Prettier parse error messages, floats

Quaqqer · Jun 23, 2024 · 2f51314 · 2f51314
1 parent 25a35a0
commit 2f51314
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Showing 5 changed files with 41 additions and 7 deletions.
diff --git a/src/ast.rs b/src/ast.rs
@@ -28,7 +28,8 @@ pub struct TrailBlock(pub Vec<Spanned<Stmt>>, pub Option<Box<Spanned<Expr>>>);
 
 #[derive(Debug)]
 pub enum Expr {
-    Int(i32),
+    Int(i64),
+    Float(f64),
     Bool(bool),
     Var(Spanned<String>),
     Block(TrailBlock),

diff --git a/src/eval.rs b/src/eval.rs
@@ -2,9 +2,10 @@ use std::collections::HashMap;
 
 use crate::{ast, span::Span};
 
-#[derive(Debug, Clone, PartialEq, Eq)]
+#[derive(Debug, Clone, PartialEq)]
 pub enum Value {
-    Int(i32),
+    Int(i64),
+    Float(f64),
     Bool(bool),
     Nil,
 }
@@ -13,6 +14,7 @@ impl Value {
     pub fn ty(&self) -> ValueType {
         match self {
             Value::Int(_) => ValueType::Int,
+            Value::Float(_) => ValueType::Float,
             Value::Bool(_) => ValueType::Bool,
             Value::Nil => ValueType::Nil,
         }
@@ -21,6 +23,7 @@ impl Value {
     pub fn repr(&self) -> String {
         match self {
             Value::Int(v) => format!("{}", v),
+            Value::Float(f) => format!("{}", f),
             Value::Bool(v) => match v {
                 true => "true".to_string(),
                 false => "false".to_string(),
@@ -32,6 +35,7 @@ impl Value {
 
 pub enum ValueType {
     Int,
+    Float,
     Bool,
     Nil,
 }
@@ -40,6 +44,7 @@ impl std::fmt::Display for ValueType {
     fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         match self {
             ValueType::Int => write!(f, "int"),
+            ValueType::Float => write!(f, "float"),
             ValueType::Bool => write!(f, "bool"),
             ValueType::Nil => write!(f, "nil"),
         }
@@ -201,6 +206,7 @@ impl Evaluator {
 
         Ok(match expr {
             ast::Expr::Int(i) => Value::Int(*i),
+            ast::Expr::Float(f) => Value::Float(*f),
             ast::Expr::Bool(b) => Value::Bool(*b),
             ast::Expr::Var(ident) => match self.lookup(&ident.v) {
                 Some(val) => val.clone(),

diff --git a/src/parser.lalrpop b/src/parser.lalrpop
@@ -85,6 +85,9 @@ Term: ast::Expr = {
 
     <int_s:r"[0-9]+">
         => ast::Expr::Int(int_s.parse().unwrap()),
+
+    <float_s:r"[0-9]+\.[0-9]*|[0-9]*\.[0-9]+">
+        => ast::Expr::Float(float_s.parse().unwrap()),
 }
 
 Spanned<T>: Spanned<T>

diff --git a/src/saft.rs b/src/saft.rs
@@ -4,6 +4,7 @@ use crate::{
     parser::SpannedStmtOrExprParser,
     span::{Span, Spanned},
 };
+use std::fmt::Write;
 
 pub struct SaftError {
     pub span: Span,
@@ -49,16 +50,16 @@ pub fn eval_stmt_or_expr(evaluator: &mut Evaluator, src: &str) -> Res<()> {
             } => bail!(
                 s,
                 "Parse error",
-                "Got unexpected EOF, expected {:?}",
-                expected
+                "Got unexpected EOF, expected {}",
+                expected_list(expected)
             ),
 
             lalrpop_util::ParseError::UnrecognizedToken { token, expected } => bail!(
                 s,
                 "Parse error",
-                "Got unexpected token '{}', expected {:?}",
+                "Got unexpected token '{}', expected {}",
                 token.1,
-                expected
+                expected_list(expected)
             ),
             lalrpop_util::ParseError::ExtraToken { token } => {
                 bail!(s, "Parse error", "Unexpected extra token '{}'", token.1)
@@ -92,3 +93,25 @@ fn parse_error_span<T, E>(err: &lalrpop_util::ParseError<usize, T, E>) -> Span {
         lalrpop_util::ParseError::User { .. } => unreachable!(),
     }
 }
+
+fn expected_list(options: Vec<String>) -> String {
+    match &options[..] {
+        [] => unreachable!("Should be at least one expected item"),
+        [choice] => choice.to_string(),
+        [one, two] => format!("{} or {}", one, two),
+        many => {
+            let mut buf = String::new();
+            let last = many.len() - 1;
+            for (i, alt) in many.iter().enumerate() {
+                if i == 0 {
+                    write!(buf, "{}", alt).unwrap();
+                } else if i == last {
+                    write!(buf, ", or {}", alt).unwrap();
+                } else {
+                    write!(buf, ", {}", alt).unwrap();
+                }
+            }
+            buf
+        }
+    }
+}
diff --git a/src/sexpr.rs b/src/sexpr.rs
@@ -87,6 +87,7 @@ impl From<&ast::Expr> for SExpr {
     fn from(value: &ast::Expr) -> Self {
         match value {
             ast::Expr::Int(i) => format!("{}", i).into(),
+            ast::Expr::Float(f) => format!("{}", f).into(),
             ast::Expr::Bool(b) => format!("{}", b).into(),
             ast::Expr::Var(v) => v.v.clone().into(),
             ast::Expr::Call { expr, args } => list!(