throw syntax error after parsing infinite floats (#2998)

src/parser/parser.rs

@@ -976,11 +976,17 @@ impl<'a, R: CharRead> Parser<'a, R> {
             Token::Literal(Literal::Rational(n)) => {
                 self.negate_number(n, negate_rat_rc, |r, _| Literal::Rational(r))
             }
-            Token::Literal(Literal::Float(n)) => self.negate_number(
+            Token::Literal(Literal::Float(n)) if F64Ptr::from_offset(n).is_infinite() => {
+		return Err(ParserError::InfiniteFloat(
+		    self.lexer.line_num,
+		    self.lexer.col_num,
+		));
+	    }
+	    Token::Literal(Literal::Float(n)) => self.negate_number(
                 **n.as_ptr(),
                 |n, _| -n,
                 |n, arena| Literal::from(float_alloc!(n, arena)),
-            ),
+	    ),
             Token::Literal(c) => {
                 let atomized = atomize_constant(&self.lexer.machine_st.atom_tbl, c);