diff options
Diffstat (limited to 'vendor/github.com/alecthomas/template/parse/parse.go')
| -rw-r--r-- | vendor/github.com/alecthomas/template/parse/parse.go | 700 |
1 files changed, 0 insertions, 700 deletions
diff --git a/vendor/github.com/alecthomas/template/parse/parse.go b/vendor/github.com/alecthomas/template/parse/parse.go deleted file mode 100644 index 0d77ade87..000000000 --- a/vendor/github.com/alecthomas/template/parse/parse.go +++ /dev/null @@ -1,700 +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 parse builds parse trees for templates as defined by text/template -// and html/template. Clients should use those packages to construct templates -// rather than this one, which provides shared internal data structures not -// intended for general use. -package parse - -import ( - "bytes" - "fmt" - "runtime" - "strconv" - "strings" -) - -// Tree is the representation of a single parsed template. -type Tree struct { - Name string // name of the template represented by the tree. - ParseName string // name of the top-level template during parsing, for error messages. - Root *ListNode // top-level root of the tree. - text string // text parsed to create the template (or its parent) - // Parsing only; cleared after parse. - funcs []map[string]interface{} - lex *lexer - token [3]item // three-token lookahead for parser. - peekCount int - vars []string // variables defined at the moment. -} - -// Copy returns a copy of the Tree. Any parsing state is discarded. -func (t *Tree) Copy() *Tree { - if t == nil { - return nil - } - return &Tree{ - Name: t.Name, - ParseName: t.ParseName, - Root: t.Root.CopyList(), - text: t.text, - } -} - -// Parse returns a map from template name to parse.Tree, created by parsing the -// templates described in the argument string. The top-level template will be -// given the specified name. If an error is encountered, parsing stops and an -// empty map is returned with the error. -func Parse(name, text, leftDelim, rightDelim string, funcs ...map[string]interface{}) (treeSet map[string]*Tree, err error) { - treeSet = make(map[string]*Tree) - t := New(name) - t.text = text - _, err = t.Parse(text, leftDelim, rightDelim, treeSet, funcs...) - return -} - -// next returns the next token. -func (t *Tree) next() item { - if t.peekCount > 0 { - t.peekCount-- - } else { - t.token[0] = t.lex.nextItem() - } - return t.token[t.peekCount] -} - -// backup backs the input stream up one token. -func (t *Tree) backup() { - t.peekCount++ -} - -// backup2 backs the input stream up two tokens. -// The zeroth token is already there. -func (t *Tree) backup2(t1 item) { - t.token[1] = t1 - t.peekCount = 2 -} - -// backup3 backs the input stream up three tokens -// The zeroth token is already there. -func (t *Tree) backup3(t2, t1 item) { // Reverse order: we're pushing back. - t.token[1] = t1 - t.token[2] = t2 - t.peekCount = 3 -} - -// peek returns but does not consume the next token. -func (t *Tree) peek() item { - if t.peekCount > 0 { - return t.token[t.peekCount-1] - } - t.peekCount = 1 - t.token[0] = t.lex.nextItem() - return t.token[0] -} - -// nextNonSpace returns the next non-space token. -func (t *Tree) nextNonSpace() (token item) { - for { - token = t.next() - if token.typ != itemSpace { - break - } - } - return token -} - -// peekNonSpace returns but does not consume the next non-space token. -func (t *Tree) peekNonSpace() (token item) { - for { - token = t.next() - if token.typ != itemSpace { - break - } - } - t.backup() - return token -} - -// Parsing. - -// New allocates a new parse tree with the given name. -func New(name string, funcs ...map[string]interface{}) *Tree { - return &Tree{ - Name: name, - funcs: funcs, - } -} - -// ErrorContext returns a textual representation of the location of the node in the input text. -// The receiver is only used when