From c8013d4982c46e09b09a083b72baee2f5c0d77b0 Mon Sep 17 00:00:00 2001 From: Christopher Speller Date: Wed, 1 Aug 2018 15:38:56 -0700 Subject: Remove accidential dependency (#9203) --- vendor/github.com/alecthomas/template/exec.go | 845 -------------------------- 1 file changed, 845 deletions(-) delete mode 100644 vendor/github.com/alecthomas/template/exec.go (limited to 'vendor/github.com/alecthomas/template/exec.go') diff --git a/vendor/github.com/alecthomas/template/exec.go b/vendor/github.com/alecthomas/template/exec.go deleted file mode 100644 index c3078e5d0..000000000 --- a/vendor/github.com/alecthomas/template/exec.go +++ /dev/null @@ -1,845 +0,0 @@ -// Copyright 2011 The Go Authors. All rights reserved. -// Use of this source code is governed by a BSD-style -// license that can be found in the LICENSE file. - -package template - -import ( - "bytes" - "fmt" - "io" - "reflect" - "runtime" - "sort" - "strings" - - "github.com/alecthomas/template/parse" -) - -// state represents the state of an execution. It's not part of the -// template so that multiple executions of the same template -// can execute in parallel. -type state struct { - tmpl *Template - wr io.Writer - node parse.Node // current node, for errors - vars []variable // push-down stack of variable values. -} - -// variable holds the dynamic value of a variable such as $, $x etc. -type variable struct { - name string - value reflect.Value -} - -// push pushes a new variable on the stack. -func (s *state) push(name string, value reflect.Value) { - s.vars = append(s.vars, variable{name, value}) -} - -// mark returns the length of the variable stack. -func (s *state) mark() int { - return len(s.vars) -} - -// pop pops the variable stack up to the mark. -func (s *state) pop(mark int) { - s.vars = s.vars[0:mark] -} - -// setVar overwrites the top-nth variable on the stack. Used by range iterations. -func (s *state) setVar(n int, value reflect.Value) { - s.vars[len(s.vars)-n].value = value -} - -// varValue returns the value of the named variable. -func (s *state) varValue(name string) reflect.Value { - for i := s.mark() - 1; i >= 0; i-- { - if s.vars[i].name == name { - return s.vars[i].value - } - } - s.errorf("undefined variable: %s", name) - return zero -} - -var zero reflect.Value - -// at marks the state to be on node n, for error reporting. -func (s *state) at(node parse.Node) { - s.node = node -} - -// doublePercent returns the string with %'s replaced by %%, if necessary, -// so it can be used safely inside a Printf format string. -func doublePercent(str string) string { - if strings.Contains(str, "%") { - str = strings.Replace(str, "%", "%%", -1) - } - return str -} - -// errorf formats the error and terminates processing. -func (s *state) errorf(format string, args ...interface{}) { - name := doublePercent(s.tmpl.Name()) - if s.node == nil { - format = fmt.Sprintf("template: %s: %s", name, format) - } else { - location, context := s.tmpl.ErrorContext(s.node) - format = fmt.Sprintf("template: %s: executing %q at <%s>: %s", location, name, doublePercent(context), format) - } - panic(fmt.Errorf(format, args...)) -} - -// errRecover is the handler that turns panics into returns from the top -// level of Parse. -func errRecover(errp *error) { - e := recover() - if e != nil { - switch err := e.(type) { - case runtime.Error: - panic(e) - case error: - *errp = err - default: - panic(e) - } - } -} - -// ExecuteTemplate applies the template associated with t that has the given name -// to the specified data object and writes the output to wr. -// If an error occurs executing the template or writing its output, -// execution stops, but partial results may already have been written to -// the output writer. -// A template may be executed safely in parallel. -func (t *Template) ExecuteTemplate(wr io.Writer, name string, data interface{}) error { - tmpl := t.tmpl[name] - if tmpl == nil { - return fmt.Errorf("template: no template %q associated with template %q", name, t.name) - } - return tmpl.Execute(wr, data) -} - -// Execute applies a parsed template to the specified data object, -// and writes the output to wr. -// If an error occurs executing the template or writing its output, -// execution stops, but partial results may already have been written to -// the output writer. -// A template may be executed safely in parallel. -func (t *Template) Execute(wr io.Writer, data interface{}) (err error) { - defer errRecover(&err) - value := reflect.ValueOf(data) - state := &state{ - tmpl: t, - wr: wr, - vars: []variable{{"$", value}}, - } - t.init() - if t.Tree == nil || t.Root == nil { - var b bytes.Buffer - for name, tmpl := range t.tmpl { - if tmpl.Tree == nil || tmpl.Root == nil { - continue - } - if b.Len() > 0 { - b.WriteString(", ") - } - fmt.Fprintf(&b, "%q", name) - } - var s string - if b.Len() > 0 { - s = "; defined templates are: " + b.String() - } - state.errorf("%q is an incomplete or empty template%s", t.Name(), s) - } - state.walk(value, t.Root) - return -} - -// Walk functions step through the major pieces of the template structure, -// generating output as they go. -func (s *state) walk(dot reflect.Value, node parse.Node) { - s.at(node) - switch node := node.(type) { - case *parse.ActionNode: - // Do not pop variables so they persist until next end. - // Also, if the action declares variables, don't print the result. - val := s.evalPipeline(dot, node.Pipe) - if len(node.Pipe.Decl) == 0 { - s.printValue(node, val) - } - case *parse.IfNode: - s.walkIfOrWith(parse.NodeIf, dot, node.Pipe, node.List, node.ElseList) - case *parse.ListNode: - for _, node := range node.Nodes { - s.walk(dot, node) - } - case *parse.RangeNode: - s.walkRange(dot, node) - case *parse.TemplateNode: - s.walkTemplate(dot, node) - case *parse.TextNode: - if _, err := s.wr.Write(node.Text); err != nil { - s.errorf("%s", err) - } - case *parse.WithNode: - s.walkIfOrWith(parse.NodeWith, dot, node.Pipe, node.List, node.ElseList) - default: - s.errorf("unknown node: %s", node) - } -} - -// walkIfOrWith walks an 'if' or 'with' node. The two control structures -// are identical in behavior except that 'with' sets dot. -func (s *state) walkIfOrWith(typ parse.NodeType, dot reflect.Value, pipe *parse.PipeNode, list, elseList *parse.ListNode) { - defer s.pop(s.mark()) - val := s.evalPipeline(dot, pipe) - truth, ok := isTrue(val) - if !ok { - s.errorf("if/with can't use %v", val) - } - if truth { - if typ == parse.NodeWith { - s.walk(val, list) - } else { - s.walk(dot, list) - } - } else if elseList != nil { - s.walk(dot, elseList) - } -} - -// isTrue reports whether the value is 'true', in the sense of not the zero of its type, -// and whether the value has a meaningful truth value. -func isTrue(val reflect.Value) (truth, ok bool) { - if !val.IsValid() { - // Something like var x interface{}, never set. It's a form of nil. - return false, true - } - switch val.Kind() { - case reflect.Array, reflect.Map, reflect.Slice, reflect.String: - truth = val.Len() > 0 - case reflect.Bool: - truth = val.Bool() - case reflect.Complex64, reflect.Complex128: - truth = val.Complex() != 0 - case reflect.Chan, reflect.Func, reflect.Ptr, reflect.Interface: - truth = !val.IsNil() - case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64: - truth = val.Int() != 0 - case reflect.Float32, reflect.Float64: - truth = val.Float() != 0 - case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64, reflect.Uintptr: - truth = val.Uint() != 0 - case reflect.Struct: - truth = true // Struct values are always true. - default: - return - } - return truth, true -} - -func (s *state) walkRange(dot reflect.Value, r *parse.RangeNode) { - s.at(r) - defer s.pop(s.mark()) - val, _ := indirect(s.evalPipeline(dot, r.Pipe)) - // mark top of stack before any variables in the body are pushed. - mark := s.mark() - oneIteration := func(index, elem reflect.Value) { - // Set top var (lexically the second if there are two) to the element. - if len(r.Pipe.Decl) > 0 { - s.setVar(1, elem) - } - // Set next var (lexically the first if there are two) to the index. - if len(r.Pipe.Decl) > 1 { - s.setVar(2, index) - } - s.walk(elem, r.List) - s.pop(mark) - } - switch val.Kind() { - case reflect.Array, reflect.Slice: - if val.Len() == 0 { - break - } - for i := 0; i < val.Len(); i++ { - oneIteration(reflect.ValueOf(i), val.Index(i)) - } - return - case reflect.Map: - if val.Len() == 0 { - break - } - for _, key := range sortKeys(val.MapKeys()) { - oneIteration(key, val.MapIndex(key)) - } - return - case reflect.Chan: - if val.IsNil() { - break - } - i := 0 - for ; ; i++ { - elem, ok := val.Recv() - if !ok { - break - } - oneIteration(reflect.ValueOf(i), elem) - } - if i == 0 { - break - } - return - case reflect.Invalid: - break // An invalid value is likely a nil map, etc. and acts like an empty map. - default: - s.errorf("range can't iterate over %v", val) - } - if r.ElseList != nil { - s.walk(dot, r.ElseList) - } -} - -func (s *state) walkTemplate(dot reflect.Value, t *parse.TemplateNode) { - s.at(t) - tmpl := s.tmpl.tmpl[t.Name] - if tmpl == nil { - s.errorf("template %q not defined", t.Name) - } - // Variables declared by the pipeline persist. - dot = s.evalPipeline(dot, t.Pipe) - newState := *s - newState.tmpl = tmpl - // No dynamic scoping: template invocations inherit no variables. - newState.vars = []variable{{"$", dot}} - newState.walk(dot, tmpl.Root) -} - -// Eval functions evaluate pipelines, commands, and their elements and extract -// values from the data structure by examining fields, calling methods, and so on. -// The printing of those values happens only through walk functions. - -// evalPipeline returns the value acquired by evaluating a pipeline. If the -// pipeline has a variable declaration, the variable will be pushed on the -// stack. Callers should therefore pop the stack after they are finished -// executing commands depending on the pipeline value. -func (s *state) evalPipeline(dot reflect.Value, pipe *parse.PipeNode) (value reflect.Value) { - if pipe == nil { - return - } - s.at(pipe) - for _, cmd := range pipe.Cmds { - value = s.evalCommand(dot, cmd, value) // previous value is this one's final arg. - // If the object has type interface{}, dig down one level to the thing inside. - if value.Kind() == reflect.Interface && value.Type().NumMethod() == 0 { - value = reflect.ValueOf(value.Interface()) // lovely! - } - } - for _, variable := range pipe.Decl { - s.push(variable.Ident[0], value) - } - return value -} - -func (s *state) notAFunction(args []parse.Node, final reflect.Value) { - if len(args) > 1 || final.IsValid() { - s.errorf("can't give argument to non-function %s", args[0]) - } -} - -func (s *state) evalCommand(dot reflect.Value, cmd *parse.CommandNode, final reflect.Value) reflect.Value { - firstWord := cmd.Args[0] - switch n := firstWord.(type) { - case *parse.FieldNode: - return s.evalFieldNode(dot, n, cmd.Args, final) - case *parse.ChainNode: - return s.evalChainNode(dot, n, cmd.Args, final) - case *parse.IdentifierNode: - // Must be a function. - return s.evalFunction(dot, n, cmd, cmd.Args, final) - case *parse.PipeNode: - // Parenthesized pipeline. The arguments are all inside the pipeline; final is ignored. - return s.evalPipeline(dot, n) - case *parse.VariableNode: - return s.evalVariableNode(dot, n, cmd.Args, final) - } - s.at(firstWord) - s.notAFunction(cmd.Args, final) - switch word := firstWord.