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Explain pushing/popping types on region labelling stack

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Ayaz Hafiz 2022-07-13 09:31:29 -04:00
parent 460b822caa
commit 759134885b
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1 changed files with 10 additions and 2 deletions
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12
crates/compiler/types/src/types.rs
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@ -2769,8 +2769,16 @@ fn instantiate_lambda_sets_as_unspecialized(
able_var: Variable,
ability_member: Symbol,
) {
// We want to pop and assign lambda sets pre-order for readability, so types
// should be pushed onto the stack in post-order
// REGION-ORDERING: done in pre-order via the following pseudo code:
//
// Type_function = \region ->
// let left_type, new_region = Type (region + 1)
// let right_type, new_region = Type (new_region)
// let func_type = left_type -[Lambda region]-> right_type
// (func_type, new_region)
//
// Since we want to pop types in pre-order, they should be pushed onto the
// stack in post-order
let mut stack = vec![typ];
let mut region = 0;