Renamed type 'channels' to 'channel'

[aaniculaesei]

Writing enum channel {c, g1, g2,vmm1,vmm2, vmm3} creates a new type called channel which is an enum. However, we already have a predefined type called channel. This causes a name collision.

There are two alternatives, which can help us to avoid the name collision:

1. Ditch the predefined type channel and define channel as an enumeration type as in enum channel {c, g1, g2,vmm1,vmm2, vmm3}
2. Keep the predefined type channel and declare several variables of type channel, which will be used throughout an ReCiPe model to allow the agents to communicate with each other. This is done like this: channel c, g1, g2, vmm1, vmm2, vmm3

Since channels are important elements in an ReCiPe model, it makes sense to have a predefined type called channel. Therefore, I chose to implement the second alternative in the grammar.

[lou1306]

Thank you, Adina. I fixed some minor issues with the PR.

• Somehow the grammar on this branch reverted to /\, \/ instead of forall, exists
• The examples in the examples/error directory were still using the old syntax

By the way, some of those examples were also using other forms of syntax that we have since changed. We should strive to always keep them up-to-date, possibly by creating an automated test suite. I'll file a new issue about this.

[lou1306]

By the way, those are not variables.

c, g1, g2, vmm1, vmm2, vmm3 are literals, not variables. The predefined type channel is still an enumeration, in the sense that actual variables of type channel may only assume one of these values.

Therefore I am a bit skeptical of the new syntax but if you have discussed it in the last meeting I can roll with it.