(type) { - case *parse.BoolNode: - return reflect.ValueOf(word.True) - case *parse.DotNode: - return dot - case *parse.NilNode: - s.errorf("nil is not a command") - case *parse.NumberNode: - return s.idealConstant(word) - case *parse.StringNode: - return reflect.ValueOf(word.Text) - } - s.errorf("can't evaluate command %q", firstWord) - panic("not reached") -} - -// idealConstant is called to return the value of a number in a context where -// we don't know the type. In that case, the syntax of the number tells us -// its type, and we use Go rules to resolve. Note there is no such thing as -// a uint ideal constant in this situation - the value must be of int type. -func (s *state) idealConstant(constant *parse.NumberNode) reflect.Value { - // These are ideal constants but we don't know the type - // and we have no context. (If it was a method argument, - // we'd know what we need.) The syntax guides us to some extent. - s.at(constant) - switch { - case constant.IsComplex: - return reflect.ValueOf(constant.Complex128) // incontrovertible. - case constant.IsFloat && !isHexConstant(constant.Text) && strings.IndexAny(constant.Text, ".eE") >= 0: - return reflect.ValueOf(constant.Float64) - case constant.IsInt: - n := int(constant.Int64) - if int64(n) != constant.Int64 { - s.errorf("%s overflows int", constant.Text) - } - return reflect.ValueOf(n) - case constant.IsUint: - s.errorf("%s overflows int", constant.Text) - } - return zero -} - -func isHexConstant(s string) bool { - return len(s) > 2 && s[0] == '0' && (s[1] == 'x' || s[1] == 'X') -} - -func (s *state) evalFieldNode(dot reflect.Value, field *parse.FieldNode, args []parse.Node, final reflect.Value) reflect.Value { - s.at(field) - return s.evalFieldChain(dot, dot, field, field.Ident, args, final) -} - -func (s *state) evalChainNode(dot reflect.Value, chain *parse.ChainNode, args []parse.Node, final reflect.Value) reflect.Value { - s.at(chain) - // (pipe).Field1.Field2 has pipe as .Node, fields as .Field. Eval the pipeline, then the fields. - pipe := s.evalArg(dot, nil, chain.Node) - if len(chain.Field) == 0 { - s.errorf("internal error: no fields in evalChainNode") - } - return s.evalFieldChain(dot, pipe, chain, chain.Field, args, final) -} - -func (s *state) evalVariableNode(dot reflect.Value, variable *parse.VariableNode, args []parse.Node, final reflect.Value) reflect.Value { - // $x.Field has $x as the first ident, Field as the second. Eval the var, then the fields. - s.at(variable) - value := s.varValue(variable.Ident[0]) - if len(variable.Ident) == 1 { - s.notAFunction(args, final) - return value - } - return s.evalFieldChain(dot, value, variable, variable.Ident[1:], args, final) -} - -// evalFieldChain evaluates .X.Y.Z possibly followed by arguments. -// dot is the environment in which to evaluate arguments, while -// receiver is the value being walked along the chain. -func (s *state) evalFieldChain(dot, receiver reflect.Value, node parse.Node, ident []string, args []parse.Node, final reflect.Value) reflect.Value { - n := len(ident) - for i := 0; i < n-1; i++ { - receiver = s.evalField(dot, ident[i], node, nil, zero, receiver) - } - // Now if it's a method, it gets the arguments. - return s.evalField(dot, ident[n-1], node, args, final, receiver) -} - -func (s *state) evalFunction(dot reflect.Value, node *parse.IdentifierNode, cmd parse.Node, args []parse.Node, final reflect.Value) reflect.Value { - s.at(node) - name := node.Ident - function, ok := findFunction(name, s.tmpl) - if !ok { - s.errorf("%q is not a defined function", name) - } - return s.evalCall(dot, function, cmd, name, args, final) -} - -// evalField evaluates an expression like (.Field) or (.Field arg1 arg2). -// The 'final' argument represents the return value from the preceding -// value of the pipeline, if any. -func (s *state) evalField(dot reflect.Value, fieldName string, node parse.Node, args []parse.Node, final, receiver reflect.Value) reflect.Value { - if !receiver.IsValid() { - return zero - } - typ := receiver.Type() - receiver, _ = indirect(receiver) - // Unless it's an interface, need to get to a value of type *T to guarantee - // we see all methods of T and *T. - ptr := receiver - if ptr.Kind() != reflect.Interface && ptr.CanAddr() { - ptr = ptr.Addr() - } - if method := ptr.MethodByName(fieldName); method.IsValid() { - return s.evalCall(dot, method, node, fieldName, args, final) - } - hasArgs := len(args) > 1 || final.IsValid() - // It's not a method; must be a field of a struct or an element of a map. The receiver must not be nil. - receiver, isNil := indirect(receiver) - if isNil { - s.errorf("nil pointer evaluating %s.