35 lines
658 B
Go
35 lines
658 B
Go
package textedit
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type indentState struct {
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started, lineStarted bool
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}
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func indentEdit(first, rest []rune) func(rune, indentState) ([]rune, indentState) {
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return func(r rune, s indentState) ([]rune, indentState) {
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if r == '\n' {
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s.started = true
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s.lineStarted = false
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return []rune{'\n'}, s
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}
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var ret []rune
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if !s.started {
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ret = append(ret, first...)
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} else if !s.lineStarted {
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ret = append(ret, rest...)
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}
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ret = append(ret, r)
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s.started = true
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s.lineStarted = true
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return ret, s
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}
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}
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func indent(first, rest []rune) Editor {
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return Func(
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indentEdit(first, rest),
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func(indentState) []rune { return nil },
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)
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}
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