fix oopsie

.gitignore

@@ -0,0 +1,3 @@
+/target
+/.vscode
+Cargo.lock

Cargo.toml

@@ -0,0 +1,9 @@
+[package]
+name = "math_interpreter"
+version = "0.1.0"
+edition = "2021"
+
+[dependencies]
+colored = "2.1.0"
+strum = "0.26"
+strum_macros = "0.26"

src/errors.rs

@@ -0,0 +1,32 @@
+use std::fmt::Display;
+
+use colored::Colorize;
+
+#[derive(Debug, Clone)]
+pub enum ErrorReason {
+    Error(String),
+}
+
+impl Display for ErrorReason {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        match self {
+            ErrorReason::Error(reason) => write!(f, "{}", reason.red()),
+        }
+    }
+}
+
+#[derive(Debug, Clone)]
+pub struct ParserError {
+    #[allow(dead_code)]
+    pub error: ErrorReason,
+    pub description: String,
+}
+
+impl ParserError {
+    pub fn new(error: ErrorReason) -> Self {
+        Self {
+            description: error.to_string(),
+            error,
+        }
+    }
+}

src/lexer.rs

@@ -0,0 +1,88 @@
+use std::iter::Peekable;
+
+use crate::{
+    errors::ErrorReason,
+    token::{Token, TokenKind, TokenValue},
+};
+
+const DIGITS: &str = ".0123456789";
+
+pub struct Lexer {
+    source: String,
+}
+
+impl Lexer {
+    pub fn new(source: String) -> Self {
+        Self { source }
+    }
+
+    pub fn tokenize(&self) -> Result<Vec<Token>, ErrorReason> {
+        let mut tokens: Vec<Token> = Vec::new();
+        let mut chars = self
+            .source
+            .chars()
+            .filter(|c| !c.is_whitespace())
+            .peekable();
+
+        while let Some(&current) = chars.peek() {
+            // Best solution i could find to making sure it doesn't skip
+            if DIGITS.contains(current) {
+                tokens.push(self.generate_number(&mut chars)?);
+            } else {
+                let token = match current {
+                    '+' => Token::new(TokenKind::Plus, None),
+                    '-' => Token::new(TokenKind::Minus, None),
+                    '*' => Token::new(TokenKind::Multiply, None),
+                    '/' => Token::new(TokenKind::Divide, None),
+                    '^' => Token::new(TokenKind::Power, None),
+                    '(' => Token::new(TokenKind::LParen, None),
+                    ')' => Token::new(TokenKind::RParen, None),
+                    _ => Token::new(
+                        TokenKind::Unknown,
+                        Some(TokenValue::StrValue(current.to_string())),
+                    ),
+                };
+                tokens.push(token);
+                chars.next();
+            }
+        }
+
+        Ok(tokens)
+    }
+
+    fn generate_number<I>(&self, chars: &mut Peekable<I>) -> Result<Token, ErrorReason>
+    where
+        I: Iterator<Item = char>,
+    {
+        let mut decimal_point_counter = 0;
+        let mut number = String::new();
+
+        while let Some(&current) = chars.peek() {
+            if current == '.' {
+                decimal_point_counter += 1;
+                if decimal_point_counter > 1 {
+                    return Err(ErrorReason::Error("Too many decimal points".into()));
+                }
+            }
+            number.push(current);
+            chars.next();
+
+            // Peek the next character and check if it's valid for a number
+            if let Some(&next_char) = chars.peek() {
+                if !DIGITS.contains(next_char) {
+                    if number.trim() == "." {
+                        return Err(ErrorReason::Error("Random decimal place found ".into()));
+                    }
+                    break;
+                }
+            }
+        }
+
+        Ok(Token::new(
+            TokenKind::Number,
+            Some(TokenValue::NumValue(number.parse::<f64>().unwrap_or_else(
+                |_| panic!("Error parsing number '{number}'"),
+            ))),
+        ))
+    }
+}

