Support for other regex flavours

src/OnigRegExp.ts

@@ -1,4 +1,4 @@
-import OnigScanner, { IOnigCaptureIndex } from './OnigScanner'
+import OnigScanner, { IOnigCaptureIndex, IOnigOptions } from './OnigScanner'
 import OnigString from './OnigString';
 
 export interface IOnigSearchResult extends IOnigCaptureIndex {
@@ -11,12 +11,13 @@ class OnigRegExp {
     /**
      * Create a new regex with the given pattern
      * @param source A string pattern
+     * @param options Optional settings to specify syntax/regex flavour
      */
-    constructor(source: string) {
+    constructor(source: string, options?: IOnigOptions) {
         this.source = source
 
         try {
-            this.scanner = new OnigScanner([this.source])
+            this.scanner = new OnigScanner([this.source], options)
         } catch (error) {
             // doesn't make much sense, but this to pass atom/node-oniguruam tests
         }

src/OnigScanner.ts

@@ -20,6 +20,29 @@ interface INativeOnigHInfo {
     regexTPtrs: Uint8Array | null
 }
 
+enum OnigSyntax {
+    ONIG_SYNTAX_ONIGURUMA,
+    ONIG_SYNTAX_ASIS,
+    ONIG_SYNTAX_POSIX_BASIC,
+    ONIG_SYNTAX_POSIX_EXTENDED,
+    ONIG_SYNTAX_EMACS,
+    ONIG_SYNTAX_GREP,
+    ONIG_SYNTAX_GNU_REGEX,
+    ONIG_SYNTAX_JAVA,
+    ONIG_SYNTAX_PERL,
+    ONIG_SYNTAX_PERL_NG,
+    ONIG_SYNTAX_RUBY,
+}
+
+export interface IOnigOptions {
+    syntax: 'perl' | 'posix' | 'java'
+}
+
+const onigSyntaxMap = new Map<string, OnigSyntax>()
+    .set('perl', OnigSyntax.ONIG_SYNTAX_PERL_NG)
+    .set('posix', OnigSyntax.ONIG_SYNTAX_POSIX_EXTENDED)
+    .set('java', OnigSyntax.ONIG_SYNTAX_JAVA)
+
 export interface IOnigCaptureIndex {
     index: number
     start: number
@@ -51,11 +74,13 @@ const cache: Cache<OnigScanner, INativeOnigHInfo> = new LRUCache({
 
 export class OnigScanner {
     private sources: string[]
+    private syntax: OnigSyntax = OnigSyntax.ONIG_SYNTAX_ONIGURUMA
     /**
      * Create a new scanner with the given patterns
      * @param patterns  An array of string patterns
+     * @param options Optional settings to specify syntax/regex flavour
      */
-    constructor(patterns: string[]) {
+    constructor(patterns: string[], options?: IOnigOptions) {
         if (onigasmH === null) {
             throw new Error(`Onigasm has not been initialized, call loadWASM from 'onigasm' exports before using any other API`)
         }
@@ -65,6 +90,15 @@ export class OnigScanner {
                 throw new TypeError(`First parameter to OnigScanner constructor must be array of (pattern) strings`)
             }
         }
+
+        if (options && typeof options.syntax === 'string') {
+            if (onigSyntaxMap.has(options.syntax)) {
+                this.syntax = onigSyntaxMap.get(options.syntax)
+            } else {
+                throw new Error(`Unsupported syntax ${options.syntax}`)
+            }
+        }
+
         this.sources = patterns.slice()
     }
 
@@ -109,7 +143,7 @@ export class OnigScanner {
             const regexTPtrs = []
             for (let i = 0; i < this.sources.length; i++) {
                 const pattern = this.sources[i];
-                status = onigasmH.ccall('compilePattern', 'number', ['string', 'number'], [pattern, regexTAddrRecieverPtr])
+                status = onigasmH.ccall('compilePattern', 'number', ['string', 'number'], [pattern, regexTAddrRecieverPtr], this.syntax)
                 if (status !== 0) {
                     const errString = onigasmH.ccall('getLastError', 'string')
                     throw new Error(errString)

src/onigasm.cc

@@ -17,14 +17,31 @@ char *getLastError()
 }
 
 EMSCRIPTEN_KEEPALIVE
-int compilePattern(UChar *pattern, int *regexTPtr)
+int compilePattern(UChar *pattern, int *regexTPtr, int syntaxCode)
 {
   int r;
   regex_t *reg;
   OnigErrorInfo einfo;
+  OnigSyntaxType *syntax;
+  // see enum OnigSyntax in `./OnigScanner.ts`
+  switch (syntaxCode)
+  {
+  case 3:
+    syntax = ONIG_SYNTAX_POSIX_EXTENDED;
+    break;
+  case 7:
+    syntax = ONIG_SYNTAX_JAVA;
+    break;
+  case 8:
+    syntax = ONIG_SYNTAX_PERL_NG;
+    break;
+  default:
+    syntax = ONIG_SYNTAX_DEFAULT;
+  }
+
   r = onig_new(&reg, pattern, pattern + strlen((char *)pattern),
                ONIG_OPTION_CAPTURE_GROUP, ONIG_ENCODING_UTF8,
-               ONIG_SYNTAX_DEFAULT, &einfo);
+               syntax, &einfo);
   if (r != ONIG_NORMAL)
   {
     lastErrCode = r;