1 files changed, 108 insertions, 0 deletions
diff --git a/ethutil/parsing.go b/ethutil/parsing.go
new file mode 100644
index 000000000..2c41fb4df
--- /dev/null
+++ b/ethutil/parsing.go
@@ -0,0 +1,108 @@
+package ethutil
+
+import (
+	"errors"
+	"fmt"
+	"math/big"
+	"strconv"
+	"strings"
+)
+
+// Op codes
+var OpCodes = map[string]string{
+	"STOP":      "0",
+	"ADD":       "1",
+	"MUL":       "2",
+	"SUB":       "3",
+	"DIV":       "4",
+	"SDIV":      "5",
+	"MOD":       "6",
+	"SMOD":      "7",
+	"EXP":       "8",
+	"NEG":       "9",
+	"LT":        "10",
+	"LE":        "11",
+	"GT":        "12",
+	"GE":        "13",
+	"EQ":        "14",
+	"NOT":       "15",
+	"MYADDRESS": "16",
+	"TXSENDER":  "17",
+
+	"PUSH": "48",
+	"POP":  "49",
+	"LOAD": "54",
+}
+
+func CompileInstr(s string) (string, error) {
+	tokens := strings.Split(s, " ")
+	if OpCodes[tokens[0]] == "" {
+		return s, errors.New(fmt.Sprintf("OP not found: %s", tokens[0]))
+	}
+
+	code := OpCodes[tokens[0]] // Replace op codes with the proper numerical equivalent
+	op := new(big.Int)
+	op.SetString(code, 0)
+
+	args := make([]*big.Int, 6)
+	for i, val := range tokens[1:len(tokens)] {
+		num := new(big.Int)
+		num.SetString(val, 0)
+		args[i] = num
+	}
+
+	// Big int equation = op + x * 256 + y * 256**2 + z * 256**3 + a * 256**4 + b * 256**5 + c * 256**6
+	base := new(big.Int)
+	x := new(big.Int)
+	y := new(big.Int)
+	z := new(big.Int)
+	a := new(big.Int)
+	b := new(big.Int)
+	c := new(big.Int)
+
+	if args[0] != nil {
+		x.Mul(args[0], big.NewInt(256))
+	}
+	if args[1] != nil {
+		y.Mul(args[1], BigPow(256, 2))
+	}
+	if args[2] != nil {
+		z.Mul(args[2], BigPow(256, 3))
+	}
+	if args[3] != nil {
+		a.Mul(args[3], BigPow(256, 4))
+	}
+	if args[4] != nil {
+		b.Mul(args[4], BigPow(256, 5))
+	}
+	if args[5] != nil {
+		c.Mul(args[5], BigPow(256, 6))
+	}
+
+	base.Add(op, x)
+	base.Add(base, y)
+	base.Add(base, z)
+	base.Add(base, a)
+	base.Add(base, b)
+	base.Add(base, c)
+
+	return base.String(), nil
+}
+
+func Instr(instr string) (int, []string, error) {
+	base := new(big.Int)
+	base.SetString(instr, 0)
+
+	args := make([]string, 7)
+	for i := 0; i < 7; i++ {
+		// int(int(val) / int(math.Pow(256,float64(i)))) % 256
+		exp := BigPow(256, i)
+		num := new(big.Int)
+		num.Div(base, exp)
+
+		args[i] = num.Mod(num, big.NewInt(256)).String()
+	}
+	op, _ := strconv.Atoi(args[0])
+
+	return op, args[1:7], nil
+}