Files
stationeers_lang/libs/parser/src/lib.rs

1125 lines
43 KiB
Rust

#[cfg(test)]
mod test;
pub mod sys_call;
pub mod tree_node;
use quick_error::quick_error;
use std::io::SeekFrom;
use sys_call::SysCall;
use tokenizer::{
self, Tokenizer, TokenizerBuffer,
token::{Keyword, Symbol, Token, TokenType},
};
use tree_node::*;
#[macro_export]
/// A macro to create a boxed value.
macro_rules! boxed {
($e:expr) => {
Box::new($e)
};
}
quick_error! {
#[derive(Debug)]
pub enum Error {
TokenizerError(err: tokenizer::Error) {
from()
display("Tokenizer Error: {}", err)
source(err)
}
UnexpectedToken(token: Token) {
display("Unexpected token: {:?}", token)
}
DuplicateIdentifier(token: Token) {
display("Duplicate identifier: {:?}", token)
}
InvalidSyntax(token: Token, reason: String) {
display("Invalid syntax: {:?}, Reason: {}", token, reason)
}
UnsupportedKeyword(token: Token) {
display("Unsupported keyword: {:?}", token)
}
UnexpectedEOF {
display("Unexpected EOF")
}
}
}
macro_rules! self_matches_peek {
($self:ident, $pattern:pat) => {
matches!($self.tokenizer.peek()?, Some(Token { token_type: $pattern, .. }))
};
($self:ident, $pattern:pat if $cond:expr) => {
matches!($self.tokenizer.peek()?, Some(Token { token_type: $pattern, .. }) if $cond)
};
}
macro_rules! token_from_option {
($token:expr) => {
match $token {
Some(ref token) => token.clone(),
None => return Err(Error::UnexpectedEOF),
}
};
}
macro_rules! extract_token_data {
($token:ident, $pattern:pat, $extraction:expr) => {
match $token.token_type {
$pattern => $extraction,
_ => return Err(Error::UnexpectedToken($token.clone())),
}
};
($token:expr, $pattern:pat, $extraction:expr) => {
match $token.token_type {
$pattern => $extraction,
_ => {
return Err(Error::UnexpectedToken($token.clone()));
}
}
};
}
macro_rules! self_matches_current {
($self:ident, $pattern:pat) => {
matches!($self.current_token, Some(Token { token_type: $pattern, .. }))
};
($self:ident, $pattern:pat if $cond:expr) => {
matches!($self.current_token, Some(Token { token_type: $pattern, .. }) if $cond)
};
}
macro_rules! token_matches {
($token:ident, $pattern:pat) => {
matches!($token.token_type, $pattern)
};
($token:expr, $pattern:pat) => {
matches!($token.token_type, $pattern)
};
($token:ident, $pattern:pat if $cond:expr) => {
matches!($token.token_type, $pattern if $cond)
};
($token:expr, $pattern:pat if $cond:expr) => {
matches!($token.token_type, $pattern if $cond)
};
}
pub struct Parser {
tokenizer: TokenizerBuffer,
current_token: Option<Token>,
}
impl Parser {
pub fn new(tokenizer: Tokenizer) -> Self {
Parser {
tokenizer: TokenizerBuffer::new(tokenizer),
current_token: None,
}
}
/// Parses all the input from the tokenizer buffer and returns the resulting expression
/// Expressions are returned in a root block expression node
pub fn parse_all(&mut self) -> Result<Option<tree_node::Expression>, Error> {
let mut expressions = Vec::<Expression>::new();
while let Some(expression) = self.parse()? {
expressions.push(expression);
}
Ok(Some(Expression::Block(BlockExpression(expressions))))
}
/// Parses the input from the tokenizer buffer and returns the resulting expression
pub fn parse(&mut self) -> Result<Option<tree_node::Expression>, Error> {
self.assign_next()?;
let expr = self.expression()?;
if self_matches_peek!(self, TokenType::Symbol(Symbol::Semicolon)) {
self.assign_next()?;
}
Ok(expr)
}
/// Assigns the next token in the tokenizer buffer to the current token
fn assign_next(&mut self) -> Result<(), Error> {
self.current_token = self.tokenizer.next_token()?;
Ok(())
}
/// Calls `assign_next` and returns the next token in the tokenizer buffer
fn get_next(&mut self) -> Result<Option<&Token>, Error> {
self.assign_next()?;
Ok(self.current_token.as_ref())
}
/// Parses an expression, handling binary operations with correct precedence.
