Fails to parse the SPI example

[jepler]

The SPI example has this code:

    out pins, 1 side 0 [1] ; Stall here on empty (sideset proceeds even if
    in pins, 1  side 1 [1] ; instruction stalls, so we stall with SCK low)

It fails to parse, because it searches for "pins," in IN_SOURCES and OUT_DESTINATIONS (note the trailing ,).

I put a hacky fix in and it did assemble, though there are remaining limitations in the core before it can be used:

diff --git a/adafruit_pioasm.py b/adafruit_pioasm.py
index 96891f9..c847298 100644
--- a/adafruit_pioasm.py
+++ b/adafruit_pioasm.py
@@ -106,7 +106,8 @@ def assemble(text_program):
         elif instruction[0] == "in":
             #                instr delay src count
             assembled.append(0b010_00000_000_00000)
-            assembled[-1] |= IN_SOURCES.index(instruction[1]) << 5
+            source = instruction[1].rstrip(",")
+            assembled[-1] |= IN_SOURCES.index(source) << 5
             count = int(instruction[-1])
             if not 1 <= count <= 32:
                 raise RuntimeError("Count out of range")
@@ -114,7 +115,8 @@ def assemble(text_program):
         elif instruction[0] == "out":
             #                instr delay dst count
             assembled.append(0b011_00000_000_00000)
-            assembled[-1] |= OUT_DESTINATIONS.index(instruction[1]) << 5
+            destination = instruction[1].rstrip(",")
+            assembled[-1] |= OUT_DESTINATIONS.index(destination) << 5
             count = int(instruction[-1])
             if not 1 <= count <= 32:
                 raise RuntimeError("Count out of range")

I'm totally sure this is not the right fix so I'm entering this as an issue instead of as a PR.

[dglaude]

If someone in Adafruit Circuit Python community know how to setup a way to automate testing, I believe this library could benefit from it. It is pure software, no hardware involved. You can have various piece of assembly code and you know exactly what binary result you expect.

I did manually run this kind of test in this PR comment: #5 (comment)

This would permit to detect regression and make sure that code that "assemble" in the past still work in the future.

[tannewt]

I was hoping to make decision to omit support for commas. I don't like entirely optional portions of a language. There should only be one canonical form. Perhaps we should simply add a friendly exception for it.