src/main.rs

@@ -0,0 +1,102 @@
+mod errors;
+mod lexer;
+mod parser;
+mod token;
+mod traits;
+
+use std::io::{stdin, stdout, Write};
+
+use colored::Colorize;
+use errors::{ErrorReason, ParserError};
+use lexer::Lexer;
+use parser::Parser;
+use token::{Token, TokenKind, TokenValue};
+
+/// Prompts user for input and returns trimmed result
+fn prompt_input(prompt: &str) -> String {
+    let mut input = String::new();
+
+    print!("{}", prompt);
+    stdout().flush().unwrap();
+    stdin().read_line(&mut input).unwrap();
+
+    input.trim().to_owned()
+}
+
+fn main() {
+    println!("MATH INTERPRETER");
+    println!("----------------");
+
+    loop {
+        let input = prompt_input("> ");
+
+        let lexer = Lexer::new(input);
+        let tokens_result = lexer.tokenize();
+        if let Err(err) = tokens_result {
+            println!("{}", err);
+            continue;
+        }
+        let tokens = tokens_result.unwrap();
+
+        let token_errors = get_tokens_errors(tokens.clone());
+        if !token_errors.is_empty() {
+            for err in token_errors {
+                println!(
+                    "{}",
+                    ParserError::new(ErrorReason::Error(format!("Invalid sequence: '{}'", err)))
+                        .description
+                );
+            }
+            println!();
+        } else {
+            pretty_print_tokens(tokens.clone());
+            let mut parser = Parser::new(tokens.into_iter());
+            let result = parser.parse_expr();
+            println!("{:?}", result);
+            println!(
+                "{} {}",
+                "RESULT:".bright_green(),
+                result.unwrap().evaluate().to_string().bright_green()
+            );
+        }
+    }
+}
+
+fn pretty_print_tokens(tokens: Vec<Token>) {
+    let token_len = tokens.len();
+    tokens.iter().enumerate().for_each(|(i, token)| {
+        if i == token_len - 1 {
+            println!("{token}");
+        } else {
+            print!("{}, ", token);
+        }
+    })
+}
+
+fn get_tokens_errors(tokens: Vec<Token>) -> Vec<String> {
+    let mut error_str: Vec<String> = vec![];
+    let mut current_sequence: String = String::new();
+    let mut tokens_iter = tokens.iter().peekable();
+    while let Some(token) = tokens_iter.next() {
+        // If there's multiple correct tokens just skip that
+        if token.kind != TokenKind::Unknown {
+            continue;
+        }
+        if let TokenValue::StrValue(value) = &token.value {
+            // Push illegal char into current sequence
+            current_sequence.push(value.chars().next().unwrap());
+        }
+
+        // Check if next value is empty or not unknown
+        // If true then push current sequence to end string
+        let peek = tokens_iter.peek();
+        if !current_sequence.is_empty()
+            && (peek.is_none() || peek.unwrap().kind != TokenKind::Unknown)
+        {
+            // Append the current sequence
+            error_str.push(current_sequence.clone());
+            current_sequence.clear();
+        }
+    }
+    error_str
+}

src/parser.rs

@@ -0,0 +1,117 @@
+// - i needed some help making the AST. i dont think i could've made ts by myself 😭
+
+use std::iter::Peekable;
+
+use crate::{
+    errors::{ErrorReason, ParserError},
+    token::{Token, TokenKind, TokenValue},
+    traits::Round,
+};
+
+#[allow(dead_code)]
+#[derive(Debug)]
+pub enum ASTNode {
+    Number(f64),
+    BinaryOp(Box<ASTNode>, TokenKind, Box<ASTNode>),
+}
+
+pub struct Parser<I: Iterator<Item = Token>> {
+    tokens: Peekable<I>,
+}
+
+impl ASTNode {
+    pub fn evaluate(&self) -> f64 {
+        match self {
+            ASTNode::Number(val) => *val,
+            ASTNode::BinaryOp(left_node, op, right_node) => {
+                let left = left_node.evaluate();
+                let right = right_node.evaluate();
+                match op {
+                    TokenKind::Plus => left + right,
+                    TokenKind::Minus => left - right,
+                    TokenKind::Multiply => left * right,
+                    TokenKind::Divide => left / right,
+                    TokenKind::Power => left.powf(right),
+                    _ => panic!("wrong operation i cbf making proper errors for this"),
+                }
+                .round_to(5)
+            }
+        }
+    }
+}
+
+impl<I: Iterator<Item = Token>> Parser<I> {
+    pub fn new(tokens: I) -> Self {
+        Self {
+            tokens: tokens.peekable(),
+        }
+    }
+
+    fn advance(&mut self) -> Option<Token> {
+        self.tokens.next()
+    }
+
+    fn peek(&mut self) -> Option<&Token> {
+        self.tokens.peek()
+    }
+
+    pub fn parse_expr(&mut self) -> Result<ASTNode, ParserError> {
+        let mut node = self.parse_term()?;
+
+        while matches!(
+            self.peek().map(|t| t.kind),
+            Some(TokenKind::Plus) | Some(TokenKind::Minus) | Some(TokenKind::Power)
+        ) {
+            let operator = self.advance().unwrap().kind;
+            let right = self.parse_term()?;
+            node = ASTNode::BinaryOp(Box::new(node), operator, Box::new(right));
+        }
+
+        Ok(node)
+    }
+
+    fn parse_term(&mut self) -> Result<ASTNode, ParserError> {
+        let mut node = self.parse_factor()?;
+
+        while matches!(
+            self.peek().map(|t| t.kind),
+            Some(TokenKind::Multiply) | Some(TokenKind::Divide)
+        ) {
+            let operator = self.advance().unwrap().kind;
+            let right = self.parse_factor()?;
+            node = ASTNode::BinaryOp(Box::new(node), operator, Box::new(right));
+        }
+
+        Ok(node)
+    }
+
+    fn parse_factor(&mut self) -> Result<ASTNode, ParserError> {
+        match self.peek().map(|t| t.kind) {
+            Some(TokenKind::Number) => {
+                let value = if let TokenValue::NumValue(val) = self.advance().unwrap().value {
+                    val
+                } else {
+                    return Err(ParserError::new(ErrorReason::Error(
+                        "Expected a number".to_string(),
+                    )));
+                };
+                Ok(ASTNode::Number(value))
+            }
+            Some(TokenKind::LParen) => {
+                self.advance(); // Consume '('
+                let node = self.parse_expr()?;
+                if self.peek().map(|t| t.kind) != Some(TokenKind::RParen) {
+                    return Err(ParserError::new(ErrorReason::Error(
+                        "Expected ')'".into(),
+                    )));
+                }
+                self.advance(); // Consume ')'
+                Ok(node)
+            }
+            _ => Err(ParserError::new(ErrorReason::Error(format!(
+                "Unexpected token: {:?}",
+                self.peek()
+            )))),
+        }
+    }
+}