Merge pull request #88 from tangiel/apostrophe

typographer: add basic support for apostrophes
yuin · Jan 11, 2020 · faaafa5 · faaafa5
2 parents 5294fa5 + 45fa0e2
commit faaafa5
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Showing 2 changed files with 32 additions and 0 deletions.
diff --git a/extension/_test/typographer.txt b/extension/_test/typographer.txt
@@ -18,3 +18,10 @@ This should "be" replaced
 //- - - - - - - - -//
 <p><strong>&ndash;</strong> <em>&mdash;</em> a&hellip;&laquo; b&raquo;</p>
 //= = = = = = = = = = = = = = = = = = = = = = = =//
+
+4
+//- - - - - - - - -//
+Some say '90s, others say 90's, but I can't say which is best.
+//- - - - - - - - -//
+<p>Some say &rsquo;90s, others say 90&rsquo;s, but I can&rsquo;t say which is best.</p>
+//= = = = = = = = = = = = = = = = = = = = = = = =//
diff --git a/extension/typographer.go b/extension/typographer.go
@@ -1,6 +1,8 @@
 package extension
 
 import (
+	"unicode"
+
 	"github.com/yuin/goldmark"
 	gast "github.com/yuin/goldmark/ast"
 	"github.com/yuin/goldmark/parser"
@@ -31,6 +33,8 @@ const (
 	LeftAngleQuote
 	// RightAngleQuote is >>
 	RightAngleQuote
+	// Apostrophe is '
+	Apostrophe
 
 	typographicPunctuationMax
 )
@@ -52,6 +56,7 @@ func newDefaultSubstitutions() [][]byte {
 	replacements[Ellipsis] = []byte("&hellip;")
 	replacements[LeftAngleQuote] = []byte("&laquo;")
 	replacements[RightAngleQuote] = []byte("&raquo;")
+	replacements[Apostrophe] = []byte("&rsquo;")
 
 	return replacements
 }
@@ -189,6 +194,26 @@ func (s *typographerParser) Parse(parent gast.Node, block text.Reader, pc parser
 			return nil
 		}
 		if c == '\'' {
+			if s.Substitutions[Apostrophe] != nil {
+				// Handle decade abbrevations such as '90s
+				if d.CanOpen && !d.CanClose && len(line) > 3 && util.IsNumeric(line[1]) && util.IsNumeric(line[2]) && line[3] == 's' {
+					after := util.ToRune(line, 4)
+					if len(line) == 3 || unicode.IsSpace(after) || unicode.IsPunct(after) {
+						node := gast.NewString(s.Substitutions[Apostrophe])
+						node.SetCode(true)
+						block.Advance(1)
+						return node
+					}
+				}
+				// Convert normal apostrophes. This is probably more flexible than necessary but
+				// converts any apostrophe in between two alphanumerics.
+				if len(line) > 1 && (unicode.IsDigit(before) || unicode.IsLetter(before)) && (util.IsAlphaNumeric(line[1])) {
+					node := gast.NewString(s.Substitutions[Apostrophe])
+					node.SetCode(true)
+					block.Advance(1)
+					return node
+				}
+			}
 			if s.Substitutions[LeftSingleQuote] != nil && d.CanOpen && !d.CanClose {
 				node := gast.NewString(s.Substitutions[LeftSingleQuote])
 				node.SetCode(true)