(string)?)?.eval(&EmptyConfiguration)
 }
 
 #[cfg(test)]
@@ -90,7 +90,15 @@ mod test {
     }
 
     #[test]
-    fn test_type_errors() {
+    fn test_boolean_examples() {
+        assert_eq!(eval("true && false"), Ok(Value::Boolean(false)));
+        assert_eq!(eval("true && false || true && true"), Ok(Value::Boolean(true)));
+        assert_eq!(eval("5 > 4 && 1 <= 1"), Ok(Value::Boolean(true)));
+        assert_eq!(eval("5.0 <= 4.9 || !(4 > 3.5)"), Ok(Value::Boolean(false)));
+    }
+
+    #[test]
+    fn test_errors() {
         assert_eq!(
             eval("-true"),
             Err(Error::expected_number(Value::Boolean(true)))
@@ -100,6 +108,6 @@ mod test {
             Err(Error::expected_number(Value::Boolean(true)))
         );
         assert_eq!(eval("true-"), Err(Error::wrong_argument_amount(1, 2)));
+        assert_eq!(eval("!(()true)"), Err(Error::AppendedToLeafNode));
     }
-
 }

src/operator/mod.rs

@@ -30,6 +30,16 @@ pub struct Mul;
 pub struct Div;
 pub struct Mod;
 
+pub struct Eq;
+pub struct Neq;
+pub struct Gt;
+pub struct Lt;
+pub struct Geq;
+pub struct Leq;
+pub struct And;
+pub struct Or;
+pub struct Not;
+
 pub struct Const {
     value: Value,
 }
@@ -216,6 +226,231 @@ impl Operator for Mod {
     }
 }
 
