Remove smt64 (0xPolygonMiden#1249)

* Remove `smt64`

* remove unused imports

* Rename Sparse Merkle Tree title

* update changelog

CHANGELOG.md

@@ -15,6 +15,7 @@
 - Introduced `std::utils` module with `is_empty_word` procedure.  Refactored `std::collections::smt`
   and `std::collections::smt64` to use the procedure (#1107).
 - Removed `checked` versions of the instructions in the `std::math::u64` module (#1142). 
+- Removed `std::collections::smt64` (#1249)
 
 #### VM Internals
 - Introduced the `Event` decorator and an associated `on_event` handler on the `Host` trait (#1119).

docs/src/tools/repl.md

@@ -130,7 +130,6 @@ If the stdlib was added to the available libraries list `!use` command will prin
 Modules available for importing:
 std::collections::mmr
 std::collections::smt
-std::collections::smt64
 ...
 std::mem
 std::sys

docs/src/user_docs/stdlib/collections.md

@@ -17,19 +17,7 @@ The following procedures are available to read data from and make updates to a M
 | pack        | Computes a commitment to the given MMR and copies the MMR to the Advice Map using the commitment as a key.<br /><br />Inputs: `[mmr_ptr, ...]`<br />Outputs: `[HASH, ...]`<br /><br /> |
 | unpack      | Load the MMR peak data based on its hash.<br /><br />Inputs: `[HASH, mmr_ptr, ...]`<br />Outputs: `[...]`<br /><br />Where:<br />- `HASH`: is the MMR peak hash, the hash is expected to be padded to an even length and to have a minimum size of 16 elements.<br />- The advice map must contain a key with `HASH`, and its value is `num_leaves \|\| hash_data`, and hash_data is the data used to computed `HASH`<br />- `mmt_ptr`: the memory location where the MMR data will be written, starting with the MMR forest (the total count of its leaves) followed by its peaks. |
 
-## Sparse Merkle Tree (64-bit key)
-
-Module `std::collections::smt64` contains procedures for manipulating key-value maps with single-element keys and 4-element values. The current implementation is a thin wrapper over a simple Sparse Merkle Tree of depth 64. In the future, this will be replaced with a compact Sparse Merkle Tree implementation.
-
-The following procedures are available to read data from and make updates to a Sparse Merkle Tree.
-
-| Procedure   | Description |
-| ----------- | ------------- |
-| get         | Returns the value located under the specified key in the Sparse Merkle Tree defined by the specified root.<br /><br />If no values had been previously inserted under the specified key, an empty word is returned.<br /><br />Inputs: `[key, ROOT, ...]`<br />Outputs: `[VALUE, ROOT, ...]`<br /><br />Fails if the tree with the specified root does not exist in the VM's advice provider. |
-| set         | Inserts the specified value under the specified key in a Sparse Merkle Tree defined by the specified root. If the insert is successful, the old value located under the specified key is returned via the stack.<br /><br />If `VALUE` is an empty word, the new state of the tree is guaranteed to be equivalent to the state as if the updated value was never inserted.<br /><br />Inputs: `[VALUE, key, ROOT, ...]`<br />Outputs: `[OLD_VALUE, NEW_ROOT, ...]`<br /><br />Fails if the tree with the specified root does not exits in the VM's advice provider. |
-| insert      | Inserts the specified value under the specified key in a Sparse Merkle Tree defined by the specified root. If the insert is successful, the old value located under the specified key is returned via the stack.<br /><br />This procedure requires that `VALUE` be a non-empty word.<br /><br />Inputs: `[VALUE, key, ROOT, ...]`<br />Outputs: `[OLD_VALUE, NEW_ROOT, ...]`<br /><br />Fails if:<br />- The tree with the specified root does not exits in the VM's advice provider.<br />- The provided value is an empty word. |
-
-## Sparse Merkle Tree (256-bit key)
+## Sparse Merkle Tree
 
 Module `std::collections::smt` contains procedures for manipulating key-value maps with 4-element keys and 4-element values. The underlying implementation is a Sparse Merkle Tree where leaves can exist only at depth 64. Initially, when a tree is empty, it is equivalent to an empty Sparse Merkle Tree of depth 64 (i.e., leaves at depth 64 are set and hash to [ZERO; 4]). When inserting non-empty values into the tree, the most significant element of the key is used to identify the corresponding leaf. All key-value pairs that map to a given leaf are inserted (ordered) in the leaf.
 

docs/src/user_docs/stdlib/main.md

@@ -27,7 +27,6 @@ Currently, Miden standard library contains just a few modules, which are listed
 | Module | Description |
 | ------ | ----------- |
 | [std::collections::mmr](./collections.md#merkle-mountain-range) | Contains procedures for manipulating [Merkle Mountain Ranges](https://github.com/opentimestamps/opentimestamps-server/blob/master/doc/merkle-mountain-range.md). |
-| [std::collections::smt64](./collections.md#sparse-merkle-tree-64) | Contains procedures for manipulating key-value maps with single-element keys and 4-element values. |
 | [std::crypto::fri::frie2f4](./crypto/fri.md#fri-extension-2-fold-4) | Contains procedures for verifying FRI proofs (field extension = 2, folding factor = 4). |
 | [std::crypto::hashes::blake3](./crypto/hashes.md#blake3) | Contains procedures for computing hashes using BLAKE3 hash function. |
 | [std::crypto::hashes::sha256](./crypto/hashes.md#sha256) | Contains procedures for computing hashes using SHA256 hash function. |

stdlib/tests/collections/mod.rs

@@ -1,8 +1,7 @@
 use test_utils::{
-    crypto::{LeafIndex, MerkleStore, RpoDigest, SimpleSmt, Smt},
-    Felt, TestError, Word, EMPTY_WORD, ONE, ZERO,
+    crypto::{MerkleStore, RpoDigest, Smt},
+    Felt, Word, EMPTY_WORD,
 };
 
 mod mmr;
 mod smt;
-mod smt64;