1 files changed, 284 insertions, 0 deletions
diff --git a/node_modules/@babel/plugin-transform-parameters/lib/rest.js b/node_modules/@babel/plugin-transform-parameters/lib/rest.js
new file mode 100644
index 00000000..2ae054b1
--- /dev/null
+++ b/node_modules/@babel/plugin-transform-parameters/lib/rest.js
@@ -0,0 +1,284 @@
+"use strict";
+
+Object.defineProperty(exports, "__esModule", {
+  value: true
+});
+exports.default = convertFunctionRest;
+var _core = require("@babel/core");
+var _shadowUtils = require("./shadow-utils.js");
+const buildRest = _core.template.statement(`
+  for (var LEN = ARGUMENTS.length,
+           ARRAY = new Array(ARRAY_LEN),
+           KEY = START;
+       KEY < LEN;
+       KEY++) {
+    ARRAY[ARRAY_KEY] = ARGUMENTS[KEY];
+  }
+`);
+const restIndex = _core.template.expression(`
+  (INDEX < OFFSET || ARGUMENTS.length <= INDEX) ? undefined : ARGUMENTS[INDEX]
+`);
+const restIndexImpure = _core.template.expression(`
+  REF = INDEX, (REF < OFFSET || ARGUMENTS.length <= REF) ? undefined : ARGUMENTS[REF]
+`);
+const restLength = _core.template.expression(`
+  ARGUMENTS.length <= OFFSET ? 0 : ARGUMENTS.length - OFFSET
+`);
+function referencesRest(path, state) {
+  if (path.node.name === state.name) {
+    return path.scope.bindingIdentifierEquals(state.name, state.outerBinding);
+  }
+  return false;
+}
+const memberExpressionOptimisationVisitor = {
+  Scope(path, state) {
+    if (!path.scope.bindingIdentifierEquals(state.name, state.outerBinding)) {
+      path.skip();
+    }
+  },
+  Flow(path) {
+    if (path.isTypeCastExpression()) return;
+    path.skip();
+  },
+  Function(path, state) {
+    const oldNoOptimise = state.noOptimise;
+    state.noOptimise = true;
+    path.traverse(memberExpressionOptimisationVisitor, state);
+    state.noOptimise = oldNoOptimise;
+    path.skip();
+  },
+  ReferencedIdentifier(path, state) {
+    const {
+      node
+    } = path;
+    if (node.name === "arguments") {
+      state.deopted = true;
+    }
+    if (!referencesRest(path, state)) return;
+    if (state.noOptimise) {
+      state.deopted = true;
+    } else {
+      const {
+        parentPath
+      } = path;
+      if (parentPath.listKey === "params" && parentPath.key < state.offset) {
+        return;
+      }
+      if (parentPath.isMemberExpression({
+        object: node
+      })) {
+        const grandparentPath = parentPath.parentPath;
+        const argsOptEligible = !state.deopted && !(grandparentPath.isAssignmentExpression() && parentPath.node === grandparentPath.node.left || grandparentPath.isLVal() || grandparentPath.isForXStatement() || grandparentPath.isUpdateExpression() || grandparentPath.isUnaryExpression({
+          operator: "delete"
+        }) || (grandparentPath.isCallExpression() || grandparentPath.isNewExpression()) && parentPath.node === grandparentPath.node.callee);
+        if (argsOptEligible) {
+          if (parentPath.node.computed) {
+            if (parentPath.get("property").isBaseType("number")) {
+              state.candidates.push({
+                cause: "indexGetter",
+                path
+              });
+              return;
+            }
+          } else if (parentPath.node.property.name === "length") {
+            state.candidates.push({
+              cause: "lengthGetter",
+              path
+            });
+            return;
+          }
+        }
+      }
+      if (state.offset === 0 && parentPath.isSpreadElement()) {
+        const call = parentPath.parentPath;
+        if (call.isCallExpression() && call.node.arguments.length === 1) {
+          state.candidates.push({
+            cause: "argSpread",
+            path
+          });
+          return;
+        }
+      }
+      state.references.push(path);
+    }
+  },
+  BindingIdentifier(path, state) {
+    if (referencesRest(path, state)) {
+      state.deopted = true;
+    }
+  }
+};
+function getParamsCount(node) {
+  let count = node.params.length;
+  if (count > 0 && _core.types.isIdentifier(node.params[0], {
+    name: "this"
+  })) {
+    count -= 1;
+  }
+  return count;
+}
+function hasRest(node) {
+  const length = node.params.length;
+  return length > 0 && _core.types.isRestElement(node.params[length - 1]);
+}
+function optimiseIndexGetter(path, argsId, offset) {
+  const offsetLiteral = _core.types.numericLiteral(offset);
+  let index;
+  const parent = path.parent;
+  if (_core.types.isNumericLiteral(parent.property)) {
+    index = _core.types.numericLiteral(parent.property.value + offset);
+  } else if (offset === 0) {
+    index = parent.property;
+  } else {
+    index = _core.types.binaryExpression("+", parent.property, _core.types.cloneNode(offsetLiteral));
