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package gcss |
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|
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import ( |
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"bytes" |
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"fmt" |
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"io" |
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"strings" |
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) |
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|
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// declaration represents a declaration of CSS. |
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type declaration struct { |
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elementBase |
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property string |
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value string |
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} |
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|
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// WriteTo writes the declaration to the writer. |
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func (dec *declaration) WriteTo(w io.Writer) (int64, error) { |
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return dec.writeTo(w, nil) |
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} |
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|
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// writeTo writes the declaration to the writer. |
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func (dec *declaration) writeTo(w io.Writer, params map[string]string) (int64, error) { |
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bf := new(bytes.Buffer) |
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|
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bf.WriteString(dec.property) |
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bf.WriteString(colon) |
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|
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for i, v := range strings.Split(dec.value, space) { |
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if i > 0 { |
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bf.WriteString(space) |
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} |
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|
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for j, w := range strings.Split(v, comma) { |
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if j > 0 { |
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bf.WriteString(comma) |
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} |
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|
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if strings.HasPrefix(w, dollarMark) { |
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// Writing to the bytes.Buffer never returns an error. |
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dec.writeParamTo(bf, strings.TrimPrefix(w, dollarMark), params) |
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} else { |
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bf.WriteString(w) |
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} |
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} |
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} |
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|
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bf.WriteString(semicolon) |
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|
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n, err := w.Write(bf.Bytes()) |
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|
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return int64(n), err |
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} |
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|
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// writeParam writes the param to the writer. |
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func (dec *declaration) writeParamTo(w io.Writer, name string, params map[string]string) (int64, error) { |
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if s, ok := params[name]; ok { |
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if strings.HasPrefix(s, dollarMark) { |
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if v, ok := dec.Context().vars[strings.TrimPrefix(s, dollarMark)]; ok { |
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return v.WriteTo(w) |
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} |
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return 0, nil |
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} |
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|
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n, err := w.Write([]byte(s)) |
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return int64(n), err |
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} |
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|
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if v, ok := dec.Context().vars[name]; ok { |
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return v.WriteTo(w) |
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} |
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|
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return 0, nil |
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} |
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|
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// declarationPV extracts a declaration property and value |
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// from the line. |
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func declarationPV(ln *line) (string, string, error) { |
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pv := strings.SplitN(strings.TrimSpace(ln.s), space, 2) |
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|
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if len(pv) < 2 { |
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return "", "", fmt.Errorf("declaration's property and value should be divided by a space [line: %d]", ln.no) |
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} |
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|
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if !strings.HasSuffix(pv[0], colon) { |
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return "", "", fmt.Errorf("property should end with a colon [line: %d]", ln.no) |
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} |
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|
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return strings.TrimSuffix(pv[0], colon), pv[1], nil |
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} |
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|
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// newDeclaration creates and returns a declaration. |
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func newDeclaration(ln *line, parent element) (*declaration, error) { |
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property, value, err := declarationPV(ln) |
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|
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if err != nil { |
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return nil, err |
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} |
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|
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if strings.HasSuffix(value, semicolon) { |
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return nil, fmt.Errorf("declaration must not end with %q [line: %d]", semicolon, ln.no) |
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} |
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|
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return &declaration{ |
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elementBase: newElementBase(ln, parent), |
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property: property, |
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value: value, |
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}, nil |
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} |
