From 3cc81812e692063fe7522b8e0ac42231d831997e Mon Sep 17 00:00:00 2001
From: Yandrik <me@yandrik.dev>
Date: Mon, 29 Nov 2021 23:22:35 +0100
Subject: [PATCH] feat: completed parser

---
 src/lib.rs        |  4 +--
 src/main.rs       |  8 ++----
 src/parser/mod.rs | 70 +++++++++++++++++++++++++++++++++++++++++++----
 3 files changed, 69 insertions(+), 13 deletions(-)

diff --git a/src/lib.rs b/src/lib.rs
index b0a77fc..88d2720 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -2,6 +2,6 @@ pub mod lexer;
 pub mod errors;
 mod parser;
 
-pub fn test() {
-    println!("{}", "hi there");
+pub fn calculate(expression: &str) -> Result<f64, parser::errors::ParserErrors> {
+    Ok(parser::parse(lexer::Lexer::new(expression))?)
 }
diff --git a/src/main.rs b/src/main.rs
index 06d5ee1..a49b4bc 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -1,9 +1,7 @@
 use s5_cb_calculator::lexer::Lexer;
 
 fn main() {
-    let mut lexer = Lexer::new("15+(30^2-5)*2/4".chars().collect());
-    while let Ok(Some(token)) = lexer.next() {
-        println!("Token: {:?}", token)
-    }
-    println!("Hello, world!");
+    println!("Hi there! Welcome to OverComplicatedCalculator v1.0!");
+    println!("To have OCC calculate something, just type it in!");
+
 }
diff --git a/src/parser/mod.rs b/src/parser/mod.rs
index 7ba9655..98ff27d 100644
--- a/src/parser/mod.rs
+++ b/src/parser/mod.rs
@@ -7,7 +7,7 @@ use crate::lexer::tokens;
 use crate::parser::errors::ParserErrors;
 use crate::parser::errors::ParserErrors::UnexpectedTokenError;
 
-mod errors;
+pub mod errors;
 
 type Result<T> = result::Result<T, errors::ParserErrors>;
 
@@ -47,6 +47,7 @@ pub fn parse(mut lexer: lexer::Lexer) -> Result<f64> {
 }
 
 pub fn s_proc(tbox: &mut TokenBox) -> Result<f64> {
+    println!("Proc S");
     let mut result = a_proc(tbox)?;
     match tbox.read_token()? {
         None => Ok(result),
@@ -55,35 +56,48 @@ pub fn s_proc(tbox: &mut TokenBox) -> Result<f64> {
 }
 
 fn a_proc(tbox: &mut TokenBox) -> Result<f64> {
+    println!("Proc A");
     let mut result = m_proc(tbox)?;
     match &tbox.read_token()? {
         Some(Token::OP(_, OpType::ADD)) => Ok(result + a_proc(tbox)?),
         Some(Token::OP(_, OpType::SUB)) => Ok(result - a_proc(tbox)?),
         None => Ok(result),
-        Some(token) => Err(ParserErrors::UnexpectedTokenError(token.clone(), String::from("A")))
+        Some(token) => {
+            tbox.regress();
+            Ok(result)
+        },
     }
 }
 
 fn m_proc(tbox: &mut TokenBox) -> Result<f64> {
+    println!("Proc M");
     let mut result = g_proc(tbox)?;
     match &tbox.read_token()? {
         Some(Token::OP(_, OpType::MUL)) => Ok(result * m_proc(tbox)?),
         Some(Token::OP(_, OpType::DIV)) => Ok(result / m_proc(tbox)?),
         None => Ok(result),
-        Some(token) => Err(UnexpectedTokenError(token.clone(), String::from("M"))),
+        Some(token) => {
+            tbox.regress();
+            Ok(result)
+        },
     }
 }
 
 fn g_proc(tbox: &mut TokenBox) -> Result<f64> {
+    println!("Proc G");
     let mut result = p_proc(tbox)?;
     match tbox.read_token()? {
         Some(Token::OP(_, OpType::POW)) => Ok(result.powf(g_proc(tbox)?)),
         None => Ok(result),
-        Some(token) => Err(UnexpectedTokenError(token.clone(), String::from("G"))),
+        Some(token) => {
+            tbox.regress();
+            Ok(result)
+        },
     }
 }
 
 fn p_proc(tbox: &mut TokenBox) -> Result<f64> {
+    println!("Proc P");
     match expect_token(tbox.read_token()?)? {
         Token::OBR(_) => {
             let result = a_proc(tbox)?;
@@ -103,9 +117,53 @@ mod test {
 
     #[test]
     fn simple_formula() -> Result<()> {
-        let res = parse(lexer::Lexer::new("15+3"))?;
+        let res = parse(lexer::Lexer::new("15+3-5*2"))?;
         println!("res: {}", res);
-        assert_eq!(res, 18.0);
+        assert_eq!(res, 8.0);
         Ok(())
     }
+
+    #[test]
+    fn skript_formula_1() -> Result<()> {
+        let res = parse(lexer::Lexer::new("2+5/3*2"))?;
+        assert_eq!(res, 5.3333333);
+        Ok(())
+    }
+
+    #[test]
+    fn skript_formula_2() -> Result<()> {
+        let res = parse(lexer::Lexer::new("(2+5)/3"))?;
+        assert_eq!(res, 2.3333333333333335);
+        Ok(())
+    }
+
+    #[test]
+    fn skript_formula_3() -> Result<()> {
+        let res = parse(lexer::Lexer::new("((10-213)*25)+27"))?;
+        assert_eq!(res, -5048.0);
+        Ok(())
+    }
+
+    #[test]
+    fn skript_formula_4() -> Result<()> {
+        let res = parse(lexer::Lexer::new("(7-3)*4^3"))?;
+        assert_eq!(res, 256.0);
+        Ok(())
+    }
+
+    #[test]
+    fn skript_error_1() {
+        assert!(matches!(
+            parse(lexer::Lexer::new("((1+1)*1-2")),
+            Err(ParserErrors::MissingTokenError)
+        ))
+    }
+
+    #[test]
+    fn skript_error_2() {
+        assert!(matches!(
+            parse(lexer::Lexer::new("a+1*3")),
+            Err(ParserErrors::LexerError(lexer::errors::LexerErrors::InvalidTokenError { token: _, pos: _ }))
+        ))
+    }
 }