1 files changed, 333 insertions, 0 deletions
diff --git a/caddyconfig/caddyfile/dispenser.go b/caddyconfig/caddyfile/dispenser.go
new file mode 100755
index 0000000..1cf5d04
--- /dev/null
+++ b/caddyconfig/caddyfile/dispenser.go
@@ -0,0 +1,333 @@
+// Copyright 2015 Matthew Holt and The Caddy Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package caddyfile
+
+import (
+	"errors"
+	"fmt"
+	"strings"
+)
+
+// Dispenser is a type that dispenses tokens, similarly to a lexer,
+// except that it can do so with some notion of structure. An empty
+// Dispenser is invalid; call NewDispenser to make a proper instance.
+type Dispenser struct {
+	filename string
+	tokens   []Token
+	cursor   int
+	nesting  int
+}
+
+// NewDispenser returns a Dispenser filled with the given tokens.
+func NewDispenser(filename string, tokens []Token) *Dispenser {
+	return &Dispenser{
+		filename: filename,
+		tokens:   tokens,
+		cursor:   -1,
+	}
+}
+
+// Next loads the next token. Returns true if a token
+// was loaded; false otherwise. If false, all tokens
+// have been consumed.
+func (d *Dispenser) Next() bool {
+	if d.cursor < len(d.tokens)-1 {
+		d.cursor++
+		return true
+	}
+	return false
+}
+
+// Prev moves to the previous token. It does the inverse
+// of Next(). Generally, this should only be used in
+// special cases such as deleting a token from the slice
+// that d is iterating. In that case, without using Prev(),
+// the dispenser would be pointing at the wrong token since
+// deleting a token implicitly advances the cursor.
+func (d *Dispenser) Prev() bool {
+	if d.cursor > 0 {
+		d.cursor--
+		return true
+	}
+	return false
+}
+
+// NextArg loads the next token if it is on the same
+// line and if it is not a block opening (open curly
+// brace). Returns true if an argument token was
+// loaded; false otherwise. If false, all tokens on
+// the line have been consumed except for potentially
+// a block opening. It handles imported tokens
+// correctly.
+func (d *Dispenser) NextArg() bool {
+	if !d.nextOnSameLine() {
+		return false
+	}
+	if d.Val() == "{" {
+		// roll back; a block opening is not an argument
+		d.cursor--
+		return false
+	}
+	return true
+}
+
+// nextOnSameLine advances the cursor if the next
+// token is on the same line of the same file.
+func (d *Dispenser) nextOnSameLine() bool {
+	if d.cursor < 0 {
+		d.cursor++
+		return true
+	}
+	if d.cursor >= len(d.tokens) {
+		return false
+	}
+	if d.cursor < len(d.tokens)-1 &&
+		d.tokens[d.cursor].File == d.tokens[d.cursor+1].File &&
+		d.tokens[d.cursor].Line+d.numLineBreaks(d.cursor) == d.tokens[d.cursor+1].Line {
+		d.cursor++
+		return true
+	}
+	return false
+}
+
+// NextLine loads the next token only if it is not on the same
+// line as the current token, and returns true if a token was
+// loaded; false otherwise. If false, there is not another token
+// or it is on the same line. It handles imported tokens correctly.
+func (d *Dispenser) NextLine() bool {
+	if d.cursor < 0 {
+		d.cursor++
+		return true
+	}
+	if d.cursor >= len(d.tokens) {
+		return false
+	}
+	if d.cursor < len(d.tokens)-1 &&
+		(d.tokens[d.cursor].File != d.tokens[d.cursor+1].File ||
+			d.tokens[d.cursor].Line+d.numLineBreaks(d.cursor) < d.tokens[d.cursor+1].Line) {
+		d.cursor++
+		return true
+	}
+	return false
+}
+
+// NextBlock can be used as the condition of a for loop
+// to load the next token as long as it opens a block or
+// is already in a block. It returns true if a token was
+// loaded, or false when the block's closing curly brace
+// was loaded and thus the block ended. Nested blocks are
+// not supported.
+func (d *Dispenser) NextBlock() bool {
+	if d.nesting > 0 {
+		d.Next()
+		if d.Val() == "}" {
+			d.nesting--
+			return false
+		}
+		return true
+	}
+	if !d.nextOnSameLine() { // block must open on same line
+		return false
+	}
+	if d.Val() != "{" {
+		d.cursor-- // roll back if not opening brace
+		return false
+	}
+	d.Next()
+	if d.Val() == "}" {
+		// open and then closed right away
+		return false
+	}
+	d.nesting++
+	return true
+}
+
+// Nested returns true if the token is currently nested
+// inside a block (i.e. an open curly brace was consumed).
+func (d *Dispenser) Nested() bool {
+	return d.nesting > 0
+}
+
+// Val gets the text of the current token. If there is no token
+// loaded, it returns empty string.
+func (d *Dispenser) Val() string {
+	if d.cursor < 0 || d.cursor >= len(d.tokens) {
+		return ""
+	}
+	return d.tokens[d.cursor].Text
+}
+
+// Line gets the line number of the current token. If there is no token
+// loaded, it returns 0.
+func (d *Dispenser) Line() int {
+	if d.cursor < 0 || d.cursor >= len(d.tokens) {
+		return 0
+	}
+	return d.tokens[d.cursor].Line
+}
+
+// File gets the filename of the current token. If there is no token loaded,
+// it returns the filename originally given when parsing started.