the node does not have a pointer to the tree inside, -// which can occur in old code. -func (t *Tree) ErrorContext(n Node) (location, context string) { - pos := int(n.Position()) - tree := n.tree() - if tree == nil { - tree = t - } - text := tree.text[:pos] - byteNum := strings.LastIndex(text, "\n") - if byteNum == -1 { - byteNum = pos // On first line. - } else { - byteNum++ // After the newline. - byteNum = pos - byteNum - } - lineNum := 1 + strings.Count(text, "\n") - context = n.String() - if len(context) > 20 { - context = fmt.Sprintf("%.20s...", context) - } - return fmt.Sprintf("%s:%d:%d", tree.ParseName, lineNum, byteNum), context -} - -// errorf formats the error and terminates processing. -func (t *Tree) errorf(format string, args ...interface{}) { - t.Root = nil - format = fmt.Sprintf("template: %s:%d: %s", t.ParseName, t.lex.lineNumber(), format) - panic(fmt.Errorf(format, args...)) -} - -// error terminates processing. -func (t *Tree) error(err error) { - t.errorf("%s", err) -} - -// expect consumes the next token and guarantees it has the required type. -func (t *Tree) expect(expected itemType, context string) item { - token := t.nextNonSpace() - if token.typ != expected { - t.unexpected(token, context) - } - return token -} - -// expectOneOf consumes the next token and guarantees it has one of the required types. -func (t *Tree) expectOneOf(expected1, expected2 itemType, context string) item { - token := t.nextNonSpace() - if token.typ != expected1 && token.typ != expected2 { - t.unexpected(token, context) - } - return token -} - -// unexpected complains about the token and terminates processing. -func (t *Tree) unexpected(token item, context string) { - t.errorf("unexpected %s in %s", token, context) -} - -// recover is the handler that turns panics into returns from the top level of Parse. -func (t *Tree) recover(errp *error) { - e := recover() - if e != nil { - if _, ok := e.(runtime.Error); ok { - panic(e) - } - if t != nil { - t.stopParse() - } - *errp = e.(error) - } - return -} - -// startParse initializes the parser, using the lexer. -func (t *Tree) startParse(funcs []map[string]interface{}, lex *lexer) { - t.Root = nil - t.lex = lex - t.vars = []string{"$"} - t.funcs = funcs -} - -// stopParse terminates parsing. -func (t *Tree) stopParse() { - t.lex = nil - t.vars = nil - t.funcs = nil -} - -// Parse parses the template definition string to construct a representation of -// the template for execution. If either action delimiter string is empty, the -// default ("{{" or "}}") is used. Embedded template definitions are added to -// the treeSet map. -func (t *Tree) Parse(text, leftDelim, rightDelim string, treeSet map[string]*Tree, funcs ...map[string]interface{}) (tree *Tree, err error) { - defer t.recover(&err) - t.ParseName = t.Name - t.startParse(funcs, lex(t.Name, text, leftDelim, rightDelim)) - t.text = text - t.parse(treeSet) - t.add(treeSet) - t.stopParse() - return t, nil -} - -// add adds tree to the treeSet. -func (t *Tree) add(treeSet map[string]*Tree) { - tree := treeSet[t.Name] - if tree == nil || IsEmptyTree(tree.Root) { - treeSet[t.Name] = t - return - } - if !IsEmptyTree(t.Root) { - t.errorf("template: multiple definition of template %q", t.Name) - } -} - -// IsEmptyTree reports whether this tree (node) is empty of everything but space. -func IsEmptyTree(n Node) bool { - switch n := n.