remove strum

Cargo.lock

@@ -2,78 +2,6 @@
 # It is not intended for manual editing.
 version = 4
 
-[[package]]
-name = "heck"
-version = "0.5.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "2304e00983f87ffb38b55b444b5e3b60a884b5d30c0fca7d82fe33449bbe55ea"
-
 [[package]]
 name = "leaf"
 version = "0.1.0"
-dependencies = [
- "strum",
-]
-
-[[package]]
-name = "proc-macro2"
-version = "1.0.95"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "02b3e5e68a3a1a02aad3ec490a98007cbc13c37cbe84a3cd7b8e406d76e7f778"
-dependencies = [
- "unicode-ident",
-]
-
-[[package]]
-name = "quote"
-version = "1.0.40"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "1885c039570dc00dcb4ff087a89e185fd56bae234ddc7f056a945bf36467248d"
-dependencies = [
- "proc-macro2",
-]
-
-[[package]]
-name = "rustversion"
-version = "1.0.21"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "8a0d197bd2c9dc6e53b84da9556a69ba4cdfab8619eb41a8bd1cc2027a0f6b1d"
-
-[[package]]
-name = "strum"
-version = "0.27.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "f64def088c51c9510a8579e3c5d67c65349dcf755e5479ad3d010aa6454e2c32"
-dependencies = [
- "strum_macros",
-]
-
-[[package]]
-name = "strum_macros"
-version = "0.27.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "c77a8c5abcaf0f9ce05d62342b7d298c346515365c36b673df4ebe3ced01fde8"
-dependencies = [
- "heck",
- "proc-macro2",
- "quote",
- "rustversion",
- "syn",
-]
-
-[[package]]
-name = "syn"
-version = "2.0.104"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "17b6f705963418cdb9927482fa304bc562ece2fdd4f616084c50b7023b435a40"
-dependencies = [
- "proc-macro2",
- "quote",
- "unicode-ident",
-]
-
-[[package]]
-name = "unicode-ident"
-version = "1.0.18"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "5a5f39404a5da50712a4c1eecf25e90dd62b613502b7e925fd4e4d19b5c96512"

Cargo.toml

@@ -4,4 +4,3 @@ version = "0.1.0"
 edition = "2024"
 
 [dependencies]
-strum = { version = "0.27", features = ["derive"] }

src/kind.rs

@@ -0,0 +1,36 @@
+pub trait Kind {
+    type Kinds;
+
+    fn kind(&self) -> Self::Kinds;
+}
+
+#[macro_export]
+macro_rules! kinds {
+    ($b:ident, $k:ident, $( $v:ident $( ( $($vty:ty = $vval:expr),* ) )?),* $(,)?) => {
+        #[derive(Debug)]
+        pub enum $b {
+            $( $v $( ( $($vty),* ) )?, )*
+        }
+        impl $crate::kind::Kind for $b {
+            type Kinds = $k;
+
+            fn kind(&self) -> $k {
+                $k (std::mem::discriminant(self))
+            }
+        }
+
+        #[derive(PartialEq, Eq, Clone, Copy)]
+        pub struct $k(std::mem::Discriminant<$b>);
+
+        impl $k {
+            $(
+                #[allow(non_upper_case_globals, dead_code)]
+                pub const $v: Self = $k (
+                    std::mem::discriminant(
+                        &( $b::$v $( ( $($vval),* ) )? )
+                    )
+                );
+            )*
+        }
+    };
+}

src/lexer.rs

@@ -1,6 +1,6 @@
-use std::{fmt, iter::Peekable};
+use std::{fmt, iter::Peekable, num::ParseIntError};
 
-use strum::EnumDiscriminants;
+use crate::kinds;
 
 #[derive(Debug)]
 pub struct Ident(String);
@@ -30,47 +30,38 @@ impl fmt::Display for Literal {
     }
 }
 
-#[derive(Debug, EnumDiscriminants)]
-#[strum_discriminants(name(TokenKind))]
-pub enum Token {
+kinds!(
+    Token,
+    TokenKind,
     Equals,
-
     Plus,
     Minus,
     Star,
     Slash,
     Percent,
     Caret,
-
     CurlyOpen,
     CurlyClose,
-
     ParenOpen,
     ParenClose,
-
     Comma,
     Semicolon,
-
+    Eol,
     Func,
     If,
     Else,
     Return,
-
     Not,
-
     EqualTo,
     NotEqualTo,
-
     And,
     Or,
-
     LessThan,
     LessThanOrEqualTo,
     GreaterThan,
     GreaterThanOrEqualTo,
-
-    Literal(Literal),
-}
+    Literal(Literal = Literal::Nil),
+);
 #[derive(PartialEq, Eq, PartialOrd, Ord, Clone, Copy)]
 pub enum Precedence {
     Min,
@@ -116,6 +107,7 @@ impl Token {
 
