domenic at domenicdenicola.com (2013-08-01T01:41:50.958Z)
Looking at the ES6 spec draft, I've drawn the following conclusions
about Completion Records. Can someone confirm?
If [[type]] is 'normal', 'return', or 'throw',
[[target]] must be 'empty' (can't be an identifier).
Moreover, if [[type]] is 'return' or 'throw',
[[value]] must be a language value (can't be 'empty').
If [[type]] is 'continue' or 'break', no restrictions:
[[target]] can be 'empty' or an Identifier,
[[value]] can be 'empty' or a language value,
and all combinations can occur.
...
The only ones whose existence is less than obvious are those where:
[[type]] is 'continue' or 'break', and [[value]] is a language value
I can see in the pseudo-code the points where they could be created
(in 12.1.1.2, 12.11.1.2, and 14.1.2), but I haven't tried to reverse-
engineer a program that would cause it to happen. Could someone explain
why it's useful to allow such Completion Records, and post a snippet of
code that would cause one to be created?
Looking at the ES6 spec draft, I've drawn the following conclusions about Completion Records. Can someone confirm? If [[type]] is 'normal', 'return', or 'throw', [[target]] must be 'empty' (can't be an identifier). Moreover, if [[type]] is 'return' or 'throw', [[value]] must be a language value (can't be 'empty'). If [[type]] is 'continue' or 'break', no restrictions: [[target]] can be 'empty' or an Identifier, [[value]] can be 'empty' or a language value, and all combinations can occur. ... The only ones whose existence is less than obvious are those where: [[type]] is 'continue' or 'break', and [[value]] is a language value I can see in the pseudo-code the points where they could be created (in 12.1.1.2, 12.11.1.2, and 14.1.2), but I haven't tried to reverse- engineer a program that would cause it to happen. Could someone explain why it's useful to allow such Completion Records, and post a snippet of code that would cause one to be created? Thanks, -Michael