forked from lug/matterbridge
87 lines
1.8 KiB
Go
87 lines
1.8 KiB
Go
package parser
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import (
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"bytes"
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"github.com/gomarkdown/markdown/ast"
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)
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// citation parses a citation. In its most simple form [@ref], we allow multiple
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// being separated by semicolons and a sub reference inside ala pandoc: [@ref, p. 23].
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// Each citation can have a modifier: !, ? or - wich mean:
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//
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// ! - normative
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// ? - formative
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// - - suppressed
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//
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// The suffix starts after a comma, we strip any whitespace before and after. If the output
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// allows for it, this can be rendered.
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func citation(p *Parser, data []byte, offset int) (int, ast.Node) {
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// look for the matching closing bracket
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i := offset + 1
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for level := 1; level > 0 && i < len(data); i++ {
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switch {
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case data[i] == '\n':
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// no newlines allowed.
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return 0, nil
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case data[i-1] == '\\':
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continue
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case data[i] == '[':
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level++
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case data[i] == ']':
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level--
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if level <= 0 {
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i-- // compensate for extra i++ in for loop
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}
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}
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}
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if i >= len(data) {
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return 0, nil
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}
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node := &ast.Citation{}
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citations := bytes.Split(data[1:i], []byte(";"))
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for _, citation := range citations {
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var suffix []byte
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citation = bytes.TrimSpace(citation)
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j := 0
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if citation[j] != '@' {
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// not a citation, drop out entirely.
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return 0, nil
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}
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if c := bytes.Index(citation, []byte(",")); c > 0 {
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part := citation[:c]
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suff := citation[c+1:]
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part = bytes.TrimSpace(part)
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suff = bytes.TrimSpace(suff)
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citation = part
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suffix = suff
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}
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citeType := ast.CitationTypeInformative
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j = 1
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switch citation[j] {
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case '!':
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citeType = ast.CitationTypeNormative
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j++
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case '?':
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citeType = ast.CitationTypeInformative
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j++
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case '-':
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citeType = ast.CitationTypeSuppressed
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j++
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}
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node.Destination = append(node.Destination, citation[j:])
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node.Type = append(node.Type, citeType)
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node.Suffix = append(node.Suffix, suffix)
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}
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return i + 1, node
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}
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