869 lines
28 KiB
Rust
869 lines
28 KiB
Rust
use crate::tokens::{Lines, Token, TokenKind, Tokens};
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use std::fmt;
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// TODO: An error should have:
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//
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// - a start
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// - an end
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// - a focus
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// - descriptive messages
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//
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// that will have to wait for now
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#[derive(PartialEq, Eq)]
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pub struct SyntaxError {
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pub start: (usize, usize),
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pub end: (usize, usize),
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pub message: String,
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}
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impl SyntaxError {
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pub fn new<T>(line: usize, column: usize, message: T) -> Self
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where
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T: ToString,
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{
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SyntaxError {
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start: (line, column),
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end: (line, column),
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message: message.to_string(),
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}
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}
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pub fn new_spanned<T>(start: (usize, usize), end: (usize, usize), message: T) -> Self
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where
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T: ToString,
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{
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SyntaxError {
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start,
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end,
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message: message.to_string(),
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}
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}
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}
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impl fmt::Debug for SyntaxError {
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fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
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write!(f, "{self}")
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}
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}
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impl fmt::Display for SyntaxError {
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fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
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write!(f, "{}:{}: {}", self.start.0, self.end.0, self.message)
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}
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}
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#[derive(Clone)]
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pub enum Literal {
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Float64(f64),
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String(String),
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Bool(bool),
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}
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#[derive(Copy, Clone)]
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pub enum UnaryOp {
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Negate,
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Not,
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}
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#[derive(Copy, Clone)]
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pub enum BinaryOp {
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Add,
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Subtract,
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Multiply,
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Divide,
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And,
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Or,
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}
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#[derive(Clone)]
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pub enum Expr<'a> {
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Literal(Literal, Token<'a>),
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Unary(UnaryOp, Token<'a>, ExprRef),
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Binary(BinaryOp, Token<'a>, ExprRef, ExprRef),
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Conditional(Token<'a>, ExprRef, ExprRef, Option<ExprRef>, Token<'a>),
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}
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#[derive(Clone)]
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pub struct ExprRef(Option<usize>);
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impl ExprRef {
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pub fn error() -> Self {
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ExprRef(None)
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}
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}
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// TODO: Eventually we will be unable to use Eq and PartialEq here, and will
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// need to do out own thing.
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#[derive(Copy, Clone)]
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pub enum Type {
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// Signals a type error. If you receive this then you know that an error
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// has already been reported; if you produce this be sure to also note
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// the error in the errors collection.
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Error,
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// Signals that the expression has a control-flow side-effect and that no
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// value will ever result from this expression. Usually this means
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// everything's fine.
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Unreachable,
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// TODO: Numeric literals should be implicitly convertable, unlike other
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// types. Maybe just "numeric literal" type?
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F64,
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String,
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Bool,
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}
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impl Type {
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pub fn is_error(&self) -> bool {
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match self {
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Type::Error => true,
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_ => false,
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}
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}
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pub fn compatible_with(&self, other: &Type) -> bool {
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// TODO: This is wrong; we because of numeric literals etc.
