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This article covers features introduced in SpiderMonkey 1.8.5
Flattens a string. This makes getting the characters of the string infallible.
Syntax
JSFlatString * JS_FlattenString(JSContext *cx, JSString *str);
| Name | Type | Description |
|---|---|---|
cx |
JSContext * |
The context. Requires request. In a JS_THREADSAFE build, the caller must be in a request on this JSContext. |
str |
JSString * |
The string to flatten. |
Description
JS_FlattenString flattens a string str and returns a pointer to JSFlatString.
To catch errors, an opaque JSFlatString type is returned.
Note: The input and output of
JS_FlattenString() are the same actual GC-thing so only one needs to be rooted.If a JSString is known to be flat, you can use JS_ASSERT_STRING_IS_FLAT to make a debug-checked cast. Example:
// In a fallible situation JSFlatString *fstr = JS_FlattenString(cx, str); if (!fstr) return false; JS_ASSERT(fstr == JS_ASSERT_STRING_IS_FLAT(str)); // in an infallible situation, for the same 'str' const jschar *chars = JS_GetFlatStringChars(fstr) JS_ASSERT(chars);