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author | Niall Sheridan <nsheridan@gmail.com> | 2016-06-06 14:44:38 +0100 |
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committer | Niall Sheridan <nsheridan@gmail.com> | 2016-06-06 14:44:38 +0100 |
commit | 067ad51b6a6ee8829612f51a6e6b2ade3eaa61b3 (patch) | |
tree | 301d2a7303e2b5db0c3fa1911d799e16f921d9dc /vendor/github.com/jmespath/go-jmespath/interpreter.go | |
parent | 5ca59399fe0880368f88d17c0c9d781d836969c6 (diff) | |
parent | a18a13fb09eac00cdacf1f74080524182b7243de (diff) |
Merge pull request #17 from nsheridan/vendor
update dependencies
Diffstat (limited to 'vendor/github.com/jmespath/go-jmespath/interpreter.go')
-rw-r--r-- | vendor/github.com/jmespath/go-jmespath/interpreter.go | 418 |
1 files changed, 418 insertions, 0 deletions
diff --git a/vendor/github.com/jmespath/go-jmespath/interpreter.go b/vendor/github.com/jmespath/go-jmespath/interpreter.go new file mode 100644 index 0000000..13c7460 --- /dev/null +++ b/vendor/github.com/jmespath/go-jmespath/interpreter.go @@ -0,0 +1,418 @@ +package jmespath + +import ( + "errors" + "reflect" + "unicode" + "unicode/utf8" +) + +/* This is a tree based interpreter. It walks the AST and directly + interprets the AST to search through a JSON document. +*/ + +type treeInterpreter struct { + fCall *functionCaller +} + +func newInterpreter() *treeInterpreter { + interpreter := treeInterpreter{} + interpreter.fCall = newFunctionCaller() + return &interpreter +} + +type expRef struct { + ref ASTNode +} + +// Execute takes an ASTNode and input data and interprets the AST directly. +// It will produce the result of applying the JMESPath expression associated +// with the ASTNode to the input data "value". +func (intr *treeInterpreter) Execute(node ASTNode, value interface{}) (interface{}, error) { + switch node.nodeType { + case ASTComparator: + left, err := intr.Execute(node.children[0], value) + if err != nil { + return nil, err + } + right, err := intr.Execute(node.children[1], value) + if err != nil { + return nil, err + } + switch node.value { + case tEQ: + return objsEqual(left, right), nil + case tNE: + return !objsEqual(left, right), nil + } + leftNum, ok := left.(float64) + if !ok { + return nil, nil + } + rightNum, ok := right.(float64) + if !ok { + return nil, nil + } + switch node.value { + case tGT: + return leftNum > rightNum, nil + case tGTE: + return leftNum >= rightNum, nil + case tLT: + return leftNum < rightNum, nil + case tLTE: + return leftNum <= rightNum, nil + } + case ASTExpRef: + return expRef{ref: node.children[0]}, nil + case ASTFunctionExpression: + resolvedArgs := []interface{}{} + for _, arg := range node.children { + current, err := intr.Execute(arg, value) + if err != nil { + return nil, err + } + resolvedArgs = append(resolvedArgs, current) + } + return intr.fCall.CallFunction(node.value.(string), resolvedArgs, intr) + case ASTField: + if m, ok := value.(map[string]interface{}); ok { + key := node.value.(string) + return m[key], nil + } + return intr.fieldFromStruct(node.value.(string), value) + case ASTFilterProjection: + left, err := intr.Execute(node.children[0], value) + if err != nil { + return nil, nil + } + sliceType, ok := left.([]interface{}) + if !ok { + if isSliceType(left) { + return intr.filterProjectionWithReflection(node, left) + } + return nil, nil + } + compareNode := node.children[2] + collected := []interface{}{} + for _, element := range sliceType { + result, err := intr.Execute(compareNode, element) + if err != nil { + return nil, err + } + if !isFalse(result) { + current, err := intr.Execute(node.children[1], element) + if err != nil { + return nil, err + } + if current != nil { + collected = append(collected, current) + } + } + } + return collected, nil + case ASTFlatten: + left, err := intr.Execute(node.children[0], value) + if err != nil { + return nil, nil + } + sliceType, ok := left.