fn expression(&mut self) -> Result<Option<tree_node::Expression>, Error> {
// Parse the Left Hand Side (unary/primary expression)
let lhs = self.unary()?;
let Some(lhs) = lhs else {
return Ok(None);
};
// check if the next or current token is an operator, comparison, or logical symbol
if self_matches_peek!(
self,
TokenType::Symbol(s) if s.is_operator() || s.is_comparison() || s.is_logical()
) {
return Ok(Some(self.infix(lhs)?));
}
// This is an edge case. We need to move back one token if the current token is an operator
// so the binary expression can pick up the operator
else if self_matches_current!(
self,
TokenType::Symbol(s) if s.is_operator() || s.is_comparison() || s.is_logical()
) {
self.tokenizer.seek(SeekFrom::Current(-1))?;
return Ok(Some(self.infix(lhs)?));
}
Ok(Some(lhs))
}
/// Parses a unary or primary expression.
/// This handles prefix operators (like negation) and atomic expressions (literals, variables, etc.),
/// but stops before consuming binary operators.
fn unary(&mut self) -> Result<Option<tree_node::Expression>, Error> {
macro_rules! matches_keyword {
($keyword:expr, $($pattern:pat),+) => {
matches!($keyword, $($pattern)|+)
};
}
let Some(current_token) = self.current_token.as_ref() else {
return Ok(None);
};
if token_matches!(current_token, TokenType::EOF) {
return Ok(None);
}
let expr = match current_token.token_type {
// match unsupported keywords
TokenType::Keyword(e) if matches_keyword!(e, Keyword::Enum, Keyword::While) => {
return Err(Error::UnsupportedKeyword(current_token.clone()));
}
// match declarations with a `let` keyword
TokenType::Keyword(Keyword::Let) => self.declaration()?,
TokenType::Keyword(Keyword::Device) => Expression::DeviceDeclaration(self.device()?),
// match functions with a `fn` keyword
TokenType::Keyword(Keyword::Fn) => Expression::Function(self.function()?),
// match if statements
TokenType::Keyword(Keyword::If) => Expression::If(self.if_expression()?),
// match syscalls with a `syscall` keyword
TokenType::Identifier(ref id) if SysCall::is_syscall(id) => {
Expression::Syscall(self.syscall()?)
}
// match a variable expression with opening parenthesis
TokenType::Identifier(_)
if self_matches_peek!(self, TokenType::Symbol(Symbol::LParen)) =>
{
Expression::Invocation(self.invocation()?)
}
// match a variable expression with an assignment
TokenType::Identifier(_)
if self_matches_peek!(self, TokenType::Symbol(Symbol::Assign)) =>
{
Expression::Assignment(self.assignment()?)
}
// match variable expressions with an identifier
TokenType::Identifier(ref id) => Expression::Variable(id.clone()),
// match block expressions with a `{` symbol
TokenType::Symbol(Symbol::LBrace) => Expression::Block(self.block()?),
// match literal expressions with a semi-colon afterwards
TokenType::Number(_) | TokenType::String(_) | TokenType::Boolean(_) => {
Expression::Literal(self.literal()?)
}
// match priority expressions with a left parenthesis
TokenType::Symbol(Symbol::LParen) => Expression::Priority(self.priority()?),
// match minus symbols to handle negative numbers or negated expressions
TokenType::Symbol(Symbol::Minus) => {
self.assign_next()?; // consume the `-` symbol
// IMPORTANT: We call `unary()` here, NOT `expression()`.
// This ensures negation binds tightly to the operand and doesn't consume binary ops.