%s", typ, fieldName) - } - switch receiver.Kind() { - case reflect.Struct: - tField, ok := receiver.Type().FieldByName(fieldName) - if ok { - field := receiver.FieldByIndex(tField.Index) - if tField.PkgPath != "" { // field is unexported - s.errorf("%s is an unexported field of struct type %s", fieldName, typ) - } - // If it's a function, we must call it. - if hasArgs { - s.errorf("%s has arguments but cannot be invoked as function", fieldName) - } - return field - } - s.errorf("%s is not a field of struct type %s", fieldName, typ) - case reflect.Map: - // If it's a map, attempt to use the field name as a key. - nameVal := reflect.ValueOf(fieldName) - if nameVal.Type().AssignableTo(receiver.Type().Key()) { - if hasArgs { - s.errorf("%s is not a method but has arguments", fieldName) - } - return receiver.MapIndex(nameVal) - } - } - s.errorf("can't evaluate field %s in type %s", fieldName, typ) - panic("not reached") -} - -var ( - errorType = reflect.TypeOf((*error)(nil)).Elem() - fmtStringerType = reflect.TypeOf((*fmt.Stringer)(nil)).Elem() -) - -// evalCall executes a function or method call. If it's a method, fun already has the receiver bound, so -// it looks just like a function call. The arg list, if non-nil, includes (in the manner of the shell), arg[0] -// as the function itself. -func (s *state) evalCall(dot, fun reflect.Value, node parse.Node, name string, args []parse.Node, final reflect.Value) reflect.Value { - if args != nil { - args = args[1:] // Zeroth arg is function name/node; not passed to function. - } - typ := fun.Type() - numIn := len(args) - if final.IsValid() { - numIn++ - } - numFixed := len(args) - if typ.IsVariadic() { - numFixed = typ.NumIn() - 1 // last arg is the variadic one. - if numIn < numFixed { - s.errorf("wrong number of args for %s: want at least %d got %d", name, typ.NumIn()-1, len(args)) - } - } else if numIn < typ.NumIn()-1 || !typ.IsVariadic() && numIn != typ.NumIn() { - s.errorf("wrong number of args for %s: want %d got %d", name, typ.NumIn(), len(args)) - } - if !goodFunc(typ) { - // TODO: This could still be a confusing error; maybe goodFunc should provide info. - s.errorf("can't call method/function %q with %d results", name, typ.NumOut()) - } - // Build the arg list. - argv := make([]reflect.Value, numIn) - // Args must be evaluated. Fixed args first. - i := 0 - for ; i < numFixed && i < len(args); i++ { - argv[i] = s.evalArg(dot, typ.In(i), args[i]) - } - // Now the ... args. - if typ.IsVariadic() { - argType := typ.In(typ.NumIn() - 1).Elem() // Argument is a slice. - for ; i < len(args); i++ { - argv[i] = s.evalArg(dot, argType, args[i]) - } - } - // Add final value if necessary. - if final.IsValid() { - t := typ.In(typ.NumIn() - 1) - if typ.IsVariadic() { - t = t.Elem() - } - argv[i] = s.validateType(final, t) - } - result := fun.Call(argv) - // If we have an error that is not nil, stop execution and return that error to the caller. - if len(result) == 2 && !result[1].IsNil() { - s.at(node) - s.errorf("error calling %s: %s", name, result[1].Interface().