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Diffstat (limited to 'src/cmd/gofix/testdata/reflect.template.go.out')
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diff --git a/src/cmd/gofix/testdata/reflect.template.go.out b/src/cmd/gofix/testdata/reflect.template.go.out new file mode 100644 index 000000000..28872dbee --- /dev/null +++ b/src/cmd/gofix/testdata/reflect.template.go.out @@ -0,0 +1,1044 @@ +// Copyright 2009 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. + +/* + Data-driven templates for generating textual output such as + HTML. + + Templates are executed by applying them to a data structure. + Annotations in the template refer to elements of the data + structure (typically a field of a struct or a key in a map) + to control execution and derive values to be displayed. + The template walks the structure as it executes and the + "cursor" @ represents the value at the current location + in the structure. + + Data items may be values or pointers; the interface hides the + indirection. + + In the following, 'field' is one of several things, according to the data. + + - The name of a field of a struct (result = data.field), + - The value stored in a map under that key (result = data[field]), or + - The result of invoking a niladic single-valued method with that name + (result = data.field()) + + Major constructs ({} are the default delimiters for template actions; + [] are the notation in this comment for optional elements): + + {# comment } + + A one-line comment. + + {.section field} XXX [ {.or} YYY ] {.end} + + Set @ to the value of the field. It may be an explicit @ + to stay at the same point in the data. If the field is nil + or empty, execute YYY; otherwise execute XXX. + + {.repeated section field} XXX [ {.alternates with} ZZZ ] [ {.or} YYY ] {.end} + + Like .section, but field must be an array or slice. XXX + is executed for each element. If the array is nil or empty, + YYY is executed instead. If the {.alternates with} marker + is present, ZZZ is executed between iterations of XXX. + + {field} + {field1 field2 ...} + {field|formatter} + {field1 field2...|formatter} + {field|formatter1|formatter2} + + Insert the value of the fields into the output. Each field is + first looked for in the cursor, as in .section and .repeated. + If it is not found, the search continues in outer sections + until the top level is reached. + + If the field value is a pointer, leading asterisks indicate + that the value to be inserted should be evaluated through the + pointer. For example, if x.p is of type *int, {x.p} will + insert the value of the pointer but {*x.p} will insert the + value of the underlying integer. If the value is nil or not a + pointer, asterisks have no effect. + + If a formatter is specified, it must be named in the formatter + map passed to the template set up routines or in the default + set ("html","str","") and is used to process the data for + output. The formatter function has signature + func(wr io.Writer, formatter string, data ...interface{}) + where wr is the destination for output, data holds the field + values at the instantiation, and formatter is its name at + the invocation site. The default formatter just concatenates + the string representations of the fields. + + Multiple formatters separated by the pipeline character | are + executed sequentially, with each formatter receiving the bytes + emitted by the one to its left. + + The delimiter strings get their default value, "{" and "}", from + JSON-template. They may be set to any non-empty, space-free + string using the SetDelims method. Their value can be printed + in the output using {.meta-left} and {.meta-right}. +*/ +package template + +import ( + "bytes" + "container/vector" + "fmt" + "io" + "io/ioutil" + "os" + "reflect" + "strings" + "unicode" + "utf8" +) + +// Errors returned during parsing and execution. Users may extract the information and reformat +// if they desire. +type Error struct { + Line int + Msg string +} + +func (e *Error) String() string { return fmt.Sprintf("line %d: %s", e.Line, e.Msg) } + +// Most of the literals are