/blockstate command

This command would let you change or test for the state of a block. This would be very, very helpful in many cases. I imagine the syntax would probably be something like this:

/blockstate <check|set> <x> <y> <z> <state>

Basically, you would specify whether to SET the blockstate to match your last argument or CHECK whether the blockstate matches (ie. "Block matches block state", "Block does not match block state").

Here's some example uses:
/blockstate set ~ ~-1 ~ {color=brown}
/blockstate check ~ ~ ~ {power=15,north=side}
/blockstate check 0 50 -32 {half=top}

What are the conditions for command success?

CHECK

• Succeeds whenever the block checked possesses all the states specified with the given values. Ignores unspecified states.

• Fails when the block does not possess a given state. (example: /blockstate check ~ ~ ~ {color=green} on dirt)

SET

• Succeeds whenever all states specified are valid states for that block and all values specified are valid values for that state.

• Succeeds even if the block already possesses every state. (example: /blockstate set ~ ~ ~ {level=3} on a full cauldron)

• Fails when the block does not possess a given state. (example: /blockstate set ~ ~ ~ {variant=podzol} on wooden planks)

• Fails when a value does not exist for a state. (example: /blockstate set ~ ~ ~ {color=asparagus} on wool)

• A failed command will NEVER update the block, even if some states are valid. (example: /blockstate set ~ ~ ~ {power=7,axis=z} on redstone dust)

Block states are completely inaccessible via commands at the moment. In the future, stuff like /testforblock and /fill will probably use block states instead of damage values. Both now and if or when this does happen, this type of command would still be very useful and strengthen the relationship between block states and commands.

Thanks for reading! <3