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remove xml.zig. This may be back later, but currently is unused

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Emil Lerch 2021-05-13 15:55:06 -07:00
parent 1b831cd91d
commit 0727fb5585
Signed by: lobo
GPG key ID: A7B62D657EF764F8
1 changed files with 0 additions and 649 deletions
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src/xml.zig
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@ -1,649 +0,0 @@
const std = @import("std");
const mem = std.mem;
const testing = std.testing;
const Allocator = mem.Allocator;
const ArenaAllocator = std.heap.ArenaAllocator;
const ArrayList = std.ArrayList;
pub const Attribute = struct {
name: []const u8, value: []const u8
};
pub const Content = union(enum) {
CharData: []const u8, Comment: []const u8, Element: *Element
};
pub const Element = struct {
pub const AttributeList = ArrayList(*Attribute);
pub const ContentList = ArrayList(Content);
tag: []const u8,
attributes: AttributeList,
children: ContentList,
fn init(tag: []const u8, alloc: *Allocator) Element {
return .{
.tag = tag,
.attributes = AttributeList.init(alloc),
.children = ContentList.init(alloc),
};
}
pub fn getAttribute(self: *Element, attrib_name: []const u8) ?[]const u8 {
for (self.attributes.items) |child| {
if (mem.eql(u8, child.name, attrib_name)) {
return child.value;
}
}
return null;
}
pub fn getCharData(self: *Element, child_tag: []const u8) ?[]const u8 {
const child = self.findChildByTag(child_tag) orelse return null;
if (child.children.items.len != 1) {
return null;
}
return switch (child.children.items[0]) {
.CharData => |char_data| char_data,
else => null,
};
}
pub fn iterator(self: *Element) ChildIterator {
return .{
.items = self.children.items,
.i = 0,
};
}
pub fn elements(self: *Element) ChildElementIterator {
return .{
.inner = self.iterator(),
};
}
pub fn findChildByTag(self: *Element, tag: []const u8) ?*Element {
return self.findChildrenByTag(tag).next();
}
pub fn findChildrenByTag(self: *Element, tag: []const u8) FindChildrenByTagIterator {
return .{
.inner = self.elements(),
.tag = tag,
};
}
pub const ChildIterator = struct {
items: []Content,
i: usize,
pub fn next(self: *ChildIterator) ?*Content {
if (self.i < self.items.len) {
self.i += 1;
return &self.items[self.i - 1];
}
return null;
}
};
pub const ChildElementIterator = struct {
inner: ChildIterator,
pub fn next(self: *ChildElementIterator) ?*Element {
while (self.inner.next()) |child| {
if (child.* != .Element) {
continue;
}
return child.*.Element;
}
return null;
}
};
pub const FindChildrenByTagIterator = struct {
inner: ChildElementIterator,
tag: []const u8,
pub fn next(self: *FindChildrenByTagIterator) ?*Element {
while (self.inner.next()) |child| {
if (!mem.eql(u8, child.tag, self.tag)) {
continue;
}
return child;
}
return null;
}
};
};
pub const XmlDecl = struct {
version: []const u8, encoding: ?[]const u8, standalone: ?bool
};
pub const Document = struct {
arena: ArenaAllocator,
xml_decl: ?*XmlDecl,
root: *Element,
pub fn deinit(self: Document) void {
var arena = self.arena; // Copy to stack so self can be taken by value.
