Prescanner adds closing quotes when

[mmatera]

Description

When an input includes characters using the ASCII code escape form, an extra quote is added at the end of the input.

How to reproduce

In the REPL, type

a="\.4Auan

Output Given

Juan

Expected behavior

The expression should result in an incomplete expression.

Syntax::sntxi: Incomplete expression; more input is needed (line 1 of "<stdin>").

The problem comes if we write the complete expression

a="\.4Auan"

because then, the final quote is interpreted as a new open string, which is not closed.

Your Environment

OS: Ubuntu Mate 22.04

Mathics 7.0.1dev0
on CPython 3.8.12 (heads/pyston_main:759470647d, Apr 1 2022, 15:36:47)
using SymPy 1.13.3, mpmath 1.3.0, numpy 1.21.4, cython 0.29.25