2 files changed, 58 insertions, 5 deletions

diff --git a/lib/index.js b/lib/index.js
index c6e88f8..ad45eac 100644
--- a/lib/index.js
+++ b/lib/index.js
@@ -123,7 +123,8 @@ module.exports = function purescriptLoader(source, map) {
     warnings: true,
     watch: false,
     output: 'output',
-    src: []
+    src: [],
+    rewriteRules: {}
   }, loaderOptions, {
     src: srcOption
   });
@@ -266,6 +267,7 @@ module.exports = function purescriptLoader(source, map) {
                 var _resolved = utils.resolvePursModule({
                   baseModulePath: baseModulePath,
                   baseModuleName: baseModuleName,
+                  rewriteRules: options.rewriteRules,
                   targetModuleName: targetModuleName
                 });
                 _this.addDependency(_resolved);
diff --git a/lib/utils.js b/lib/utils.js
index 3c73fc6..5767fc2 100644
--- a/lib/utils.js
+++ b/lib/utils.js
@@ -1,5 +1,7 @@
 'use strict';
 
+var _slicedToArray = function () { function sliceIterator(arr, i) { var _arr = []; var _n = true; var _d = false; var _e = undefined; try { for (var _i = arr[Symbol.iterator](), _s; !(_n = (_s = _i.next()).done); _n = true) { _arr.push(_s.value); if (i && _arr.length === i) break; } } catch (err) { _d = true; _e = err; } finally { try { if (!_n && _i["return"]) _i["return"](); } finally { if (_d) throw _e; } } return _arr; } return function (arr, i) { if (Array.isArray(arr)) { return arr; } else if (Symbol.iterator in Object(arr)) { return sliceIterator(arr, i); } else { throw new TypeError("Invalid attempt to destructure non-iterable instance"); } }; }();
+
 var _createClass = function () { function defineProperties(target, props) { for (var i = 0; i < props.length; i++) { var descriptor = props[i]; descriptor.enumerable = descriptor.enumerable || false; descriptor.configurable = true; if ("value" in descriptor) descriptor.writable = true; Object.defineProperty(target, descriptor.key, descriptor); } } return function (Constructor, protoProps, staticProps) { if (protoProps) defineProperties(Constructor.prototype, protoProps); if (staticProps) defineProperties(Constructor, staticProps); return Constructor; }; }();
 
 function _toArray(arr) { return Array.isArray(arr) ? arr : Array.from(arr); }
@@ -54,11 +56,60 @@ var diffPursModuleNames = function diffPursModuleNames(from, target, parts) {
 
   return head_from === head_target ? diffPursModuleNames(tail_from, tail_target, parts) : parts.concat(repeat('..', from.length), target);
 };
-exports.resolvePursModule = function (_ref) {
-  var baseModulePath = _ref.baseModulePath,
-      baseModuleName = _ref.baseModuleName,
-      targetModuleName = _ref.targetModuleName;
 
+var normalizeRewriteRuleDest = function normalizeRewriteRuleDest(_ref) {
+  var dest = _ref.dest,
+      moduleName = _ref.moduleName;
+  return typeof dest === 'function' ? dest(moduleName) : dest;
+};
+var rewrite = function rewrite(_ref2) {
+  var rules = _ref2.rules,
+      moduleName = _ref2.moduleName;
+
+  var moduleNameParts = moduleName.split('.');
+  var _iteratorNormalCompletion = true;
+  var _didIteratorError = false;
+  var _iteratorError = undefined;
+
+  try {
+    for (var _iterator = Object.entries(rules)[Symbol.iterator](), _step; !(_iteratorNormalCompletion = (_step = _iterator.next()).done); _iteratorNormalCompletion = true) {
+      var _step$value = _slicedToArray(_step.value, 2),
+          rule = _step$value[0],
+          dest = _step$value[1];
+
+      var ruleParts = rule.split('.');
+      var matched = ruleParts.every(function (part, i) {
+        return part === '*' || part === moduleNameParts[i];
+      });
+      if (!matched) continue;
+      var rest = moduleNameParts.slice(ruleParts.length);
+      var base = normalizeRewriteRuleDest({ dest: dest, moduleName: moduleName });
+      return path.join.apply(path, [base].concat(_toConsumableArray(rest))) + '.purs';
+    }
+  } catch (err) {
+    _didIteratorError = true;
+    _iteratorError = err;
+  } finally {
+    try {
+      if (!_iteratorNormalCompletion && _iterator.return) {
+        _iterator.return();
+      }
+    } finally {
+      if (_didIteratorError) {
+        throw _iteratorError;
+      }
+    }
+  }
+};
+
+exports.resolvePursModule = function (_ref3) {
+  var baseModulePath = _ref3.baseModulePath,
+      baseModuleName = _ref3.baseModuleName,
+      rewriteRules = _ref3.rewriteRules,
+      targetModuleName = _ref3.targetModuleName;
+
+  var rewrittenModulePath = rewrite({ rules: rewriteRules, moduleName: targetModuleName });
+  if (rewrittenModulePath) return rewrittenModulePath;
   var parts = diffPursModuleNames(baseModuleName.split('.'), targetModuleName.split('.'), []);
   return parts.length ? path.resolve(baseModulePath, path.join.apply(path, _toConsumableArray(parts)) + '.purs') : baseModulePath;
 };