Files
lamm/src/tokenizer.rs

368 lines
12 KiB
Rust

use std::collections::HashMap;
use std::sync::{Arc, Mutex};
use crate::{CodeIter, Type};
use crate::error::Error;
use super::Value;
use std::io::BufRead;
use std::ops::Range;
#[derive(Debug, Clone, PartialEq, Eq, Hash)]
pub enum Op {
Add,
Sub,
Mul,
Div,
FloorDiv,
Exp,
Equ,
Mod,
LazyEqu,
TypeDeclaration,
FunctionDefine(usize),
FunctionDeclare(usize),
LambdaDefine(usize),
Arrow,
Compose,
Id,
If,
IfElse,
GreaterThan,
LessThan,
EqualTo,
NotEqualTo,
GreaterThanOrEqualTo,
LessThanOrEqualTo,
Not,
IntCast,
FloatCast,
BoolCast,
StringCast,
Print,
OpenArray,
CloseArray,
OpenStatement,
CloseStatement,
Empty,
And,
Or,
Head,
Tail,
Init,
Fini,
Export,
NonCall,
}
#[derive(Debug, Clone, PartialEq)]
pub enum TokenType {
Identifier(String),
Operator(Op),
Constant(Value),
Type(Type),
}
impl TokenType {
/// Parse a single token
fn parse(s: &str) -> Result<Self, Error> {
Ok(match s {
// Match keywords first
"true" => TokenType::Constant(Value::Bool(true)),
"false" => TokenType::Constant(Value::Bool(false)),
"nil" => TokenType::Constant(Value::Nil),
"int" => TokenType::Operator(Op::IntCast),
"float" => TokenType::Operator(Op::FloatCast),
"bool" => TokenType::Operator(Op::BoolCast),
"string" => TokenType::Operator(Op::StringCast),
"print" => TokenType::Operator(Op::Print),
"empty" => TokenType::Operator(Op::Empty),
"head" => TokenType::Operator(Op::Head),
"tail" => TokenType::Operator(Op::Tail),
"init" => TokenType::Operator(Op::Init),
"fini" => TokenType::Operator(Op::Fini),
"export" => TokenType::Operator(Op::Export),
// Types
"Any" => TokenType::Type(Type::Any),
"Int" => TokenType::Type(Type::Int),
"Float" => TokenType::Type(Type::Float),
"Bool" => TokenType::Type(Type::Bool),
"String" => TokenType::Type(Type::String),
// then identifiers and numbers
_ => {
if s.starts_with(char::is_alphabetic) {
TokenType::Identifier(s.to_string())
} else if s.starts_with(|c: char| c.is_digit(10)) {
if let Ok(int) = s.parse::<i64>() {
TokenType::Constant(Value::Int(int))
} else if let Ok(float) = s.parse::<f64>() {
TokenType::Constant(Value::Float(float))
} else {
return Err(Error::new(format!("Invalid numeric constant `{s}`")));
}
} else {
return Err(Error::new(format!("Couldn't match token `{s}`")));
}
}
})
}
}
#[derive(Debug, Clone)]
pub struct Token {
t: TokenType,
pub lexeme: String,
pub line: usize,
pub location: Range<usize>,
}
impl Token {
pub fn new(t: TokenType, lexeme: String, line: usize, column: usize) -> Self {
Self {
t,
line,
location: column..column + lexeme.len(),
lexeme,
}
}
pub fn token(&self) -> TokenType {
self.t.clone()
}
}
/// Tokenize an input stream of source code for a Parser
#[derive(Clone)]
pub(crate) struct Tokenizer<R: BufRead> {
reader: Arc<Mutex<CodeIter<R>>>,
}
impl<R: BufRead> Tokenizer<R> {
pub fn new(reader: Arc<Mutex<CodeIter<R>>>) -> Self {
Self {
reader,
}
}
fn next_char(&mut self) -> Option<char> {
let mut reader = self.reader.lock().unwrap();
let c = reader.next();
c
}
fn next_char_if(&mut self, func: impl FnOnce(&char) -> bool) -> Option<char> {
let mut reader = self.reader.lock().unwrap();
let c = reader.next_if(func);
c
}
fn getpos(&self) -> (usize, usize) {
let reader = self.reader.lock().unwrap();
let r = reader.getpos();
r
}
fn get_dot_count(&mut self) -> usize {
let mut total = 0;
while let Some(n) = self.next_char_if(|&c| c == ':' || c == '.').map(|c| match c {
':' => 2,
'.' => 1,
_ => unreachable!(),
}) {
total += n;
}
total
}
/// Tokenizes more input and adds them to the internal queue
fn tokenize(&mut self) -> Result<Option<Token>, Error> {
let operators: HashMap<&'static str, Op> = HashMap::from([
("+", Op::Add),
("-", Op::Sub),
("*", Op::Mul),
("/", Op::Div),
("//", Op::FloorDiv),
("**", Op::Exp),
("%", Op::Mod),
("=", Op::Equ),
(".", Op::LazyEqu),
("?.", Op::TypeDeclaration),
(":", Op::FunctionDefine(1)),
("?:", Op::FunctionDeclare(1)),
(";", Op::LambdaDefine(1)),
("->", Op::Arrow),
("~", Op::Compose),
(",", Op::Id),
("?", Op::If),
("??", Op::IfElse),
(">", Op::GreaterThan),
("<", Op::LessThan),
(">=", Op::GreaterThanOrEqualTo),
("<=", Op::LessThanOrEqualTo),
("==", Op::EqualTo),
