Simple Summary
Change mapping syntax from var: map(key_type, val_type) to var: HashMap[key_type, val_type]
Motivation
Mapping syntax was changed in #564. While it made for easier understanding of how mappings work in practice, it precludes the use of the Python standard function map(fn, iter) -> iter for anything in Vyper to use. We propose adopting a MyPy-like type structure, which will make working with mappings (and nested mappings) more apparent, and open up the keyword map to future use as an iterator operation.
Specification
The syntax for mappings would change from var: map(key_type, val_type) to var: HashMap[key_type, val_type]. This looks like the following in practice:
struct MyStruct: ...
my_mapping: HashMap[uint256, MyStruct]
my_nested_map: HashMap[bytes32, HashMap[uint256, address]]
@public
def foo():
self.my_mapping[1] = MyStruct({...}) # Same access as before
self.my_nested_map[blk.hash][1] = msg.sender # Same access as beforeBackwards Compatibility
This VIP will break the current syntax for defining mappings
Dependencies
Depends on #564
References
No references
Copyright
Copyright and related rights waived via CC0
Simple Summary
Change mapping syntax from
var: map(key_type, val_type)tovar: HashMap[key_type, val_type]Motivation
Mapping syntax was changed in #564. While it made for easier understanding of how mappings work in practice, it precludes the use of the Python standard function
map(fn, iter) -> iterfor anything in Vyper to use. We propose adopting a MyPy-like type structure, which will make working with mappings (and nested mappings) more apparent, and open up the keywordmapto future use as an iterator operation.Specification
The syntax for mappings would change from
var: map(key_type, val_type)tovar: HashMap[key_type, val_type]. This looks like the following in practice:Backwards Compatibility
This VIP will break the current syntax for defining mappings
Dependencies
Depends on #564
References
No references
Copyright
Copyright and related rights waived via CC0