Testing, Verification, and Analysis of Software
String Variables and String Constraints
Constraints on strings of unknown length occur in a wide variety of real-world problems in software/hardware testing, verification, and analysis: examples are test case generation, program analysis, model checking, and web security.
We proposed [SFP13, SFP15] the addition of bounded-length string decision variables and string constraints (such as CONCAT, REVERSE, SUBSTRING, etc) to constraint-based modelling languages and CP solvers, reminding also of a simple default way [HFP13b] of implementing them via fixed-length arrays. Experiments show that CP solvers belong to the state of the art for constraint solving over fixed-length and bounded-length string variables.
Also see Pierre Flener's invited lecture on string variables in verification at the Master Class on CP and Verification at CPAIOR 2015.