// e.g. `-1 + 2` parses as `(-1) + 2`
let inner_expr = self.unary()?.ok_or(Error::UnexpectedEOF)?;
Expression::Negation(boxed!(inner_expr))
}
// match logical NOT `!`
TokenType::Symbol(Symbol::LogicalNot) => {
self.assign_next()?; // consume the `!` symbol
let inner_expr = self.unary()?.ok_or(Error::UnexpectedEOF)?;
Expression::Logical(LogicalExpression::Not(boxed!(inner_expr)))
}
_ => {
return Err(Error::UnexpectedToken(current_token.clone()));
}
};
Ok(Some(expr))
}
fn get_infix_child_node(&mut self) -> Result<tree_node::Expression, Error> {
let current_token = token_from_option!(self.current_token);
match current_token.token_type {
// A literal number or boolean
TokenType::Number(_) | TokenType::Boolean(_) => self.literal().map(Expression::Literal),
// A plain variable
TokenType::Identifier(ident)
if !self_matches_peek!(self, TokenType::Symbol(Symbol::LParen)) =>
{
Ok(Expression::Variable(ident))
}
// A priority expression ( -> (1 + 2) <- + 3 )
TokenType::Symbol(Symbol::LParen) => self.priority().map(Expression::Priority),
// A function invocation
TokenType::Identifier(_)
if self_matches_peek!(self, TokenType::Symbol(Symbol::LParen)) =>
{
self.invocation().map(Expression::Invocation)
}
// Handle Negation
TokenType::Symbol(Symbol::Minus) => {
self.assign_next()?;
// recurse to handle double negation or simple negation of atoms
let inner = self.get_infix_child_node()?;
Ok(Expression::Negation(boxed!(inner)))
}
// Handle Logical Not
TokenType::Symbol(Symbol::LogicalNot) => {
self.assign_next()?;
let inner = self.get_infix_child_node()?;
Ok(Expression::Logical(LogicalExpression::Not(boxed!(inner))))
}
_ => Err(Error::UnexpectedToken(current_token.clone())),
}
}
fn device(&mut self) -> Result<DeviceDeclarationExpression, Error> {
// sanity check, make sure current token is a `device` keyword
let current_token = token_from_option!(self.current_token);
if !self_matches_current!(self, TokenType::Keyword(Keyword::Device)) {
return Err(Error::UnexpectedToken(current_token.clone()));
}
let identifier = extract_token_data!(
token_from_option!(self.get_next()?),
TokenType::Identifier(ref id),
id.clone()
);
let current_token = token_from_option!(self.get_next()?).clone();
if !token_matches!(current_token, TokenType::Symbol(Symbol::Assign)) {
return Err(Error::UnexpectedToken(current_token));
}
let device = extract_token_data!(
token_from_option!(self.get_next()?),
TokenType::String(ref id),
id.clone()
);
Ok(DeviceDeclarationExpression {
name: identifier,
device,
})
}
fn assignment(&mut self) -> Result<AssignmentExpression, Error> {
let identifier = extract_token_data!(
token_from_option!(self.current_token),
TokenType::Identifier(ref id),
id.clone()
);
let current_token = token_from_option!(self.get_next()?).clone();
if !token_matches!(current_token, TokenType::Symbol(Symbol::Assign)) {
return Err(Error::UnexpectedToken(current_token));
}
self.assign_next()?;
let expression = self.expression()?.ok_or(Error::UnexpectedEOF)?;
Ok(AssignmentExpression {
identifier,
expression: boxed!(expression),
})
}
/// Handles mathmatical and logical expressions in the explicit order of operations
fn infix(&mut self, previous: Expression) -> Result<Expression, Error> {
// We cannot use recursion here, as we need to handle the precedence of the operators
// We need to use a loop to parse the binary expressions.
let mut current_token = token_from_option!(self.get_next()?).clone();
// first, make sure the previous expression supports binary expressions
match previous {
Expression::Binary(_)
| Expression::Logical(_)
| Expression::Invocation(_)
| Expression::Priority(_)
| Expression::Literal(_)
| Expression::Variable(_)
| Expression::Negation(_) => {}
_ => {
return Err(Error::InvalidSyntax(
current_token.clone(),
String::from("Invalid expression for binary/logical operation"),
));
}
}
let mut expressions = vec![previous]; // 1, 2, 3
// operators Vec should be `expressions.len() - 1`
let mut operators = Vec::<Symbol>::new(); // +, +
// build the expressions and operators vectors
while token_matches!(
current_token,
TokenType::Symbol(s) if s.is_operator() || s.is_comparison() || s.is_logical()
) {
// We are guaranteed to have an operator/comparison/logical symbol here as we checked in the while loop
let operator = extract_token_data!(current_token, TokenType::Symbol(s), s);
operators.push(operator);
self.assign_next()?;
expressions.push(self.get_infix_child_node()?);
current_token = token_from_option!(self.get_next()?).clone();
}
// validate the vectors and make sure operators.len() == expressions.len() - 1
if operators.len() != expressions.len() - 1 {
return Err(Error::InvalidSyntax(
current_token.clone(),
String::from("Invalid number of operators"),
));
}
// Every time we find a valid operator, we pop 2 off the expressions and add one back.
