'break' and 'continue' support for 'scan' and 'volume'

docs/scarpet/api/BlockIterations.md

@@ -8,11 +8,19 @@ Evaluates expression over area of blocks defined by its center (`cx, cy, cz`), e
 by `dx, dy, dz` blocks, or optionally in negative with `d` coords, and `p` coords in positive values. `expr` 
 receives `_x, _y, _z` as coords of current analyzed block and `_`, which represents the block itself.
 
+Returns number of successful evaluations of `expr` (with `true` boolean result) unless called in void context, 
+which would cause the expression not be evaluated for their boolean value.
+
+`scan` also handles `continue` and `break` statements, using `continue`'s return value to use in place of expression
+return value. `break` return value has no effect.
+
 ### `volume(x1, y1, z1, x2, y2, z2, expr)`
 
 Evaluates expression for each block in the area, the same as the `scan`function, but using two opposite corners of 
 the rectangular cuboid. Any corners can be specified, its like you would do with `/fill` command.
 
+For return value and handling `break` and `continue` statements, see `scan` function above.
+
 ### `neighbours(x, y, z), neighbours(block), neighbours(l(x,y,z))`
 
 Returns the list of 6 neighbouring blocks to the argument. Commonly used with other loop functions like `for`.

docs/scarpet/language/LoopsAndHigherOrderFunctions.md

@@ -10,16 +10,17 @@ and maps, where the iterator returns all the map keys
 ### `break(), break(expr), continue(), continue(expr)`
 
 These allow to control execution of a loop either skipping current iteration code, using `continue`, or finishing the 
-current loop, using `break`. `break` and `continue` can only be used inside `for, while, loop, map, filter and reduce` 
+current loop, using `break`. `break` and `continue` can only be used inside `for`, `c_for`, `while`, `loop`, `map`,
+`filter`, `reduce` as well as Minecraft API block loops, `scan` and `volume` 
 functions, while `break` can be used in `first` as well. Outside of the internal expressions of these functions, 
-calling `break` or `continue` will cause an error. In case of the nexted loops, and more complex setups, use 
+calling `break` or `continue` will cause an error. In case of the nested loops, and more complex setups, use 
 custom `try` and `throw` setup.
 
 Please check corresponding loop function description what `continue` and `break` do in their contexts, but in 
 general case, passed values to `break` and `continue` will be used in place of the return value of the internal 
 iteration expression.
 
-### `cfor(init, condition, increment, body)`
+### `c_for(init, condition, increment, body)`
 
 `c_for` Mimics c-style tri-arg (plus body) for loops. Return value of `c_for` is number of iterations performed in the
  loop. Unlike other loops, the `body` is not provided with pre-initialized `_` style variables - all initialization