Find agent skills by outcome

- `ts(data

start

- Update with `setTxtProgressBar(pb

value)`. Close with `close(pb)`.

- Style 1: rotating `|/-\`

style 2: simple progress. Only style 3 shows percentage.

- `format(object.size(x)

units = MB)` for human-readable output.

- Works with factors

matrices

- `txtProgressBar(min

max

Data

- `relist(flesh

skeleton)` — `flesh` is the flat data

- Inverse of `unlist`: given a flat vector and a skeleton list

reconstructs the nested structure.

- Does add new names not in `x` — it uses `x[names(val)] <- val` internally

so any name in `val` gets added or replaced.

- `modifyList(x

val)` replaces elements of list `x` with those in `val` by **name**.

- `FUN` argument applies a function to each combination: `combn(5

- Checks attributes

names

- `combn(n

m)` or `combn(x

- Returns `TRUE` or a character string describing the difference — NOT `FALSE`. Use `isTRUE(all.equal(x

y))` in conditionals.

- Custom conditions: `stop(errorCondition(msg

class = myError))` then catch with `tryCatch(...

- Tests near equality with tolerance (default `1.5e-8`

i.e.

- `tryCatch(expr

error = function(e) e)` returns the error condition object.

- `tryCatch` unwinds the call stack — handler runs in the calling environment

not where the error occurred. Cannot resume execution.

- `lengths(x)` returns the length of each element of a list. Equivalent to `sapply(x

length)` but faster (implemented in C).

- `Find(f

x)` returns the **first** element where `f(elem)` is `TRUE`. `Find(f

- `Position(f

x)` returns the **index** of the first match (like `Find` but returns position

- `Map(f

...)` is a simple wrapper for `mapply(f

- `Filter(f

x)` keeps elements where `f(elem)` is `TRUE`. Unlike `x[sapply(x

- `Reduce(f