+func (d *Dispenser) File() string {
+	if d.cursor < 0 || d.cursor >= len(d.tokens) {
+		return d.filename
+	}
+	if tokenFilename := d.tokens[d.cursor].File; tokenFilename != "" {
+		return tokenFilename
+	}
+	return d.filename
+}
+
+// Args is a convenience function that loads the next arguments
+// (tokens on the same line) into an arbitrary number of strings
+// pointed to in targets. If there are fewer tokens available
+// than string pointers, the remaining strings will not be changed
+// and false will be returned. If there were enough tokens available
+// to fill the arguments, then true will be returned.
+func (d *Dispenser) Args(targets ...*string) bool {
+	for i := 0; i < len(targets); i++ {
+		if !d.NextArg() {
+			return false
+		}
+		*targets[i] = d.Val()
+	}
+	return true
+}
+
+// RemainingArgs loads any more arguments (tokens on the same line)
+// into a slice and returns them. Open curly brace tokens also indicate
+// the end of arguments, and the curly brace is not included in
+// the return value nor is it loaded.
+func (d *Dispenser) RemainingArgs() []string {
+	var args []string
+	for d.NextArg() {
+		args = append(args, d.Val())
+	}
+	return args
+}
+
+// NewFromNextTokens returns a new dispenser with a copy of
+// the tokens from the current token until the end of the
+// "directive" whether that be to the end of the line or
+// the end of a block that starts at the end of the line.
+func (d *Dispenser) NewFromNextTokens() *Dispenser {
+	var tkns []Token
+	tkns = append(tkns, d.Token())
+	for d.NextArg() {
+		tkns = append(tkns, d.Token())
+	}
+	if d.Next() && d.Val() == "{" {
+		tkns = append(tkns, d.Token())
+		for d.NextBlock() {
+			for d.Nested() {
+				tkns = append(tkns, d.Token())
+				d.NextBlock()
+			}
+		}
+		tkns = append(tkns, d.Token())
+	} else {
+		d.cursor--
+	}
+	return NewDispenser(d.filename, tkns)
+}
+
+// Token returns the current token.
+func (d *Dispenser) Token() Token {
+	if d.cursor < 0 || d.cursor >= len(d.tokens) {
+		return Token{}
+	}
+	return d.tokens[d.cursor]
+}
+
+// Cursor returns the current cursor (token index).
+func (d *Dispenser) Cursor() int {
+	return d.cursor
+}
+
+// ArgErr returns an argument error, meaning that another
+// argument was expected but not found. In other words,
+// a line break or open curly brace was encountered instead of
+// an argument.
+func (d *Dispenser) ArgErr() error {
+	if d.Val() == "{" {
+		return d.Err("Unexpected token '{', expecting argument")
+	}
+	return d.Errf("Wrong argument count or unexpected line ending after '%s'", d.Val())
+}
+
+// SyntaxErr creates a generic syntax error which explains what was
+// found and what was expected.
+func (d *Dispenser) SyntaxErr(expected string) error {
+	msg := fmt.Sprintf("%s:%d - Syntax error: Unexpected token '%s', expecting '%s'", d.File(), d.Line(), d.Val(), expected)
+	return errors.New(msg)
+}
+
+// EOFErr returns an error indicating that the dispenser reached
+// the end of the input when searching for the next token.
+func (d *Dispenser) EOFErr() error {
+	return d.Errf("Unexpected EOF")
+}
+
+// Err generates a custom parse-time error with a message of msg.
+func (d *Dispenser) Err(msg string) error {
+	msg = fmt.Sprintf("%s:%d - Error during parsing: %s", d.File(), d.Line(), msg)
+	return errors.New(msg)
+}
+
+// Errf is like Err, but for formatted error messages
+func (d *Dispenser) Errf(format string, args ...interface{}) error {
+	return d.Err(fmt.Sprintf(format, args...))
+}
+
+// Delete deletes the current token and returns the updated slice
+// of tokens. The cursor is not advanced to the next token.
+// Because deletion modifies the underlying slice, this method
+// should only be called if you have access to the original slice
+// of tokens and/or are using the slice of tokens outside this
+// Dispenser instance. If you do not re-assign the slice with the
+// return value of this method, inconsistencies in the token
+// array will become apparent (or worse, hide from you like they
+// did me for 3 and a half freaking hours late one night).
+func (d *Dispenser) Delete() []Token {
+	if d.cursor >= 0 && d.cursor < len(d.tokens)-1 {
+		d.tokens = append(d.tokens[:d.cursor], d.tokens[d.cursor+1:]...)
+		d.cursor--
+	}
+	return d.tokens
+}
+
+// numLineBreaks counts how many line breaks are in the token
+// value given by the token index tknIdx. It returns 0 if the
+// token does not exist or there are no line breaks.
+func (d *Dispenser) numLineBreaks(tknIdx int) int {
+	if tknIdx < 0 || tknIdx >= len(d.tokens) {
+		return 0
+	}
+	return strings.Count(d.tokens[tknIdx].Text, "\n")
+}
+
+// isNewLine determines whether the current token is on a different
+// line (higher line number) than the previous token. It handles imported
+// tokens correctly. If there isn't a previous token, it returns true.
+func (d *Dispenser) isNewLine() bool {
+	if d.cursor < 1 {
+		return true
+	}
+	if d.cursor > len(d.tokens)-1 {
+		return false
+	}
+	return d.tokens[d.cursor-1].File != d.tokens[d.cursor].File ||
+		d.tokens[d.cursor-1].Line+d.numLineBreaks(d.cursor-1) < d.tokens[d.cursor].Line
+}