// This means that we need to keep track of the current iteration to ensure we are
// removing the correct expressions from the vector
// --- PRECEDENCE LEVEL 1: Exponent (**) ---
for (i, operator) in operators.iter().enumerate().rev() {
if operator == &Symbol::Exp {
let right = expressions.remove(i + 1);
let left = expressions.remove(i);
expressions.insert(
i,
Expression::Binary(BinaryExpression::Exponent(boxed!(left), boxed!(right))),
);
}
}
operators.retain(|symbol| symbol != &Symbol::Exp);
// --- PRECEDENCE LEVEL 2: Multiplicative (*, /, %) ---
let mut current_iteration = 0;
for (i, operator) in operators.iter().enumerate() {
if matches!(operator, Symbol::Slash | Symbol::Asterisk | Symbol::Percent) {
let index = i - current_iteration;
let left = expressions.remove(index);
let right = expressions.remove(index);
match operator {
Symbol::Asterisk => expressions.insert(
index,
Expression::Binary(BinaryExpression::Multiply(boxed!(left), boxed!(right))),
),
Symbol::Slash => expressions.insert(
index,
Expression::Binary(BinaryExpression::Divide(boxed!(left), boxed!(right))),
),
Symbol::Percent => expressions.insert(
index,
Expression::Binary(BinaryExpression::Modulo(boxed!(left), boxed!(right))),
),
_ => unreachable!(),
}
current_iteration += 1;
}
}
operators
.retain(|symbol| !matches!(symbol, Symbol::Asterisk | Symbol::Percent | Symbol::Slash));
// --- PRECEDENCE LEVEL 3: Additive (+, -) ---
current_iteration = 0;
for (i, operator) in operators.iter().enumerate() {
if matches!(operator, Symbol::Plus | Symbol::Minus) {
let index = i - current_iteration;
let left = expressions.remove(index);
let right = expressions.remove(index);
match operator {
Symbol::Plus => expressions.insert(
index,
Expression::Binary(BinaryExpression::Add(boxed!(left), boxed!(right))),
),
Symbol::Minus => expressions.insert(
index,
Expression::Binary(BinaryExpression::Subtract(boxed!(left), boxed!(right))),
),
_ => unreachable!(),
}
current_iteration += 1;
}
}
operators.retain(|symbol| !matches!(symbol, Symbol::Plus | Symbol::Minus));
// --- PRECEDENCE LEVEL 4: Comparison (<, >, <=, >=) ---
current_iteration = 0;
for (i, operator) in operators.iter().enumerate() {
if operator.is_comparison() && !matches!(operator, Symbol::Equal | Symbol::NotEqual) {
let index = i - current_iteration;
let left = expressions.remove(index);
let right = expressions.remove(index);
match operator {
Symbol::LessThan => expressions.insert(
index,
Expression::Logical(LogicalExpression::LessThan(
boxed!(left),
boxed!(right),
)),
),
Symbol::GreaterThan => expressions.insert(
index,
Expression::Logical(LogicalExpression::GreaterThan(
boxed!(left),
boxed!(right),
)),
),
Symbol::LessThanOrEqual => expressions.insert(
index,
Expression::Logical(LogicalExpression::LessThanOrEqual(
boxed!(left),
boxed!(right),
)),
),
Symbol::GreaterThanOrEqual => expressions.insert(
index,
Expression::Logical(LogicalExpression::GreaterThanOrEqual(
boxed!(left),
boxed!(right),
)),
),
_ => unreachable!(),
}
current_iteration += 1;
}
}
operators.retain(|symbol| {
!symbol.is_comparison() || matches!(symbol, Symbol::Equal | Symbol::NotEqual)
});
// --- PRECEDENCE LEVEL 5: Equality (==, !=) ---
current_iteration = 0;
for (i, operator) in operators.iter().enumerate() {
if matches!(operator, Symbol::Equal | Symbol::NotEqual) {
let index = i - current_iteration;
let left = expressions.remove(index);
let right = expressions.remove(index);
match operator {
Symbol::Equal => expressions.insert(
index,
Expression::Logical(LogicalExpression::Equal(boxed!(left), boxed!(right))),
),
Symbol::NotEqual => expressions.insert(
index,
Expression::Logical(LogicalExpression::NotEqual(
boxed!(left),
boxed!(right),
)),
),
_ => unreachable!(),
}
current_iteration += 1;
}
}
operators.retain(|symbol| !matches!(symbol, Symbol::Equal | Symbol::NotEqual));
// --- PRECEDENCE LEVEL 6: Logical AND (&&) ---
