github.com/linchen2chris/hugo@v0.0.0-20230307053224-cec209389705/markup/blackfriday/anchors.go (about)

     1  // Copyright 2022 The Hugo Authors. All rights reserved.
     2  //
     3  // Licensed under the Apache License, Version 2.0 (the "License");
     4  // you may not use this file except in compliance with the License.
     5  // You may obtain a copy of the License at
     6  // http://www.apache.org/licenses/LICENSE-2.0
     7  //
     8  // Unless required by applicable law or agreed to in writing, software
     9  // distributed under the License is distributed on an "AS IS" BASIS,
    10  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    11  // See the License for the specific language governing permissions and
    12  // limitations under the License.
    13  
    14  // Package blackfriday holds some copmpability functions for the old Blackfriday v1 Markdown engine.
    15  package blackfriday
    16  
    17  import "unicode"
    18  
    19  // SanitizedAnchorName is how Blackfriday sanitizes anchor names.
    20  // Implementation borrowed from https://github.com/russross/blackfriday/blob/a477dd1646916742841ed20379f941cfa6c5bb6f/block.go#L1464
    21  // Note that Hugo removed its Blackfriday support in v0.100.0, but you can still use this strategy for
    22  // auto ID generation.
    23  func SanitizedAnchorName(text string) string {
    24  	var anchorName []rune
    25  	futureDash := false
    26  	for _, r := range text {
    27  		switch {
    28  		case unicode.IsLetter(r) || unicode.IsNumber(r):
    29  			if futureDash && len(anchorName) > 0 {
    30  				anchorName = append(anchorName, '-')
    31  			}
    32  			futureDash = false
    33  			anchorName = append(anchorName, unicode.ToLower(r))
    34  		default:
    35  			futureDash = true
    36  		}
    37  	}
    38  	return string(anchorName)
    39  }