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match (self, other) {
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(Type::F64, Type::F64) => true,
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(Type::String, Type::String) => true,
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(Type::Bool, Type::Bool) => true,
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(Type::Unreachable, Type::Unreachable) => true,
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// Avoid introducing more errors
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(Type::Error, _) => true,
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(_, Type::Error) => true,
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(_, _) => false,
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}
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}
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}
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impl std::fmt::Debug for Type {
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fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
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write!(f, "{self}")
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}
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}
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impl std::fmt::Display for Type {
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fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
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use Type::*;
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match self {
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Error => write!(f, "<< INTERNAL ERROR >>"),
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Unreachable => write!(f, "<< UNREACHABLE >>"),
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F64 => write!(f, "f64"),
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String => write!(f, "string"),
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Bool => write!(f, "bool"),
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}
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}
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}
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pub struct TypeRef(Option<usize>);
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pub struct SyntaxTree<'a> {
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pub errors: Vec<SyntaxError>,
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expressions: Vec<Expr<'a>>,
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}
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impl<'a> SyntaxTree<'a> {
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pub fn new() -> Self {
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SyntaxTree {
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errors: Vec::new(),
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expressions: Vec::new(),
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}
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}
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pub fn add_error(&mut self, error: SyntaxError) {
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self.errors.push(error);
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}
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pub fn add_expr(&mut self, expr: Expr<'a>) -> ExprRef {
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let index = self.expressions.len();
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self.expressions.push(expr);
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ExprRef(Some(index))
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}
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pub fn dump_expr(&self, expr: &ExprRef) -> String {
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match expr.0 {
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Some(idx) => {
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let expr = &self.expressions[idx];
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match expr {
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Expr::Literal(_, tok) => tok.to_string(),
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Expr::Unary(_, tok, e) => {
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format!("({tok} {})", self.dump_expr(e))
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}
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Expr::Binary(_, tok, l, r) => {
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format!("({tok} {} {})", self.dump_expr(l), self.dump_expr(r))
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}
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Expr::Conditional(tok, cond, t, e, _) => {
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if let Some(e) = e {
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format!(
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"({tok} {} {} {})",
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self.dump_expr(cond),
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self.dump_expr(t),
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self.dump_expr(e)
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)
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} else {
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format!("({tok} {} {})", self.dump_expr(cond), self.dump_expr(t))
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}
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}
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}
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}
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None => "<|EOF|>".to_string(),
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}
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}
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pub fn expr_span(&self, expr: &ExprRef) -> Option<(Token<'a>, Token<'a>)> {
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let expr = match expr.0 {
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Some(idx) => &self.expressions[idx],
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None => return None,
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};
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match expr {
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Expr::Literal(_, tok) => Some((tok.clone(), tok.clone())),
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Expr::Unary(_, tok, arg) => {
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let arg = self.expr_span(arg);
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match arg {
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None => None,
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Some((_, end)) => Some((tok.clone(), end)),
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}
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}
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Expr::Binary(_, _, left, right) => {
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let left = self.expr_span(left);
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let right = self.expr_span(right);
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match (left, right) {
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(None, _) => None,
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(_, None) => None,
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(Some((start, _)), Some((_, end))) => Some((start, end)),
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}
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}
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Expr::Conditional(head, _, _, _, tail) => Some((head.clone(), tail.clone())),
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}
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}
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pub fn expr_type(&mut self, expr: &ExprRef, lines: &Lines, value_required: bool) -> Type {
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// TODO: Cache and work on demand? Or is this just fine?
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let exr = expr.clone();
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let expr = match expr.0 {
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Some(idx) => &self.expressions[idx],
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None => return Type::Error,
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};
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match expr {
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Expr::Literal(lit, _) => match lit {
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Literal::Float64(_) => Type::F64,
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Literal::String(_) => Type::String,
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Literal::Bool(_) => Type::Bool,
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},
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// Figure out the main thing. Check for a... trait?
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Expr::Unary(op, tok, arg) => {
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let op = op.clone();
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let arg = arg.clone();
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let tok = tok.clone();
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let arg_type = self.expr_type(&arg, lines, true);
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match (op, arg_type) {
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(UnaryOp::Negate, Type::F64) => Type::F64,
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(UnaryOp::Not, Type::Bool) => Type::Bool,
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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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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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// Propagate existing errors without additional complaint.
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(_, Type::Error) => Type::Error,
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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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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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}
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}
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Expr::Binary(op, tok, left, right) => {
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let op = op.clone();
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let tok = tok.clone();
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let left = left.clone();
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let right = right.clone();
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let left_type = self.expr_type(&left, lines, true);
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let right_type = self.expr_type(&right, lines, true);
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match (op, left_type, right_type) {
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(
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BinaryOp::Add | BinaryOp::Subtract | BinaryOp::Multiply | BinaryOp::Divide,
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Type::F64,
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Type::F64,
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) => Type::F64,
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(BinaryOp::Add, Type::String, Type::String) => Type::String,
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(BinaryOp::And | BinaryOp::Or, Type::Bool, Type::Bool) => Type::Bool,
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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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self.errors.push(SyntaxError::new(
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line,
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col,
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format!(
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"cannot apply '{tok}' to an argument that doesn't yield a value (on the right)"
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),
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));
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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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self.errors.push(SyntaxError::new(
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line,
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col,
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format!(
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"cannot apply '{tok}' to an argument that doesn't yield a value (on the left)"
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),
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));
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Type::Error
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}
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// Propagate existing errors without additional complaint.
