67 lines
1.7 KiB
Plaintext
67 lines
1.7 KiB
Plaintext
import "@std/mem"
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import "@std/arraylist"
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import "@std/hashmap"
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InternError :: enum { out_of_space }
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StringId :: alias u32
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NO_STR :: maxval!(StringId)
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# cross-cutting concern, hence global singleton (owned by main.hon)
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STRINGS StringPool := undefined
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StringPool :: struct {
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ids hashmap.StringHashMap(StringId) # string → id
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strings arraylist.ArrayList([]u8) # id → owned string
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allocator mem.Allocator
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}
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init proc(allocator mem.Allocator) StringPool {
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return StringPool{
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ids = hashmap.init(allocator),
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strings = arraylist.init(allocator),
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allocator = allocator,
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}
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}
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deinit proc(pool @mut StringPool) void {
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hashmap.deinit(&pool.ids)
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for pool.strings.items |str| {
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mem.free(pool.allocator, str)
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}
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arraylist.deinit(&pool.strings)
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}
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intern proc(pool @mut StringPool, str []u8) StringId ! (mem.AllocError | InternError) {
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if hashmap.get(&pool.ids, str) |id| return id
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if (pool.strings.items.len >= usize(NO_STR)) return .out_of_space
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id StringId :: StringId(pool.strings.items.len)
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owned_str []mut u8 :: try mem.alloc(u8, pool.allocator, str.len)
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errdefer mem.free(pool.allocator, owned_str)
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memcopy!(owned_str, str)
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try arraylist.append(&pool.strings, owned_str)
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errdefer _ = arraylist.pop(&pool.strings)
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hashmap.put(&pool.ids, owned_str, id) catch |err| {
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match err {
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.key_exists: unreachable
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else: return err
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}
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}
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return id
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}
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get_str proc(pool @StringPool, id StringId) ?[]u8 {
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if (usize(id) >= pool.strings.items.len) return null
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return pool.strings.items[usize(id)]
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}
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get_id proc(pool @StringPool, str []u8) ?StringId {
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return hashmap.get(&pool.ids, str)
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}
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