Deleted old parser

This commit is contained in:
Erin 2021-06-06 20:05:18 +02:00 committed by ondra05
parent 08b4fff20d
commit 935ba3b791
4 changed files with 0 additions and 687 deletions

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@ -1,87 +0,0 @@
use crate::variables::Value;
#[derive(Debug, Clone, Hash, PartialEq, Eq)]
pub struct Iden(pub String);
#[derive(Debug, Clone, PartialEq)]
pub enum Item {
Expr(Expr),
Stmt(Stmt),
}
impl From<Expr> for Item {
fn from(e: Expr) -> Self {
Item::Expr(e)
}
}
impl From<Iden> for Item {
fn from(i: Iden) -> Self {
Item::Expr(Expr::Identifier(i))
}
}
impl From<Stmt> for Item {
fn from(s: Stmt) -> Self {
Item::Stmt(s)
}
}
#[derive(Debug, Clone, PartialEq)]
pub enum Expr {
Add { left: Box<Expr>, right: Box<Expr> },
Subtract { left: Box<Expr>, right: Box<Expr> },
Multiply { left: Box<Expr>, right: Box<Expr> },
Divide { left: Box<Expr>, right: Box<Expr> },
Lt { left: Box<Expr>, right: Box<Expr> },
Gt { left: Box<Expr>, right: Box<Expr> },
Eq { left: Box<Expr>, right: Box<Expr> },
Neq { left: Box<Expr>, right: Box<Expr> },
And { left: Box<Expr>, right: Box<Expr> },
Or { left: Box<Expr>, right: Box<Expr> },
Not(Box<Expr>),
Literal(Value),
Identifier(Iden),
}
impl From<Iden> for Expr {
fn from(i: Iden) -> Self {
Self::Identifier(i)
}
}
#[derive(Debug, Clone, PartialEq)]
pub enum Stmt {
VariableDeclaration {
iden: Iden,
init: Option<Expr>,
},
FunctionDeclaration {
iden: Iden,
args: Vec<Iden>,
body: Vec<Item>,
},
BfFDeclaration {
iden: Iden,
body: String,
},
If {
cond: Expr,
body: Vec<Item>,
},
FunctionCall {
iden: Iden,
args: Vec<Expr>,
},
Loop {
body: Vec<Item>,
},
VarAssignment {
iden: Iden,
value: Expr,
},
Break,
HopBack,
Print(Expr),
Melo(Iden),
}

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@ -1,311 +0,0 @@
pub mod item;
mod ops;
mod utils;
use item::Item;
use crate::{
error::{Error, ErrorKind},
lexer::PeekableLexer,
parser::item::{Expr, Stmt},
variables::Value,
};
use crate::{lexer::Token, parser::item::Iden};
pub type ParseResult = Result<Item, Error>;
/// Parser structure / state machine
pub struct Parser<'a> {
lexer: PeekableLexer<'a>,
ast: Vec<Item>,
tdark: bool,
}
impl<'a> Parser<'a> {
/// Create a new parser object
pub fn new(source: &'a str) -> Self {
Self {
lexer: PeekableLexer::lexer(source),
ast: Vec::new(),
tdark: false,
}
}
pub fn init(&mut self) -> Result<Vec<Item>, Error> {
loop {
let token = self.lexer.next();
match token {
Some(Token::Comment) => continue,
Some(Token::TDark) => {
let mut block = self.tdark_block()?;
self.ast.append(&mut block);
}
None => return Ok(self.ast.clone()),
_ => {
let item = self.parse_item(token)?;
self.ast.push(item);
}
}
}
}
fn parse_item(&mut self, token: Option<Token>) -> ParseResult {
if matches!(token, None) {
return Err(Error {
kind: ErrorKind::EndOfTokenStream,
position: self.lexer.span(),
});
}
let token = token.unwrap();
let start = self.lexer.span().start;
match token {
Token::Identifier(_)
| Token::Aboolean(_)
| Token::Boolean(_)
| Token::Integer(_)
| Token::String(_)
| Token::Nul
| Token::LeftParenthesis
| Token::Assignment
| Token::LogNot => self.parse_ops(token),
// Control flow
Token::If => self.if_cond(),
Token::Loop => self.loop_block(),
Token::HopBack => {
self.require(Token::Semicolon)?;
Ok(Stmt::HopBack.into())
}
Token::Break => {
self.require(Token::Semicolon)?;
Ok(Stmt::Break.into())
}
// Declarations
Token::Variable => self.variable_declaration(),
Token::Function => self.function_declaration(),
Token::BfFunction => self.bff_declaration(),
// Prefix keywords
// Melo - ban variable from next usage (runtime error)
Token::Melo => {
let e = self.require_iden()?;
