Merge pull request #164 from overlay-market/s/remove-utils-errors

Remove `contracts/utils/Errors.sol`

contracts/libraries/LogExpMath.sol

@@ -23,8 +23,6 @@
 // XXX: 0.8.10; unchecked functions
 pragma solidity 0.8.10;
 
-import "../utils/Errors.sol";
-
 /* solhint-disable */
 
 /**
@@ -115,14 +113,14 @@ library LogExpMath {
             // x^y = exp(y * ln(x)).
 
             // The ln function takes a signed value, so we need to make sure x fits in the signed 256 bit range.
-            _require(x < 2 ** 255, Errors.X_OUT_OF_BOUNDS);
+            require(x < 2 ** 255, "x out of bounds");
             int256 x_int256 = int256(x);
 
             // We will compute y * ln(x) in a single step. Depending on the value of x, we can either use ln or ln_36. In
             // both cases, we leave the division by ONE_18 (due to fixed point multiplication) to the end.
 
             // This prevents y * ln(x) from overflowing, and at the same time guarantees y fits in the signed 256 bit range.
-            _require(y < MILD_EXPONENT_BOUND, Errors.Y_OUT_OF_BOUNDS);
+            require(y < MILD_EXPONENT_BOUND, "y out of bounds");
             int256 y_int256 = int256(y);
 
             int256 logx_times_y;
@@ -141,9 +139,9 @@ library LogExpMath {
             logx_times_y /= ONE_18;
 
             // Finally, we compute exp(y * ln(x)) to arrive at x^y
-            _require(
+            require(
                 MIN_NATURAL_EXPONENT <= logx_times_y && logx_times_y <= MAX_NATURAL_EXPONENT,
-                Errors.PRODUCT_OUT_OF_BOUNDS
+                "product out of bounds"
             );
 
             return uint256(exp(logx_times_y));
@@ -156,7 +154,7 @@ library LogExpMath {
      * Reverts if `x` is smaller than MIN_NATURAL_EXPONENT, or larger than `MAX_NATURAL_EXPONENT`.
      */
     function exp(int256 x) internal pure returns (int256) {
-        _require(x >= MIN_NATURAL_EXPONENT && x <= MAX_NATURAL_EXPONENT, Errors.INVALID_EXPONENT);
+        require(x >= MIN_NATURAL_EXPONENT && x <= MAX_NATURAL_EXPONENT, "invalid exponent");
 
         unchecked {
             if (x < 0) {
@@ -328,7 +326,7 @@ library LogExpMath {
      */
     function ln(int256 a) internal pure returns (int256) {
         // The real natural logarithm is not defined for negative numbers or zero.
-        _require(a > 0, Errors.OUT_OF_BOUNDS);
+        require(a > 0, "out of bounds");
 
         unchecked {
             if (LN_36_LOWER_BOUND < a && a < LN_36_UPPER_BOUND) {