test wasm of the term package

src/terminal/c_api.zig

@@ -1,5 +1,8 @@
 // This is the C-ABI API for the terminal package. This isn't used
 // by other Zig programs but by C or WASM interfacing.
+//
+// NOTE: This is far, far from complete. We did a very minimal amount to
+// prove that compilation works, but we haven't completed coverage yet.
 
 const std = @import("std");
 const builtin = @import("builtin");
@@ -7,10 +10,10 @@ const Allocator = std.mem.Allocator;
 const Terminal = @import("main.zig").Terminal;
 
 // The allocator that we want to use.
-const alloc = if (builtin.target.isWasm())
-    std.heap.page_allocator
+const alloc = if (builtin.link_libc)
+    std.heap.c_allocator
 else
-    std.heap.c_allocator;
+    std.heap.page_allocator;
 
 export fn terminal_new(cols: usize, rows: usize) ?*Terminal {
     const term = Terminal.init(alloc, cols, rows) catch return null;
@@ -25,3 +28,9 @@ export fn terminal_free(ptr: ?*Terminal) void {
         alloc.destroy(v);
     }
 }
+
+export fn terminal_print(ptr: ?*Terminal, char: u32) void {
+    if (ptr) |t| {
+        t.print(@intCast(u21, char)) catch return null;
+    }
+}