[fine] Tokens is not Iterator
It was not pulling its weight
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c4d2b82968
commit
d2d144a5ec
2 changed files with 107 additions and 152 deletions
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@ -267,7 +267,7 @@ impl<'a> SyntaxTree<'a> {
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// This is dumb and should be punished, probably.
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(_, Type::Unreachable) => {
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let (line, col) = lines.position(tok.start());
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let (line, col) = lines.position(tok.start);
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self.errors.push(SyntaxError::new(line, col, format!("cannot apply a unary operator to something that doesn't yield a value")));
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Type::Error
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}
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@ -277,7 +277,7 @@ impl<'a> SyntaxTree<'a> {
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// Missed the whole table, must be an error.
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(_, arg_type) => {
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let (line, col) = lines.position(tok.start());
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let (line, col) = lines.position(tok.start);
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self.errors.push(SyntaxError::new(line, col, format!("cannot apply unary operator '{tok}' to expression of type '{arg_type}'")));
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Type::Error
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}
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@ -305,7 +305,7 @@ impl<'a> SyntaxTree<'a> {
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// This is dumb and should be punished, probably.
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(_, _, Type::Unreachable) => {
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let (line, col) = lines.position(tok.start());
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let (line, col) = lines.position(tok.start);
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self.errors.push(SyntaxError::new(
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line,
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col,
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@ -316,7 +316,7 @@ impl<'a> SyntaxTree<'a> {
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Type::Error
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}
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(_, Type::Unreachable, _) => {
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let (line, col) = lines.position(tok.start());
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let (line, col) = lines.position(tok.start);
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self.errors.push(SyntaxError::new(
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line,
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col,
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@ -333,7 +333,7 @@ impl<'a> SyntaxTree<'a> {
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// Missed the whole table, it must be an error.
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(_, left_type, right_type) => {
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let (line, col) = lines.position(tok.start());
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let (line, col) = lines.position(tok.start);
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self.errors.push(SyntaxError::new(line, col, format!("cannot apply binary operator '{tok}' to expressions of type '{left_type}' (on the left) and '{right_type}' (on the right)")));
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Type::Error
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}
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@ -354,8 +354,8 @@ impl<'a> SyntaxTree<'a> {
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.expr_span(&cond)
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.expect("If the expression has a type it must have a span");
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let start = lines.position(span.0.start());
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let end = lines.position(span.1.start());
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let start = lines.position(span.0.start);
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let end = lines.position(span.1.start);
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self.errors.push(SyntaxError::new_spanned(
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start,
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end,
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@ -374,8 +374,8 @@ impl<'a> SyntaxTree<'a> {
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let span = self
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.expr_span(&exr)
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.expect("How did I get this far with a broken parse?");
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let start = lines.position(span.0.start());
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let end = lines.position(span.1.start());
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let start = lines.position(span.0.start);
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let end = lines.position(span.1.start);
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self.errors.push(SyntaxError::new_spanned(
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start,
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end,
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@ -392,8 +392,8 @@ impl<'a> SyntaxTree<'a> {
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let span = self
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.expr_span(&exr)
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.expect("How did I get this far with a broken parse?");
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let start = lines.position(span.0.start());
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let end = lines.position(span.1.start());
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let start = lines.position(span.0.start);
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let end = lines.position(span.1.start);
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self.errors.push(SyntaxError::new_spanned(
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start,
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end,
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@ -431,13 +431,8 @@ const UNARY_POWER: u8 = 7; // ! -
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// const CALL_POWER: u8 = 8; // . ()
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// const PRIMARY_POWER: u8 = 9;
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fn token_power<'a>(token: &Option<Token<'a>>) -> Option<u8> {
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let token = match token {
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Some(t) => t,
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None => return None,
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};
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match token.kind() {
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fn token_power<'a>(token: &Token<'a>) -> Option<u8> {
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match token.kind {
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TokenKind::Equal => Some(ASSIGNMENT_POWER),
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TokenKind::Or => Some(OR_POWER),
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TokenKind::And => Some(AND_POWER),
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@ -454,8 +449,8 @@ fn token_power<'a>(token: &Option<Token<'a>>) -> Option<u8> {
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pub struct Parser<'a> {
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tokens: Tokens<'a>,
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tree: SyntaxTree<'a>,
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current: Option<Token<'a>>,
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previous: Option<Token<'a>>,
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current: Token<'a>,
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previous: Token<'a>,
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panic_mode: bool,
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}
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@ -465,8 +460,8 @@ impl<'a> Parser<'a> {
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let mut parser = Parser {
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tokens: Tokens::new(source),
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tree: SyntaxTree::new(),
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current: None,
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previous: None,