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(_, Type::Error, _) => Type::Error,
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(_, _, Type::Error) => Type::Error,
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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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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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}
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}
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Expr::Conditional(_, cond, then_exp, else_exp, _) => {
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let cond = cond.clone();
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let then_exp = then_exp.clone();
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let else_exp = else_exp.clone();
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let cond_type = self.expr_type(&cond, lines, true);
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let then_type = self.expr_type(&then_exp, lines, value_required);
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let else_type = else_exp.map(|e| self.expr_type(&e, lines, value_required));
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if !cond_type.compatible_with(&Type::Bool) {
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if !cond_type.is_error() {
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let span = self
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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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self.errors.push(SyntaxError::new_spanned(
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start,
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end,
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"the condition of an `if` expression must be a boolean",
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));
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}
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return Type::Error;
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}
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match (then_type, else_type) {
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(Type::Error, _) => Type::Error,
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(_, Some(Type::Error)) => Type::Error,
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// It's an error to have a missing else branch if the value is required
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(_, None) if value_required => {
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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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self.errors.push(SyntaxError::new_spanned(
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start,
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end,
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"this `if` expression must have both a `then` clause and an `else` clause, so it can produce a value",
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));
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Type::Error
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}
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// If the value is required then the branches must be
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// compatible, and the type of the expression is the type
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// of the `then` branch.
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(then_type, Some(else_type)) if value_required => {
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if !then_type.compatible_with(&else_type) {
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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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self.errors.push(SyntaxError::new_spanned(
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start,
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end,
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format!("the type of the `then` branch ({then_type}) must match the type of the `else` branch ({else_type})"),
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));
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Type::Error
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} else {
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then_type
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}
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}
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// The value must not be required, just mark this as unreachable.
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(_, _) => {
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assert!(!value_required);
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Type::Unreachable
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}
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}
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}
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}
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}
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}
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// BINDING POWERS. When parsing expressions we only accept expressions that
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// meet a minimum binding power. (This is like "precedence" but I just super
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// don't like that terminology.)
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const ASSIGNMENT_POWER: u8 = 0; // =
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const OR_POWER: u8 = 1; // or
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const AND_POWER: u8 = 2; // and
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const EQUALITY_POWER: u8 = 3; // == !=
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const COMPARISON_POWER: u8 = 4; // < > <= >=
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const TERM_POWER: u8 = 5; // + -
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const FACTOR_POWER: u8 = 6; // * /
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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: &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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TokenKind::EqualEqual | TokenKind::BangEqual => Some(EQUALITY_POWER),
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TokenKind::Less | TokenKind::Greater | TokenKind::GreaterEqual | TokenKind::LessEqual => {
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Some(COMPARISON_POWER)
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}
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TokenKind::Plus | TokenKind::Minus => Some(TERM_POWER),
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TokenKind::Star | TokenKind::Slash => Some(FACTOR_POWER),
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_ => None,
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}
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}
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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: Token<'a>,
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previous: Token<'a>,
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panic_mode: bool,
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}
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impl<'a> Parser<'a> {
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pub fn new(source: &'a str) -> Self {
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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: 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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parser
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}
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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(TokenKind::EOF, "expected end of expression");
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(self.tree, expr, self.tokens.lines())
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}
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fn expression(&mut self) -> ExprRef {
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self.expression_with_power(0)
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}
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fn expression_with_power(&mut self, minimum_power: u8) -> ExprRef {
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self.trace("expression with power");
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self.advance();
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let mut expr = self.prefix_expression();
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loop {
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let power = match token_power(&self.current) {
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Some(p) => p,
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None => break, // EOF, end of expression?
