The first presentation about the language Oslo was by Don Box and David Langworty. It was really good to see that I don't have to know T-SQL anymore!
Why "M"
- We want creating and interacting with oslo content to be simple and natural
- Having a box-and-line design experience is an important enabler
- Having a complementary textual experience is equally important
- M is how we achieve the latter
What is "M"
- "M" is a language for defining domain models and textual domain-specific languages (DSLs)
- M domain models define schema and query over structured data
- Values, constraints, and views
- Natural projection to SQL
- M DSLS define projections from Unicode text to structured data
- Rule-based transformation
- Grammar driven text editor integration
What "M" is not
- An object-oriented language
- No polymorphism, virtual dispatch
- "ls-a" determined based on structural subtyping, not stipulation
- A data access technology
- M domain models compile down to T-SQL
- Tool chain supports course-grained loading/unloading of schemas and values - not an OLTP solution
- A replacement for T-SQL
- Far less expansive feature set
- Tool chain supports linking/invoking T-SQ
So Oslo is an abstraction on T-SQL and although it is not finished yet, it is already fun to play with. A little example:
First to start with a normal table:
Module Contacts
{
People
{
{ Name="persona", Age=29 },
{ Name="personb", Age=28 }
}
}
This actually means that we defined a schema and filled the table with two rows.
Next up constraints:
Module Contacts
{
-- Constraints:
People :
{
Name : Text where value.Count <= 30;
Age : Integer32;
}*;
People
{
{ Name="persona", Age=29 },
{ Name="personb", Age=28 }
}
}
What you see here is a constraint on the People table, which in T-SQL would look like this:
Create table [Contacts].[People]
{
[Age] int not null,
[Name] nvarchar(28) not null
}
It's still another language to learn, but I like this more then T-SQL.