([]interface{}) + if !ok { + // If we can't type convert to []interface{}, there's + // a chance this could still work via reflection if we're + // dealing with user provided types. + if isSliceType(left) { + return intr.flattenWithReflection(left) + } + return nil, nil + } + flattened := []interface{}{} + for _, element := range sliceType { + if elementSlice, ok := element.([]interface{}); ok { + flattened = append(flattened, elementSlice...) + } else if isSliceType(element) { + reflectFlat := []interface{}{} + v := reflect.ValueOf(element) + for i := 0; i < v.Len(); i++ { + reflectFlat = append(reflectFlat, v.Index(i).Interface()) + } + flattened = append(flattened, reflectFlat...) + } else { + flattened = append(flattened, element) + } + } + return flattened, nil + case ASTIdentity, ASTCurrentNode: + return value, nil + case ASTIndex: + if sliceType, ok := value.([]interface{}); ok { + index := node.value.(int) + if index < 0 { + index += len(sliceType) + } + if index < len(sliceType) && index >= 0 { + return sliceType[index], nil + } + return nil, nil + } + // Otherwise try via reflection. + rv := reflect.ValueOf(value) + if rv.Kind() == reflect.Slice { + index := node.value.(int) + if index < 0 { + index += rv.Len() + } + if index < rv.Len() && index >= 0 { + v := rv.Index(index) + return v.Interface(), nil + } + } + return nil, nil + case ASTKeyValPair: + return intr.Execute(node.children[0], value) + case ASTLiteral: + return node.value, nil + case ASTMultiSelectHash: + if value == nil { + return nil, nil + } + collected := make(map[string]interface{}) + for _, child := range node.children { + current, err := intr.Execute(child, value) + if err != nil { + return nil, err + } + key := child.value.(string) + collected[key] = current + } + return collected, nil + case ASTMultiSelectList: + if value == nil { + return nil, nil + } + collected := []interface{}{} + for _, child := range node.children { + current, err := intr.Execute(child, value) + if err != nil { + return nil, err + } + collected = append(collected, current) + } + return collected, nil + case ASTOrExpression: + matched, err := intr.Execute(node.children[0], value) + if err != nil { + return nil, err + } + if isFalse(matched) { + matched, err = intr.Execute(node.children[1], value) + if err != nil { + return nil, err + } + } + return matched, nil + case ASTAndExpression: + matched, err := intr.Execute(node.children[0], value) + if err != nil { + return nil, err + } + if isFalse(matched) { + return matched, nil + } + return intr.Execute(node.children[1], value) + case ASTNotExpression: + matched, err := intr.Execute(node.children[0], value) + if err != nil { + return nil, err + } + if isFalse(matched) { + return true, nil + } + return false, nil + case ASTPipe: + result := value + var err error + for _, child := range node.children { + result, err = intr.Execute(child, result) + if err != nil { + return nil, err + } + } + return result, nil + case ASTProjection: + left, err := intr.Execute(node.children[0], value) + if err != nil { + return nil, err + } + sliceType, ok := left.([]interface{}) + if !ok { + if isSliceType(left) { + return intr.projectWithReflection(node, left) + } + return nil, nil + } + collected := []interface{}{} + var current interface{} + for _, element := range sliceType { + current, err = intr.Execute(node.children[1], element) + if err != nil { + return nil, err + } + if current != nil { + collected = append(collected, current) + } + } + return collected, nil + case ASTSubexpression, ASTIndexExpression: + left, err := intr.Execute(node.children[0], value) + if err != nil { + return nil, err + } + return intr.Execute(node.children[1], left) + case ASTSlice: + sliceType, ok := value.