49 lines
1020 B
Go
49 lines
1020 B
Go
package markdown
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import (
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"fmt"
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"regexp"
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"strings"
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)
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var underlineRe = regexp.MustCompile(`(?m)_([^_]+)_`)
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// underline returns the terminal-formatted underline text @t
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func underline(t string) string {
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return fmt.Sprintf("\x1b[4m%s\x1b[24m", strings.Replace(t, "\x1b[0m", "\x1b[0m\x1b[4m", -1))
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}
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// underlineTransform the @input text using markdown-like syntax :
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// - "normal _underline_ normal"
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func underlineTransform(input string) (string, error) {
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output := ""
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cursor := int(0)
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// 1. Replace for each match
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for _, match := range underlineRe.FindAllStringSubmatchIndex(input, -1) {
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// (1) add gap between input start OR previous match
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output += input[cursor:match[0]]
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cursor = match[1]
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// (2) extract features
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text := ""
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if match[3]-match[2] > 0 {
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text = input[match[2]:match[3]]
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}
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// (3) replace text with bold text
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output += underline(text)
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}
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// 2. Add end of input
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if cursor < len(input) {
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output += input[cursor:]
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}
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// 3. print final output
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return output, nil
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}
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