#33: New blog post

docs/_posts/2023-11-11-jactl-1.3.0.md

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+---
+layout:     post
+title:      "Announcing Jactl 1.3.0"
+date:       2023-11-10 15:11:44 +1100
+categories: blog
+author:     "James Crawford"
+---
+
+Jactl 1.3.0 fixes a few minor bugs and adds some language features.
+The main new feature is to support the ability to checkpoint script instance execution state and have it
+restored and resumed on another instance after a failure.
+
+## Enhancements
+
+### Native support for JSON encoding and decoding ([#16](https://github.com/jaccomoc/jactl/issues/16))
+
+Jactl can convert objects into JSON using the `toJson()` method:
+```groovy
+def x = [a:1,b:[x:3,y:4],c:['a','b','c']]
+x.toJson()         // {"a":1,"b":{"x":3,"y":4},"c":["a","b","c"]}
+```
+
+The corresponding `fromJson()` method on strings will convert back from JSON to simple objects:
+```groovy
+def json = '{"a":1,"b":{"x":3,"y":4},"c":["a","b","c"]}'
+json.fromJson()   // [a:1, b:[x:3, y:4], c:['a', 'b', 'c']] 
+```
+
+For user defined classes, Jactl will generate a `toJson()` method and a class static method `fromJson()`:
+```groovy
+class X { int i; String s }
+X x = new X(i:3, s:'abc')
+x.toJson()      // {"i":3,"s":"abc"}
+x = X.fromJson('{"i":3,"s":"abc"}')
+```
+
+### Native array support ([#17](https://github.com/jaccomoc/jactl/issues/17))
+
+Jactl now supports array types, including multidimensional arrays.
+Previously, lists were used in place of arrays but for performance sensitive code, arrays can now be used instead.
+```groovy
+int[] someInts = [1,2,3,4]
+```
+
+The usual list methods (`each()`, `filter()`, `map()`, etc.) also apply to arrays:
+```groovy
+String[] strArr = ['abc', 'xyz', 'x']
+strArr.map{ it.size() }.sum()     // result is 7
+```
+
+### List-specific versions of min(), max(), sum(), and avg() ([#19](https://github.com/jaccomoc/jactl/issues/19))
+
+This enhancement was just an optimisation to improve the performance of these methods when applied to simple lists.
+
+### Support checkpointing of execution state ([#20](https://github.com/jaccomoc/jactl/issues/20))
+
+This enhancement leveraged the existing ability suspends script execution and resume later when scripts perform
+blocking operations.
+Scripts can now perform a `checkpoint()` call whenever they want to checkpoint their current state.
+The application in which Jactl is embedded can then persist or repicate this state so that if a failure occurs the
+state can be restored and the script can continue running from where it left off.
+
+See the [Jactl Integration Guide](/integration-guide) for information on how to integrate this feature with your application.
+
+The [Jactl Language Guide](/language-guide#checkpointing) for information about the `checkpoint()` function.
+
+There is also a blog post that discusses a [Proof of Concept]({{ site.baseurl }}{% link _posts/2023-11-10-checkpoint-poc.md %}) project where checkpoint
+persistence and replication was implemented, along with tests showing the restoration and resumption of scripts that
+were running when failures occurred.
+
+### Substring and subList functions should support 0 as end index when start index is negative ([#22](https://github.com/jaccomoc/jactl/issues/22))
+
+This enhancement allows you to use negative indexes with the `substring()` and `subList()` functions that are interpreted
+as being relative to the end of the string/list:
+```groovy
+'abcde'.substring(-2)      // result is 'de'
+'abcde'.substring(-3,-1)   // result is 'cd'
+
+[1,2,3,4].subList(-2,0)    // result is [3, 4]
+```
+
+### New '??' operator for existence test ([#23](https://github.com/jaccomoc/jactl/issues/23))
+
+A new `??` operator allows you to test for existence:
+```groovy
+def x
+?? x.a.b.c         // returns false rather than giving an error
+```
+
+### Add byte and byte[] types to support binary data ([#24](https://github.com/jaccomoc/jactl/issues/24))
+
+Jactl now supports `byte` and `byte[]` data types to better support binary data.
+Jactl also supports appropriate conversions:
+```groovy
+'abc' as byte[]    // result is [97, 98, 99]
+```
+
+## Bug fixes
+
+* [#18:](https://github.com/jaccomoc/jactl/issues/18) Non-numeric operand error using 'new' immediately after newline
+* [#21:](https://github.com/jaccomoc/jactl/issues/21) Regex capture variable usage can sometimes lead to "No match found" error
+* [#26:](https://github.com/jaccomoc/jactl/issues/26) className() method on instances cannot be passed by value
+* [#27:](https://github.com/jaccomoc/jactl/issues/27) Base class field initialisers not being invoked when using named arg constructor
+* [#30:](https://github.com/jaccomoc/jactl/issues/30) JSON decoding is not initialising missing fields in base classes
+* [#31:](https://github.com/jaccomoc/jactl/issues/31) Inner class of base class should be visible to child class
+* [#32:](https://github.com/jaccomoc/jactl/issues/32) Null for string in regex match should return false