current_iteration = 0;
for (i, operator) in operators.iter().enumerate() {
if matches!(operator, Symbol::LogicalAnd) {
let index = i - current_iteration;
let left = expressions.remove(index);
let right = expressions.remove(index);
expressions.insert(
index,
Expression::Logical(LogicalExpression::And(boxed!(left), boxed!(right))),
);
current_iteration += 1;
}
}
operators.retain(|symbol| !matches!(symbol, Symbol::LogicalAnd));
// --- PRECEDENCE LEVEL 7: Logical OR (||) ---
current_iteration = 0;
for (i, operator) in operators.iter().enumerate() {
if matches!(operator, Symbol::LogicalOr) {
let index = i - current_iteration;
let left = expressions.remove(index);
let right = expressions.remove(index);
expressions.insert(
index,
Expression::Logical(LogicalExpression::Or(boxed!(left), boxed!(right))),
);
current_iteration += 1;
}
}
operators.retain(|symbol| !matches!(symbol, Symbol::LogicalOr));
// Ensure there is only one expression left in the expressions vector, and no operators left
if expressions.len() != 1 || !operators.is_empty() {
return Err(Error::InvalidSyntax(
current_token.clone(),
String::from("Invalid number of operators"),
));
}
// Edge case. If the current token is a semi-colon, RParen, we need to set current token to the previous token
if token_matches!(
current_token,
TokenType::Symbol(Symbol::Semicolon) | TokenType::Symbol(Symbol::RParen)
) {
self.tokenizer.seek(SeekFrom::Current(-1))?;
}
Ok(expressions.pop().unwrap())
}
fn priority(&mut self) -> Result<Box<Expression>, Error> {
let current_token = token_from_option!(self.current_token);
if !token_matches!(current_token, TokenType::Symbol(Symbol::LParen)) {
return Err(Error::UnexpectedToken(current_token.clone()));
}
self.assign_next()?;
let expression = self.expression()?.ok_or(Error::UnexpectedEOF)?;
let current_token = token_from_option!(self.get_next()?);
if !token_matches!(current_token, TokenType::Symbol(Symbol::RParen)) {
return Err(Error::UnexpectedToken(current_token.clone()));
}
Ok(boxed!(expression))
}
fn invocation(&mut self) -> Result<InvocationExpression, Error> {
let identifier = extract_token_data!(
token_from_option!(self.current_token),
TokenType::Identifier(ref id),
id.clone()
);
// Ensure the next token is a left parenthesis
let current_token = token_from_option!(self.get_next()?);
if !token_matches!(current_token, TokenType::Symbol(Symbol::LParen)) {
return Err(Error::UnexpectedToken(current_token.clone()));
}
let mut arguments = Vec::<Expression>::new();
// We need to make sure the expressions are NOT BlockExpressions, as they are not allowed
while !token_matches!(
token_from_option!(self.get_next()?),
TokenType::Symbol(Symbol::RParen)
) {
let current_token = token_from_option!(self.current_token);
let expression = self.expression()?.ok_or(Error::UnexpectedEOF)?;
if let Expression::Block(_) = expression {
return Err(Error::InvalidSyntax(
current_token,
String::from("Block expressions are not allowed in function invocations"),
));
}
arguments.push(expression);
// make sure the next token is a comma or right parenthesis
if !self_matches_peek!(self, TokenType::Symbol(Symbol::Comma))
&& !self_matches_peek!(self, TokenType::Symbol(Symbol::RParen))
{
return Err(Error::UnexpectedToken(
token_from_option!(self.get_next()?).clone(),
));
}
// edge case: if the next token is not a right parenthesis, increment the current token
//
// This will allow the loop to break on a right parenthesis with the next iteration
// which is incremented by the loop
if !self_matches_peek!(self, TokenType::Symbol(Symbol::RParen)) {
self.assign_next()?;
}
}
Ok(InvocationExpression {
name: identifier,
arguments,
})
}
fn block(&mut self) -> Result<BlockExpression, Error> {
let mut expressions = Vec::<Expression>::new();
let current_token = token_from_option!(self.current_token);
// sanity check: make sure the current token is a left brace