self.require(Token::Semicolon)?;
Ok(Stmt::Melo(e).into())
}
_ => Err(Error {
kind: ErrorKind::SyntaxError("Unexpected token".to_owned()),
position: start..self.lexer.span().end,
}),
}
}
/// Parse variable declaration
///
/// `var [iden] = [literal];`
fn variable_declaration(&mut self) -> ParseResult {
let iden = self.require_iden()?;
let peek = self.lexer.peek().clone();
let init = match peek {
Some(Token::Semicolon) => {
self.lexer.next();
None
}
Some(Token::Assignment) => {
self.lexer.next();
let next = self.lexer.next();
let mut value = self.parse_expr(next)?;
loop {
let peek = self.lexer.peek().clone();
value = match peek {
Some(Token::Semicolon) => break,
None => {
return Err(Error {
kind: ErrorKind::EndOfTokenStream,
position: self.lexer.span(),
})
}
Some(t) => self.parse_operation(Some(t), value)?,
};
}
self.lexer.next();
Some(value)
}
_ => {
return Err(Error {
kind: ErrorKind::SyntaxError("Unexpected token".to_owned()),
position: self.lexer.span(),
})
}
};
Ok(Stmt::VariableDeclaration { iden, init }.into())
}
/// Declare function
///
/// `functio [iden] ([expr], [expr]) { ... }
fn function_declaration(&mut self) -> ParseResult {
let iden = self.require_iden()?;
self.require(Token::LeftParenthesis)?;
let mut args = vec![];
loop {
let next = self.lexer.next();
match next {
Some(Token::RightParenthesis) => break,
Some(Token::Identifier(i)) => args.push(Iden(i)),
_ => return Err(self.unexpected_token(None)),
}
}
self.require(Token::LeftBrace)?;
// Parse function body
let body = self.parse_body()?;
Ok(Stmt::FunctionDeclaration { iden, args, body }.into())
}
/// Declare BF FFI Function
///
/// `bff [iden] { ... }`
fn bff_declaration(&mut self) -> ParseResult {
let iden = self.require_iden()?;
self.require(Token::LeftBrace)?;
let mut body = String::new();
loop {
let token = {
match self.lexer.next() {
Some(t) => t,
None => {
return Err(Error {
kind: ErrorKind::EndOfTokenStream,
position: self.lexer.span(),
})
}
}
};
body.push_str(match token {
Token::OpGt
| Token::OpLt
| Token::Addition
| Token::Subtract
| Token::FullStop
| Token::Comma
| Token::LeftBracket
| Token::RightBracket => self.lexer.slice(),
Token::RightBrace => break,
_ => return Err(self.unexpected_token(None)),
});
}
Ok(Stmt::BfFDeclaration { iden, body }.into())
}
/// Parse If-stmt
pub fn if_cond(&mut self) -> ParseResult {
self.require(Token::LeftParenthesis)?;
let cond = self.parse_paren()?;
self.require(Token::LeftBrace)?;
let body = self.parse_body()?;
Ok(Stmt::If { cond, body }.into())
}
/// Parse loop
pub fn loop_block(&mut self) -> ParseResult {
self.require(Token::LeftBrace)?;
let body = self.parse_body()?;
Ok(Stmt::Loop { body }.into())
}
/// T-Dark block parsing
pub fn tdark_block(&mut self) -> Result<Vec<Item>, Error> {
self.require(Token::LeftBrace)?;
self.tdark = true;
let mut body = Vec::new();
loop {
let token = {
match self.lexer.next() {
Some(t) => t,
None => {
return Err(Error {
kind: ErrorKind::EndOfTokenStream,
position: self.lexer.span(),
})
}
}
};
if token == Token::RightBrace {
break;
}
body.push(self.parse_item(Some(token))?);
}
self.tdark = false;
Ok(body)
}
}
#[cfg(test)]
mod tests {
use super::*;
use Expr::*;
use Stmt::*;
#[test]
fn control_flow() {
let code = r#"loop { var a = 3 + 2; if (a == 5) { break; } }"#;
let expected: &[Item] = &[Item::Stmt(Loop {
body: vec![
VariableDeclaration {
iden: Iden("a".to_owned()),
init: Some(Add {
left: Box::new(Literal(Value::Int(3))),
right: Box::new(Literal(Value::Int(2))),
}),
}
.into(),
If {
cond: Eq {
left: Box::new(Iden("a".to_owned()).into()),
right: Box::new(Literal(Value::Int(5)).into()),
},
body: vec![Break.into()],
}
.into(),
],
})];