+impl Operator for Eq {
+    fn precedence(&self) -> i32 {
+        80
+    }
+
+    fn argument_amount(&self) -> usize {
+        2
+    }
+
+    fn eval(&self, arguments: &[Value], _configuration: &Configuration) -> Result<Value, Error> {
+        expect_argument_amount(arguments.len(), 2)?;
+
+        if arguments[0] == arguments[1] {
+            Ok(Value::Boolean(true))
+        } else {
+            Ok(Value::Boolean(false))
+        }
+    }
+}
+
+impl Operator for Neq {
+    fn precedence(&self) -> i32 {
+        80
+    }
+
+    fn argument_amount(&self) -> usize {
+        2
+    }
+
+    fn eval(&self, arguments: &[Value], _configuration: &Configuration) -> Result<Value, Error> {
+        expect_argument_amount(arguments.len(), 2)?;
+
+        if arguments[0] != arguments[1] {
+            Ok(Value::Boolean(true))
+        } else {
+            Ok(Value::Boolean(false))
+        }
+    }
+}
+
+impl Operator for Gt {
+    fn precedence(&self) -> i32 {
+        80
+    }
+
+    fn argument_amount(&self) -> usize {
+        2
+    }
+
+    fn eval(&self, arguments: &[Value], _configuration: &Configuration) -> Result<Value, Error> {
+        expect_argument_amount(arguments.len(), 2)?;
+        expect_number(&arguments[0])?;
+        expect_number(&arguments[1])?;
+
+        if arguments[0].is_int() && arguments[1].is_int() {
+            if arguments[0].as_int().unwrap() > arguments[1].as_int().unwrap() {
+                Ok(Value::Boolean(true))
+            } else {
+                Ok(Value::Boolean(false))
+            }
+        } else {
+            if arguments[0].as_float().unwrap() > arguments[1].as_float().unwrap() {
+                Ok(Value::Boolean(true))
+            } else {
+                Ok(Value::Boolean(false))
+            }
+        }
+    }
+}
+
+impl Operator for Lt {
+    fn precedence(&self) -> i32 {
+        80
+    }
+
+    fn argument_amount(&self) -> usize {
+        2
+    }
+
+    fn eval(&self, arguments: &[Value], _configuration: &Configuration) -> Result<Value, Error> {
+        expect_argument_amount(arguments.len(), 2)?;
+        expect_number(&arguments[0])?;
+        expect_number(&arguments[1])?;
+
+        if arguments[0].is_int() && arguments[1].is_int() {
+            if arguments[0].as_int().unwrap() < arguments[1].as_int().unwrap() {
+                Ok(Value::Boolean(true))
+            } else {
+                Ok(Value::Boolean(false))
+            }
+        } else {
+            if arguments[0].as_float().unwrap() < arguments[1].as_float().unwrap() {
+                Ok(Value::Boolean(true))
+            } else {
+                Ok(Value::Boolean(false))
+            }
+        }
+    }
+}
+
+impl Operator for Geq {
+    fn precedence(&self) -> i32 {
+        80
+    }
+
+    fn argument_amount(&self) -> usize {
+        2
+    }
+
+    fn eval(&self, arguments: &[Value], _configuration: &Configuration) -> Result<Value, Error> {
+        expect_argument_amount(arguments.len(), 2)?;
+        expect_number(&arguments[0])?;
+        expect_number(&arguments[1])?;
+
+        if arguments[0].is_int() && arguments[1].is_int() {
+            if arguments[0].as_int().unwrap() >= arguments[1].as_int().unwrap() {
+                Ok(Value::Boolean(true))
+            } else {
+                Ok(Value::Boolean(false))
+            }
+        } else {
+            if arguments[0].as_float().unwrap() >= arguments[1].as_float().unwrap() {
+                Ok(Value::Boolean(true))
+            } else {
+                Ok(Value::Boolean(false))
+            }
+        }
+    }
+}
+
+impl Operator for Leq {
+    fn precedence(&self) -> i32 {
+        80
+    }
+
+    fn argument_amount(&self) -> usize {
+        2
+    }
+
+    fn eval(&self, arguments: &[Value], _configuration: &Configuration) -> Result<Value, Error> {
+        expect_argument_amount(arguments.len(), 2)?;
+        expect_number(&arguments[0])?;
+        expect_number(&arguments[1])?;
+
+        if arguments[0].is_int() && arguments[1].is_int() {
+            if arguments[0].as_int().unwrap() <= arguments[1].as_int().unwrap() {
+                Ok(Value::Boolean(true))
+            } else {
+                Ok(Value::Boolean(false))
+            }
+        } else {
+            if arguments[0].as_float().unwrap() <= arguments[1].as_float().unwrap() {
+                Ok(Value::Boolean(true))
+            } else {
+                Ok(Value::Boolean(false))
+            }
+        }
+    }
+}
+
+impl Operator for And {
+    fn precedence(&self) -> i32 {
+        75
+    }
+
+    fn argument_amount(&self) -> usize {
+        2
+    }
+
+    fn eval(&self, arguments: &[Value], _configuration: &Configuration) -> Result<Value, Error> {
+        expect_argument_amount(arguments.len(), 2)?;
+        let a = expect_boolean(&arguments[0])?;
+        let b = expect_boolean(&arguments[1])?;
+
+            if a && b {
+                Ok(Value::Boolean(true))
+            } else {
+                Ok(Value::Boolean(false))
+            }
+    }
+}
+
+impl Operator for Or {
+    fn precedence(&self) -> i32 {
+        70
+    }
+
+    fn argument_amount(&self) -> usize {
+        2
+    }
+
+    fn eval(&self, arguments: &[Value], _configuration: &Configuration) -> Result<Value, Error> {
+        expect_argument_amount(arguments.len(), 2)?;
+        let a = expect_boolean(&arguments[0])?;
+        let b = expect_boolean(&arguments[1])?;
+
+        if a || b {
+            Ok(Value::Boolean(true))
+        } else {
+            Ok(Value::Boolean(false))
+        }
+    }
+}
+
+impl Operator for Not {
+    fn precedence(&self) -> i32 {
+        110
+    }
+
+    fn argument_amount(&self) -> usize {
+        1
+    }
+
+    fn eval(&self, arguments: &[Value], _configuration: &Configuration) -> Result<Value, Error> {
+        expect_argument_amount(arguments.len(), 1)?;
+        let a = expect_boolean(&arguments[0])?;
+
+        if !a {
+            Ok(Value::Boolean(true))
+        } else {
+            Ok(Value::Boolean(false))
+        }
+    }
+}
+
 impl Operator for Const {
     fn precedence(&self) -> i32 {
         200