("!=", Op::NotEqualTo),
("[", Op::OpenArray),
("]", Op::CloseArray),
("(", Op::OpenStatement),
(")", Op::CloseStatement),
("!", Op::Not),
("&&", Op::And),
("||", Op::Or),
("\\", Op::NonCall),
]);
let c = if let Some(c) = self.next_char() {
c
} else {
return Ok(None);
};
if c.is_alphanumeric() {
let mut token = String::from(c);
while let Some(c) = self.next_char_if(|&c| c.is_alphanumeric() || c == '.' || c == '\'') {
token.push(c);
}
let (line, column) = self.getpos();
Ok(Some(Token::new(TokenType::parse(&token).map_err(|e| e.location(line, column - token.len() + 1..column + 1))?, token.clone(), line, column - token.len() + 1)))
} else if c == '#' {
while self.next_char_if(|&c| c != '\n').is_some() {}
self.tokenize()
} else if c == '\"' {
let mut token = String::new();
let (line, col) = self.getpos();
while let Some(c) = self.next_char() {
match c {
'"' => {
let (line, col) = self.getpos();
return Ok(Some(Token::new(TokenType::Constant(
Value::String(token.clone())), token, line, col)));
}
'\n' => return Err(
Error::new("Unclosed string literal".into())
.location(line, col..col+token.len()+1)
.note("newlines are not allowed in string literals (try \\n)".into())),
'\\' => match self.next_char() {
Some('\\') => token.push('\\'),
Some('n') => token.push('\n'),
Some('t') => token.push('\t'),
Some('r') => token.push('\r'),
Some('\"') => token.push('"'),
Some(c) => token.push(c),
None => return Err(
Error::new("Unclosed string literal".into())
.location(line, col..token.len()+1)
.note("end of file found before \"".into())),
}
_ => token.push(c),
};
}
Err(Error::new("Unclosed string literal".into())
.location(line, col..self.getpos().1+1)
.note("end of file found before \"".into()))
} else if operators.keys().any(|x| x.starts_with(c)) {
let mut token = String::from(c);
loop {
// get a list of all tokens this current token could possibly be
let possible: HashMap<&'static str, Op> = operators
.clone().into_iter()
.filter(|(key, _)| key.starts_with(&token))
.collect();
// checks if a character is "expected", aka based on how many chars
// we have eaten so far, which characters out of the current nominees
// are expected in the next position
let is_expected = |c: &char|
possible.iter().any(|(op, _)| match op.chars().nth(token.len()) {
Some(i) => *c == i,
None => false,
});
match possible.len() {
1 => {
// if the current operator exists in possible, we push it
// if not, we need to make sure that the next characters
// we grab *actually* match the last operator
if let Some(op) = possible.get(token.as_str()) {
let t = TokenType::Operator(match op {
// special handling for "dynamic" operators
Op::FunctionDefine(n) => Op::FunctionDefine(n + self.get_dot_count()),
Op::FunctionDeclare(n) => Op::FunctionDeclare(n + self.get_dot_count()),
Op::LambdaDefine(n) => Op::LambdaDefine(n + self.get_dot_count()),
op => op.clone(),
});
let (line, col) = self.getpos();
let token = Token::new(t, token, line, col);
return Ok(Some(token));
} else {
let next = match self.next_char_if(is_expected) {
Some(c) => c,
None => {
let (line, col) = self.getpos();
return Err(
Error::new(format!("the operator {token} is undefined"))
.location(line, col - token.len()..col))
}
};
token.push(next);
}
}
0 => unreachable!(),
_ => {
let c = self.next_char_if(is_expected);
let next = match c {
Some(c) => c,
None => {
let t = TokenType::Operator(match possible.get(token.as_str()).unwrap() {
// special handling for "dynamic" operators
Op::FunctionDefine(n) => Op::FunctionDefine(n + self.get_dot_count()),
Op::FunctionDeclare(n) => Op::FunctionDeclare(n + self.get_dot_count()),
Op::LambdaDefine(n) => Op::LambdaDefine(n + self.get_dot_count()),
op => op.clone(),
});
let (line, col) = self.getpos();
let token = Token::new(t, token, line, col);
return Ok(Some(token))
}
};
token.push(next);
}
}
}
} else if c.is_whitespace() {
self.tokenize()
} else {
let (line, col) = self.getpos();
Err(Error::new(format!("an unidentified character {c} was found"))
.location(line, col..col+1))
}
}
}
impl<R: BufRead> Iterator for Tokenizer<R> {
type Item = Result<Token, Error>;
fn next(&mut self) -> Option<Self::Item> {
self.tokenize().transpose()
}
}