11.1. Miscellaneous contract annotations

The CONTRACTS module provides compile-time type constraints for generic function arguments. Annotations like [expect_any_array], [expect_any_enum], [expect_any_numeric], and [expect_any_struct] restrict which types can instantiate a generic parameter, producing clear error messages on mismatch.

See tutorial_contracts for a hands-on tutorial.

All functions and symbols are in “contracts” module, use require to get access to it.

require daslib/contracts

Example:

require daslib/contracts

    [!expect_dim(a)]
    def process(a) {
        return "scalar"
    }

    [expect_dim(a)]
    def process(a) {
        return "array"
    }

    [export]
    def main() {
        var arr : int[3]
        print("{process(42)}\n")
        print("{process(arr)}\n")
    }
    // output:
    // scalar
    // array

11.1.1. Function annotations

expect_any_array

[expect_any_array(argname)] contract, which only accepts array<T>, T[], or das`vector<T>

expect_any_enum

[expect_any_enum(argname)] contract, which only accepts enumerations

expect_any_bitfield

[expect_any_bitfield(argname)] contract, which only accepts bitfields

expect_any_vector_type

[expect_any_vector_type(argname)] contract, which only accepts vector types, i.e. int2, float3, range, etc

expect_any_struct

[expect_any_struct(argname)] contract, which only accepts structs (but not classes)

expect_any_numeric

[expect_any_numeric(argname)] contract, which only accepts numeric types (int, float, etc)

expect_any_workhorse

[expect_any_workhorse(argname)] contract, which only accepts workhorse types (int, float, etc) Workhorse types are: bool,int*,uint*,float*,double,range and urange, range64 and urange64, string,enumeration,and non-smart pointers

expect_any_workhorse_raw

[expect_any_workhorse_raw(argname)] contract, which only accepts workhorse types which are raw (not pointer or bool)

expect_any_tuple

[expect_any_tuple(argname)] contract, which only accepts tuples

expect_any_variant

[expect_any_variant(argname)] contract, which only accepts variants

expect_any_function

[expect_any_function(argname)] contract, which only accepts functions

expect_any_lambda

[expect_any_lambda(argname)] contract, which only accepts lambdas

expect_ref

[expect_ref(argname)] contract, which only accepts references

expect_pointer

[expect_pointer(argname)] contract, which only accepts pointers

expect_class

[expect_class(argname)] contract, which only accepts class instances

expect_value_handle

[expect_value_handle(argname)] contract, which only accepts value handles

11.1.2. Type queries

isYetAnotherVectorTemplate (td: TypeDeclPtr) : bool

isYetAnotherVectorTemplate(td: TypeDeclPtr): bool

returns true if the given type declaration is a das::vector template bound on C++ side

Arguments:

td : TypeDeclPtr