[Oberon] Negative integer literals in Oberon

[Guy T.]

I’m following this thread with great interest. 

As I’m building a compiler for the ESP32 IOT chip, I’m facing issues as I’m transforming the compiler to allow relatively easy integration with C functions present in the ESP-IDF framework (This is *the* framework needed to access some hidden part of the chip). For that, I’ve defined new forms for arrays, records, procedures and pointers to be compatible with the C language syntax and semantic. I also need to add 16bits unsigned and 64bits signed integers. I may have to add unsigned integer depending on the needs. I already added bit-wise AND, OR and XOR standard functions that I may get rid of depending on the suitability of SETs to get good code readability. I miss a lot enumeration as the C enum is in used everywhere in the ESP-IDF framework (but I’m not for now implementing it in Oberon). I’m also considering variable number of parameter for C procedure calls… 

I try to find ways to get the interaction with the ESP-IDF framework as easy as possible for the Oberon programmer (in occurence, me…) without loosing the sense of the language. 

What I wanted to show is the context of added functionalities required to get Oberon inter-operate with an existing framework. The most important aspect for me is the readability for the developer (and long term support readability) without loosing too much of the simplicity of the language.

Guy