runtime/syntax/syntax_converter.go

   1 package main
   2
   3 import (
   4         "fmt"
   5         "io/ioutil"
   6         "os"
   7         "regexp"
   8         "strings"
   9 )
  10
  11 type SingleRule struct {
  12         color string
  13         regex string
  14 }
  15
  16 type MultiRule struct {
  17         color string
  18         start string
  19         end   string
  20 }
  21
  22 // JoinRule takes a syntax rule (which can be multiple regular expressions)
  23 // and joins it into one regular expression by ORing everything together
  24 func JoinRule(rule string) string {
  25         split := strings.Split(rule, `" "`)
  26         joined := strings.Join(split, "|")
  27         joined = joined
  28         return joined
  29 }
  30
  31 func parseFile(text, filename string) (filetype, syntax, header string, rules []interface{}) {
  32         lines := strings.Split(text, "\n")
  33
  34         // Regex for parsing syntax statements
  35         syntaxParser := regexp.MustCompile(`syntax "(.*?)"\s+"(.*)"+`)
  36         // Regex for parsing header statements
  37         headerParser := regexp.MustCompile(`header "(.*)"`)
  38
  39         // Regex for parsing standard syntax rules
  40         ruleParser := regexp.MustCompile(`color (.*?)\s+(?:\((.+?)?\)\s+)?"(.*)"`)
  41         // Regex for parsing syntax rules with start="..." end="..."
  42         ruleStartEndParser := regexp.MustCompile(`color (.*?)\s+(?:\((.+?)?\)\s+)?start="(.*)"\s+end="(.*)"`)
  43
  44         for lineNum, line := range lines {
  45                 line = strings.TrimSpace(line)
  46                 if line == "" {
  47                         continue
  48                 }
  49                 if strings.HasPrefix(line, "#") {
  50                         continue
  51                 }
  52                 if strings.HasPrefix(line, "syntax") {
  53                         syntaxMatches := syntaxParser.FindSubmatch([]byte(line))
  54                         if len(syntaxMatches) == 3 {
  55                                 filetype = string(syntaxMatches[1])
  56                                 syntax = JoinRule(string(syntaxMatches[2]))
  57                         } else {
  58                                 fmt.Println(filename, lineNum, "Syntax statement is not valid: "+line)
  59                                 continue
  60                         }
  61                 }
  62                 if strings.HasPrefix(line, "header") {
  63                         // Header statement
  64                         headerMatches := headerParser.FindSubmatch([]byte(line))
  65                         if len(headerMatches) == 2 {
  66                                 header = JoinRule(string(headerMatches[1]))
  67                         } else {
  68                                 fmt.Println(filename, lineNum, "Header statement is not valid: "+line)
  69                                 continue
  70                         }
  71                 }
  72
  73                 // Syntax rule, but it could be standard or start-end
  74                 if ruleParser.MatchString(line) {
  75                         // Standard syntax rule
  76                         // Parse the line
  77                         submatch := ruleParser.FindSubmatch([]byte(line))
  78                         var color string
  79                         var regexStr string
  80                         var flags string
  81                         if len(submatch) == 4 {
  82                                 // If len is 4 then the user specified some additional flags to use
  83                                 color = string(submatch[1])
  84                                 flags = string(submatch[2])
  85                                 if flags != "" {
  86                                         regexStr = "(?" + flags + ")" + JoinRule(string(submatch[3]))
  87                                 } else {
  88                                         regexStr = JoinRule(string(submatch[3]))
  89                                 }
  90                         } else if len(submatch) == 3 {
  91                                 // If len is 3, no additional flags were given
  92                                 color = string(submatch[1])
  93                                 regexStr = JoinRule(string(submatch[2]))
  94                         } else {
  95                                 // If len is not 3 or 4 there is a problem
  96                                 fmt.Println(filename, lineNum, "Invalid statement: "+line)
  97                                 continue
  98                         }
  99
 100                         rules = append(rules, SingleRule{color, regexStr})
 101                 } else if ruleStartEndParser.MatchString(line) {
 102                         // Start-end syntax rule
 103                         submatch := ruleStartEndParser.FindSubmatch([]byte(line))
 104                         var color string
 105                         var start string
 106                         var end string
 107                         // Use m and s flags by default
 108                         flags := "ms"
 109                         if len(submatch) == 5 {
 110                                 // If len is 5 the user provided some additional flags
 111                                 color = string(submatch[1])
 112                                 flags += string(submatch[2])
 113                                 start = string(submatch[3])
 114                                 end = string(submatch[4])
 115                         } else if len(submatch) == 4 {
 116                                 // If len is 4 the user did not provide additional flags
 117                                 color = string(submatch[1])
 118                                 start = string(submatch[2])
 119                                 end = string(submatch[3])
 120                         } else {
 121                                 // If len is not 4 or 5 there is a problem
 122                                 fmt.Println(filename, lineNum, "Invalid statement: "+line)
 123                                 continue
 124                         }
 125
 126                         // rules[color] = "(?" + flags + ")" + "(" + start + ").*?(" + end + ")"
 127                         rules = append(rules, MultiRule{color, start, end})
 128                 }
 129         }
 130
 131         return
 132 }
 133
 134 func generateFile(filetype, syntax, header string, rules []interface{}) string {
 135         output := ""
 136
 137         output += fmt.Sprintf("filetype: %s\n\n", filetype)
 138         output += fmt.Sprintf("detect: \n    filename: \"%s\"\n", strings.Replace(syntax, "\\", "\\\\", -1))
 139
 140         if header != "" {
 141                 output += fmt.Sprintf("    header: \"%s\"\n", strings.Replace(header, "\\", "\\\\", -1))
 142         }
 143
 144         output += "\nrules:\n"
 145
 146         for _, r := range rules {
 147                 if rule, ok := r.(SingleRule); ok {
 148                         output += fmt.Sprintf("    - %s: \"%s\"\n", rule.color, strings.Replace(strings.Replace(rule.regex, "\\", "\\\\", -1), "\"", "\\\"", -1))
 149                 } else if rule, ok := r.(MultiRule); ok {
 150                         output += fmt.Sprintf("    - %s:\n", rule.color)
 151                         output += fmt.Sprintf("        start: \"%s\"\n", strings.Replace(strings.Replace(rule.start, "\\", "\\\\", -1), "\"", "\\\"", -1))
 152                         output += fmt.Sprintf("        end: \"%s\"\n", strings.Replace(strings.Replace(rule.end, "\\", "\\\\", -1), "\"", "\\\"", -1))
 153                         output += fmt.Sprintf("        rules: []\n\n")
 154                 }
 155         }
 156
 157         return output
 158 }
 159
 160 func main() {
 161         if len(os.Args) < 2 {
 162                 fmt.Println("no args")
 163                 return
 164         }
 165
 166         data, _ := ioutil.ReadFile(os.Args[1])
 167         fmt.Print(generateFile(parseFile(string(data), os.Args[1])))
 168 }