287 lines
7.8 KiB
Rust
287 lines
7.8 KiB
Rust
extern crate itertools;
|
|
|
|
use language::{ParseError};
|
|
use std::collections::HashMap;
|
|
use std::rc::Rc;
|
|
use std::iter::{Enumerate, Peekable};
|
|
use self::itertools::Itertools;
|
|
use std::str::Chars;
|
|
|
|
#[allow(dead_code)]
|
|
#[derive(Debug, PartialEq)]
|
|
pub enum TokenType {
|
|
Newline, Semicolon,
|
|
|
|
LParen, RParen,
|
|
LSquareBracket, RSquareBracket,
|
|
LAngleBracket, RAngleBracket,
|
|
LCurlyBrace, RCurlyBrace,
|
|
Pipe,
|
|
|
|
Comma, Period, Colon, Underscore,
|
|
|
|
Operator(Rc<String>),
|
|
DigitGroup(Rc<String>), HexNumberSigil, BinNumberSigil,
|
|
StrLiteral(Rc<String>),
|
|
Identifier(Rc<String>),
|
|
Keyword(Kw),
|
|
|
|
Error(String),
|
|
}
|
|
|
|
#[derive(Debug, Clone, Copy, PartialEq)]
|
|
pub enum Kw {
|
|
If, Else,
|
|
Func,
|
|
For,
|
|
Match,
|
|
Var, Const, Let, In,
|
|
Alias, Type, SelfType, SelfIdent,
|
|
Trait, Impl,
|
|
True, False
|
|
}
|
|
|
|
lazy_static! {
|
|
static ref KEYWORDS: HashMap<&'static str, Kw> =
|
|
hashmap! {
|
|
"if" => Kw::If,
|
|
"else" => Kw::Else,
|
|
"fn" => Kw::Func,
|
|
"for" => Kw::For,
|
|
"match" => Kw::Match,
|
|
"var" => Kw::Var,
|
|
"const" => Kw::Const,
|
|
"let" => Kw::Let,
|
|
"in" => Kw::In,
|
|
"alias" => Kw::Alias,
|
|
"type" => Kw::Type,
|
|
"Self" => Kw::SelfType,
|
|
"self" => Kw::SelfIdent,
|
|
"trait" => Kw::Trait,
|
|
"impl" => Kw::Impl,
|
|
"true" => Kw::True,
|
|
"false" => Kw::False,
|
|
};
|
|
}
|
|
|
|
#[derive(Debug)]
|
|
pub struct Token {
|
|
token_type: TokenType,
|
|
offset: usize,
|
|
}
|
|
|
|
impl Token {
|
|
pub fn get_error(&self) -> Option<&String> {
|
|
match self.token_type {
|
|
TokenType::Error(ref s) => Some(s),
|
|
_ => None,
|
|
}
|
|
}
|
|
}
|
|
|
|
fn is_digit(c: &char) -> bool {
|
|
c.is_digit(10)
|
|
}
|
|
|
|
type CharIter<'a> = Peekable<Enumerate<Chars<'a>>>;
|
|
|
|
pub fn tokenize(input: &str) -> Vec<Token> {
|
|
use self::TokenType::*;
|
|
|
|
let mut tokens: Vec<Token> = Vec::new();
|
|
let mut input: CharIter = input.chars().enumerate().peekable();
|
|
|
|
while let Some((idx, c)) = input.next() {
|
|
let cur_tok_type = match c {
|
|
'#' => {
|
|
if let Some(&(_, '{')) = input.peek() {
|
|
} else {
|
|
while let Some((_, c)) = input.next() {
|
|
if c == '\n' {
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
continue;
|
|
},
|
|
c if c.is_whitespace() && c != '\n' => continue,
|
|
'\n' => Newline, ';' => Semicolon,
|
|
':' => Colon, ',' => Comma, '.' => Period,
|
|
'(' => LParen, ')' => RParen,
|
|
'{' => LCurlyBrace, '}' => RCurlyBrace,
|
|
'<' => LAngleBracket, '>' => RAngleBracket,
|
|
'[' => LSquareBracket, ']' => RSquareBracket,
|
|
'|' => Pipe,
|
|
'"' => handle_quote(&mut input),
|
|
c if is_digit(&c) => handle_digit(c, &mut input),
|
|