+  }
+  const {
+    scope,
+    parentPath
+  } = path;
+  if (!scope.isPure(index)) {
+    const temp = scope.generateUidIdentifierBasedOnNode(index);
+    scope.push({
+      id: temp,
+      kind: "var"
+    });
+    parentPath.replaceWith(restIndexImpure({
+      ARGUMENTS: argsId,
+      OFFSET: offsetLiteral,
+      INDEX: index,
+      REF: _core.types.cloneNode(temp)
+    }));
+  } else {
+    parentPath.replaceWith(restIndex({
+      ARGUMENTS: argsId,
+      OFFSET: offsetLiteral,
+      INDEX: index
+    }));
+    const replacedParentPath = parentPath;
+    const offsetTestPath = replacedParentPath.get("test");
+    const valRes = offsetTestPath.get("left").evaluate();
+    if (valRes.confident) {
+      if (valRes.value === true) {
+        replacedParentPath.replaceWith(scope.buildUndefinedNode());
+      } else {
+        offsetTestPath.replaceWith(offsetTestPath.get("right"));
+      }
+    }
+  }
+}
+function optimiseLengthGetter(path, argsId, offset) {
+  if (offset) {
+    path.parentPath.replaceWith(restLength({
+      ARGUMENTS: argsId,
+      OFFSET: _core.types.numericLiteral(offset)
+    }));
+  } else {
+    path.replaceWith(argsId);
+  }
+}
+function convertFunctionRest(path) {
+  const {
+    node,
+    scope
+  } = path;
+  if (!hasRest(node)) return false;
+  const restPath = path.get(`params.${node.params.length - 1}.argument`);
+  if (!restPath.isIdentifier()) {
+    const shadowedParams = new Set();
+    (0, _shadowUtils.collectShadowedParamsNames)(restPath, path.scope, shadowedParams);
+    let needsIIFE = shadowedParams.size > 0;
+    if (!needsIIFE) {
+      const state = {
+        needsOuterBinding: false,
+        scope
+      };
+      restPath.traverse(_shadowUtils.iifeVisitor, state);
+      needsIIFE = state.needsOuterBinding;
+    }
+    if (needsIIFE) {
+      path.ensureBlock();
+      path.set("body", _core.types.blockStatement([(0, _shadowUtils.buildScopeIIFE)(shadowedParams, path.node.body)]));
+    }
+  }
+  let rest = restPath.node;
+  node.params.pop();
+  if (_core.types.isPattern(rest)) {
+    const pattern = rest;
+    rest = scope.generateUidIdentifier("ref");
+    const declar = _core.types.variableDeclaration("let", [_core.types.variableDeclarator(pattern, rest)]);
+    path.ensureBlock();
+    node.body.body.unshift(declar);
+  } else if (rest.name === "arguments") {
+    scope.rename(rest.name);
+  }
+  const argsId = _core.types.identifier("arguments");
+  const paramsCount = getParamsCount(node);
+  const state = {
+    references: [],
+    offset: paramsCount,
+    argumentsNode: argsId,
+    outerBinding: scope.getBindingIdentifier(rest.name),
+    candidates: [],
+    name: rest.name,
+    deopted: false
+  };
+  path.traverse(memberExpressionOptimisationVisitor, state);
+  if (!state.deopted && !state.references.length) {
+    for (const {
+      path,
+      cause
+    } of state.candidates) {
+      const clonedArgsId = _core.types.cloneNode(argsId);
+      switch (cause) {
+        case "indexGetter":
+          optimiseIndexGetter(path, clonedArgsId, state.offset);
+          break;
+        case "lengthGetter":
+          optimiseLengthGetter(path, clonedArgsId, state.offset);
+          break;
+        default:
+          path.replaceWith(clonedArgsId);
+      }
+    }
+    return true;
+  }
+  state.references.push(...state.candidates.map(({
+    path
+  }) => path));
+  const start = _core.types.numericLiteral(paramsCount);
+  const key = scope.generateUidIdentifier("key");
+  const len = scope.generateUidIdentifier("len");
+  let arrKey, arrLen;
+  if (paramsCount) {
+    arrKey = _core.types.binaryExpression("-", _core.types.cloneNode(key), _core.types.cloneNode(start));
+    arrLen = _core.types.conditionalExpression(_core.types.binaryExpression(">", _core.types.cloneNode(len), _core.types.cloneNode(start)), _core.types.binaryExpression("-", _core.types.cloneNode(len), _core.types.cloneNode(start)), _core.types.numericLiteral(0));
+  } else {
+    arrKey = _core.types.identifier(key.name);
+    arrLen = _core.types.identifier(len.name);
+  }
+  const loop = buildRest({
+    ARGUMENTS: argsId,
+    ARRAY_KEY: arrKey,
+    ARRAY_LEN: arrLen,
+    START: start,
+    ARRAY: rest,
+    KEY: key,
+    LEN: len
+  });
+  if (state.deopted) {
+    node.body.body.unshift(loop);
+  } else {
+    let target = path.getEarliestCommonAncestorFrom(state.references).getStatementParent();
+    target.findParent(path => {
+      if (path.isLoop()) {
+        target = path;
+      } else {
+        return path.isFunction();
+      }
+    });
+    target.insertBefore(loop);
+  }
+  return true;
+}
+
+//# sourceMappingURL=rest.js.map