Delimiting Mata code with mata: ... end vs. mata { ... }

[Bert Lloyd]

Dear Matalisters,

When writing Mata code in a do-file, are there important differences between the following two ways of delimiting the Mata content?

Method 1: mata: ... end

mata :
  a
  b
end

Method 2: mata { ... }

mata {
  a
  b
}

Method 2 can be included in loops and Stata programs, are there any downsides?

Thanks,
BL

[Bert Lloyd]

In case others come across this in the future, I have been using Method 2 extensively (intensively? both?) for the last 6 months in loops and ado-files and have not noticed any ill effects.

[Bert Lloyd]

I have found an instance in do-files in which mata { ... } and mata : ... end behave differently: mata { ... } seems not to like mata describe statements. An illustrative example, assuming X is an object currently defined in Mata:

mata {
  mata describe X
}

returns an error, while

mata :
  mata describe X
end

performs as expected.