From 91bd015e9b33f3ab902a72d218b869a285223d8e Mon Sep 17 00:00:00 2001
From: Erin <erin@erindesu.cz>
Date: Sun, 2 May 2021 00:39:08 +0200
Subject: [PATCH] Added basic math operations - cargo fmt

---
 src/main.rs         |  5 ++++-
 src/parser/mod.rs   | 12 +++++------
 src/parser/ops.rs   | 51 ++++++++++++++++++++++++++++++++++++++++++---
 src/parser/utils.rs |  9 +++++---
 4 files changed, 63 insertions(+), 14 deletions(-)

diff --git a/src/main.rs b/src/main.rs
index eb43c6b5..fb7e7b55 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -37,7 +37,10 @@ fn main() {
             println!("{:#?}", ast);
         }
         None => {
-            println!("Hi [AbleScript {}] - AST Printer", env!("CARGO_PKG_VERSION"));
+            println!(
+                "Hi [AbleScript {}] - AST Printer",
+                env!("CARGO_PKG_VERSION")
+            );
             repl::repl();
         }
     }
diff --git a/src/parser/mod.rs b/src/parser/mod.rs
index 4c416913..e90a8d58 100644
--- a/src/parser/mod.rs
+++ b/src/parser/mod.rs
@@ -53,7 +53,11 @@ impl<'a> Parser<'a> {
         let start = self.lexer.span().start;
 
         match token {
-            Token::Identifier(_) => self.parse_ops(token).map(|x| x.into()),
+            Token::Identifier(_)
+            | Token::Aboolean(_)
+            | Token::Boolean(_)
+            | Token::Integer(_)
+            | Token::String(_) => self.parse_ops(token),
             // Control flow
             Token::If => self.if_cond(),
 
@@ -62,12 +66,6 @@ impl<'a> Parser<'a> {
             Token::Function => self.function_declaration(),
             Token::BfFunction => self.bff_declaration(),
 
-            // Literals
-            Token::String(x) => Ok(Expr::Literal(Value::Str(x)).into()),
-            Token::Integer(x) => Ok(Expr::Literal(Value::Int(x)).into()),
-            Token::Boolean(x) => Ok(Expr::Literal(Value::Bool(x)).into()),
-            Token::Aboolean(x) => Ok(Expr::Literal(Value::Abool(x)).into()),
-
             // Prefix keywords
             // Melo - ban variable from next usage (runtime error)
             Token::Melo => {
diff --git a/src/parser/ops.rs b/src/parser/ops.rs
index c9591531..024b1376 100644
--- a/src/parser/ops.rs
+++ b/src/parser/ops.rs
@@ -2,14 +2,59 @@ use super::*;
 
 type ExprResult = Result<Expr, Error>;
 
+#[macro_export]
+macro_rules! gen_infix {
+    ($($fn_name: ident => $type: tt);*$(;)?) => {$(
+        fn $fn_name(&mut self, left: Expr) -> ExprResult {
+            let next = self.lexer.next();
+            let right = self.ensure_expr(next)?;
+            Ok(Expr::$type { left: Box::new(left), right: Box::new(right) })
+        })*
+    };
+}
+
 impl<'a> Parser<'a> {
-    /// Parse operations (got identifier/value)
-    pub(super) fn parse_ops(&mut self, token: Token) -> ExprResult {
-        todo!()
+    pub(super) fn parse_ops(&mut self, token: Token) -> ParseResult {
+        let mut buf: Expr = self.ensure_expr(Some(token))?;
+
+        loop {
+            buf = match self.lexer.next() {
+                Some(Token::Addition) => self.addition(buf)?,
+                Some(Token::Subtract) => self.subtract(buf)?,
+                Some(Token::Multiply) => self.multiply(buf)?,
+                Some(Token::Divide) => self.divide(buf)?,
+                _ => return Ok(buf.into()),
+            }
+        }
+    }
+
+    // Generate infix
+    gen_infix! {
+        addition => Add;
+        subtract => Subtract;
+        multiply => Multiply;
+        divide => Divide;
+    }
+
+    /// Ensure that input token is an expression
+    fn ensure_expr(&mut self, token: Option<Token>) -> ExprResult {
+        let token = token.ok_or(Error {
+            kind: ErrorKind::EndOfTokenStream,
+            position: self.lexer.span(),
+        })?;
+        match token {
+            Token::Boolean(b) => Ok(Expr::Literal(Value::Bool(b))),
+            Token::Integer(i) => Ok(Expr::Literal(Value::Int(i))),
+            Token::String(s) => Ok(Expr::Literal(Value::Str(s))),
+            Token::Aboolean(a) => Ok(Expr::Literal(Value::Abool(a))),
+            Token::Identifier(i) => Ok(Expr::Identifier(Iden(i))),
+            t => Err(self.unexpected_token(Some(t))),
+        }
     }
 
     /// Parse function call
     fn fn_call(&mut self, iden: Iden) -> ExprResult {
+        return todo!();
         self.lexer.next();
         let mut args: Vec<Expr> = Vec::new();
 
diff --git a/src/parser/utils.rs b/src/parser/utils.rs
index 8ccfce80..1706fbea 100644
--- a/src/parser/utils.rs
+++ b/src/parser/utils.rs
@@ -2,7 +2,10 @@ use crate::error::{Error, ErrorKind};
 use crate::lexer::Token;
 use crate::variables::Abool;
 
-use super::{Parser, item::{Iden, Item}};
+use super::{
+    item::{Iden, Item},
+    Parser,
+};
 
 pub fn abool2num(abool: Abool) -> i32 {
     match abool {
@@ -37,7 +40,7 @@ impl<'a> Parser<'a> {
         } else {
             Err(Error {
                 kind: ErrorKind::InvalidIdentifier,
-                position: self.lexer.span(), 
+                position: self.lexer.span(),
             })
         }
     }
@@ -50,7 +53,7 @@ impl<'a> Parser<'a> {
                 self.lexer.slice(),
                 s
             ),
-            None => format!("Unexpected token: `{}`)", self.lexer.slice(),),
+            None => format!("Unexpected token: `{}`", self.lexer.slice(),),
         };
         Error {
             kind: ErrorKind::SyntaxError(error_msg),