(error)) - } - return result[0] -} - -// canBeNil reports whether an untyped nil can be assigned to the type. See reflect.Zero. -func canBeNil(typ reflect.Type) bool { - switch typ.Kind() { - case reflect.Chan, reflect.Func, reflect.Interface, reflect.Map, reflect.Ptr, reflect.Slice: - return true - } - return false -} - -// validateType guarantees that the value is valid and assignable to the type. -func (s *state) validateType(value reflect.Value, typ reflect.Type) reflect.Value { - if !value.IsValid() { - if typ == nil || canBeNil(typ) { - // An untyped nil interface{}. Accept as a proper nil value. - return reflect.Zero(typ) - } - s.errorf("invalid value; expected %s", typ) - } - if typ != nil && !value.Type().AssignableTo(typ) { - if value.Kind() == reflect.Interface && !value.IsNil() { - value = value.Elem() - if value.Type().AssignableTo(typ) { - return value - } - // fallthrough - } - // Does one dereference or indirection work? We could do more, as we - // do with method receivers, but that gets messy and method receivers - // are much more constrained, so it makes more sense there than here. - // Besides, one is almost always all you need. - switch { - case value.Kind() == reflect.Ptr && value.Type().Elem().AssignableTo(typ): - value = value.Elem() - if !value.IsValid() { - s.errorf("dereference of nil pointer of type %s", typ) - } - case reflect.PtrTo(value.Type()).AssignableTo(typ) && value.CanAddr(): - value = value.Addr() - default: - s.errorf("wrong type for value; expected %s; got %s", typ, value.Type()) - } - } - return value -} - -func (s *state) evalArg(dot reflect.Value, typ reflect.Type, n parse.Node) reflect.Value { - s.at(n) - switch arg := n.(type) { - case *parse.DotNode: - return s.validateType(dot, typ) - case *parse.NilNode: - if canBeNil(typ) { - return reflect.Zero(typ) - } - s.errorf("cannot assign nil to %s", typ) - case *parse.FieldNode: - return s.validateType(s.evalFieldNode(dot, arg, []parse.Node{n}, zero), typ) - case *parse.VariableNode: - return s.validateType(s.evalVariableNode(dot, arg, nil, zero), typ) - case *parse.PipeNode: - return s.validateType(s.evalPipeline(dot, arg), typ) - case *parse.IdentifierNode: - return s.evalFunction(dot, arg, arg, nil, zero) - case *parse.ChainNode: - return s.validateType(s.evalChainNode(dot, arg, nil, zero), typ) - } - switch typ.Kind() { - case reflect.Bool: - return s.evalBool(typ, n) - case reflect.Complex64, reflect.Complex128: - return s.evalComplex(typ, n) - case reflect.Float32, reflect.Float64: - return s.evalFloat(typ, n) - case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64: - return s.evalInteger(typ, n) - case reflect.Interface: - if typ.NumMethod() == 0 { - return s.evalEmptyInterface(dot, n) - } - case reflect.String: - return s.evalString(typ, n) - case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64, reflect.Uintptr: - return s.evalUnsignedInteger(typ, n) - } - s.errorf("can't handle %s for arg of type %s", n, typ) - panic("not reached") -} - -func (s *state) evalBool(typ reflect.Type, n parse.Node) reflect.Value { - s.at(n) - if n, ok := n.(*parse.BoolNode); ok { - value := reflect.New(typ).Elem() - value.SetBool(n.True) - return value - } - s.errorf("expected bool; found %s", n) - panic("not reached") -} - -func (s *state) evalString(typ reflect.Type, n parse.Node) reflect.Value { - s.at(n) - if n, ok := n.(*parse.StringNode); ok { - value := reflect.New(typ).Elem() - value.SetString(n.Text) - return value - } - s.errorf("expected string; found %s", n) - panic("not reached") -} - -func (s *state) evalInteger(typ reflect.Type, n parse.Node) reflect.Value { - s.at(n) - if n, ok := n.(*parse.NumberNode); ok && n.IsInt { - value := reflect.New(typ).Elem() - value.SetInt(n.Int64) - return value - } - s.errorf("expected integer; found %s", n) - panic("not reached") -} - -func (s *state) evalUnsignedInteger(typ reflect.Type, n parse.Node) reflect.Value { - s.at(n) - if n, ok := n.(*parse.NumberNode); ok && n.IsUint { - value := reflect.New(typ).Elem() - value.SetUint(n.Uint64) - return value - } - s.errorf("expected unsigned integer; found %s", n) - panic("not reached") -} - -func (s *state) evalFloat(typ reflect.Type, n parse.Node) reflect.Value { - s.at(n) - if n, ok := n.