source: code/trunk/vendor/github.com/yosssi/gcss/mixin_declaration.go@ 75

package gcss

import (
        "fmt"
        "io"
        "strings"
)

// mixinDeclaration represents a mixin declaration.
type mixinDeclaration struct {
        elementBase
        name       string
        paramNames []string
}

// WriteTo writes the selector to the writer.
func (md *mixinDeclaration) WriteTo(w io.Writer) (int64, error) {
        return 0, nil
}

// mixinNP extracts a mixin name and parameters from the line.
func mixinNP(ln *line, isDeclaration bool) (string, []string, error) {
        s := strings.TrimSpace(ln.s)

        if !strings.HasPrefix(s, dollarMark) {
                return "", nil, fmt.Errorf("mixin must start with %q [line: %d]", dollarMark, ln.no)
        }

        s = strings.TrimPrefix(s, dollarMark)

        np := strings.Split(s, openParenthesis)

        if len(np) != 2 {
                return "", nil, fmt.Errorf("mixin's format is invalid [line: %d]", ln.no)
        }

        paramsS := strings.TrimSpace(np[1])

        if !strings.HasSuffix(paramsS, closeParenthesis) {
                return "", nil, fmt.Errorf("mixin must end with %q [line: %d]", closeParenthesis, ln.no)
        }

        paramsS = strings.TrimSuffix(paramsS, closeParenthesis)

        if strings.Index(paramsS, closeParenthesis) != -1 {
                return "", nil, fmt.Errorf("mixin's format is invalid [line: %d]", ln.no)
        }

        var params []string

        if paramsS != "" {
                params = strings.Split(paramsS, comma)
        }

        for i, p := range params {
                p = strings.TrimSpace(p)

                if isDeclaration {
                        if !strings.HasPrefix(p, dollarMark) {
                                return "", nil, fmt.Errorf("mixin's parameter must start with %q [line: %d]", dollarMark, ln.no)
                        }

                        p = strings.TrimPrefix(p, dollarMark)
                }

                params[i] = p
        }

        return np[0], params, nil
}

// newMixinDeclaration creates and returns a mixin declaration.
func newMixinDeclaration(ln *line, parent element) (*mixinDeclaration, error) {
        name, paramNames, err := mixinNP(ln, true)

        if err != nil {
                return nil, err
        }

        return &mixinDeclaration{
                elementBase: newElementBase(ln, parent),
                name:        name,
                paramNames:  paramNames,
        }, nil
}