ref: 723ec555e75fbfa94d90d3ecbcd5775d6c7800e1
dir: /parser/pageparser/pagelexer_intro.go/
// Copyright 2018 The Hugo Authors. All rights reserved.
//
// 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 pageparser provides a parser for Hugo content files (Markdown, HTML etc.) in Hugo.
// This implementation is highly inspired by the great talk given by Rob Pike called "Lexical Scanning in Go"
// It's on YouTube, Google it!.
// See slides here: http://cuddle.googlecode.com/hg/talk/lex.html
package pageparser
func lexIntroSection(l *pageLexer) stateFunc {
l.summaryDivider = summaryDivider
LOOP:
for {
r := l.next()
if r == eof {
break
}
switch {
case r == '+':
return l.lexFrontMatterSection(TypeFrontMatterTOML, r, "TOML", delimTOML)
case r == '-':
return l.lexFrontMatterSection(TypeFrontMatterYAML, r, "YAML", delimYAML)
case r == '{':
return lexFrontMatterJSON
case r == '#':
return lexFrontMatterOrgMode
case r == byteOrderMark:
l.emit(TypeIgnore)
case !isSpace(r) && !isEndOfLine(r):
if r == '<' {
l.backup()
if l.hasPrefix(htmlCommentStart) {
// This may be commented out front matter, which should
// still be read.
l.consumeToNextLine()
l.isInHTMLComment = true
l.emit(TypeIgnore)
continue LOOP
} else {
return l.errorf("plain HTML documents not supported")
}
}
break LOOP
}
}
// Now move on to the shortcodes.
return lexMainSection
}
func lexEndFromtMatterHTMLComment(l *pageLexer) stateFunc {
l.isInHTMLComment = false
right := l.index(htmlCommentEnd)
if right == -1 {
return l.errorf("starting HTML comment with no end")
}
l.pos += right + len(htmlCommentEnd)
l.emit(TypeIgnore)
// Now move on to the shortcodes.
return lexMainSection
}
func lexFrontMatterJSON(l *pageLexer) stateFunc {
// Include the left delimiter
l.backup()
var (
inQuote bool
level int
)
for {
r := l.next()
switch {
case r == eof:
return l.errorf("unexpected EOF parsing JSON front matter")
case r == '{':
if !inQuote {
level++
}
case r == '}':
if !inQuote {
level--
}
case r == '"':
inQuote = !inQuote
case r == '\\':
// This may be an escaped quote. Make sure it's not marked as a
// real one.
l.next()
}
if level == 0 {
break
}
}
l.consumeCRLF()
l.emit(TypeFrontMatterJSON)
return lexMainSection
}
func lexFrontMatterOrgMode(l *pageLexer) stateFunc {
/*
#+TITLE: Test File For chaseadamsio/goorgeous
#+AUTHOR: Chase Adams
#+DESCRIPTION: Just another golang parser for org content!
*/
l.summaryDivider = summaryDividerOrg
l.backup()
if !l.hasPrefix(delimOrg) {
return lexMainSection
}
// Read lines until we no longer see a #+ prefix
LOOP:
for {
r := l.next()
switch {
case r == '\n':
if !l.hasPrefix(delimOrg) {
break LOOP
}
case r == eof:
break LOOP
}
}
l.emit(TypeFrontMatterORG)
return lexMainSection
}
// Handle YAML or TOML front matter.
func (l *pageLexer) lexFrontMatterSection(tp ItemType, delimr rune, name string, delim []byte) stateFunc {
for i := 0; i < 2; i++ {
if r := l.next(); r != delimr {
return l.errorf("invalid %s delimiter", name)
}
}
// Let front matter start at line 1
wasEndOfLine := l.consumeCRLF()
// We don't care about the delimiters.
l.ignore()
var r rune
for {
if !wasEndOfLine {
r = l.next()
if r == eof {
return l.errorf("EOF looking for end %s front matter delimiter", name)
}
}
if wasEndOfLine || isEndOfLine(r) {
if l.hasPrefix(delim) {
l.emit(tp)
l.pos += 3
l.consumeCRLF()
l.ignore()
break
}
}
wasEndOfLine = false
}
return lexMainSection
}