src/token/mod.rs

@@ -1,13 +1,28 @@
 use value::{FloatType, IntType};
+use error::Error;
 
-#[derive(Clone, PartialEq)]
+#[derive(Clone, PartialEq, Debug)]
 pub enum Token {
     // Single character tokens
+    // Arithmetic
     Plus,
     Minus,
     Star,
     Slash,
     Percent,
+
+    // Logic
+    Eq,
+    Neq,
+    Gt,
+    Lt,
+    Geq,
+    Leq,
+    And,
+    Or,
+    Not,
+
+    // Precedence
     LBrace,
     RBrace,
     Whitespace,
@@ -19,21 +34,37 @@ pub enum Token {
     Boolean(bool),
 }
 
-enum PartialToken {
+#[derive(Clone, Debug, PartialEq)]
+pub enum PartialToken {
     Token(Token),
     Literal(String),
+    Eq,
+    ExclamationMark,
+    Gt,
+    Lt,
+    Ampersand,
+    VerticalBar,
 }
 
 // Make this a const fn as soon as match gets stable (issue #57563)
-fn char_to_token(c: char) -> PartialToken {
+fn char_to_partial_token(c: char) -> PartialToken {
     match c {
         '+' => PartialToken::Token(Token::Plus),
         '-' => PartialToken::Token(Token::Minus),
         '*' => PartialToken::Token(Token::Star),
         '/' => PartialToken::Token(Token::Slash),
         '%' => PartialToken::Token(Token::Percent),
+
+        '=' => PartialToken::Eq,
+        '!' => PartialToken::ExclamationMark,
+        '>' => PartialToken::Gt,
+        '<' => PartialToken::Lt,
+        '&' => PartialToken::Ampersand,
+        '|' => PartialToken::VerticalBar,
+
         '(' => PartialToken::Token(Token::LBrace),
         ')' => PartialToken::Token(Token::RBrace),
+
         c => {
             if c.is_whitespace() {
                 PartialToken::Token(Token::Whitespace)
@@ -53,9 +84,21 @@ impl Token {
             Token::Star => false,
             Token::Slash => false,
             Token::Percent => false,
+
+            Token::Eq => false,
+            Token::Neq => false,
+            Token::Gt => false,
+            Token::Lt => false,
+            Token::Geq => false,
+            Token::Leq => false,
+            Token::And => false,
+            Token::Or => false,
+            Token::Not => false,
+
             Token::LBrace => false,
             Token::RBrace => true,
             Token::Whitespace => false,
+
             Token::Identifier(_) => true,
             Token::Float(_) => true,
             Token::Int(_) => true,
@@ -68,7 +111,7 @@ impl Token {
 fn str_to_tokens(string: &str) -> Vec<PartialToken> {
     let mut result = Vec::new();
     for c in string.chars() {
-        let partial_token = char_to_token(c);
+        let partial_token = char_to_partial_token(c);
 
         let if_let_successful =
             if let (Some(PartialToken::Literal(last)), PartialToken::Literal(literal)) =
@@ -87,13 +130,18 @@ fn str_to_tokens(string: &str) -> Vec<PartialToken> {
     result
 }
 