arena.deinit();
}
};
const ParseContext = struct {
source: []const u8,
offset: usize,
line: usize,
column: usize,
fn init(source: []const u8) ParseContext {
return .{
.source = source,
.offset = 0,
.line = 0,
.column = 0,
};
}
fn peek(self: *ParseContext) ?u8 {
return if (self.offset < self.source.len) self.source[self.offset] else null;
}
fn consume(self: *ParseContext) !u8 {
if (self.offset < self.source.len) {
return self.consumeNoEof();
}
return error.UnexpectedEof;
}
fn consumeNoEof(self: *ParseContext) u8 {
std.debug.assert(self.offset < self.source.len);
const c = self.source[self.offset];
self.offset += 1;
if (c == '\n') {
self.line += 1;
self.column = 0;
} else {
self.column += 1;
}
return c;
}
fn eat(self: *ParseContext, char: u8) bool {
self.expect(char) catch return false;
return true;
}
fn expect(self: *ParseContext, expected: u8) !void {
if (self.peek()) |actual| {
if (expected != actual) {
return error.UnexpectedCharacter;
}
_ = self.consumeNoEof();
return;
}
return error.UnexpectedEof;
}
fn eatStr(self: *ParseContext, text: []const u8) bool {
self.expectStr(text) catch return false;
return true;
}
fn expectStr(self: *ParseContext, text: []const u8) !void {
if (self.source.len < self.offset + text.len) {
return error.UnexpectedEof;
} else if (std.mem.startsWith(u8, self.source[self.offset..], text)) {
var i: usize = 0;
while (i < text.len) : (i += 1) {
_ = self.consumeNoEof();
}
return;
}
return error.UnexpectedCharacter;
}
fn eatWs(self: *ParseContext) bool {
var ws = false;
while (self.peek()) |ch| {
switch (ch) {
' ', '\t', '\n', '\r' => {
ws = true;
_ = self.consumeNoEof();
},
else => break,
}
}
return ws;
}
fn expectWs(self: *ParseContext) !void {
if (!self.eatWs()) return error.UnexpectedCharacter;
}
fn currentLine(self: ParseContext) []const u8 {
var begin: usize = 0;
if (mem.lastIndexOfScalar(u8, self.source[0..self.offset], '\n')) |prev_nl| {
begin = prev_nl + 1;
}
var end = mem.indexOfScalarPos(u8, self.source, self.offset, '\n') orelse self.source.len;
return self.source[begin..end];
}
};
test "ParseContext" {
{
var ctx = ParseContext.init("I like pythons");
testing.expectEqual(@as(?u8, 'I'), ctx.peek());
testing.expectEqual(@as(u8, 'I'), ctx.consumeNoEof());
testing.expectEqual(@as(?u8, ' '), ctx.peek());
testing.expectEqual(@as(u8, ' '), try ctx.consume());
testing.expect(ctx.eat('l'));
testing.expectEqual(@as(?u8, 'i'), ctx.peek());
testing.expectEqual(false, ctx.eat('a'));
testing.expectEqual(@as(?u8, 'i'), ctx.peek());
try ctx.expect('i');
testing.expectEqual(@as(?u8, 'k'), ctx.peek());
testing.expectError(error.UnexpectedCharacter, ctx.expect('a'));
testing.expectEqual(@as(?u8, 'k'), ctx.peek());
testing.expect(ctx.eatStr("ke"));
testing.expectEqual(@as(?u8, ' '), ctx.peek());
testing.expect(ctx.eatWs());
testing.expectEqual(@as(?u8, 'p'), ctx.peek());
testing.expectEqual(false, ctx.eatWs());
testing.expectEqual(@as(?u8, 'p'), ctx.peek());
testing.expectEqual(false, ctx.eatStr("aaaaaaaaa"));
testing.expectEqual(@as(?u8, 'p'), ctx.peek());
testing.expectError(error.UnexpectedEof, ctx.expectStr("aaaaaaaaa"));
testing.expectEqual(@as(?u8, 'p'), ctx.peek());
testing.expectError(error.UnexpectedCharacter, ctx.expectStr("pytn"));
testing.expectEqual(@as(?u8, 'p'), ctx.peek());
try ctx.expectStr("python");
testing.expectEqual(@as(?u8, 's'), ctx.peek());
}
{
var ctx = ParseContext.init("");
testing.expectEqual(ctx.peek(), null);
testing.expectError(error.UnexpectedEof, ctx.consume());
testing.expectEqual(ctx.eat('p'), false);
testing.expectError(error.UnexpectedEof, ctx.expect('p'));
}
}
pub const ParseError = error{ IllegalCharacter, UnexpectedEof, UnexpectedCharacter, UnclosedValue, UnclosedComment, InvalidName, InvalidEntity, InvalidStandaloneValue, NonMatchingClosingTag, InvalidDocument, OutOfMemory };
pub fn parse(backing_allocator: *Allocator, source: []const u8) !Document {
var ctx = ParseContext.init(source);
return try parseDocument(&ctx, backing_allocator);
}
fn parseDocument(ctx: *ParseContext, backing_allocator: *Allocator) !Document {
