1 files changed, 126 insertions, 0 deletions
diff --git a/src/string_mutable.zig b/src/string_mutable.zig
new file mode 100644
index 000000000..d846bf312
--- /dev/null
+++ b/src/string_mutable.zig
@@ -0,0 +1,126 @@
+const std = @import("std");
+const expect = std.testing.expect;
+
+usingnamespace @import("string_types.zig");
+
+pub const MutableString = struct {
+    allocator: *std.mem.Allocator,
+    list: std.ArrayListUnmanaged(u8),
+
+    pub fn init(allocator: *std.mem.Allocator, capacity: usize) !MutableString {
+        return MutableString{ .allocator = allocator, .list = try std.ArrayListUnmanaged(u8).initCapacity(allocator, capacity) };
+    }
+
+    pub fn initCopy(allocator: *std.mem.Allocator, str: anytype) !MutableString {
+        var mutable = try MutableString.init(allocator, std.mem.len(str));
+        try mutable.copy(str);
+        return mutable;
+    }
+
+    // Convert it to an ASCII identifier. Note: If you change this to a non-ASCII
+    // identifier, you're going to potentially cause trouble with non-BMP code
+    // points in target environments that don't support bracketed Unicode escapes.
+
+    pub fn ensureValidIdentifier(str: string, allocator: *std.mem.Allocator) !string {
+        if (str.len == 0) {
+            return "_";
+        }
+
+        var mutable = try MutableString.init(allocator, 0);
+
+        var needsGap = false;
+        for (str) |c| {
+            if (std.ascii.isLower(c) or std.ascii.isUpper(c) or (mutable.len() > 0 and std.ascii.isAlNum(c))) {
+                if (needsGap) {
+                    try mutable.appendChar('_');
+                    needsGap = false;
+                }
+                try mutable.appendChar(c);
+            } else if (!needsGap) {
+                needsGap = true;
+            }
+        }
+
+        if (mutable.len() > 0) {
+            return mutable.list.toOwnedSlice(allocator);
+        } else {
+            return str;
+        }
+    }
+
+    pub fn len(self: *MutableString) usize {
+        return self.list.items.len;
+    }
+
+    pub fn copy(self: *MutableString, str: anytype) !void {
+        try self.list.ensureCapacity(self.allocator, std.mem.len(str[0..]));
+
+        if (self.list.items.len == 0) {
+            try self.list.insertSlice(self.allocator, 0, str);
+        } else {
+            try self.list.replaceRange(self.allocator, 0, std.mem.len(str[0..]), str[0..]);
+        }
+    }
+
+    pub fn deinit(self: *MutableString) !void {
+        self.list.deinit(self.allocator);
+    }
+
+    pub fn appendChar(self: *MutableString, char: u8) !void {
+        try self.list.append(self.allocator, char);
+    }
+
+    pub fn appendCharAssumeCapacity(self: *MutableString, char: u8) !void {
+        try self.list.appendAssumeCapacity(self.allocator, char);
+    }
+
+    pub fn append(self: *MutableString, char: []const u8) !void {
+        try self.list.appendSlice(self.allocator, char);
+    }
+
+    pub fn appendAssumeCapacity(self: *MutableString, char: []const u8) !void {
+        try self.list.appendSliceAssumeCapacity(self.allocator, char);
+    }
+
+    // pub fn deleteAt(self: *MutableString, i: usize)  {
+    //     self.list.swapRemove(i);
+    // }
+
+    pub fn containsChar(self: *MutableString, char: u8) bool {
+        return self.indexOfChar(char) != null;
+    }
+
+    pub fn indexOfChar(self: *MutableString, char: u8) ?usize {
+        return std.mem.indexOfScalar(@TypeOf(char), self.list.items, char);
+    }
+
+    pub fn lastIndexOfChar(self: *MutableString, char: u8) ?usize {
+        return std.mem.lastIndexOfScalar(@TypeOf(char), self.list.items, char);
+    }
+
+    pub fn lastIndexOf(self: *MutableString, str: u8) ?usize {
+        return std.mem.lastIndexOf(u8, self.list.items, str);
+    }
+
+    pub fn indexOf(self: *MutableString, str: u8) ?usize {
+        return std.mem.indexOf(u8, self.list.items, str);
+    }
+
+    pub fn eql(self: *MutableString, other: anytype) bool {
+        return std.mem.eql(u8, self.list.items, other);
+    }
+};
+
+test "MutableString" {
+    const alloc = std.heap.page_allocator;
+
+    var str = try MutableString.initCopy(alloc, "hello");
+    expect(str.eql("hello"));
+}
+
+test "MutableString.ensureValidIdentifier" {
+    const alloc = std.heap.page_allocator;
+
+    std.testing.expectEqualStrings("jquery", try MutableString.ensureValidIdentifier("jquery", alloc));
+    std.testing.expectEqualStrings("jquery_foo", try MutableString.ensureValidIdentifier("jquery😋foo", alloc));
+}