(type) { - case nil: - return true - case *ActionNode: - case *IfNode: - case *ListNode: - for _, node := range n.Nodes { - if !IsEmptyTree(node) { - return false - } - } - return true - case *RangeNode: - case *TemplateNode: - case *TextNode: - return len(bytes.TrimSpace(n.Text)) == 0 - case *WithNode: - default: - panic("unknown node: " + n.String()) - } - return false -} - -// parse is the top-level parser for a template, essentially the same -// as itemList except it also parses {{define}} actions. -// It runs to EOF. -func (t *Tree) parse(treeSet map[string]*Tree) (next Node) { - t.Root = t.newList(t.peek().pos) - for t.peek().typ != itemEOF { - if t.peek().typ == itemLeftDelim { - delim := t.next() - if t.nextNonSpace().typ == itemDefine { - newT := New("definition") // name will be updated once we know it. - newT.text = t.text - newT.ParseName = t.ParseName - newT.startParse(t.funcs, t.lex) - newT.parseDefinition(treeSet) - continue - } - t.backup2(delim) - } - n := t.textOrAction() - if n.Type() == nodeEnd { - t.errorf("unexpected %s", n) - } - t.Root.append(n) - } - return nil -} - -// parseDefinition parses a {{define}} ... {{end}} template definition and -// installs the definition in the treeSet map. The "define" keyword has already -// been scanned. -func (t *Tree) parseDefinition(treeSet map[string]*Tree) { - const context = "define clause" - name := t.expectOneOf(itemString, itemRawString, context) - var err error - t.Name, err = strconv.Unquote(name.val) - if err != nil { - t.error(err) - } - t.expect(itemRightDelim, context) - var end Node - t.Root, end = t.itemList() - if end.Type() != nodeEnd { - t.errorf("unexpected %s in %s", end, context) - } - t.add(treeSet) - t.stopParse() -} - -// itemList: -// textOrAction* -// Terminates at {{end}} or {{else}}, returned separately. -func (t *Tree) itemList() (list *ListNode, next Node) { - list = t.newList(t.peekNonSpace().pos) - for t.peekNonSpace().typ != itemEOF { - n := t.textOrAction() - switch n.Type() { - case nodeEnd, nodeElse: - return list, n - } - list.append(n) - } - t.errorf("unexpected EOF") - return -} - -// textOrAction: -// text | action -func (t *Tree) textOrAction() Node { - switch token := t.nextNonSpace(); token.typ { - case itemElideNewline: - return t.elideNewline() - case itemText: - return t.newText(token.pos, token.val) - case itemLeftDelim: - return t.action() - default: - t.unexpected(token, "input") - } - return nil -} - -// elideNewline: -// Remove newlines trailing rightDelim if \\ is present. -func (t *Tree) elideNewline() Node { - token := t.peek() - if token.typ != itemText { - t.unexpected(token, "input") - return nil - } - - t.next() - stripped := strings.TrimLeft(token.val, "\n\r") - diff := len(token.val) - len(stripped) - if diff > 0 { - // This is a bit nasty. We mutate the token in-place to remove - // preceding newlines. - token.pos += Pos(diff) - token.val = stripped - } - return t.newText(token.pos, token.val) -} - -// Action: -// control -// command ("|" command)* -// Left delim is past. Now get actions. -// First word could be a keyword such as range. -func (t *Tree) action() (n Node) { - switch token := t.nextNonSpace(); token.typ { - case itemElse: - return t.elseControl() - case itemEnd: - return t.endControl() - case itemIf: - return t.ifControl() - case itemRange: - return t.rangeControl() - case itemTemplate: - return t.templateControl() - case itemWith: - return t.withControl() - } - t.backup() - // Do not pop variables; they persist until "end". - return t.newAction(t.peek().pos, t.lex.lineNumber(), t.pipeline("command")) -} - -// Pipeline: -// declarations? command ('|' command)* -func (t *Tree) pipeline(context string) (pipe *PipeNode) { - var decl []*VariableNode - pos := t.peekNonSpace().pos - // Are there declarations? - for { - if v := t.peekNonSpace(); v.typ == itemVariable { - t.next() - // Since space is a token, we need 3-token look-ahead here in the worst case: - // in "$x foo" we need to read "foo" (as opposed to ":=") to know that $x is an - // argument variable rather than a declaration. So remember the token - // adjacent to the variable so we can push it back if necessary. - tokenAfterVariable := t.peek() - if next := t.peekNonSpace(); next.typ == itemColonEquals || (next.typ == itemChar && next.val == ",") { - t.nextNonSpace() - variable := t.newVariable(v.pos, v.val) - decl = append(decl, variable) - t.vars = append(t.vars, v.val) - if next.typ == itemChar && next.val == "," { - if context == "range" && len(decl) < 2 { - continue - } - t.errorf("too many declarations in %s", context) - } - } else if tokenAfterVariable.typ == itemSpace { - t.backup3(v, tokenAfterVariable) - } else { - t.backup2(v) - } - } - break - } - pipe = t.newPipeline(pos, t.lex.lineNumber(), decl) - for { - switch token := t.nextNonSpace(); token.typ { - case itemRightDelim, itemRightParen: - if len(pipe.Cmds) == 0 { - t.errorf("missing value for %s", context) - } - if token.typ == itemRightParen { - t.backup() - } - return - case itemBool, itemCharConstant, itemComplex, itemDot, itemField, itemIdentifier, - itemNumber, itemNil, itemRawString, itemString, itemVariable, itemLeftParen: - t.backup() - pipe.append(t.command()) - default: - t.unexpected(token, context) - } - } -} - -func (t *Tree) parseControl(allowElseIf bool, context string) (pos Pos, line int, pipe *PipeNode, list, elseList *ListNode) { - defer t.popVars(len(t.vars)) - line = t.lex.lineNumber() - pipe = t.pipeline(context) - var next Node - list, next = t.itemList() - switch next.Type() { - case nodeEnd: //done - case nodeElse: - if allowElseIf { - // Special case for "else if". If the "else" is followed immediately by an "if", - // the elseControl will have left the "if" token pending. Treat - // {{if a}}_{{else if b}}_{{end}} - // as - // {{if a}}_{{else}}{{if b}}_{{end}}{{end}}. - // To do this, parse the if as usual and stop at it {{end}}; the subsequent{{end}} - // is assumed. This technique works even for long if-else-if chains. - // TODO: Should we allow else-if in with and range? - if t.peek().typ == itemIf { - t.next() // Consume the "if" token. - elseList = t.newList(next.Position()) - elseList.append(t.ifControl()) - // Do not consume the next item - only one {{end}} required. - break - } - } - elseList, next = t.itemList() - if next.Type() != nodeEnd { - t.errorf("expected end; found %s", next) - } - } - return pipe.Position(), line, pipe, list, elseList -} - -// If: -// {{if pipeline}} itemList {{end}} -// {{if pipeline}} itemList {{else}} itemList {{end}} -// If keyword is past. -func (t *Tree) ifControl() Node { - return t.newIf(t.parseControl(true, "if")) -} - -// Range: -// {{range pipeline}} itemList {{end}} -// {{range pipeline}} itemList {{else}} itemList {{end}} -// Range keyword is past. -func (t *Tree) rangeControl() Node { - return t.newRange(t.parseControl(false, "range")) -} - -// With: -// {{with pipeline}} itemList {{end}} -// {{with pipeline}} itemList {{else}} itemList {{end}} -// If keyword is past. -func (t *Tree) withControl() Node { - return t.newWith(t.parseControl(false, "with")) -} - -// End: -// {{end}} -// End keyword is past. -func (t *Tree) endControl() Node { - return t.newEnd(t.expect(itemRightDelim, "end").pos) -} - -// Else: -// {{else}} -// Else keyword is past. -func (t *Tree) elseControl() Node { - // Special case for "else if". - peek := t.peekNonSpace() - if peek.typ == itemIf { - // We see "{{else if ... " but in effect rewrite it to {{else}}{{if ... ". - return t.newElse(peek.pos, t.lex.lineNumber()) - } - return t.newElse(t.expect(itemRightDelim, "else").pos, t.lex.lineNumber()) -} - -// Template: -// {{template stringValue pipeline}} -// Template keyword is past. The name must be something that can evaluate -// to a string. -func (t *Tree) templateControl() Node { - var name string - token := t.nextNonSpace() - switch token.typ { - case itemString, itemRawString: - s, err := strconv.Unquote(token.val) - if err != nil { - t.error(err) - } - name = s - default: - t.unexpected(token, "template invocation") - } - var pipe *PipeNode - if t.nextNonSpace().typ != itemRightDelim { - t.backup() - // Do not pop variables; they persist until "end". - pipe = t.pipeline("template") - } - return t.newTemplate(token.pos, t.lex.lineNumber(), name, pipe) -} - -// command: -// operand (space operand)* -// space-separated arguments up to a pipeline character or right delimiter. -// we consume the pipe character but leave the right delim to terminate the action. -func (t *Tree) command() *CommandNode { - cmd := t.newCommand(t.peekNonSpace().pos) - for { - t.peekNonSpace() // skip leading spaces. - operand := t.operand() - if operand != nil { - cmd.append(operand) - } - switch token := t.next(); token.typ { - case itemSpace: - continue - case itemError: - t.errorf("%s", token.val) - case itemRightDelim, itemRightParen: - t.backup() - case itemPipe: - default: - t.errorf("unexpected %s in operand; missing space?", token) - } - break - } - if len(cmd.Args) == 0 { - t.errorf("empty command") - } - return cmd -} - -// operand: -// term .Field* -// An operand is a space-separated component of a command, -// a term possibly followed by field accesses. -// A nil return means the next item is not an operand. -func (t *Tree) operand() Node { - node := t.term() - if node == nil { - return nil - } - if t.peek().typ == itemField { - chain := t.newChain(t.peek().pos, node) - for t.peek().typ == itemField { - chain.Add(t.next().val) - } - // Compatibility with original API: If the term is of type NodeField - // or NodeVariable, just put more fields on the original. - // Otherwise, keep the Chain node. - // TODO: Switch to Chains always when we can. - switch node.Type() { - case NodeField: - node = t.newField(chain.Position(), chain.String()) - case NodeVariable: - node = t.newVariable(chain.Position(), chain.String()) - default: - node = chain - } - } - return node -} - -// term: -// literal (number, string, nil, boolean) -// function (identifier) -// . -// .Field -// $ -// '(' pipeline ')' -// A term is a simple "expression". -// A nil return means the next item is not a term. -func (t *Tree) term() Node { - switch token := t.nextNonSpace(); token.typ { - case itemError: - t.errorf("%s", token.val) - case itemIdentifier: - if !t.hasFunction(token.val) { - t.errorf("function %q not defined", token.val) - } - return NewIdentifier(token.val).SetTree(t).SetPos(token.pos) - case itemDot: - return t.newDot(token.pos) - case itemNil: - return t.newNil(token.pos) - case itemVariable: - return t.useVar(token.pos, token.val) - case itemField: - return t.newField(token.pos, token.val) - case itemBool: - return t.newBool(token.pos, token.val == "true") - case itemCharConstant, itemComplex, itemNumber: - number, err := t.newNumber(token.pos, token.val, token.typ) - if err != nil { - t.error(err) - } - return number - case itemLeftParen: - pipe := t.pipeline("parenthesized pipeline") - if token := t.next(); token.typ != itemRightParen { - t.errorf("unclosed right paren: unexpected %s", token) - } - return pipe - case itemString, itemRawString: - s, err := strconv.Unquote(token.val) - if err != nil { - t.error(err) - } - return t.newString(token.pos, token.val, s) - } - t.backup() - return nil -} - -// hasFunction reports if a function name exists in the Tree's maps. -func (t *Tree) hasFunction(name string) bool { - for _, funcMap := range t.funcs { - if funcMap == nil { - continue - } - if funcMap[name] != nil { - return true - } - } - return false -} - -// popVars trims the variable list to the specified length -func (t *Tree) popVars(n int) { - t.vars = t.vars[:n] -} - -// useVar returns a node for a variable reference. It errors if the -// variable is not defined. -func (t *Tree) useVar(pos Pos, name string) Node { - v := t.newVariable(pos, name) - for _, varName := range t.vars { - if varName == v.Ident[0] { - return v - } - } - t.errorf("undefined variable %q", v.Ident[0]) - return nil -} |