if !token_matches!(current_token, TokenType::Symbol(Symbol::LBrace)) {
return Err(Error::UnexpectedToken(current_token.clone()));
}
while !self_matches_peek!(
self,
TokenType::Symbol(Symbol::RBrace) | TokenType::Keyword(Keyword::Return)
) {
let expression = self.parse()?.ok_or(Error::UnexpectedEOF)?;
expressions.push(expression);
}
// print the current token for debugging
let current_token = token_from_option!(self.get_next()?);
if token_matches!(current_token, TokenType::Keyword(Keyword::Return)) {
self.assign_next()?;
let expression = self.expression()?.ok_or(Error::UnexpectedEOF)?;
let return_expr = Expression::Return(boxed!(expression));
expressions.push(return_expr);
// check for semicolon
let next = token_from_option!(self.get_next()?);
if !token_matches!(next, TokenType::Symbol(Symbol::Semicolon)) {
return Err(Error::UnexpectedToken(next.clone()));
}
// check for right brace
let next = token_from_option!(self.get_next()?);
if !token_matches!(next, TokenType::Symbol(Symbol::RBrace)) {
return Err(Error::UnexpectedToken(next.clone()));
}
}
Ok(BlockExpression(expressions))
}
fn declaration(&mut self) -> Result<Expression, Error> {
let current_token = token_from_option!(self.current_token);
if !self_matches_current!(self, TokenType::Keyword(Keyword::Let)) {
return Err(Error::UnexpectedToken(current_token.clone()));
}
let identifier = extract_token_data!(
token_from_option!(self.get_next()?),
TokenType::Identifier(ref id),
id.clone()
);
let current_token = token_from_option!(self.get_next()?).clone();
if !token_matches!(current_token, TokenType::Symbol(Symbol::Assign)) {
return Err(Error::UnexpectedToken(current_token.clone()));
}
self.assign_next()?;
let assignment_expression = self.expression()?.ok_or(Error::UnexpectedEOF)?;
// make sure the next token is a semi-colon
let current_token = token_from_option!(self.get_next()?);
if !token_matches!(current_token, TokenType::Symbol(Symbol::Semicolon)) {
return Err(Error::UnexpectedToken(current_token.clone()));
}
Ok(Expression::Declaration(
identifier,
boxed!(assignment_expression),
))
}
fn literal(&mut self) -> Result<Literal, Error> {
let current_token = token_from_option!(self.current_token);
let literal = match current_token.token_type {
TokenType::Number(num) => Literal::Number(num),
TokenType::String(string) => Literal::String(string),
TokenType::Boolean(boolean) => Literal::Boolean(boolean),
_ => return Err(Error::UnexpectedToken(current_token.clone())),
};
Ok(literal)
}
fn if_expression(&mut self) -> Result<IfExpression, Error> {
let current_token = token_from_option!(self.current_token);
if !self_matches_current!(self, TokenType::Keyword(Keyword::If)) {
return Err(Error::UnexpectedToken(current_token.clone()));
}
// consume 'if'
let next = token_from_option!(self.get_next()?);
if !token_matches!(next, TokenType::Symbol(Symbol::LParen)) {
return Err(Error::UnexpectedToken(next.clone()));
}
self.assign_next()?;
// parse condition
let condition = self.expression()?.ok_or(Error::UnexpectedEOF)?;
// check for ')'
let next = token_from_option!(self.get_next()?);
if !token_matches!(next, TokenType::Symbol(Symbol::RParen)) {
return Err(Error::UnexpectedToken(next.clone()));
}
// check for '{'
let next = token_from_option!(self.get_next()?);
if !token_matches!(next, TokenType::Symbol(Symbol::LBrace)) {
return Err(Error::UnexpectedToken(next.clone()));
}
// parse body
let body = self.block()?;
// check for 'else'
let else_branch = if self_matches_peek!(self, TokenType::Keyword(Keyword::Else)) {
self.assign_next()?; // consume 'else'
if self_matches_peek!(self, TokenType::Keyword(Keyword::If)) {
// else if ...
self.assign_next()?;
Some(boxed!(Expression::If(self.if_expression()?)))
} else if self_matches_peek!(self, TokenType::Symbol(Symbol::LBrace)) {
// else { ... }
self.assign_next()?;
Some(boxed!(Expression::Block(self.block()?)))