(*parse.NumberNode); ok && n.IsFloat { - value := reflect.New(typ).Elem() - value.SetFloat(n.Float64) - return value - } - s.errorf("expected float; found %s", n) - panic("not reached") -} - -func (s *state) evalComplex(typ reflect.Type, n parse.Node) reflect.Value { - if n, ok := n.(*parse.NumberNode); ok && n.IsComplex { - value := reflect.New(typ).Elem() - value.SetComplex(n.Complex128) - return value - } - s.errorf("expected complex; found %s", n) - panic("not reached") -} - -func (s *state) evalEmptyInterface(dot reflect.Value, n parse.Node) reflect.Value { - s.at(n) - switch n := n.(type) { - case *parse.BoolNode: - return reflect.ValueOf(n.True) - case *parse.DotNode: - return dot - case *parse.FieldNode: - return s.evalFieldNode(dot, n, nil, zero) - case *parse.IdentifierNode: - return s.evalFunction(dot, n, n, nil, zero) - case *parse.NilNode: - // NilNode is handled in evalArg, the only place that calls here. - s.errorf("evalEmptyInterface: nil (can't happen)") - case *parse.NumberNode: - return s.idealConstant(n) - case *parse.StringNode: - return reflect.ValueOf(n.Text) - case *parse.VariableNode: - return s.evalVariableNode(dot, n, nil, zero) - case *parse.PipeNode: - return s.evalPipeline(dot, n) - } - s.errorf("can't handle assignment of %s to empty interface argument", n) - panic("not reached") -} - -// indirect returns the item at the end of indirection, and a bool to indicate if it's nil. -// We indirect through pointers and empty interfaces (only) because -// non-empty interfaces have methods we might need. -func indirect(v reflect.Value) (rv reflect.Value, isNil bool) { - for ; v.Kind() == reflect.Ptr || v.Kind() == reflect.Interface; v = v.Elem() { - if v.IsNil() { - return v, true - } - if v.Kind() == reflect.Interface && v.NumMethod() > 0 { - break - } - } - return v, false -} - -// printValue writes the textual representation of the value to the output of -// the template. -func (s *state) printValue(n parse.Node, v reflect.Value) { - s.at(n) - iface, ok := printableValue(v) - if !ok { - s.errorf("can't print %s of type %s", n, v.Type()) - } - fmt.Fprint(s.wr, iface) -} - -// printableValue returns the, possibly indirected, interface value inside v that -// is best for a call to formatted printer. -func printableValue(v reflect.Value) (interface{}, bool) { - if v.Kind() == reflect.Ptr { - v, _ = indirect(v) // fmt.Fprint handles nil. - } - if !v.IsValid() { - return "", true - } - - if !v.Type().Implements(errorType) && !v.Type().Implements(fmtStringerType) { - if v.CanAddr() && (reflect.PtrTo(v.Type()).Implements(errorType) || reflect.PtrTo(v.Type()).Implements(fmtStringerType)) { - v = v.Addr() - } else { - switch v.Kind() { - case reflect.Chan, reflect.Func: - return nil, false - } - } - } - return v.Interface(), true -} - -// Types to help sort the keys in a map for reproducible output. - -type rvs []reflect.Value - -func (x rvs) Len() int { return len(x) } -func (x rvs) Swap(i, j int) { x[i], x[j] = x[j], x[i] } - -type rvInts struct{ rvs } - -func (x rvInts) Less(i, j int) bool { return x.rvs[i].Int() < x.rvs[j].Int() } - -type rvUints struct{ rvs } - -func (x rvUints) Less(i, j int) bool { return x.rvs[i].Uint() < x.rvs[j].Uint() } - -type rvFloats struct{ rvs } - -func (x rvFloats) Less(i, j int) bool { return x.rvs[i].Float() < x.rvs[j].Float() } - -type rvStrings struct{ rvs } - -func (x rvStrings) Less(i, j int) bool { return x.rvs[i].String() < x.rvs[j].String() } - -// sortKeys sorts (if it can) the slice of reflect.Values, which is a slice of map keys. -func sortKeys(v []reflect.Value) []reflect.Value { - if len(v) <= 1 { - return v - } - switch v[0].Kind() { - case reflect.Float32, reflect.Float64: - sort.Sort(rvFloats{v}) - case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64: - sort.Sort(rvInts{v}) - case reflect.String: - sort.Sort(rvStrings{v}) - case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64, reflect.Uintptr: - sort.Sort(rvUints{v}) - } - return v -} -- cgit v1.2.3-1-g7c22