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};
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if power < minimum_power {
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break;
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}
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self.advance();
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expr = self.infix_expression(power, expr);
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}
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expr
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}
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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;
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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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|
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TokenKind::If => self.conditional(),
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|
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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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}
|
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|
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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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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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| TokenKind::Slash
|
|
| TokenKind::And
|
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| TokenKind::Or => self.binary(power, left),
|
|
_ => panic!("Unknown infix operator, dispatch error?"),
|
|
}
|
|
}
|
|
|
|
fn number(&mut self) -> ExprRef {
|
|
let token = &self.previous;
|
|
// What kind is it? For now let's just ... make it good.
|
|
|
|
let literal = match token.as_str().parse::<f64>() {
|
|
Ok(v) => Literal::Float64(v),
|
|
Err(e) => {
|
|
self.error(format!("invalid f64: {e}"));
|
|
return ExprRef::error();
|
|
}
|
|
};
|
|
|
|
self.tree.add_expr(Expr::Literal(literal, token.clone()))
|
|
}
|
|
|
|
fn string(&mut self) -> ExprRef {
|
|
let token = &self.previous;
|
|
|
|
let mut result = String::new();
|
|
let mut input = token.as_str().chars();
|
|
|
|
assert!(input.next().is_some()); // Delimiter
|
|
while let Some(ch) = input.next() {
|
|
match ch {
|
|
'\\' => match input.next().unwrap() {
|
|
'n' => result.push('\n'),
|
|
'r' => result.push('\r'),
|
|
't' => result.push('\t'),
|
|
ch => result.push(ch),
|
|
},
|
|
_ => result.push(ch),
|
|
}
|
|
}
|
|
result.pop(); // We pushed the other delimiter on, whoops.
|
|
|
|
let literal = Literal::String(result);
|
|
self.tree.add_expr(Expr::Literal(literal, token.clone()))
|
|
}
|
|
|
|
fn grouping(&mut self) -> ExprRef {
|
|
let result = self.expression();
|
|
self.consume(TokenKind::RightParen, "expected ')' after an expression");
|
|
result
|
|
}
|
|
|
|
fn conditional(&mut self) -> ExprRef {
|
|
let token = self.previous.clone();
|
|
let condition_expr = self.expression();
|
|
self.consume(TokenKind::LeftBrace, "expected '{' to start an 'if' block");
|
|
let then_expr = self.expression();
|
|
self.consume(TokenKind::RightBrace, "expected '}' to end an 'if' block");
|
|
let else_expr = if self.current.kind == TokenKind::Else {
|
|
self.advance();
|
|
if self.current.kind == TokenKind::If {
|
|
self.advance();
|
|
Some(self.conditional())
|
|
} else {
|
|
self.consume(
|
|
TokenKind::LeftBrace,
|
|
"expected '{' to start an 'else' block",
|
|
);
|
|
let else_expr = self.expression();
|
|
