Add Hash.roc builtin module

crates/compiler/builtins/roc/Hash.roc

@@ -0,0 +1,68 @@
+interface Hash
+    exposes [
+        Hash,
+        Hasher,
+        hash,
+        addBytes,
+        addU8,
+        addU16,
+        addU32,
+        addU64,
+        addU128,
+        addI8,
+        addI16,
+        addI32,
+        addI64,
+        addI128,
+        complete,
+    ] imports []
+
+## A value that can hashed.
+Hash has
+    ## Hashes a value into a [Hasher].
+    ## Note that [hash] does not produce a hash value itself; the hasher must be
+    ## [complete]d in order to extract the hash value.
+    hash : a, hasher -> hasher | a has Hash, hasher has Hasher
+
+## Describes a hashing algorithm that is fed bytes and produces an integer hash.
+##
+## The [Hasher] ability describes general-purpose hashers. It only allows
+## emission of 64-bit unsigned integer hashes. It is not suitable for
+## cryptographically-secure hashing.
+Hasher has
+    ## Adds a list of bytes to the hasher.
+    addBytes : a, List U8 -> a | a has Hasher
+
+    ## Adds a single U8 to the hasher.
+    addU8 : a, U8 -> a | a has Hasher
+
+    ## Adds a single U16 to the hasher.
+    addU16 : a, U16 -> a | a has Hasher
+
+    ## Adds a single U32 to the hasher.
+    addU32 : a, U32 -> a | a has Hasher
+
+    ## Adds a single U64 to the hasher.
+    addU64 : a, U64 -> a | a has Hasher
+
+    ## Adds a single U128 to the hasher.
+    addU128 : a, U128 -> a | a has Hasher
+
+    ## Adds a single I8 to the hasher.
+    addI8 : a, I8 -> a | a has Hasher
+
+    ## Adds a single I16 to the hasher.
+    addI16 : a, I16 -> a | a has Hasher
+
+    ## Adds a single I32 to the hasher.
+    addI32 : a, I32 -> a | a has Hasher
+
+    ## Adds a single I64 to the hasher.
+    addI64 : a, I64 -> a | a has Hasher
+
+    ## Adds a single I128 to the hasher.
+    addI128 : a, I128 -> a | a has Hasher
+
+    ## Completes the hasher, extracting a hash value from its
+    ## accumulated hash state.
+    complete : a -> U64 | a has Hasher