Huỳnh Trần Khanh (Jun 15 2021 at 08:16): Huỳnh Trần Khanh (Jun 15 2021 at 08:16):it seems that the instructions inside the block can't pop anything off the stack (aside from the items that they previously pushed) right? then why is the block type still t1* -> t2*? that implies that there is a mechanism for a block to pop items from outside the stack right? if that is true, how could I express that in WAT?
Huỳnh Trần Khanh (Jun 15 2021 at 08:16):apologies in advance, I'm new here.
Huỳnh Trần Khanh (Jun 15 2021 at 08:16):and new to webassembly in general
Huỳnh Trần Khanh (Jun 15 2021 at 08:20):oops this chat room is dead, maybe I should look for an answer on my own, sorry
Huỳnh Trần Khanh (Jun 15 2021 at 11:02):oops I mean outside the block not outside the stack, message editing is disabled for some reason
fitzgen (he/him) (Jun 15 2021 at 15:16):the block can pop any values in the t1* or that it pushes itself, but it can't pop any off from before the t1*
Huỳnh Trần Khanh (Jun 16 2021 at 01:43):this is somewhat... unclear. this implies that t1* can be nonempty, but can you post an example where t1* is nonempty? because I don't think a block can pop anything from outside the block
Huỳnh Trần Khanh (Jun 16 2021 at 01:55):also... I can understand the reduction rules but the typing rules are really confusing to me. do you have any resources to help me understand WASM typing better? by typing I mean the validation aspect of the spec
Huỳnh Trần Khanh (Jun 16 2021 at 09:16):ah answered my own question. a block can take parameters. wow.
Huỳnh Trần Khanh (Jun 16 2021 at 09:16):https://github.com/WebAssembly/spec/blob/master/test/core/block.wast#L277
bjorn3 (Jun 16 2021 at 14:07):I think this was introduced by the multi-value wasm proposal: https://github.com/WebAssembly/spec/commit/484180ba3d9d7638ba1cb400b699ffede796927c#diff-cfc42e9323c5feaffe9643627c8a9853faa19bf583ceb07e30580e0896055d20R169
Last updated: Dec 23 2024 at 12:05 UTC