1 files changed, 73 insertions, 37 deletions

diff --git a/lua/mason-core/platform.lua b/lua/mason-core/platform.lua
index 15ebdd47..f1a25666 100644
--- a/lua/mason-core/platform.lua
+++ b/lua/mason-core/platform.lua
@@ -1,4 +1,4 @@
-local fun = require "mason-core.functional.function"
+local _ = require "mason-core.functional"
 
 local M = {}
 
@@ -21,28 +21,83 @@ local arch_aliases = {
 }
 
 M.arch = arch_aliases[uname.machine] or uname.machine
+M.sysname = uname.sysname
 
-M.is_win = vim.fn.has "win32" == 1
-M.is_unix = vim.fn.has "unix" == 1
-M.is_mac = vim.fn.has "mac" == 1
-M.is_linux = not M.is_mac and M.is_unix
+M.is_headless = #vim.api.nvim_list_uis() == 0
 
--- PATH separator
-M.path_sep = M.is_win and ";" or ":"
+-- @return string @The libc found on the system, musl or glibc (glibc if ldd is not found)
+local get_libc = _.lazy(function()
+    local _, _, libc_exit_code = os.execute "ldd --version 2>&1 | grep -q musl"
+    if libc_exit_code == 0 then
+        return "musl"
+    else
+        return "glibc"
+    end
+end)
 
-M.is_headless = #vim.api.nvim_list_uis() == 0
+-- Most of the code that calls into these functions executes outside of the main event loop, where API/fn functions are
+-- disabled. We evaluate these immediately here to avoid issues with main loop synchronization.
+local cached_features = {
+    ["win"] = vim.fn.has "win32",
+    ["win32"] = vim.fn.has "win32",
+    ["win64"] = vim.fn.has "win64",
+    ["mac"] = vim.fn.has "mac",
+    ["unix"] = vim.fn.has "unix",
+    ["linux"] = vim.fn.has "linux",
+}
+
+---@type fun(env: string): boolean
+local check_env = _.memoize(_.cond {
+    {
+        _.equals "musl",
+        function()
+            return get_libc() == "musl"
+        end,
+    },
+    {
+        _.equals "gnu",
+        function()
+            return get_libc() == "glibc"
+        end,
+    },
+    { _.equals "openbsd", _.always(uname.sysname == "OpenBSD") },
+    { _.T, _.F },
+})
+
+---Table that allows for checking whether the provided targets apply to the current system.
+---Each key is a target tuple consisting of at most 3 targets, in the following order:
+--- 1) OS (e.g. linux, unix, mac, win) - Mandatory
+--- 2) Architecture (e.g. arm64, x64) - Optional
+--- 3) Environment (e.g. gnu, musl, openbsd) - Optional
+---Each target is separated by a "_" character, like so: "linux_x64_musl".
+---@type table<string, boolean>
+M.is = setmetatable({}, {
+    __index = function(__, key)
+        local os, arch, env = unpack(vim.split(key, "_", { plain = true }))
+        if not cached_features[os] or cached_features[os] ~= 1 then
+            return false
+        end
+        if arch and arch ~= M.arch then
+            return false
+        end
+        if env and not check_env(env) then
+            return false
+        end
+        return true
+    end,
+})
 
 ---@generic T
 ---@param platform_table table<Platform, T>
 ---@return T
 local function get_by_platform(platform_table)
-    if M.is_mac then
+    if M.is.mac then
         return platform_table.mac or platform_table.unix
-    elseif M.is_linux then
+    elseif M.is.linux then
         return platform_table.linux or platform_table.unix
-    elseif M.is_unix then
+    elseif M.is.unix then
         return platform_table.unix
-    elseif M.is_win then
+    elseif M.is.win then
         return platform_table.win
     else
         return nil
@@ -59,7 +114,7 @@ function M.when(cases)
 end
 
 ---@type async fun(): table
-M.os_distribution = fun.lazy(function()
+M.os_distribution = _.lazy(function()
     local Result = require "mason-core.result"
 
     ---Parses the provided contents of an /etc/\*-release file and identifies the Linux distribution.
@@ -122,8 +177,8 @@ M.os_distribution = fun.lazy(function()
 end)
 
 ---@type async fun(): Result<string>
-M.get_homebrew_prefix = fun.lazy(function()
-    assert(M.is_mac, "Can only locate Homebrew installation on Mac systems.")
+M.get_homebrew_prefix = _.lazy(function()
+    assert(M.is.mac, "Can only locate Homebrew installation on Mac systems.")
     local spawn = require "mason-core.spawn"
     return spawn
         .brew({ "--prefix" })
@@ -135,31 +190,9 @@ M.get_homebrew_prefix = fun.lazy(function()
         end)
 end)
 
--- @return string @The libc found on the system, musl or glibc (glibc if ldd is not found)
-M.get_libc = fun.lazy(function()
-    local _, _, libc_exit_code = os.execute "ldd --version 2>&1 | grep -q musl"
-    if libc_exit_code == 0 then
-        return "musl"
-    else
-        return "glibc"
-    end
-end)
-
----@type table<string, boolean>
-M.is = setmetatable({}, {
-    __index = function(_, key)
-        local platform, arch = unpack(vim.split(key, "_", { plain = true }))
-        if arch and M.arch ~= arch then
-            return false
-        end
-        return M["is_" .. platform] == true
-    end,
-})
-
 ---@async
 function M.get_node_version()
     local spawn = require "mason-core.spawn"
-    local _ = require "mason-core.functional"
 
     return spawn.node({ "--version" }):map(function(result)
         -- Parses output such as "v16.3.1" into major, minor, patch
@@ -168,4 +201,7 @@ function M.get_node_version()
     end)
 end
 
+-- PATH separator
+M.path_sep = M.is.win and ";" or ":"
+
 return M