Advanced practice · word problems and test suites
Practical CEL course
Turn precise requirements into CEL expressions. Each challenge gives you a scenario, fixed test data, expected results, a hint, and an explained solution.
From requirements to rules
Split a word problem into small conditions and combine them into one testable expression.
Safe nested data
Distinguish missing members, null, and invalid content before an expression uses a value.
Decisions over collections
Combine universal, existential, filtering, and transformation macros in one rule.
Validation and boundaries
Design rules with explicit outcomes for optional data, zero values, and boundary cases.
Time-based rules
Compare instants, durations, and optional interval ends without comparing unparsed text.
Capstone scenarios
Independently combine safe data access, collections, time, and multi-level decisions.
Need the language foundation first? Open the general CEL course.