aces. +var lbrace = []byte{'{'} +var rbrace = []byte{'}'} +var space = []byte{' '} +var tab = []byte{'\t'} + +// The various types of "tokens", which are plain text or (usually) brace-delimited descriptors +const ( + tokAlternates = iota + tokComment + tokEnd + tokLiteral + tokOr + tokRepeated + tokSection + tokText + tokVariable +) + +// FormatterMap is the type describing the mapping from formatter +// names to the functions that implement them. +type FormatterMap map[string]func(io.Writer, string, ...interface{}) + +// Built-in formatters. +var builtins = FormatterMap{ + "html": HTMLFormatter, + "str": StringFormatter, + "": StringFormatter, +} + +// The parsed state of a template is a vector of xxxElement structs. +// Sections have line numbers so errors can be reported better during execution. + +// Plain text. +type textElement struct { + text []byte +} + +// A literal such as .meta-left or .meta-right +type literalElement struct { + text []byte +} + +// A variable invocation to be evaluated +type variableElement struct { + linenum int + word []string // The fields in the invocation. + fmts []string // Names of formatters to apply. len(fmts) > 0 +} + +// A .section block, possibly with a .or +type sectionElement struct { + linenum int // of .section itself + field string // cursor field for this block + start int // first element + or int // first element of .or block + end int // one beyond last element +} + +// A .repeated block, possibly with a .or and a .alternates +type repeatedElement struct { + sectionElement // It has the same structure... + altstart int // ... except for alternates + altend int +} + +// Template is the type that represents a template definition. +// It is unchanged after parsing. +type Template struct { + fmap FormatterMap // formatters for variables + // Used during parsing: + ldelim, rdelim []byte // delimiters; default {} + buf []byte // input text to process + p int // position in buf + linenum int // position in input + // Parsed results: + elems *vector.Vector +} + +// Internal state for executing a Template. As we evaluate the struct, +// the data item descends into the fields associated with sections, etc. +// Parent is used to walk upwards to find variables higher in the tree. +type state struct { + parent *state // parent in hierarchy + data reflect.Value // the driver data for this section etc. + wr io.Writer // where to send output + buf [2]bytes.Buffer // alternating buffers used when chaining formatters +} + +func (parent *state) clone(data reflect.Value) *state { + return &state{parent: parent, data: data, wr: parent.wr} +} + +// New creates a new template with the specified formatter map (which +// may be nil) to define auxiliary functions for formatting variables. +func New(fmap FormatterMap) *Template { + t := new(Template) + t.fmap = fmap + t.ldelim = lbrace + t.rdelim = rbrace + t.elems = new(vector.Vector) + return t +} + +// Report error and stop executing. The line number must be provided explicitly. +func (t *Template) execError(st *state, line int, err string, args ...interface{}) { + panic(&Error{line, fmt.Sprintf(err, args...)}) +} + +// Report error, panic to terminate parsing. +// The line number comes from the template state. +func (t *Template) parseError(err string, args ...interface{}) { + panic(&Error{t.linenum, fmt.Sprintf(err, args...)}) +} + +// Is this an exported - upper case - name? +func isExported(name string) bool { + rune, _ := utf8.DecodeRuneInString(name) + return unicode.IsUpper(rune) +} + +// -- Lexical analysis + +// Is c a white space character? +func white(c uint8) bool { return c == ' ' || c == '\t' || c == '\r' || c == '\n' } + +// Safely, does s[n:n+len(t)] == t? +func equal(s []byte, n int, t []byte) bool { + b := s[n:] + if len(t) > len(b) { // not enough space left for a match. + return false + } + for i, c := range t { + if c != b[i] { + return false + } + } + return true +} + +// nextItem returns the next item from the input buffer. If the returned +// item is empty, we are at EOF. The item will be either a +// delimited string or a non-empty string between