Output loops

[majastrz]

For-expressions are now supported in output values. This fixes #1615.

Additional changes:

• Simplified KV loop example.
• Fixed bug in loop emit limit detection logic that allowed unsupported loop usages in certain cases.

[majastrz]

public sealed class ForSyntaxValidatorVisitor : SyntaxVisitor

There was a bug that allowed things like:

var foo = {
 a: [for thing in things: thing]
}

While fixing I also rewrote this to simplify the implementation. (Switched to using the call stack instead of a separate stack among other things.)

---

Refers to: src/Bicep.Core/Emit/ForSyntaxValidatorVisitor.cs:12 in 7fd642d. [](commit_id = 7fd642d, deletion_comment = False)

[majastrz]

[i] [](start = 28, length = 3)

Supporting direct references to collections will make this a lot less awkward. It'll come in a different PR, though.

[codecov-io]

Codecov Report

Merging #1628 (7fd642d) into main (bf776ac) will increase coverage by 0.00%.
The diff coverage is 100.00%.

@@           Coverage Diff           @@
##             main    #1628   +/-   ##
=======================================
  Coverage   95.15%   95.15%           
=======================================
  Files         363      363           
  Lines       20085    20098   +13     
  Branches       13       13           
=======================================
+ Hits        19111    19125   +14     
+ Misses        974      973    -1     

Flag	Coverage Δ
dotnet	95.61% <100.00%> (+<0.01%)	⬆️
typescript	27.40% <ø> (ø)

Flags with carried forward coverage won't be shown. Click here to find out more.

Impacted Files	Coverage Δ
src/Bicep.Core/Diagnostics/DiagnosticBuilder.cs	100.00% <100.00%> (ø)
src/Bicep.Core/Emit/ExpressionConverter.cs	96.34% <100.00%> (+0.03%)	⬆️
src/Bicep.Core/Emit/ExpressionEmitter.cs	98.71% <100.00%> (+<0.01%)	⬆️
src/Bicep.Core/Emit/ForSyntaxValidatorVisitor.cs	100.00% <100.00%> (+1.66%)	⬆️
src/Bicep.Core/Emit/TemplateWriter.cs	98.41% <100.00%> (+0.01%)	⬆️