let ast = Parser::new(code).init().unwrap();
assert_eq!(ast, expected)
}
#[test]
fn tdark() {
let code = r#"T-Dark { var lang = nul; lang print; }"#;
let expected: &[Item] = &[
VariableDeclaration {
iden: Iden("script".to_owned()),
init: Some(Literal(Value::Nul)),
}
.into(),
Print(Iden("script".to_owned()).into()).into(),
];
let ast = Parser::new(code).init().unwrap();
assert_eq!(ast, expected)
}
}

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@ -1,197 +0,0 @@
use super::*;
type ExprResult = Result<Expr, Error>;
/// Generate infix expression by pattern left <op> right
///
/// Credits: `@! ! Reiter#4543`
#[macro_export]
macro_rules! gen_infix {
($($fn_name: ident => $type: tt);*$(;)?) => {$(
/// Generated function for infix operator
fn $fn_name(&mut self, left: Expr) -> ExprResult {
self.lexer.next();
let next = self.lexer.next();
let right = self.parse_expr(next)?;
Ok(Expr::$type { left: Box::new(left), right: Box::new(right) })
})*
};
}
impl<'a> Parser<'a> {
pub(super) fn parse_ops(&mut self, token: Token) -> ParseResult {
// Statements
match self.lexer.peek() {
Some(Token::LeftParenthesis) => return self.fn_call(token),
Some(Token::Assignment) => return self.parse_assignment(token),
_ => (),
}
let mut buf: Expr = self.parse_expr(Some(token))?;
loop {
let peek = self.lexer.peek().clone();
buf = match peek {
// Print statement
Some(Token::Print) => {
self.lexer.next();
self.require(Token::Semicolon)?;
return Ok(Stmt::Print(buf).into());
}
None => return Ok(buf.into()),
// An expression
_ => self.parse_operation(peek, buf)?,
}
}
}
/// Match and perform
pub(super) fn parse_operation(&mut self, token: Option<Token>, buf: Expr) -> ExprResult {
match token {
Some(Token::Addition) => self.addition(buf),
Some(Token::Subtract) => self.subtract(buf),
Some(Token::Multiply) => self.multiply(buf),
Some(Token::Divide) => self.divide(buf),
Some(Token::OpLt) => self.cmplt(buf),
Some(Token::OpGt) => self.cmpgt(buf),
Some(Token::OpEq) => self.cmpeq(buf),
Some(Token::OpNeq) => self.cmpneq(buf),
Some(Token::LogAnd) => self.logand(buf),
Some(Token::LogOr) => self.logor(buf),
Some(Token::LeftParenthesis) => Err(Error {
kind: ErrorKind::SyntaxError("Function call isn't an expression!".to_owned()),
position: self.lexer.span(),
}),
Some(_) | None => Err(self.unexpected_token(None)),
}
}
fn parse_assignment(&mut self, token: Token) -> ParseResult {
self.lexer.next();
// Extract identifier
let iden = if let Token::Identifier(i) = token {
Iden(i)
} else {
return Err(Error {
kind: ErrorKind::InvalidIdentifier,
position: self.lexer.span(),
});
};
let next = self.lexer.next();
let mut value = self.parse_expr(next)?;
loop {
let peek = self.lexer.peek().clone();
value = match peek {
Some(Token::Semicolon) => break,
None => {
return Err(Error {
kind: ErrorKind::EndOfTokenStream,
position: self.lexer.span(),
})
}
Some(t) => self.parse_operation(Some(t), value)?,
};
}
self.lexer.next();
Ok(Stmt::VarAssignment { iden, value }.into())
}
// Generate infix
gen_infix! {
addition => Add;
subtract => Subtract;
multiply => Multiply;
divide => Divide;
cmplt => Lt;
cmpgt => Gt;
cmpeq => Eq;
cmpneq => Neq;
logand => And;
logor => Or;
}
/// Ensure that input token is an expression
pub(super) fn parse_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(if self.tdark {
s.replace("lang", "script")
} else {
s
}))),
Token::Aboolean(a) => Ok(Expr::Literal(Value::Abool(a))),
Token::Identifier(i) => Ok(Expr::Identifier(Iden(if self.tdark {
i.replace("lang", "script")
} else {
i
}))),
Token::Nul => Ok(Expr::Literal(Value::Nul)),
Token::LogNot => {
let next = self.lexer.next();
Ok(Expr::Not(Box::new(self.parse_expr(next)?)))