delimited +// strings. Tokens stop at (but include, if plain text) a newline. +// Action tokens on a line by themselves drop any space on +// either side, up to and including the newline. +func (t *Template) nextItem() []byte { + startOfLine := t.p == 0 || t.buf[t.p-1] == '\n' + start := t.p + var i int + newline := func() { + t.linenum++ + i++ + } + // Leading white space up to but not including newline + for i = start; i < len(t.buf); i++ { + if t.buf[i] == '\n' || !white(t.buf[i]) { + break + } + } + leadingSpace := i > start + // What's left is nothing, newline, delimited string, or plain text + switch { + case i == len(t.buf): + // EOF; nothing to do + case t.buf[i] == '\n': + newline() + case equal(t.buf, i, t.ldelim): + left := i // Start of left delimiter. + right := -1 // Will be (immediately after) right delimiter. + haveText := false // Delimiters contain text. + i += len(t.ldelim) + // Find the end of the action. + for ; i < len(t.buf); i++ { + if t.buf[i] == '\n' { + break + } + if equal(t.buf, i, t.rdelim) { + i += len(t.rdelim) + right = i + break + } + haveText = true + } + if right < 0 { + t.parseError("unmatched opening delimiter") + return nil + } + // Is this a special action (starts with '.' or '#') and the only thing on the line? + if startOfLine && haveText { + firstChar := t.buf[left+len(t.ldelim)] + if firstChar == '.' || firstChar == '#' { + // It's special and the first thing on the line. Is it the last? + for j := right; j < len(t.buf) && white(t.buf[j]); j++ { + if t.buf[j] == '\n' { + // Yes it is. Drop the surrounding space and return the {.foo} + t.linenum++ + t.p = j + 1 + return t.buf[left:right] + } + } + } + } + // No it's not. If there's leading space, return that. + if leadingSpace { + // not trimming space: return leading white space if there is some. + t.p = left + return t.buf[start:left] + } + // Return the word, leave the trailing space. + start = left + break + default: + for ; i < len(t.buf); i++ { + if t.buf[i] == '\n' { + newline() + break + } + if equal(t.buf, i, t.ldelim) { + break + } + } + } + item := t.buf[start:i] + t.p = i + return item +} + +// Turn a byte array into a white-space-split array of strings. +func words(buf []byte) []string { + s := make([]string, 0, 5) + p := 0 // position in buf + // one word per loop + for i := 0; ; i++ { + // skip white space + for ; p < len(buf) && white(buf[p]); p++ { + } + // grab word + start := p + for ; p < len(buf) && !white(buf[p]); p++ { + } + if start == p { // no text left + break + } + s = append(s, string(buf[start:p])) + } + return s +} + +// Analyze an item and return its token type and, if it's an action item, an array of +// its constituent words. +func (t *Template) analyze(item []byte) (tok int, w []string) { + // item is known to be non-empty + if !equal(item, 0, t.ldelim) { // doesn't start with left delimiter + tok = tokText + return + } + if !equal(item, len(item)-len(t.rdelim), t.rdelim) { // doesn't end with right delimiter + t.parseError("internal error: unmatched opening delimiter") // lexing should prevent this + return + } + if len(item) <= len(t.ldelim)+len(t.rdelim) { // no contents + t.parseError("empty directive") + return + } + // Comment + if item[len(t.ldelim)] == '#' { + tok = tokComment + return + } + // Split into words + w = words(item[len(t.ldelim) : len(item)-len(t.rdelim)]) // drop final delimiter + if len(w) == 0 { + t.parseError("empty directive") + return + } + if len(w) > 0 && w[0][0] != '.' { + tok = tokVariable + return + } + switch w[0] { + case ".meta-left", ".meta-right", ".space", ".tab": + tok = tokLiteral + return + case ".or": + tok = tokOr + return + case ".end": + tok = tokEnd + return + case ".section": + if len(w) != 2 { + t.parseError("incorrect fields for .section: %s", item) + return + } + tok = tokSection + return + case ".repeated": + if len(w) != 3 || w[1] != "section" { + t.parseError("incorrect fields for .repeated: %s", item) + return + } + tok = tokRepeated + return + case ".alternates": + if len(w) != 2 || w[1] != "with" { + t.parseError("incorrect fields for .alternates: %s", item) + return + } + tok = tokAlternates + return + } + t.parseError("bad directive: %s", item) + return +} + +// formatter returns the Formatter with the given name in the Template, or nil if none exists. +func (t *Template) formatter(name string) func(io.Writer, string, ...interface{}) { + if t.fmap != nil { + if fn := t.fmap[name]; fn != nil { + return fn + } + } + return builtins[name] +} + +// -- Parsing + +// Allocate a new variable-evaluation element. +func (t *Template) newVariable(words []string) *variableElement { + // After the final space-separated argument, formatters may be specified separated + // by pipe symbols, for example: {a b c|d|e} + + // Until we learn otherwise, formatters contains a single name: "", the default formatter. + formatters := []string{""} + lastWord := words[len(words)-1] + bar := strings.IndexRune(lastWord, '|') + if bar >= 0 { + words[len(words)-1] = lastWord[0:bar] + formatters = strings.Split(lastWord[bar+1:], "|", -1) + } + + // We could remember the function address here and avoid the lookup later, + // but it's more dynamic to let the user change the map contents underfoot. + // We do require the name to be present, though. + + // Is it in user-supplied map? + for _, f := range formatters { + if t.formatter(f) == nil { + t.parseError("unknown formatter: %q", f) + } + } + return &variableElement{t.linenum, words, formatters} +} + +// Grab the next item. If it's simple, just append it to the template. +// Otherwise return its details. +func (t *Template) parseSimple(item []byte) (done bool, tok int, w []string) { + tok, w = t.analyze(item) + done = true // assume for simplicity + switch tok { + case tokComment: + return + case tokText: + t.elems.Push(&textElement{item}) + return + case tokLiteral: + switch w[0] { + case ".meta-left": + t.elems.Push(&literalElement{t.ldelim}) + case ".meta-right": + t.elems.Push(&literalElement{t.rdelim}) + case ".space": + t.elems.Push(&literalElement{space}) + case ".tab": + t.elems.Push(&literalElement{tab}) + default: + t.parseError("internal error: unknown literal: %s", w[0]) + } + return + case tokVariable: + t.elems.Push(t.newVariable(w)) + return + } + return false, tok, w +} + +// parseRepeated and parseSection are mutually recursive + +func (t *Template) parseRepeated(words []string) *repeatedElement { + r := new(repeatedElement) + t.elems.Push(r) + r.linenum = t.linenum + r.field = words[2] + // Scan section, collecting true and false (.or) blocks. + r.start = t.elems.Len() + r.or = -1 + r.altstart = -1 + r.altend = -1 +Loop: + for { + item := t.nextItem() + if len(item) == 0 { + t.parseError("missing .end for .repeated section") + break + } + done, tok, w := t.parseSimple(item) + if done { + continue + } + switch tok { + case tokEnd: + break Loop + case tokOr: + if r.or >= 0 { + t.parseError("extra .or in .repeated section") + break Loop + } + r.altend = t.elems.Len() + r.or = t.elems.Len() + case tokSection: + t.parseSection(w) + case tokRepeated: + t.parseRepeated(w) + case tokAlternates: + if r.altstart >= 0 { + t.parseError("extra .alternates in .repeated section") + break Loop + } + if r.or >= 0 { + t.parseError(".alternates inside .or block in .repeated section") + break Loop + } + r.altstart = t.elems.Len() + default: + t.parseError("internal error: unknown repeated section item: %s", item) + break Loop + } + } + if r.altend < 0 { + r.altend = t.elems.Len() + } + r.end = t.elems.Len() + return r +} + +func (t *Template) parseSection(words []string) *sectionElement { + s := new(sectionElement) + t.elems.Push(s) + s.linenum = t.linenum + s.field = words[1] + // Scan section, collecting true and false (.or) blocks. + s.start = t.elems.Len() + s.or = -1 +Loop: + for { + item := t.nextItem() + if len(item) == 0 { + t.parseError("missing .end for .section") + break + } + done, tok, w := t.parseSimple(item) + if done { + continue + } + switch tok { + case tokEnd: + break Loop + case tokOr: + if s.or >= 0 { + t.parseError("extra .or in .section") + break Loop + } + s.or = t.elems.Len() + case tokSection: + t.parseSection(w) + case tokRepeated: + t.parseRepeated(w) + case