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current: Token::new(TokenKind::EOF, 0, ""),
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previous: Token::new(TokenKind::EOF, 0, ""),
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panic_mode: false,
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};
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parser.advance();
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@ -475,7 +470,7 @@ impl<'a> Parser<'a> {
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pub fn parse(mut self) -> (SyntaxTree<'a>, ExprRef, Lines) {
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let expr = self.expression();
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self.consume(None, "expected end of expression");
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self.consume(TokenKind::EOF, "expected end of expression");
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(self.tree, expr, self.tokens.lines())
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}
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@ -505,30 +500,24 @@ impl<'a> Parser<'a> {
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fn prefix_expression(&mut self) -> ExprRef {
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self.trace("prefix");
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let token = self.previous.as_ref();
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match token {
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Some(token) => match token.kind() {
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TokenKind::Bang => self.unary(),
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TokenKind::LeftParen => self.grouping(),
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TokenKind::Number => self.number(),
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TokenKind::Minus => self.unary(),
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TokenKind::String => self.string(),
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let token = &self.previous;
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match token.kind {
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TokenKind::Bang => self.unary(),
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TokenKind::LeftParen => self.grouping(),
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TokenKind::Number => self.number(),
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TokenKind::Minus => self.unary(),
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TokenKind::String => self.string(),
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TokenKind::True => self
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.tree
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.add_expr(Expr::Literal(Literal::Bool(true), token.clone())),
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TokenKind::False => self
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.tree
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.add_expr(Expr::Literal(Literal::Bool(false), token.clone())),
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TokenKind::True => self
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.tree
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.add_expr(Expr::Literal(Literal::Bool(true), token.clone())),
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TokenKind::False => self
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.tree
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.add_expr(Expr::Literal(Literal::Bool(false), token.clone())),
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TokenKind::If => self.conditional(),
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TokenKind::If => self.conditional(),
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_ => {
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self.error("expected an expression");
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ExprRef::error()
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}
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},
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None => {
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_ => {
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self.error("expected an expression");
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ExprRef::error()
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}
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@ -537,8 +526,7 @@ impl<'a> Parser<'a> {
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fn infix_expression(&mut self, power: u8, left: ExprRef) -> ExprRef {
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self.trace("infix");
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let kind = self.previous.as_ref().unwrap().kind();
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match kind {
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match self.previous.kind {
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TokenKind::Plus
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| TokenKind::Minus
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| TokenKind::Star
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@ -550,7 +538,7 @@ impl<'a> Parser<'a> {
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}
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fn number(&mut self) -> ExprRef {
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let token = self.previous.as_ref().unwrap();
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let token = &self.previous;
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// What kind is it? For now let's just ... make it good.
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let literal = match token.as_str().parse::<f64>() {
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@ -565,7 +553,7 @@ impl<'a> Parser<'a> {
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}
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fn string(&mut self) -> ExprRef {
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let token = self.previous.as_ref().unwrap();
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let token = &self.previous;
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let mut result = String::new();
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let mut input = token.as_str().chars();
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@ -590,51 +578,34 @@ impl<'a> Parser<'a> {
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fn grouping(&mut self) -> ExprRef {
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let result = self.expression();
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self.consume(
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Some(TokenKind::RightParen),
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"expected ')' after an expression",
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);
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self.consume(TokenKind::RightParen, "expected ')' after an expression");
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result
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}
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fn conditional(&mut self) -> ExprRef {
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let token = self.previous.as_ref().unwrap().clone();
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let token = self.previous.clone();
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let condition_expr = self.expression();
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self.consume(
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Some(TokenKind::LeftBrace),
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"expected '{' to start an 'if' block",
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);
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self.consume(TokenKind::LeftBrace, "expected '{' to start an 'if' block");
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let then_expr = self.expression();
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self.consume(
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Some(TokenKind::RightBrace),
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"expected '}' to end an 'if' block",
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);
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let else_expr = match &self.current {
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Some(token) if token.kind() == TokenKind::Else => {
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self.consume(TokenKind::RightBrace, "expected '}' to end an 'if' block");
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let else_expr = if self.current.kind == TokenKind::Else {
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self.advance();
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if self.current.kind == TokenKind::If {
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self.advance();
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match &self.current {
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// Allow `else if` without another `{`.
