package tezos-protocol-012-Psithaca

The type for context handler.

The type for context trees.

The type for context keys.

The type for context values.

mem t k is an Lwt promise that resolves to true iff k is bound to a value in t.

mem_tree t k is like mem but for trees.

get t k is an Lwt promise that resolves to Ok v if k is bound to the value v in t and Storage_ErrorMissing_key otherwise.

get_tree is like get but for trees.

find t k is an Lwt promise that resolves to Some v if k is bound to the value v in t and None otherwise.

find_tree t k is like find but for trees.

list t key is the list of files and sub-nodes stored under k in t. The result order is not specified but is stable.

offset and length are used for pagination.

init t k v is an Lwt promise that resolves to Ok c if:

• k is unbound in t;
• k is bound to v in c;
• and c is similar to t otherwise.

It is Storage_errorExisting_key if k is already bound in t.

init_tree is like init but for trees.

update t k v is an Lwt promise that resolves to Ok c if:

• k is bound in t;
• k is bound to v in c;
• and c is similar to t otherwise.

It is Storage_errorMissing_key if k is not already bound in t.

update_tree is like update but for trees.

add t k v is an Lwt promise that resolves to c such that:

• k is bound to v in c;
• and c is similar to t otherwise.

If k was already bound in t to a value that is physically equal to v, the result of the function is a promise that resolves to t. Otherwise, the previous binding of k in t disappears.

add_tree is like add but for trees.

remove t k v is an Lwt promise that resolves to c such that:

• k is unbound in c;
• and c is similar to t otherwise.

remove_existing t k v is an Lwt promise that resolves to Ok c if:

• k is bound in t to a value;
• k is unbound in c;
• and c is similar to t otherwise.

remove_existing_tree t k v is an Lwt promise that reolves to Ok c if:

• k is bound in t to a tree;
• k is unbound in c;
• and c is similar to t otherwise.

add_or_remove t k v is:

• add t k x if v is Some x;
• remove t k otherwise.

add_or_remove_tree t k v is:

• add_tree t k x if v is Some x;
• remove t k otherwise.

fold ?depth t root ~init ~f recursively folds over the trees and values of t. The f callbacks are called with a key relative to root. f is never called with an empty key for values; i.e., folding over a value is a no-op.

Elements are traversed in lexical order of keys.

The depth is 0-indexed. If depth is set (by default it is not), then f is only called when the conditions described by the parameter is true:

• Eq d folds over nodes and contents of depth exactly d.
• Lt d folds over nodes and contents of depth strictly less than d.
• Le d folds over nodes and contents of depth less than or equal to d.
• Gt d folds over nodes and contents of depth strictly more than d.
• Ge d folds over nodes and contents of depth more than or equal to d.