I dont quite understand why my grammar is working

[Korporal]

I have a grammar that I recently modified to remove semicolons. There's no need for statement separators now when multiple statements share a line nor is there any need for a continuation token when a statement spans multiple lines.

However it is also doing something I want it to do but I don't understand why!

Consider:

first

      dcl data fixed bin(15) based(p) defined = 100

second

      dcl data fixed bin(15) based(p) defined

third

      dcl data fixed bin(15) based(p) = 100;

fourth

      dcl data fixed bin(15) based(p) 

Both the based and the defined are optional attributes on a declaration. In first it parses it as a declaration up to and including the based(p) and sees the rest as an assignment to a variable named 'defined'.

In the second it sees it as a declaration with both a based and defined attribute.

In the third it sees it as a declaration up to an including the bin(15) and sees the rest as an assignment to an array member 'based(p)`.

In the fourth it sees it as a declaration with a based attribute.

Before I tested these cased I expected the first and third to fail, being seen as declarations followed by an illegal = 100.

By design this grammar allows identifiers to be the same as keywords, that is keywords are not reserved, FYI.

This seems odd to me, like if I'd asked how to get a grammar to do these things I'd have been told "You can't, that's impossible"...

Is this LL(*) in action? is the parser looking ahead to find a match no matter how far it must look?