var doc = Document{
.arena = ArenaAllocator.init(backing_allocator),
.xml_decl = null,
.root = undefined,
};
errdefer doc.deinit();
try trySkipComments(ctx, &doc.arena.allocator);
doc.xml_decl = try tryParseProlog(ctx, &doc.arena.allocator);
_ = ctx.eatWs();
try trySkipComments(ctx, &doc.arena.allocator);
doc.root = (try tryParseElement(ctx, &doc.arena.allocator)) orelse return error.InvalidDocument;
_ = ctx.eatWs();
try trySkipComments(ctx, &doc.arena.allocator);
if (ctx.peek() != null) return error.InvalidDocument;
return doc;
}
fn parseAttrValue(ctx: *ParseContext, alloc: *Allocator) ![]const u8 {
const quote = try ctx.consume();
if (quote != '"' and quote != '\'') return error.UnexpectedCharacter;
const begin = ctx.offset;
while (true) {
const c = ctx.consume() catch return error.UnclosedValue;
if (c == quote) break;
}
const end = ctx.offset - 1;
return try dupeAndUnescape(alloc, ctx.source[begin..end]);
}
fn parseEqAttrValue(ctx: *ParseContext, alloc: *Allocator) ![]const u8 {
_ = ctx.eatWs();
try ctx.expect('=');
_ = ctx.eatWs();
return try parseAttrValue(ctx, alloc);
}
fn parseNameNoDupe(ctx: *ParseContext) ![]const u8 {
// XML's spec on names is very long, so to make this easier
// we just take any character that is not special and not whitespace
const begin = ctx.offset;
while (ctx.peek()) |ch| {
switch (ch) {
' ', '\t', '\n', '\r' => break,
'&', '"', '\'', '<', '>', '?', '=', '/' => break,
else => _ = ctx.consumeNoEof(),
}
}
const end = ctx.offset;
if (begin == end) return error.InvalidName;
return ctx.source[begin..end];
}
fn tryParseCharData(ctx: *ParseContext, alloc: *Allocator) !?[]const u8 {
const begin = ctx.offset;
while (ctx.peek()) |ch| {
switch (ch) {
'<', '>' => break,
else => _ = ctx.consumeNoEof(),
}
}
const end = ctx.offset;
if (begin == end) return null;
return try dupeAndUnescape(alloc, ctx.source[begin..end]);
}
fn parseContent(ctx: *ParseContext, alloc: *Allocator) ParseError!Content {
if (try tryParseCharData(ctx, alloc)) |cd| {
return Content{ .CharData = cd };
} else if (try tryParseComment(ctx, alloc)) |comment| {
return Content{ .Comment = comment };
} else if (try tryParseElement(ctx, alloc)) |elem| {
return Content{ .Element = elem };
} else {
return error.UnexpectedCharacter;
}
}
fn tryParseAttr(ctx: *ParseContext, alloc: *Allocator) !?*Attribute {
const name = parseNameNoDupe(ctx) catch return null;
_ = ctx.eatWs();
try ctx.expect('=');
_ = ctx.eatWs();
const value = try parseAttrValue(ctx, alloc);
const attr = try alloc.create(Attribute);
attr.name = try mem.dupe(alloc, u8, name);
attr.value = value;
return attr;
}
fn tryParseElement(ctx: *ParseContext, alloc: *Allocator) !?*Element {
const start = ctx.offset;
if (!ctx.eat('<')) return null;
const tag = parseNameNoDupe(ctx) catch {
ctx.offset = start;
return null;
};
const element = try alloc.create(Element);
element.* = Element.init(try std.mem.dupe(alloc, u8, tag), alloc);
while (ctx.eatWs()) {
const attr = (try tryParseAttr(ctx, alloc)) orelse break;
try element.attributes.append(attr);
}
if (ctx.eatStr("/>")) {
return element;
}
try ctx.expect('>');
while (true) {
if (ctx.peek() == null) {
return error.UnexpectedEof;
} else if (ctx.eatStr("</")) {
break;
}
const content = try parseContent(ctx, alloc);
try element.children.append(content);
}
const closing_tag = try parseNameNoDupe(ctx);
if (!std.mem.eql(u8, tag, closing_tag)) {
return error.NonMatchingClosingTag;
}
_ = ctx.eatWs();
try ctx.expect('>');
return element;
}
test "tryParseElement" {
var arena = std.heap.ArenaAllocator.init(testing.allocator);
defer arena.deinit();
var alloc = &arena.allocator;
{
var ctx = ParseContext.init("<= a='b'/>");
testing.expectEqual(@as(?*Element, null), try tryParseElement(&ctx, alloc));
testing.expectEqual(@as(?u8, '<'), ctx.peek());
}
{
var ctx = ParseContext.init("<python size='15' color = \"green\"/>");
const elem = try tryParseElement(&ctx, alloc);
testing.expectEqualSlices(u8, elem.?.tag, "python");
const size_attr = elem.?.attributes.items[0];
testing.expectEqualSlices(u8, size_attr.name, "size");