}
Token::LeftParenthesis => self.parse_paren(),
t => Err(self.unexpected_token(Some(t))),
}
}
/// Parse parenthesieted expression
pub(super) fn parse_paren(&mut self) -> ExprResult {
let next = self.lexer.next();
let mut buf = self.parse_expr(next)?;
loop {
let peek = self.lexer.peek().clone();
buf = match peek {
Some(Token::RightParenthesis) => {
self.lexer.next();
return Ok(buf);
}
None => return Ok(buf),
Some(t) => self.parse_operation(Some(t), buf)?,
};
}
}
/// Parse function call
fn fn_call(&mut self, token: Token) -> ParseResult {
let iden = if let Token::Identifier(i) = token {
Iden(i)
} else {
return Err(Error {
kind: ErrorKind::InvalidIdentifier,
position: self.lexer.span(),
});
};
self.lexer.next();
let mut args = Vec::new();
loop {
let next = self.lexer.next();
// No argument function
if matches!(next, Some(Token::RightParenthesis)) {
break;
}
args.push(self.parse_expr(next)?);
match self.lexer.next() {
Some(Token::RightParenthesis) => break,
Some(Token::Comma) => continue,
_ => return Err(self.unexpected_token(None)),
}
}
self.require(Token::Semicolon)?;
Ok(Stmt::FunctionCall { iden, args }.into())
}
}

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use crate::{
error::{Error, ErrorKind},
lexer::Token,
variables::Abool,
};
use super::{
item::{Iden, Item},
Parser,
};
pub fn abool2num(abool: Abool) -> i32 {
match abool {
Abool::Never => -1,
Abool::Sometimes => 0,
Abool::Always => 1,
}
}
pub fn num2abool(number: i32) -> Abool {
match number {
-1 => Abool::Never,
0 => Abool::Sometimes,
1 => Abool::Always,
_ => Abool::Sometimes,
}
}
impl<'a> Parser<'a> {
/// Require type of token as next and return it's value (sometimes irrelevant)
pub(super) fn require(&mut self, with: Token) -> Result<String, Error> {
if self.lexer.next() == Some(with.clone()) {
Ok(self.lexer.slice().to_owned())
} else {
Err(self.unexpected_token(Some(with)))
}
}
/// Require an identifier on next and return it
pub(super) fn require_iden(&mut self) -> Result<Iden, Error> {
if let Some(Token::Identifier(id)) = self.lexer.next() {
if self.tdark {
Ok(Iden(id.replace("lang", "script")))
} else {
Ok(Iden(id))
}
} else {
Err(Error {
kind: ErrorKind::InvalidIdentifier,
position: self.lexer.span(),
})
}
}
/// Throw unexpected token error (optionally what was expected)
pub(super) fn unexpected_token(&mut self, expected: Option<Token>) -> Error {
let error_msg = match expected {
Some(s) => format!(
"Unexpected token: `{}` (required: `{:?}`)",
self.lexer.slice(),
s
),
None => format!("Unexpected token: `{}`", self.lexer.slice(),),
};
Error {
kind: ErrorKind::SyntaxError(error_msg),
position: self.lexer.span(),
}
}
pub(super) fn parse_body(&mut self) -> Result<Vec<Item>, Error> {
let mut body = Vec::new();
loop {
let token = {
match self.lexer.next() {
Some(t) => t,
None => {
return Err(Error {
kind: ErrorKind::EndOfTokenStream,
position: self.lexer.span(),
})
}
}
};
if token == Token::RightBrace {
break;
}
body.push(self.parse_item(Some(token))?);
}
Ok(body)
}
}