([]interface{}) + if !ok { + if isSliceType(value) { + return intr.sliceWithReflection(node, value) + } + return nil, nil + } + parts := node.value.([]*int) + sliceParams := make([]sliceParam, 3) + for i, part := range parts { + if part != nil { + sliceParams[i].Specified = true + sliceParams[i].N = *part + } + } + return slice(sliceType, sliceParams) + case ASTValueProjection: + left, err := intr.Execute(node.children[0], value) + if err != nil { + return nil, nil + } + mapType, ok := left.(map[string]interface{}) + if !ok { + return nil, nil + } + values := make([]interface{}, len(mapType)) + for _, value := range mapType { + values = append(values, value) + } + collected := []interface{}{} + for _, element := range values { + current, err := intr.Execute(node.children[1], element) + if err != nil { + return nil, err + } + if current != nil { + collected = append(collected, current) + } + } + return collected, nil + } + return nil, errors.New("Unknown AST node: " + node.nodeType.String()) +} + +func (intr *treeInterpreter) fieldFromStruct(key string, value interface{}) (interface{}, error) { + rv := reflect.ValueOf(value) + first, n := utf8.DecodeRuneInString(key) + fieldName := string(unicode.ToUpper(first)) + key[n:] + if rv.Kind() == reflect.Struct { + v := rv.FieldByName(fieldName) + if !v.IsValid() { + return nil, nil + } + return v.Interface(), nil + } else if rv.Kind() == reflect.Ptr { + // Handle multiple levels of indirection? + if rv.IsNil() { + return nil, nil + } + rv = rv.Elem() + v := rv.FieldByName(fieldName) + if !v.IsValid() { + return nil, nil + } + return v.Interface(), nil + } + return nil, nil +} + +func (intr *treeInterpreter) flattenWithReflection(value interface{}) (interface{}, error) { + v := reflect.ValueOf(value) + flattened := []interface{}{} + for i := 0; i < v.Len(); i++ { + element := v.Index(i).Interface() + if reflect.TypeOf(element).Kind() == reflect.Slice { + // Then insert the contents of the element + // slice into the flattened slice, + // i.e flattened = append(flattened, mySlice...) + elementV := reflect.ValueOf(element) + for j := 0; j < elementV.Len(); j++ { + flattened = append( + flattened, elementV.Index(j).Interface()) + } + } else { + flattened = append(flattened, element) + } + } + return flattened, nil +} + +func (intr *treeInterpreter) sliceWithReflection(node ASTNode, value interface{}) (interface{}, error) { + v := reflect.ValueOf(value) + parts := node.value.([]*int) + sliceParams := make([]sliceParam, 3) + for i, part := range parts { + if part != nil { + sliceParams[i].Specified = true + sliceParams[i].N = *part + } + } + final := []interface{}{} + for i := 0; i < v.Len(); i++ { + element := v.Index(i).Interface() + final = append(final, element) + } + return slice(final, sliceParams) +} + +func (intr *treeInterpreter) filterProjectionWithReflection(node ASTNode, value interface{}) (interface{}, error) { + compareNode := node.children[2] + collected := []interface{}{} + v := reflect.ValueOf(value) + for i := 0; i < v.Len(); i++ { + element := v.Index(i).Interface() + result, err := intr.Execute(compareNode, element) + if err != nil { + return nil, err + } + if !isFalse(result) { + current, err := intr.Execute(node.children[1], element) + if err != nil { + return nil, err + } + if current != nil { + collected = append(collected, current) + } + } + } + return collected, nil +} + +func (intr *treeInterpreter) projectWithReflection(node ASTNode, value interface{}) (interface{}, error) { + collected := []interface{}{} + v := reflect.ValueOf(value) + for i := 0; i < v.Len(); i++ { + element := v.Index(i).Interface() + result, err := intr.Execute(node.children[1], element) + if err != nil { + return nil, err + } + if result != nil { + collected = append(collected, result) + } + } + return collected, nil +} |