tokAlternates: + t.parseError(".alternates not in .repeated") + default: + t.parseError("internal error: unknown section item: %s", item) + } + } + s.end = t.elems.Len() + return s +} + +func (t *Template) parse() { + for { + item := t.nextItem() + if len(item) == 0 { + break + } + done, tok, w := t.parseSimple(item) + if done { + continue + } + switch tok { + case tokOr, tokEnd, tokAlternates: + t.parseError("unexpected %s", w[0]) + case tokSection: + t.parseSection(w) + case tokRepeated: + t.parseRepeated(w) + default: + t.parseError("internal error: bad directive in parse: %s", item) + } + } +} + +// -- Execution + +// Evaluate interfaces and pointers looking for a value that can look up the name, via a +// struct field, method, or map key, and return the result of the lookup. +func (t *Template) lookup(st *state, v reflect.Value, name string) reflect.Value { + for v.IsValid() { + typ := v.Type() + if n := v.Type().NumMethod(); n > 0 { + for i := 0; i < n; i++ { + m := typ.Method(i) + mtyp := m.Type + if m.Name == name && mtyp.NumIn() == 1 && mtyp.NumOut() == 1 { + if !isExported(name) { + t.execError(st, t.linenum, "name not exported: %s in type %s", name, st.data.Type()) + } + return v.Method(i).Call(nil)[0] + } + } + } + switch av := v; av.Kind() { + case reflect.Ptr: + v = av.Elem() + case reflect.Interface: + v = av.Elem() + case reflect.Struct: + if !isExported(name) { + t.execError(st, t.linenum, "name not exported: %s in type %s", name, st.data.Type()) + } + return av.FieldByName(name) + case reflect.Map: + if v := av.MapIndex(reflect.NewValue(name)); v.IsValid() { + return v + } + return reflect.Zero(typ.Elem()) + default: + return reflect.Value{} + } + } + return v +} + +// indirectPtr returns the item numLevels levels of indirection below the value. +// It is forgiving: if the value is not a pointer, it returns it rather than giving +// an error. If the pointer is nil, it is returned as is. +func indirectPtr(v reflect.Value, numLevels int) reflect.Value { + for i := numLevels; v.IsValid() && i > 0; i++ { + if p := v; p.Kind() == reflect.Ptr { + if p.IsNil() { + return v + } + v = p.Elem() + } else { + break + } + } + return v +} + +// Walk v through pointers and interfaces, extracting the elements within. +func indirect(v reflect.Value) reflect.Value { +loop: + for v.IsValid() { + switch av := v; av.Kind() { + case reflect.Ptr: + v = av.Elem() + case reflect.Interface: + v = av.Elem() + default: + break loop + } + } + return v +} + +// If the data for this template is a struct, find the named variable. +// Names of the form a.b.c are walked down the data tree. +// The special name "@" (the "cursor") denotes the current data. +// The value coming in (st.data) might need indirecting to reach +// a struct while the return value is not indirected - that is, +// it represents the actual named field. Leading stars indicate +// levels of indirection to be applied to the value. +func (t *Template) findVar(st *state, s string) reflect.Value { + data := st.data + flattenedName := strings.TrimLeft(s, "*") + numStars := len(s) - len(flattenedName) + s = flattenedName + if s == "@" { + return indirectPtr(data, numStars) + } + for _, elem := range strings.Split(s, ".", -1) { + // Look up field; data must be a struct or map. + data = t.lookup(st, data, elem) + if !data.IsValid() { + return reflect.Value{} + } + } + return indirectPtr(data, numStars) +} + +// Is there no data to look at? +func empty(v reflect.Value) bool { + v = indirect(v) + if !v.IsValid() { + return true + } + switch v.Kind() { + case reflect.Bool: + return v.Bool() == false + case reflect.String: + return v.String() == "" + case reflect.Struct: + return false + case reflect.Map: + return false + case reflect.Array: + return v.Len() == 0 + case reflect.Slice: + return v.Len() == 0 + } + return false +} + +// Look up a variable or method, up through the parent if necessary. +func (t *Template) varValue(name string, st *state) reflect.Value { + field := t.findVar(st, name) + if !field.IsValid() { + if st.parent == nil { + t.execError(st, t.linenum, "name not found: %s in type %s", name, st.data.Type()) + } + return t.varValue(name, st.parent) + } + return field +} + +func (t *Template) format(wr io.Writer, fmt string, val []interface{}, v *variableElement, st *state) { + fn := t.formatter(fmt) + if fn == nil { + t.execError(st, v.linenum, "missing formatter %s for variable %s", fmt, v.word[0]) + } + fn(wr, fmt, val...) +} + +// Evaluate a variable, looking up through the parent if necessary. +// If it has a formatter attached ({var|formatter}) run that too. +func (t *Template) writeVariable(v *variableElement, st *state) { + // Turn the words of the invocation into values. + val := make([]interface{}, len(v.word)) + for i, word := range v.word { + val[i] = t.varValue(word, st).Interface() + } + + for i, fmt := range v.fmts[:len(v.fmts)-1] { + b := &st.buf[i&1] + b.Reset() + t.format(b, fmt, val, v, st) + val = val[0:1] + val[0] = b.Bytes() + } + t.format(st.wr, v.fmts[len(v.fmts)-1], val, v, st) +} + +// Execute element i. Return next index to execute. +func (t *Template) executeElement(i int, st *state) int { + switch elem := t.elems.At(i).(type) { + case *textElement: + st.wr.Write(elem.text) + return i + 1 + case *literalElement: + st.wr.Write(elem.text) + return i + 1 + case *variableElement: + t.writeVariable(elem, st) + return i + 1 + case *sectionElement: + t.executeSection(elem, st) + return elem.end + case *repeatedElement: + t.executeRepeated(elem, st) + return elem.end + } + e := t.elems.At(i) + t.execError(st, 0, "internal error: bad directive in execute: %v %T\n", reflect.NewValue(e).Interface(), e) + return 0 +} + +// Execute the template. +func (t *Template) execute(start, end int, st *state) { + for i := start; i < end; { + i = t.executeElement(i, st) + } +} + +// Execute a .section +func (t *Template) executeSection(s *sectionElement, st *state) { + // Find driver data for this section. It must be in the current struct. + field := t.varValue(s.field, st) + if !field.IsValid() { + t.execError(st, s.linenum, ".section: cannot find field %s in %s", s.field, st.data.Type()) + } + st = st.clone(field) + start, end := s.start, s.or + if !empty(field) { + // Execute the normal block. + if end < 0 { + end = s.end + } + } else { + // Execute the .or block. If it's missing, do nothing. + start, end = s.or, s.end + if start < 0 { + return + } + } + for i := start; i < end; { + i = t.executeElement(i, st) + } +} + +// Return the result of calling the Iter method on v, or nil. +func iter(v reflect.Value) reflect.Value { + for j := 0; j < v.Type().NumMethod(); j++ { + mth := v.Type().Method(j) + fv := v.Method(j) + ft := fv.Type() + // TODO(rsc): NumIn() should return 0 here, because ft is from a curried FuncValue. + if mth.Name != "Iter" || ft.NumIn() != 1 || ft.NumOut() != 1 { + continue + } + ct := ft.Out(0) + if ct.Kind() != reflect.Chan || + ct.ChanDir()&reflect.RecvDir == 0 { + continue + } + return fv.Call(nil)[0] + } + return reflect.Value{} +} + +// Execute a .repeated section +func (t *Template) executeRepeated(r *repeatedElement, st *state) { + // Find driver data for this section. It must be in the current struct. + field := t.varValue(r.field, st) + if !field.IsValid() { + t.execError(st, r.linenum, ".repeated: cannot find field %s in %s", r.field, st.data.Type()) + } + field = indirect(field) + + start, end := r.start, r.or + if end < 0 { + end = r.end + } + if r.altstart >= 0 { + end = r.altstart + } + first := true + + // Code common to all the loops. + loopBody := func(newst *state) { + // .alternates between elements + if !first && r.altstart >= 0 { + for i := r.altstart; i < r.altend; { + i = t.executeElement(i, newst) + } + } + first = false + for i := start; i < end; { + i = t.executeElement(i, newst) + } + } + + if array := field; array.Kind() == reflect.Array || array.Kind() == reflect.Slice { + for j := 0; j < array.Len(); j++ { + loopBody(st.clone(array.Index(j))) + } + } else if m := field; m.Kind() == reflect.Map { + for _, key := range m.MapKeys() { + loopBody(st.clone(m.MapIndex(key))) + } + } else if ch := iter(field); ch.IsValid() { + for { + e, ok := ch.Recv() + if !ok { + break + } + loopBody(st.clone(e)) + } + } else { + t.execError(st, r.linenum, ".repeated: cannot repeat %s (type %s)", + r.field, field.Type()) + } + + if first { + // Empty. Execute the .or block, once. If it's missing, do nothing. + start, end := r.or, r.end + if start >= 0 { + newst := st.clone(field) + for i := start; i < end; { + i = t.executeElement(i, newst) + } + } + return + } +} + +// A valid delimiter must contain no white space and be non-empty. +func validDelim(d []byte) bool { + if len(d) == 0 { + return false + } + for _, c := range d { + if white(c) { + return false + } + } + return true +} + +// checkError is a deferred function to turn a panic with type *Error into a plain error return. +// Other panics are unexpected and so are re-enabled. +func checkError(error *os.Error) { + if v := recover(); v != nil { + if e, ok := v.(*Error); ok { + *error = e + } else { + // runtime errors should crash + panic(v) + } + } +} + +// -- Public interface + +// Parse initializes a Template by parsing its definition. The string +// s contains the template text. If any errors occur, Parse returns +// the error. +func (t *Template) Parse(s string) (err os.Error) { + if t.elems == nil { + return &Error{1, "template not allocated with New"} + } + if !validDelim(t.ldelim) || !validDelim(t.rdelim) { + return &Error{1, fmt.Sprintf("bad delimiter strings %q %q", t.ldelim, t.rdelim)} + } + defer checkError(&err) + t.buf = []byte(s) + t.p = 0 + t.linenum = 1 + t.parse() + return nil +} + +// ParseFile is like Parse but reads the template definition from the +// named file. +func (t *Template) ParseFile(filename string) (err os.Error) { + b, err := ioutil.ReadFile(filename) + if err != nil { + return err + } + return t.Parse(string(b)) +} + +// Execute applies a parsed template to the specified data object, +// generating output to wr. +func (t *Template) Execute(wr io.Writer, data interface{}) (err os.Error) { + // Extract the driver data. + val := reflect.NewValue(data) + defer checkError(&err) + t.p = 0 + t.execute(0, t.elems.Len(), &state{parent: nil, data: val, wr: wr}) + return nil +} + +// SetDelims sets the left and right delimiters for operations in the +// template. They are validated during parsing. They could be +// validated here but it's better to keep the routine simple. The +// delimiters are very rarely invalid and Parse has the necessary +// error-handling interface already. +func (t *Template) SetDelims(left, right string) { + t.ldelim = []byte(left) + t.rdelim = []byte(right) +} + +// Parse creates a Template with default parameters (such as {} for +// metacharacters). The string s contains the template text while +// the formatter map fmap, which may be nil, defines auxiliary functions +// for formatting variables. The template is returned. If any errors +// occur, err will be non-nil. +func Parse(s string, fmap FormatterMap) (t *Template, err os.Error) { + t = New(fmap) + err = t.Parse(s) + if err != nil { + t = nil + } + return +} + +// ParseFile is a wrapper function that creates a Template with default +// parameters (such as {} for metacharacters). The filename identifies +// a file containing the template text, while the formatter map fmap, which +// may be nil, defines auxiliary functions for formatting variables. +// The template is returned. If any errors occur, err will be non-nil. +func ParseFile(filename string, fmap FormatterMap) (t *Template, err os.Error) { + b, err := ioutil.ReadFile(filename) + if err != nil { + return nil, err + } + return Parse(string(b), fmap) +} + +// MustParse is like Parse but panics if the template cannot be parsed. +func MustParse(s string, fmap FormatterMap) *Template { + t, err := Parse(s, fmap) + if err != nil { + panic("template.MustParse error: " + err.String()) + } + return t +} + +// MustParseFile is like ParseFile but panics if the file cannot be read +// or the template cannot be parsed. +func MustParseFile(filename string, fmap FormatterMap) *Template { + b, err := ioutil.ReadFile(filename) + if err != nil { + panic("template.MustParseFile error: " + err.String()) + } + return MustParse(string(b), fmap) +} |