1 files changed, 11 insertions, 8 deletions
diff --git a/src/root.zig b/src/root.zig
index 939549f..19d7bf5 100644
--- a/src/root.zig
+++ b/src/root.zig
@@ -33,18 +33,22 @@ fn isIntern(T: type) bool {
     } and (@import("builtin").is_test or @import("root").zsanettIntern(T));
 }
 
+/// Memoized root environment.
+var root_env: ?*janet.Table = null;
 /// Associative list of Zig and wrapped Janet functions.
 var fn_map: HashMap(*const anyopaque, janet.CFunction) = undefined;
 
 /// Initializes global Janet state, that is thread local.
 pub fn init() void {
     _ = janet.init(); // always 0
+    root_env = janet.coreEnv(null);
     fn_map = .empty;
 }
 
 /// Frees resources managed by Janet.
 pub fn deinit() void {
     fn_map.deinit(c_allocator);
+    root_env = null;
     janet.deinit();
 }
 
@@ -107,7 +111,7 @@ fn getArg(T: type, argv: [*c]Value, n: i32) !T {
 
 fn raise(err: anyerror) Value {
     const symb = janet.symbol("error", 5);
-    const fun = janet.resolveExt(janet.coreEnv(null), symb).value;
+    const fun = janet.resolveExt(root_env, symb).value;
     const name = @errorName(err);
     var msg: [*]u8 = @ptrCast(janet.smalloc(name.len * 2));
     var n: u16 = 0;
@@ -348,8 +352,8 @@ test "isomorphism" {
 /// Evaluates the Janet program given in str.
 pub fn eval(comptime T: type, str: []const u8, src: [*:0]const u8) !T {
     var ret: Value = undefined;
-    const errflags = janet.dobytes(janet.coreEnv(null),
-                                   str.ptr, @intCast(str.len), src, &ret);
+    const errflags = janet.dobytes(root_env, str.ptr, @intCast(str.len),
+                                   src, &ret);
     // Errors are already logged by Janet,
     // among them only one is returned and not machine-readable.
     return if (errflags == 0) unwrap(T, ret) else error.JanetError;
@@ -364,7 +368,7 @@ test eval {
 /// Binds val to name.
 pub fn def(name: [*:0]const u8, val: anytype,
            documentation: [*:0]const u8) !void {
-    janet.def(janet.coreEnv(null), name, try wrap(val), documentation);
+    janet.def(root_env, name, try wrap(val), documentation);
 }
 
 test def {
@@ -386,7 +390,7 @@ test def {
 /// Gets value.
 pub fn resolve(T: type, name: []const u8) !T {
     const symbol = janet.symbol(name.ptr, @intCast(name.len));
-    return try unwrap(T, janet.resolveExt(janet.coreEnv(null), symbol).value);
+    return try unwrap(T, janet.resolveExt(root_env, symbol).value);
 }
 
 test resolve {
@@ -413,11 +417,10 @@ pub fn defn(comptime fun: anytype, reg: struct {
         },
         zeroes(janet.RegExt),
     };
-    const env = janet.coreEnv(null);
     if (reg.prefix) |prefix|
-        janet.cfunsExtPrefix(env, prefix, &cfuns)
+        janet.cfunsExtPrefix(root_env, prefix, &cfuns)
     else
-        janet.cfunsExt(env, null, &cfuns);
+        janet.cfunsExt(root_env, null, &cfuns);
 }
 
 test defn {