c if c.is_alphabetic() || c == '_' => handle_alphabetic(c, &mut input), //TODO I'll probably have to rewrite this if I care about types being uppercase, also type parameterization
|
|
c => handle_operator(c, &mut input),
|
|
};
|
|
tokens.push(Token { token_type: cur_tok_type, offset: idx });
|
|
}
|
|
tokens
|
|
}
|
|
|
|
fn handle_digit(c: char, input: &mut CharIter) -> TokenType {
|
|
use self::TokenType::*;
|
|
|
|
if c == '0' && input.peek().map_or(false, |&(_, c)| { c == 'x' }) {
|
|
input.next();
|
|
HexNumberSigil
|
|
} else if c == '0' && input.peek().map_or(false, |&(_, c)| { c == 'b' }) {
|
|
input.next();
|
|
BinNumberSigil
|
|
} else {
|
|
let mut buf = c.to_string();
|
|
buf.extend(input.peeking_take_while(|&(_, ref c)| is_digit(c)).map(|(_, c)| { c }));
|
|
DigitGroup(Rc::new(buf))
|
|
}
|
|
}
|
|
|
|
fn handle_quote(input: &mut CharIter) -> TokenType {
|
|
let mut buf = String::new();
|
|
loop {
|
|
match input.next().map(|(_, c)| { c }) {
|
|
Some('"') => break,
|
|
Some('\\') => {
|
|
let next = input.peek().map(|&(_, c)| { c });
|
|
if next == Some('n') {
|
|
input.next();
|
|
buf.push('\n')
|
|
} else if next == Some('"') {
|
|
input.next();
|
|
buf.push('"');
|
|
} else if next == Some('t') {
|
|
input.next();
|
|
buf.push('\t');
|
|
}
|
|
},
|
|
Some(c) => buf.push(c),
|
|
None => return TokenType::Error(format!("Unclosed string")),
|
|
}
|
|
}
|
|
TokenType::StrLiteral(Rc::new(buf))
|
|
}
|
|
|
|
fn handle_alphabetic(c: char, input: &mut CharIter) -> TokenType {
|
|
let mut buf = String::new();
|
|
buf.push(c);
|
|
if c == '_' && input.peek().map(|&(_, c)| { !c.is_alphabetic() }).unwrap_or(true) {
|
|
return TokenType::Identifier(Rc::new(format!("_")))
|
|
}
|
|
|
|
loop {
|
|
match input.peek().map(|&(_, c)| { c }) {
|
|
Some(c) if c.is_alphanumeric() => {
|
|
input.next();
|
|
buf.push(c);
|
|
},
|
|
_ => break,
|
|
}
|
|
}
|
|
|
|
match KEYWORDS.get(buf.as_str()) {
|
|
Some(kw) => TokenType::Keyword(kw.clone()),
|
|
None => TokenType::Identifier(Rc::new(buf)),
|
|
}
|
|
}
|
|
|
|
fn handle_operator(c: char, input: &mut CharIter) -> TokenType {
|
|
let mut buf = String::new();
|
|
buf.push(c);
|
|
loop {
|
|
match input.peek().map(|&(_, c)| { c }) {
|
|
Some(c) if !c.is_alphabetic() && !c.is_whitespace() => {
|
|
input.next();
|
|
buf.push(c);
|
|
},
|
|
_ => break
|
|
}
|
|
}
|
|
TokenType::Operator(Rc::new(buf))
|
|
}
|
|
|
|
#[cfg(test)]
|
|
mod schala_tokenizer_tests {
|
|
use super::*;
|
|
use super::TokenType::*;
|
|
use super::Kw::*;
|
|
|
|
macro_rules! ident { ($ident:expr) => { Identifier(Rc::new($ident.to_string())) } }
|
|
macro_rules! op { ($ident:expr) => { Operator(Rc::new($ident.to_string())) } }
|
|
|
|
#[test]
|
|
fn tokens() {
|
|
let a = tokenize("let a: A<B> = c ++ d");
|
|
let token_types: Vec<TokenType> = a.into_iter().map(move |t| t.token_type).collect();
