124 lines
No EOL
3.4 KiB
Go
124 lines
No EOL
3.4 KiB
Go
package parser
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import (
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"errors"
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"fmt"
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"io/ioutil"
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"strings"
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)
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// THE HYLIA PARSER
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type Element struct {
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Name string
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Content string
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FilePath string
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NestedElements []Element
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Variables map[string]string
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}
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func ParseFile(filename string) ([]Element, map[string]string, error) {
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// Hey, does the file we're trying to parse actually exist?
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data, err := ioutil.ReadFile(filename)
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if err != nil {
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return nil, nil, err
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}
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elements, variables, err := parseElements(string(data), filename)
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if err != nil {
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return nil, nil, fmt.Errorf("failed to parse elements: %w", err)
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}
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return elements, variables, nil
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}
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func parseElements(content, filename string) ([]Element, map[string]string, error) {
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elements := []Element{}
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variables := make(map[string]string)
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lines := strings.Split(content, "\n")
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var currentElement *Element
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var nestedContent strings.Builder
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for _, line := range lines {
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line = strings.TrimSpace(line)
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if strings.HasPrefix(line, "<var ") {
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name := extractAttributeValue(line, "name")
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if name == "" {
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return nil, nil, errors.New("Variable is missing a name ('name' attribute)")
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}
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valueStart := strings.Index(line, ">")
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valueEnd := strings.Index(line, "</var>")
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if valueStart == -1 || valueEnd == -1 {
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return nil, nil, errors.New("invalid variable structure")
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}
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value := strings.TrimSpace(line[valueStart+1 : valueEnd])
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variables[name] = value
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} else if strings.HasPrefix(line, "<element") {
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if currentElement != nil {
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currentElement.Content = nestedContent.String()
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parsedNested, nestedVars, _ := parseElements(nestedContent.String(), filename)
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currentElement.NestedElements = parsedNested
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mergeVariables(variables, nestedVars)
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elements = append(elements, *currentElement)
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nestedContent.Reset()
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}
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name := extractAttributeValue(line, "name")
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if name == "" {
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return nil, nil, errors.New("Element is missing a name ('name' attribute)")
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}
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currentElement = &Element{Name: name, FilePath: filename}
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} else if strings.HasPrefix(line, "</element>") {
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if currentElement != nil {
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currentElement.Content = nestedContent.String()
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parsedNested, nestedVars, _ := parseElements(nestedContent.String(), filename)
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currentElement.NestedElements = parsedNested
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mergeVariables(variables, nestedVars)
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elements = append(elements, *currentElement)
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nestedContent.Reset()
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currentElement = nil
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}
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} else {
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if currentElement != nil {
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nestedContent.WriteString(line + "\n")
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}
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}
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}
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return elements, variables, nil
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}
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func mergeVariables(target, source map[string]string) {
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for key, value := range source {
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target[key] = value
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}
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}
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// Extracts an attribute
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func extractAttributeValue(tag, attribute string) string {
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prefix := fmt.Sprintf(`%s="`, attribute)
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start := strings.Index(tag, prefix)
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if start == -1 {
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return ""
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}
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start += len(prefix)
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end := strings.Index(tag[start:], `"`)
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if end == -1 {
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return ""
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}
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return tag[start : start+end]
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}
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// Extracts an <element>
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func extractElementContent(tag, content string) (string, error) {
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start := strings.Index(content, tag)
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if start == -1 {
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return "", errors.New("element tag not found in content")
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}
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end := strings.Index(content[start:], "</element>")
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if end == -1 {
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return "", errors.New("missing end tag of element")
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}
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return content[start+len(tag) : start+end], nil
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} |