self.consume(TokenKind::RightBrace, "Expected '}' to end an 'else' block");
|
|
Some(else_expr)
|
|
}
|
|
} else {
|
|
None
|
|
};
|
|
let tail = self.previous.clone();
|
|
self.tree.add_expr(Expr::Conditional(
|
|
token,
|
|
condition_expr,
|
|
then_expr,
|
|
else_expr,
|
|
tail,
|
|
))
|
|
}
|
|
|
|
fn unary(&mut self) -> ExprRef {
|
|
let token = self.previous.clone();
|
|
let kind = token.kind;
|
|
let expr = self.expression_with_power(UNARY_POWER);
|
|
let op = match kind {
|
|
TokenKind::Minus => UnaryOp::Negate,
|
|
TokenKind::Bang => UnaryOp::Not,
|
|
_ => panic!("unsuitable unary: {:?}: no op", kind),
|
|
};
|
|
|
|
self.tree.add_expr(Expr::Unary(op, token, expr))
|
|
}
|
|
|
|
fn binary(&mut self, power: u8, left: ExprRef) -> ExprRef {
|
|
let token = self.previous.clone();
|
|
let op = match token.kind {
|
|
TokenKind::Plus => BinaryOp::Add,
|
|
TokenKind::Minus => BinaryOp::Subtract,
|
|
TokenKind::Star => BinaryOp::Multiply,
|
|
TokenKind::Slash => BinaryOp::Divide,
|
|
TokenKind::And => BinaryOp::And,
|
|
TokenKind::Or => BinaryOp::Or,
|
|
_ => panic!("unsuitable binary: {:?}: no op", self.previous),
|
|
};
|
|
let right = self.expression_with_power(power + 1);
|
|
self.tree.add_expr(Expr::Binary(op, token, left, right))
|
|
}
|
|
|
|
fn advance(&mut self) {
|
|
self.previous = self.current.clone();
|
|
self.current = self.tokens.next();
|
|
while self.current.kind == TokenKind::Error {
|
|
self.error_at_current(self.current.to_string());
|
|
self.current = self.tokens.next();
|
|
}
|
|
}
|
|
|
|
fn consume(&mut self, kind: TokenKind, error: &str) {
|
|
if self.current.kind == kind {
|
|
self.advance();
|
|
} else {
|
|
self.error_at_current(error);
|
|
}
|
|
}
|
|
|
|
fn error<T>(&mut self, message: T)
|
|
where
|
|
T: Into<String>,
|
|
{
|
|
self.error_at(self.previous.clone(), message)
|
|
}
|
|
|
|
fn error_at_current<T>(&mut self, message: T)
|
|
where
|
|
T: Into<String>,
|
|
{
|
|
self.error_at(self.current.clone(), message)
|
|
}
|
|
|
|
fn error_at<T>(&mut self, token: Token<'a>, message: T)
|
|
where
|
|
T: Into<String>,
|
|
{
|
|
if self.panic_mode {
|
|
return;
|
|
}
|
|
self.panic_mode = true;
|
|
|
|
let message: String = message.into();
|
|
let (line, column) = self.tokens.token_position(&token);
|
|
let mut final_message = "Error ".to_string();
|
|
|
|
if token.kind == TokenKind::EOF {
|
|
final_message.push_str("at end")
|
|
} else if token.kind != TokenKind::Error {
|
|
final_message.push_str("at '");
|
|
final_message.push_str(token.as_str());
|
|
final_message.push_str("'");
|
|
}
|
|
final_message.push_str(": ");
|
|
final_message.push_str(&message);
|
|
|
|
self.tree
|
|
.add_error(SyntaxError::new(line, column, final_message));
|
|
}
|
|
|
|
fn trace(&self, _msg: &str) {
|
|
// let cpos = self.tokens.token_position(&self.current);
|
|
// let ppos = self.tokens.token_position(&self.previous);
|
|
|
|
// eprintln!(
|
|
// "[{}:{}:{}] [{}:{}:{}]: {msg}",
|
|
// ppos.0,
|
|
// ppos.1,
|
|
// self.previous
|
|
// .as_ref()
|
|
// .map(|t| t.as_str())
|
|
// .unwrap_or("<eof>"),
|
|
// cpos.0,
|
|
// cpos.1,
|
|
// self.current.as_ref().map(|t| t.as_str()).unwrap_or("<eof>")
|
|
// );
|
|
}
|
|
}
|
|
|
|
#[cfg(test)]
|
|
mod tests {
|
|
use super::*;
|
|
use pretty_assertions::assert_eq;
|
|
|
|
fn test_successful_expression_parse(source: &str, expected: &str, expected_type: Type) {
|
|
let (mut tree, expr, lines) = Parser::new(source).parse();
|
|
assert_eq!(
|
|
Vec::<SyntaxError>::new(),
|
|
tree.errors,
|
|
"Expected successful parse"
|
|
);
|
|
assert_eq!(
|
|
expected,
|
|
tree.dump_expr(&expr),
|
|
