lua: Add account balances

balance_lua.go

@@ -0,0 +1,56 @@
+package main
+
+import (
+	"github.com/yuin/gopher-lua"
+	"math/big"
+)
+
+type Balance struct {
+	Security *Security
+	Amount   *big.Rat
+}
+
+const luaBalanceTypeName = "balance"
+
+// Registers my balance type to given L.
+func luaRegisterBalances(L *lua.LState) {
+	mt := L.NewTypeMetatable(luaBalanceTypeName)
+	L.SetGlobal("balance", mt)
+	L.SetField(mt, "__tostring", L.NewFunction(luaBalance__tostring))
+	L.SetField(mt, "__eq", L.NewFunction(luaBalance__eq))
+	L.SetField(mt, "__metatable", lua.LString("protected"))
+}
+
+func BalanceToLua(L *lua.LState, balance *Balance) *lua.LUserData {
+	ud := L.NewUserData()
+	ud.Value = balance
+	L.SetMetatable(ud, L.GetTypeMetatable(luaBalanceTypeName))
+	return ud
+}
+
+// Checks whether the first lua argument is a *LUserData with *Balance and returns this *Balance.
+func luaCheckBalance(L *lua.LState, n int) *Balance {
+	ud := L.CheckUserData(n)
+	if balance, ok := ud.Value.(*Balance); ok {
+		return balance
+	}
+	L.ArgError(n, "balance expected")
+	return nil
+}
+
+func luaBalance__tostring(L *lua.LState) int {
+	b := luaCheckBalance(L, 1)
+
+	L.Push(lua.LString(b.Security.Symbol + b.Amount.FloatString(b.Security.Precision)))
+
+	return 1
+}
+
+func luaBalance__eq(L *lua.LState) int {
+	a := luaCheckBalance(L, 1)
+	b := luaCheckBalance(L, 2)
+
+	L.Push(lua.LBool(a.Security.SecurityId == b.Security.SecurityId && a.Amount.Cmp(b.Amount) == 0))
+
+	return 1
+}