} else {
return Err(Error::UnexpectedToken(
token_from_option!(self.get_next()?).clone(),
));
}
} else {
None
};
Ok(IfExpression {
condition: boxed!(condition),
body,
else_branch,
})
}
fn function(&mut self) -> Result<FunctionExpression, Error> {
let current_token = token_from_option!(self.current_token);
// Sanify check that the current token is a `fn` keyword
if !self_matches_current!(self, TokenType::Keyword(Keyword::Fn)) {
return Err(Error::UnexpectedToken(current_token.clone()));
}
let fn_ident = extract_token_data!(
token_from_option!(self.get_next()?),
TokenType::Identifier(ref id),
id.clone()
);
// make sure next token is a left parenthesis
let current_token = token_from_option!(self.get_next()?);
if !token_matches!(current_token, TokenType::Symbol(Symbol::LParen)) {
return Err(Error::UnexpectedToken(current_token.clone()));
}
let mut arguments = Vec::<String>::new();
// iterate through the arguments. While expression while increment the current token
// with the `token_from_option!(self.get_next()?)` macro
while !token_matches!(
token_from_option!(self.get_next()?),
TokenType::Symbol(Symbol::RParen)
) {
let current_token = token_from_option!(self.current_token);
let argument =
extract_token_data!(current_token, TokenType::Identifier(ref id), id.clone());
if arguments.contains(&argument) {
return Err(Error::DuplicateIdentifier(current_token.clone()));
}
arguments.push(argument);
// make sure the next token is a comma or right parenthesis
if !self_matches_peek!(self, TokenType::Symbol(Symbol::Comma))
&& !self_matches_peek!(self, TokenType::Symbol(Symbol::RParen))
{
return Err(Error::UnexpectedToken(
token_from_option!(self.get_next()?).clone(),
));
}
// edge case: if the next token is not a right parenthesis, increment the current token
//
// This will allow the loop to break on a right parenthesis with the next iteration
// which is incremented by the loop
if !self_matches_peek!(self, TokenType::Symbol(Symbol::RParen)) {
self.assign_next()?;
}
}
// make sure the next token is a left brace
let current_token = token_from_option!(self.get_next()?);
if !token_matches!(current_token, TokenType::Symbol(Symbol::LBrace)) {
return Err(Error::UnexpectedToken(current_token.clone()));
};
Ok(FunctionExpression {
name: fn_ident,
arguments,
body: self.block()?,
})
}
fn syscall(&mut self) -> Result<SysCall, Error> {
/// Checks the length of the arguments and returns an error if the length is not equal to the expected length
fn check_length(
parser: &Parser,
arguments: &[Expression],
length: usize,
) -> Result<(), Error> {
if arguments.len() != length {
return Err(Error::InvalidSyntax(
token_from_option!(parser.current_token).clone(),
format!("Expected {} arguments", length),
));
}
Ok(())
}
/// Converts an expression to "literal or variable" expression
macro_rules! literal_or_variable {
($iter:expr) => {
match $iter {
Some(Expression::Literal(literal)) => {
LiteralOrVariable::Literal(literal.clone())
}
Some(Expression::Variable(ident)) => LiteralOrVariable::Variable(ident.clone()),
_ => {
return Err(Error::UnexpectedToken(
token_from_option!(self.current_token).clone(),
))
}
}
};
}
/// Gets the argument from the expression and returns an error if the expression does not match the expected pattern
macro_rules! get_arg {
($matcher: ident, $arg: expr) => {
match $arg {
LiteralOrVariable::$matcher(i) => i,
_ => {
return Err(Error::InvalidSyntax(
token_from_option!(self.current_token).clone(),
String::from("Expected a variable"),
))
}
}
};
}
// A syscall is essentially an invocation expression with a syscall identifier. So we can reuse the invocation function
let invocation = self.invocation()?;
match invocation.name.as_str() {
// system calls
"yield" => {
check_length(self, &invocation.arguments, 0)?;
Ok(SysCall::System(sys_call::System::Yield))
}
"sleep" => {
check_length(self, &invocation.arguments, 1)?;
let mut arg = invocation.arguments.iter();
let argument = literal_or_variable!(arg.next());
Ok(SysCall::System(sys_call::System::Sleep(argument)))
}
"loadFromDevice" => {
check_length(self, &invocation.arguments, 2)?;
let mut args = invocation.arguments.iter();
let device = literal_or_variable!(args.next());
let Some(Expression::Literal(Literal::String(variable))) = args.next() else {
return Err(Error::UnexpectedToken(
token_from_option!(self.current_token).clone(),
));
};