-/// Resolves all literals in the given vector of partial tokens by converting them to complex tokens.
-fn resolve_literals(tokens: &Vec<PartialToken>) -> Vec<Token> {
-    tokens
-        .iter()
-        .map(|token| match token {
-            PartialToken::Token(token) => token.clone(),
+/// Resolves all partial tokens by converting them to complex tokens.
+fn resolve_literals(mut tokens: &[PartialToken]) -> Result<Vec<Token>, Error> {
+    let mut result = Vec::new();
+    while tokens.len() > 0 {
+        let first = tokens[0].clone();
+        let second = tokens.get(1).cloned();
+        let mut cutoff = 2;
+
+        result.push(match first {
+            PartialToken::Token(token) => {cutoff = 1; token},
             PartialToken::Literal(literal) => {
+                cutoff = 1;
                 if let Ok(number) = literal.parse::<IntType>() {
                     Token::Int(number)
                 } else if let Ok(number) = literal.parse::<FloatType>() {
@@ -103,11 +151,50 @@ fn resolve_literals(tokens: &Vec<PartialToken>) -> Vec<Token> {
                 } else {
                     Token::Identifier(literal.to_string())
                 }
-            }
-        })
-        .collect()
+            },
+            PartialToken::Eq => {
+                match second {
+                    Some(PartialToken::Eq) => Token::Eq,
+                    _ => return Err(Error::unmatched_partial_token(first, second)),
+                }
+            },
+            PartialToken::ExclamationMark => {
+                match second {
+                    Some(PartialToken::Eq) => Token::Eq,
+                    _ => {cutoff = 1; Token::Not},
+                }
+            },
+            PartialToken::Gt => {
+                match second {
+                    Some(PartialToken::Eq) => Token::Geq,
+                    _ => {cutoff = 1; Token::Gt},
+                }
+            },
+            PartialToken::Lt => {
+                match second {
+                    Some(PartialToken::Eq) => Token::Leq,
+                    _ => {cutoff = 1; Token::Lt},
+                }
+            },
+            PartialToken::Ampersand => {
+                match second {
+                    Some(PartialToken::Ampersand) => Token::And,
+                    _ => return Err(Error::unmatched_partial_token(first, second)),
+                }
+            },
+            PartialToken::VerticalBar => {
+                match second {
+                    Some(PartialToken::VerticalBar) => Token::Or,
+                    _ => return Err(Error::unmatched_partial_token(first, second)),
+                }
+            },
+        });
+
+        tokens = &tokens[cutoff..];
+    }
+    Ok(result)
 }
 
-pub fn tokenize(string: &str) -> Vec<Token> {
+pub fn tokenize(string: &str) -> Result<Vec<Token>, Error> {
     resolve_literals(&str_to_tokens(string))
 }

src/tree/mod.rs

@@ -88,6 +88,17 @@ pub fn tokens_to_operator_tree(tokens: Vec<Token>) -> Result<Node, Error> {
             Token::Star => Some(Node::new(Mul)),
             Token::Slash => Some(Node::new(Div)),
             Token::Percent => Some(Node::new(Mod)),
+
+            Token::Eq => Some(Node::new(Eq)),
+            Token::Neq => Some(Node::new(Neq)),
+            Token::Gt => Some(Node::new(Gt)),
+            Token::Lt => Some(Node::new(Lt)),
+            Token::Geq => Some(Node::new(Geq)),
+            Token::Leq => Some(Node::new(Leq)),
+            Token::And => Some(Node::new(And)),
+            Token::Or => Some(Node::new(Or)),
+            Token::Not => Some(Node::new(Not)),
+            
             Token::LBrace => {
                 root.push(Node::root_node());
                 None
@@ -100,6 +111,7 @@ pub fn tokens_to_operator_tree(tokens: Vec<Token>) -> Result<Node, Error> {
                 }
             }
             Token::Whitespace => None,
+            
             Token::Identifier(identifier) => Some(Node::new(Identifier::new(identifier))),
             Token::Float(number) => Some(Node::new(Const::new(Value::Float(number)))),
             Token::Int(number) => Some(Node::new(Const::new(Value::Int(number)))),