|
|
assert_eq!(token_types, vec![Keyword(Let), ident!("a"), Colon, ident!("A"),
|
|
LAngleBracket, ident!("B"), RAngleBracket, op!("="), ident!("c"), op!("++"), ident!("d")]);
|
|
}
|
|
}
|
|
|
|
/*
|
|
Schala EBNF grammar
|
|
|
|
|
|
type alias <name> = <other type>
|
|
|
|
type <name> = struct { <field> : <type>,* }
|
|
type <name> = Variant1 | Variant2(type, type) | Variant3 struct { }
|
|
|
|
|
|
'' = literal, all other symbols are nonterminals
|
|
|
|
program := (statement delimiter ?)*
|
|
delimiter := 'Newline' | ';'
|
|
statement := declaration | expression
|
|
|
|
declaration := module | function | type_decl
|
|
|
|
type_decl := 'type' type_format
|
|
type_format := 'alias' '=' type | type_constructor
|
|
type_constructor := capital_ident '=' type_rhs
|
|
type_rhs := struct_decl | type_variant ('|' type_variant)*
|
|
struct_decl := 'struct' '{' (ident ':' type)* '}'
|
|
type_variant := capital_ident | tuple_type | capital_ident struct_decl
|
|
tuple_type := // something like Variant(a,b)
|
|
type := // something like Type[A[b]]
|
|
|
|
ascription := expression (':' type)+
|
|
|
|
function := 'fn' prototype '{' (statement)* '}'
|
|
prototype := identifier '(' identlist ')'
|
|
identlist := identifier (',' identifier)* | ε
|
|
|
|
|
|
declaration := FN prototype LCurlyBrace (statement)* RCurlyBrace
|
|
prototype := identifier LParen identlist RParen
|
|
identlist := Ident (Comma Ident)* | ε
|
|
exprlist := Expression (Comma Expression)* | ε
|
|
itemlist := Ident COLON Expression (Comma Ident COLON Expression)* | ε
|
|
|
|
expression := postop_expression (op postop_expression)*
|
|
postop_expression := primary_expression postop
|
|
primary_expression := number_expr | String | identifier_expr | paren_expr | conditional_expr | while_expr | lambda_expr | list_expr | struct_expr
|
|
number_expr := (PLUS | MINUS ) number_expr | Number
|
|
identifier_expr := call_expression | Variable
|
|
list_expr := LSquareBracket exprlist RSquareBracket
|
|
struct_expr := LCurlyBrace itemlist RCurlyBrace
|
|
call_expression := Identifier LParen exprlist RParen
|
|
while_expr := WHILE primary_expression LCurlyBrace (expression delimiter)* RCurlyBrace
|
|
paren_expr := LParen expression RParen
|
|
conditional_expr := IF expression LCurlyBrace (expression delimiter)* RCurlyBrace (LCurlyBrace (expresion delimiter)* RCurlyBrace)?
|
|
lambda_expr := FN LParen identlist RParen LCurlyBrace (expression delimiter)* RCurlyBrace
|
|
lambda_call := | LParen exprlist RParen
|
|
postop := ε | LParen exprlist RParen | LBracket expression RBracket
|
|
op := '+', '-', etc.
|
|
*/
|
|
|
|
#[allow(dead_code)]
|
|
#[derive(Debug)]
|
|
pub struct AST { }
|
|
|
|
#[allow(dead_code)]
|
|
pub fn parse(_input: Vec<Token>) -> Result<AST, ParseError> {
|
|
Ok(AST { })
|
|
}
|