Performance Premature optimization Avoiding memory allocations Don’t create intermediate strings when writing to an IO Use string interpolation instead of concatenation Avoid IO...

Connection DB module DB#connect DB#open When to use one or the other? Connection Configuration Advanced Connection Setup Connection A connection is one of the key parts wh...

Crystal Platform Support Tier 1 Tier 2 Tier 3 Crystal Platform Support The Crystal compiler runs on, and compiles to, a great number of platforms, though not all platforms ar...

Constants Pseudo Constants Dynamic assignment Constants Constants can be declared at the top level or inside other types. They must start with a capital letter: PI = 3.14 ...

Crystal Platform Support Tier 1 Tier 2 Tier 3 Crystal Platform Support The Crystal compiler runs on, and compiles to, a great number of platforms, though not all platforms ar...

Crystal Platform Support Tier 1 Tier 2 Tier 3 Crystal Platform Support The Crystal compiler runs on, and compiles to, a great number of platforms, though not all platforms ar...

Performance Premature optimization Avoiding memory allocations Don’t create intermediate strings when writing to an IO Use string interpolation instead of concatenation Avoid IO...

Performance Premature optimization Avoiding memory allocations Don’t create intermediate strings when writing to an IO Use string interpolation instead of concatenation Avoid IO...

Testing Crystal Code Anatomy of a spec file Expectations Equivalence, Identity and Type Truthiness Comparisons Other matchers Expecting errors Focusing on a group of specs ...

Performance Premature optimization Avoiding memory allocations Don’t create intermediate strings when writing to an IO Use string interpolation instead of concatenation Avoid IO...