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Some(token) if token.kind() == TokenKind::If => {
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self.advance();
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Some(self.conditional())
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}
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_ => {
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self.consume(
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Some(TokenKind::LeftBrace),
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"expected '{' to start an 'else' block",
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);
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let else_expr = self.expression();
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self.consume(
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Some(TokenKind::RightBrace),
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"Expected '}' to end an 'else' block",
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);
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Some(else_expr)
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}
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}
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Some(self.conditional())
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} else {
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self.consume(
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TokenKind::LeftBrace,
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"expected '{' to start an 'else' block",
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);
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let else_expr = self.expression();
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self.consume(TokenKind::RightBrace, "Expected '}' to end an 'else' block");
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Some(else_expr)
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}
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_ => None,
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} else {
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None
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};
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let tail = self.previous.as_ref().unwrap().clone();
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let tail = self.previous.clone();
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self.tree.add_expr(Expr::Conditional(
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token,
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condition_expr,
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@ -645,8 +616,8 @@ impl<'a> Parser<'a> {
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}
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fn unary(&mut self) -> ExprRef {
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let token = self.previous.as_ref().unwrap().clone();
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let kind = token.kind();
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let token = self.previous.clone();
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let kind = token.kind;
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let expr = self.expression_with_power(UNARY_POWER);
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let op = match kind {
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TokenKind::Minus => UnaryOp::Negate,
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@ -658,8 +629,8 @@ impl<'a> Parser<'a> {
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}
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fn binary(&mut self, power: u8, left: ExprRef) -> ExprRef {
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let token = self.previous.as_ref().unwrap().clone();
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let op = match token.kind() {
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let token = self.previous.clone();
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let op = match token.kind {
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TokenKind::Plus => BinaryOp::Add,
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TokenKind::Minus => BinaryOp::Subtract,
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TokenKind::Star => BinaryOp::Multiply,
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@ -673,25 +644,19 @@ impl<'a> Parser<'a> {
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}
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fn advance(&mut self) {
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self.previous = self.current.take();
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loop {
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self.previous = self.current.clone();
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self.current = self.tokens.next();
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while self.current.kind == TokenKind::Error {
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self.error_at_current(self.current.to_string());
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self.current = self.tokens.next();
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match &self.current {
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Some(token) if token.kind() == TokenKind::Error => {
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self.error_at_current(token.to_string())
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}
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_ => break,
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}
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}
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}
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fn consume(&mut self, kind: Option<TokenKind>, error: &str) {
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match (&self.current, kind) {
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(Some(token), Some(kind)) if token.kind() == kind => self.advance(),
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(None, None) => (),
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_ => {
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self.error_at_current(error);
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}
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fn consume(&mut self, kind: TokenKind, error: &str) {
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if self.current.kind == kind {
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self.advance();
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} else {
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self.error_at_current(error);
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}
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}
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@ -709,7 +674,7 @@ impl<'a> Parser<'a> {
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self.error_at(self.current.clone(), message)
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}
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fn error_at<T>(&mut self, token: Option<Token<'a>>, message: T)
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fn error_at<T>(&mut self, token: Token<'a>, message: T)
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where
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T: Into<String>,
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{
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@ -721,15 +686,13 @@ impl<'a> Parser<'a> {
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let message: String = message.into();
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let (line, column) = self.tokens.token_position(&token);
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let mut final_message = "Error ".to_string();
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match token {
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None => final_message.push_str("at end"),
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Some(t) => {
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if t.kind() != TokenKind::Error {
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final_message.push_str("at '");
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final_message.push_str(t.as_str());
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final_message.push_str("'");
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}
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}
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if token.kind == TokenKind::EOF {
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final_message.push_str("at end")
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} else if token.kind != TokenKind::Error {
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final_message.push_str("at '");
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final_message.push_str(token.as_str());
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final_message.push_str("'");
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}
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final_message.push_str(": ");
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final_message.push_str(&message);
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