 #[derive(Debug)]
 pub enum LexError {
+    InvalidInteger(ParseIntError),
     InvalidEscape(char),
     UnexpectedCharacter(char),
     UnexpectedEnd,
@@ -123,12 +115,18 @@ pub enum LexError {
 impl fmt::Display for LexError {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         match self {
+            Self::InvalidInteger(err) => write!(f, "invalid integer: {err}"),
             Self::UnexpectedEnd => write!(f, "unexpected end of source"),
             Self::UnexpectedCharacter(c) => write!(f, "unexpected char '{c}'"),
             Self::InvalidEscape(c) => write!(f, "\"\\{c}\" is not a valid string escape"),
         }
     }
 }
+impl From<ParseIntError> for LexError {
+    fn from(err: ParseIntError) -> Self {
+        Self::InvalidInteger(err)
+    }
+}
 
 pub type Result<T> = std::result::Result<T, LexError>;
 
@@ -139,6 +137,10 @@ where
     chars: Peekable<I>,
 }
 
+fn t(tk: Token) -> Option<Result<Token>> {
+    Some(Ok(tk))
+}
+
 impl<I> Lexer<I>
 where
     I: Iterator<Item = char>,
@@ -209,7 +211,7 @@ where
         }
     }
 
-    fn lex_integer(&mut self) -> Token {
+    fn lex_integer(&mut self) -> Result<Token> {
         let mut n_str = String::new();
 
         // we don't lex negatives. the impl for that is
@@ -221,9 +223,9 @@ where
 
         // we can only read digits 0 to 9 so this should not fail
         // .. unless we overflow
-        let n = n_str.parse().unwrap();
+        let n = n_str.parse()?;
 
-        Token::Literal(Literal::Integer(n))
+        Ok(Token::Literal(Literal::Integer(n)))
     }
 
     fn lex_string(&mut self) -> Result<Token> {
@@ -283,18 +285,21 @@ where
                 // , comma
                 ',' => self.eat_to(Token::Comma),
 
+                // ; semicolon
+                ';' => self.eat_to(Token::Semicolon),
+
                 // = equals
                 // or == equal to
                 '=' => match self.eat_peek() {
                     Some('=') => self.eat_to(Token::EqualTo),
-                    _ => Some(Ok(Token::Equals)),
+                    _ => t(Token::Equals),
                 },
 
                 // ! not
                 // or != not equal to
                 '!' => match self.eat_peek() {
                     Some('=') => self.eat_to(Token::NotEqualTo),
-                    _ => Some(Ok(Token::Not)),
+                    _ => t(Token::Not),
                 },
 
                 // && and
@@ -307,21 +312,21 @@ where
                 // or >= greater than/equal to
                 '>' => match self.eat_peek() {
                     Some('=') => self.eat_to(Token::GreaterThanOrEqualTo),
-                    _ => Some(Ok(Token::GreaterThan)),
+                    _ => t(Token::GreaterThan),
                 },
 
                 // < less than
                 // or <= less than/equal to
                 '<' => match self.eat_peek() {
                     Some('=') => self.eat_to(Token::LessThanOrEqualTo),
-                    _ => Some(Ok(Token::LessThan)),
+                    _ => t(Token::LessThan),
                 },
 
                 // a-zA-Z_ start of word
                 'a'..='z' | 'A'..='Z' | '_' => Some(Ok(self.lex_word())),
 
                 // 0-9 integer
-                '0'..='9' => Some(Ok(self.lex_integer())),
+                '0'..='9' => Some(self.lex_integer()),
 
                 // " strings
                 '"' => Some(self.lex_string()),
@@ -336,9 +341,6 @@ where
                     continue;
                 }
 
-                // ; semicolon
-                ';' => self.eat_to(Token::Semicolon),
-
                 // unexpected character
                 c => Some(Err(LexError::UnexpectedCharacter(c))),
             };

src/main.rs

@@ -2,6 +2,7 @@ use std::time::Instant;
 
 use crate::{lexer::Lexer, parser::Parser};
 
+mod kind;
 mod lexer;
 mod parser;
 

src/parser.rs

@@ -1,8 +1,9 @@
 use std::{fmt, iter::Peekable};
 
-use strum::IntoDiscriminant;
-
-use crate::lexer::{Associativity, LexError, Literal, Precedence, Token, TokenKind};
+use crate::{
+    kind::Kind,
+    lexer::{Associativity, LexError, Literal, Precedence, Token, TokenKind},
+};
 
 pub mod util;
 
@@ -96,7 +97,7 @@ where
     fn expect_next(&mut self, kind: TokenKind) -> Result<()> {
         let t = self.try_next()?;
 
-        if t.discriminant() != kind {
+        if t.kind() != kind {
             return Err(ParseError::UnexpectedToken(t));
         }
 
@@ -104,7 +105,7 @@ where
     }
     fn is_next(&mut self, kind: Option<TokenKind>) -> bool {
         match self.try_peek() {
-            Ok(t) if Some(t.discriminant()) == kind => true,
+            Ok(t) if Some(t.kind()) == kind => true,
             Ok(_) => false,
 
             Err(ParseError::UnexpectedEnd) if kind.is_none() => true,