Ok(SysCall::System(sys_call::System::LoadFromDevice(
device,
LiteralOrVariable::Variable(variable.clone()),
)))
}
"loadBatch" => {
check_length(self, &invocation.arguments, 3)?;
let mut args = invocation.arguments.iter();
let device_hash = literal_or_variable!(args.next());
let logic_type = get_arg!(Literal, literal_or_variable!(args.next()));
let batch_mode = get_arg!(Literal, literal_or_variable!(args.next()));
Ok(SysCall::System(sys_call::System::LoadBatch(
device_hash,
logic_type,
batch_mode,
)))
}
"loadBatchNamed" => {
check_length(self, &invocation.arguments, 4)?;
let mut args = invocation.arguments.iter();
let device_hash = literal_or_variable!(args.next());
let name_hash = get_arg!(Literal, literal_or_variable!(args.next()));
let logic_type = get_arg!(Literal, literal_or_variable!(args.next()));
let batch_mode = get_arg!(Literal, literal_or_variable!(args.next()));
Ok(SysCall::System(sys_call::System::LoadBatchNamed(
device_hash,
name_hash,
logic_type,
batch_mode,
)))
}
"setOnDevice" => {
check_length(self, &invocation.arguments, 3)?;
let mut args = invocation.arguments.iter();
let device = literal_or_variable!(args.next());
let Literal::String(logic_type) =
get_arg!(Literal, literal_or_variable!(args.next()))
else {
return Err(Error::UnexpectedToken(
token_from_option!(self.current_token).clone(),
));
};
let variable = literal_or_variable!(args.next());
Ok(SysCall::System(sys_call::System::SetOnDevice(
device,
Literal::String(logic_type),
variable,
)))
}
// math calls
"acos" => {
check_length(self, &invocation.arguments, 1)?;
let arg = literal_or_variable!(invocation.arguments.first());
Ok(SysCall::Math(sys_call::Math::Acos(arg)))
}
"asin" => {
check_length(self, &invocation.arguments, 1)?;
let arg = literal_or_variable!(invocation.arguments.first());
Ok(SysCall::Math(sys_call::Math::Asin(arg)))
}
"atan" => {
check_length(self, &invocation.arguments, 1)?;
let arg = literal_or_variable!(invocation.arguments.first());
Ok(SysCall::Math(sys_call::Math::Atan(arg)))
}
"atan2" => {
check_length(self, &invocation.arguments, 2)?;
let mut args = invocation.arguments.iter();
let arg1 = literal_or_variable!(args.next());
let arg2 = literal_or_variable!(args.next());
Ok(SysCall::Math(sys_call::Math::Atan2(arg1, arg2)))
}
"abs" => {
check_length(self, &invocation.arguments, 1)?;
let arg = literal_or_variable!(invocation.arguments.first());
Ok(SysCall::Math(sys_call::Math::Abs(arg)))
}
"ceil" => {
check_length(self, &invocation.arguments, 1)?;
let arg = literal_or_variable!(invocation.arguments.first());
Ok(SysCall::Math(sys_call::Math::Ceil(arg)))
}
"cos" => {
check_length(self, &invocation.arguments, 1)?;
let arg = literal_or_variable!(invocation.arguments.first());
Ok(SysCall::Math(sys_call::Math::Cos(arg)))
}
"floor" => {
check_length(self, &invocation.arguments, 1)?;
let arg = literal_or_variable!(invocation.arguments.first());
Ok(SysCall::Math(sys_call::Math::Floor(arg)))
}
"log" => {
check_length(self, &invocation.arguments, 1)?;
let arg = literal_or_variable!(invocation.arguments.first());
Ok(SysCall::Math(sys_call::Math::Log(arg)))
}
"max" => {
check_length(self, &invocation.arguments, 2)?;
let mut args = invocation.arguments.iter();
let arg1 = literal_or_variable!(args.next());
let arg2 = literal_or_variable!(args.next());
Ok(SysCall::Math(sys_call::Math::Max(arg1, arg2)))
}
"min" => {
check_length(self, &invocation.arguments, 2)?;
let mut args = invocation.arguments.iter();
let arg1 = literal_or_variable!(args.next());
let arg2 = literal_or_variable!(args.next());
Ok(SysCall::Math(sys_call::Math::Min(arg1, arg2)))
}
"rand" => {
check_length(self, &invocation.arguments, 0)?;
Ok(SysCall::Math(sys_call::Math::Rand))
}
"sin" => {
check_length(self, &invocation.arguments, 1)?;
let arg = literal_or_variable!(invocation.arguments.first());
Ok(SysCall::Math(sys_call::Math::Sin(arg)))
}
"sqrt" => {
check_length(self, &invocation.arguments, 1)?;
let arg = literal_or_variable!(invocation.arguments.first());
Ok(SysCall::Math(sys_call::Math::Sqrt(arg)))
}
"tan" => {
check_length(self, &invocation.arguments, 1)?;
let arg = literal_or_variable!(invocation.arguments.first());
Ok(SysCall::Math(sys_call::Math::Tan(arg)))
}
"trunc" => {
check_length(self, &invocation.arguments, 1)?;
let arg = literal_or_variable!(invocation.arguments.first());
Ok(SysCall::Math(sys_call::Math::Trunc(arg)))
}
_ => todo!(),
}
}
}