in src/aws-client.js [17948:18161]
visit: function(node, value) {
var matched, current, result, first, second, field, left, right, collected, i;
switch (node.type) {
case "Field":
if (value === null ) {
return null;
} else if (isObject(value)) {
field = value[node.name];
if (field === undefined) {
return null;
} else {
return field;
}
} else {
return null;
}
break;
case "Subexpression":
result = this.visit(node.children[0], value);
for (i = 1; i < node.children.length; i++) {
result = this.visit(node.children[1], result);
if (result === null) {
return null;
}
}
return result;
case "IndexExpression":
left = this.visit(node.children[0], value);
right = this.visit(node.children[1], left);
return right;
case "Index":
if (!isArray(value)) {
return null;
}
var index = node.value;
if (index < 0) {
index = value.length + index;
}
result = value[index];
if (result === undefined) {
result = null;
}
return result;
case "Slice":
if (!isArray(value)) {
return null;
}
var sliceParams = node.children.slice(0);
var computed = this.computeSliceParams(value.length, sliceParams);
var start = computed[0];
var stop = computed[1];
var step = computed[2];
result = [];
if (step > 0) {
for (i = start; i < stop; i += step) {
result.push(value[i]);
}
} else {
for (i = start; i > stop; i += step) {
result.push(value[i]);
}
}
return result;
case "Projection":
// Evaluate left child.
var base = this.visit(node.children[0], value);
if (!isArray(base)) {
return null;
}
collected = [];
for (i = 0; i < base.length; i++) {
current = this.visit(node.children[1], base[i]);
if (current !== null) {
collected.push(current);
}
}
return collected;
case "ValueProjection":
// Evaluate left child.
base = this.visit(node.children[0], value);
if (!isObject(base)) {
return null;
}
collected = [];
var values = objValues(base);
for (i = 0; i < values.length; i++) {
current = this.visit(node.children[1], values[i]);
if (current !== null) {
collected.push(current);
}
}
return collected;
case "FilterProjection":
base = this.visit(node.children[0], value);
if (!isArray(base)) {
return null;
}
var filtered = [];
var finalResults = [];
for (i = 0; i < base.length; i++) {
matched = this.visit(node.children[2], base[i]);
if (!isFalse(matched)) {
filtered.push(base[i]);
}
}
for (var j = 0; j < filtered.length; j++) {
current = this.visit(node.children[1], filtered[j]);
if (current !== null) {
finalResults.push(current);
}
}
return finalResults;
case "Comparator":
first = this.visit(node.children[0], value);
second = this.visit(node.children[1], value);
switch(node.name) {
case TOK_EQ:
result = strictDeepEqual(first, second);
break;
case TOK_NE:
result = !strictDeepEqual(first, second);
break;
case TOK_GT:
result = first > second;
break;
case TOK_GTE:
result = first >= second;
break;
case TOK_LT:
result = first < second;
break;
case TOK_LTE:
result = first <= second;
break;
default:
throw new Error("Unknown comparator: " + node.name);
}
return result;
case TOK_FLATTEN:
var original = this.visit(node.children[0], value);
if (!isArray(original)) {
return null;
}
var merged = [];
for (i = 0; i < original.length; i++) {
current = original[i];
if (isArray(current)) {
merged.push.apply(merged, current);
} else {
merged.push(current);
}
}
return merged;
case "Identity":
return value;
case "MultiSelectList":
if (value === null) {
return null;
}
collected = [];
for (i = 0; i < node.children.length; i++) {
collected.push(this.visit(node.children[i], value));
}
return collected;
case "MultiSelectHash":
if (value === null) {
return null;
}
collected = {};
var child;
for (i = 0; i < node.children.length; i++) {
child = node.children[i];
collected[child.name] = this.visit(child.value, value);
}
return collected;
case "OrExpression":
matched = this.visit(node.children[0], value);
if (isFalse(matched)) {
matched = this.visit(node.children[1], value);
}
return matched;
case "AndExpression":
first = this.visit(node.children[0], value);
if (isFalse(first) === true) {
return first;
}
return this.visit(node.children[1], value);
case "NotExpression":
first = this.visit(node.children[0], value);
return isFalse(first);
case "Literal":
return node.value;
case TOK_PIPE:
left = this.visit(node.children[0], value);
return this.visit(node.children[1], left);
case TOK_CURRENT:
return value;
case "Function":
var resolvedArgs = [];
for (i = 0; i < node.children.length; i++) {
resolvedArgs.push(this.visit(node.children[i], value));
}
return this.runtime.callFunction(node.name, resolvedArgs);
case "ExpressionReference":
var refNode = node.children[0];
// Tag the node with a specific attribute so the type
// checker verify the type.
refNode.jmespathType = TOK_EXPREF;
return refNode;
default:
throw new Error("Unknown node type: " + node.type);
}
},