Parser - Support for function calls
This commit is contained in:
parent
2e7a897c47
commit
acbce309fa
1 changed files with 36 additions and 3 deletions
|
@ -525,6 +525,7 @@ impl Parser {
|
|||
/// primary := "(" expression ")"
|
||||
/// primary := FALSE | TRUE | NIL | STRING | NUMBER
|
||||
/// primary := IDENTIFIER
|
||||
/// primary := call
|
||||
/// ```
|
||||
fn parse_primary(&mut self) -> ParserResult<ast::ExprNode> {
|
||||
if self.expect(&[TokenType::LeftParen]).is_some() {
|
||||
|
@ -542,14 +543,46 @@ impl Parser {
|
|||
TokenType::Number(_) | &TokenType::String(_) => Ok(ast::ExprNode::Litteral {
|
||||
value: self.advance().clone(),
|
||||
}),
|
||||
TokenType::Identifier(_) => Ok(ast::ExprNode::Variable {
|
||||
name: self.advance().clone(),
|
||||
}),
|
||||
TokenType::Identifier(_) => {
|
||||
let identifier = self.advance().clone();
|
||||
if self.expect(&[TokenType::LeftParen]).is_some() {
|
||||
self.parse_call(identifier)
|
||||
} else {
|
||||
Ok(ast::ExprNode::Variable { name: identifier })
|
||||
}
|
||||
}
|
||||
_ => Err(ParserError::new(self.peek(), "expected expression")),
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
/// Parse the following rules:
|
||||
/// ```
|
||||
/// call := IDENTIFIER "(" arguments? ")"
|
||||
/// arguments := expression ( "," expression )*
|
||||
/// ```
|
||||
/// The `identifier` has already been read and is provided to the method;
|
||||
/// the opening parenthesis has already been skipped.
|
||||
fn parse_call(&mut self, name: Token) -> Result<ast::ExprNode, ParserError> {
|
||||
let mut arguments = Vec::new();
|
||||
if !self.check(&TokenType::RightParen) {
|
||||
loop {
|
||||
arguments.push(self.parse_expression()?);
|
||||
if self.expect(&[TokenType::Comma]).is_some() {
|
||||
break;
|
||||
}
|
||||
}
|
||||
}
|
||||
let right_paren = self
|
||||
.consume(&TokenType::RightParen, "')' expected after arguments")?
|
||||
.clone();
|
||||
Ok(ast::ExprNode::Call {
|
||||
name,
|
||||
right_paren,
|
||||
arguments,
|
||||
})
|
||||
}
|
||||
|
||||
/* -------------- *
|
||||
* HELPER METHODS *
|
||||
* -------------- */
|
||||
|
|
Loading…
Reference in a new issue