Abstract String processing is ubiquitous across computer science, and arguably more so in web programming — where it is also a critical part of security issues such as injection attacks. In recent years, a number of string solvers have been developed to solve combinatorial problems involving string variables and constraints. We examine the dashed string approach to string constraint solving, which represents an unknown string as a sequence of blocks of characters with bounds on their cardinalities. The solving approach relies on propagation of information about the blocks of characters that arise from reasoning about the constraints in which they occur. This approach shows promising performance on many benchmarks involving constraints like string length, equality, concatenation, and regular expression membership. In this paper, we formally review the definition, the properties and the use of dashed strings for string constraint solving, and we provide an empirical validation that confirms the effectiveness of this approach.

中文翻译：

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用于字符串约束求解的虚线字符串

摘要 字符串处理在计算机科学中无处不在，可以说在 Web 编程中更是如此——它也是注入攻击等安全问题的关键部分。近年来，已经开发了许多字符串求解器来解决涉及字符串变量和约束的组合问题。我们研究了字符串约束求解的虚线字符串方法，该方法将未知字符串表示为具有基数边界的字符块序列。求解方法依赖于关于字符块的信息的传播，这些字符块是由于对它们出现的约束进行推理而产生的。这种方法在涉及字符串长度、相等性、连接和正则表达式成员资格等约束的许多基准测试中显示出良好的性能。在本文中，