Unsure is a stack based esolang, based off of brain-flak, and is made up entirely of words people tend to say while thinking of an answer.

Unsure has two stacks, one of which is the active stack.

It is made up of words, separated by spaces. Invalid words will trigger a warning containing only the invalid word. It is impossible for an unsure program to error. All non-alphabetic characters are converted to spaces, and all leading or trailing (or duplicate) spaces are removed. Unsure is case insensitive.

Uses regular expressions, so um+ means um with any number of additional ms.

• um+: Push the number of ms to the active stack (um = 1, ummm = 3, etc.)
• er+: Pop an item from the active stack once per r, and push their sum
• heh: Pop the active stack, and push the result (if any) to the non-active stack
• oops: Discard the top of the active stack
• uh+: Duplicate the top of the active stack once per h
• well: Push the current height of the active stack
• yeah: Negate the number on top of the stack
• hm+: Take input once per m, and push to the stack in reverse (so first input on top), -1 if no more input
• okay: Pop the stack and output the result
• then: Swap the active stack
• but: If the top of the active stack is 0 (or empty), will skip ahead to the next no (skipping any which are preceded by another but), or terminate if there is no valid no
• wait: If the active stack is not empty and the top is not 0, jumps to the last but
• no: Does nothing on its own

Add two inputs:

ehh err okay

Infinite loop:

um but wait

Add all inputs:

but no hm um err wait oops but um yeah err heh wait then well but oops heh then err then well wait then okay

The interpreter is a JS function, which takes code as a string as the first argument, and input as the second. If the third argument is set to true, the input should be a string. Otherwise, it should be an array of numbers.