"The parse structure of the expressions did not match"
|
|
);
|
|
|
|
// TODO: 'assert_eq' is probably wrong here
|
|
let expr_type = tree.expr_type(&expr, &lines, true);
|
|
assert!(
|
|
expected_type.compatible_with(&expr_type),
|
|
"The type of the expression did not match. expected: {expected_type}, actual: {expr_type}"
|
|
);
|
|
}
|
|
|
|
macro_rules! test_expr {
|
|
($name:ident, $input:expr, $expected:expr, $type:expr) => {
|
|
#[test]
|
|
fn $name() {
|
|
test_successful_expression_parse($input, $expected, $type);
|
|
}
|
|
};
|
|
}
|
|
|
|
test_expr!(number_expr, "12", "12", Type::F64);
|
|
test_expr!(add_expr, "1 + 2", "(+ 1 2)", Type::F64);
|
|
test_expr!(
|
|
prec_expr,
|
|
"1 + 2 * 3 - 7 * 7",
|
|
"(- (+ 1 (* 2 3)) (* 7 7))",
|
|
Type::F64
|
|
);
|
|
test_expr!(unary, "-((23)) * 5", "(* (- 23) 5)", Type::F64);
|
|
test_expr!(
|
|
strings,
|
|
r#" "Hello " + 'world!' "#,
|
|
r#"(+ "Hello " 'world!')"#,
|
|
Type::String
|
|
);
|
|
|
|
test_expr!(
|
|
booleans,
|
|
"true and false or false and !true",
|
|
"(or (and true false) (and false (! true)))",
|
|
Type::Bool
|
|
);
|
|
|
|
test_expr!(
|
|
if_expression,
|
|
"if true { 23 } else { 45 }",
|
|
"(if true 23 45)",
|
|
Type::F64
|
|
);
|
|
// test_expr!(
|
|
// if_with_return,
|
|
// "if true { 23 } else { return 'nothing' }",
|
|
// "",
|
|
// Type::F64
|
|
// );
|
|
|
|
// ========================================================================
|
|
// Type Error Tests
|
|
// ========================================================================
|
|
|
|
fn test_type_error_expression(source: &str, expected_errors: Vec<&str>) {
|
|
let (mut tree, expr, lines) = Parser::new(source).parse();
|
|
assert_eq!(
|
|
Vec::<SyntaxError>::new(),
|
|
tree.errors,
|
|
"Expected successful parse"
|
|
);
|
|
|
|
let expr_type = tree.expr_type(&expr, &lines, true);
|
|
assert!(expr_type.is_error());
|
|
|
|
let actual_errors = tree
|
|
.errors
|
|
.iter()
|
|
.map(|e| e.message.as_str())
|
|
.collect::<Vec<_>>();
|
|
assert_eq!(expected_errors, actual_errors);
|
|
}
|
|
|
|
macro_rules! test_type_error_expr {
|
|
($name:ident, $input:expr, $($s:expr),+) => {
|
|
#[test]
|
|
fn $name() {
|
|
let expected_errors: Vec<&str> = (vec![$($s),*]);
|
|
test_type_error_expression($input, expected_errors);
|
|
}
|
|
}
|
|
}
|
|
|
|
test_type_error_expr!(
|
|
negate_string,
|
|
"-('what?')",
|
|
"cannot apply unary operator '-' to expression of type 'string'"
|
|
);
|
|
|
|
test_type_error_expr!(
|
|
add_string_number,
|
|
"'what?' + 5",
|
|
"cannot apply binary operator '+' to expressions of type 'string' (on the left) and 'f64' (on the right)"
|
|
);
|
|
|
|
test_type_error_expr!(
|
|
add_number_string,
|
|
"5 + 'what?'",
|
|
"cannot apply binary operator '+' to expressions of type 'f64' (on the left) and 'string' (on the right)"
|
|
);
|
|
|
|
test_type_error_expr!(
|
|
errors_propagate_do_not_duplicate,
|
|
"!'hello' / 27 * -('what?') + 23",
|
|
"cannot apply unary operator '!' to expression of type 'string'",
|
|
"cannot apply unary operator '-' to expression of type 'string'"
|
|
);
|
|
|
|
test_type_error_expr!(
|
|
if_not_bool,
|
|
"if 23 { 1 } else { 2 }",
|
|
"the condition of an `if` expression must be a boolean"
|
|
);
|
|
|
|
test_type_error_expr!(
|
|
if_arm_mismatch,
|
|
"if true { 1 } else { '1' }",
|
|
"the type of the `then` branch (f64) must match the type of the `else` branch (string)"
|
|
);
|
|
|
|
test_type_error_expr!(
|
|
if_no_else,
|
|
"if true { 1 }",
|
|
"this `if` expression must have both a `then` clause and an `else` clause, so it can produce a value"
|
|
);
|
|
}
|