testing.expectEqualSlices(u8, size_attr.value, "15");
const color_attr = elem.?.attributes.items[1];
testing.expectEqualSlices(u8, color_attr.name, "color");
testing.expectEqualSlices(u8, color_attr.value, "green");
}
{
var ctx = ParseContext.init("<python>test</python>");
const elem = try tryParseElement(&ctx, alloc);
testing.expectEqualSlices(u8, elem.?.tag, "python");
testing.expectEqualSlices(u8, elem.?.children.items[0].CharData, "test");
}
{
var ctx = ParseContext.init("<a>b<c/>d<e/>f<!--g--></a>");
const elem = try tryParseElement(&ctx, alloc);
testing.expectEqualSlices(u8, elem.?.tag, "a");
testing.expectEqualSlices(u8, elem.?.children.items[0].CharData, "b");
testing.expectEqualSlices(u8, elem.?.children.items[1].Element.tag, "c");
testing.expectEqualSlices(u8, elem.?.children.items[2].CharData, "d");
testing.expectEqualSlices(u8, elem.?.children.items[3].Element.tag, "e");
testing.expectEqualSlices(u8, elem.?.children.items[4].CharData, "f");
testing.expectEqualSlices(u8, elem.?.children.items[5].Comment, "g");
}
}
fn tryParseProlog(ctx: *ParseContext, alloc: *Allocator) !?*XmlDecl {
const start = ctx.offset;
if (!ctx.eatStr("<?") or !mem.eql(u8, try parseNameNoDupe(ctx), "xml")) {
ctx.offset = start;
return null;
}
const decl = try alloc.create(XmlDecl);
decl.encoding = null;
decl.standalone = null;
// Version info is mandatory
try ctx.expectWs();
try ctx.expectStr("version");
decl.version = try parseEqAttrValue(ctx, alloc);
if (ctx.eatWs()) {
// Optional encoding and standalone info
var require_ws = false;
if (ctx.eatStr("encoding")) {
decl.encoding = try parseEqAttrValue(ctx, alloc);
require_ws = true;
}
if (require_ws == ctx.eatWs() and ctx.eatStr("standalone")) {
const standalone = try parseEqAttrValue(ctx, alloc);
if (std.mem.eql(u8, standalone, "yes")) {
decl.standalone = true;
} else if (std.mem.eql(u8, standalone, "no")) {
decl.standalone = false;
} else {
return error.InvalidStandaloneValue;
}
}
_ = ctx.eatWs();
}
try ctx.expectStr("?>");
return decl;
}
test "tryParseProlog" {
var arena = std.heap.ArenaAllocator.init(testing.allocator);
defer arena.deinit();
var alloc = &arena.allocator;
{
var ctx = ParseContext.init("<?xmla version='aa'?>");
testing.expectEqual(@as(?*XmlDecl, null), try tryParseProlog(&ctx, alloc));
testing.expectEqual(@as(?u8, '<'), ctx.peek());
}
{
var ctx = ParseContext.init("<?xml version='aa'?>");
const decl = try tryParseProlog(&ctx, alloc);
testing.expectEqualSlices(u8, "aa", decl.?.version);
testing.expectEqual(@as(?[]const u8, null), decl.?.encoding);
testing.expectEqual(@as(?bool, null), decl.?.standalone);
}
{
var ctx = ParseContext.init("<?xml version=\"aa\" encoding = 'bbb' standalone \t = 'yes'?>");
const decl = try tryParseProlog(&ctx, alloc);
testing.expectEqualSlices(u8, "aa", decl.?.version);
testing.expectEqualSlices(u8, "bbb", decl.?.encoding.?);
testing.expectEqual(@as(?bool, true), decl.?.standalone.?);
}
}
fn trySkipComments(ctx: *ParseContext, alloc: *Allocator) !void {
while (try tryParseComment(ctx, alloc)) |_| {
_ = ctx.eatWs();
}
}
fn tryParseComment(ctx: *ParseContext, alloc: *Allocator) !?[]const u8 {
if (!ctx.eatStr("<!--")) return null;
const begin = ctx.offset;
while (!ctx.eatStr("-->")) {
_ = ctx.consume() catch return error.UnclosedComment;
}
const end = ctx.offset - "-->".len;
return try mem.dupe(alloc, u8, ctx.source[begin..end]);
}
fn unescapeEntity(text: []const u8) !u8 {
const EntitySubstition = struct {
text: []const u8, replacement: u8
};
const entities = [_]EntitySubstition{
.{ .text = "&lt;", .replacement = '<' },
.{ .text = "&gt;", .replacement = '>' },
.{ .text = "&amp;", .replacement = '&' },
.{ .text = "&apos;", .replacement = '\'' },
.{ .text = "&quot;", .replacement = '"' },
};
for (entities) |entity| {
if (std.mem.eql(u8, text, entity.text)) return entity.replacement;
}
return error.InvalidEntity;
}
fn dupeAndUnescape(alloc: *Allocator, text: []const u8) ![]const u8 {
const str = try alloc.alloc(u8, text.len);
var j: usize = 0;
var i: usize = 0;
while (i < text.len) : (j += 1) {
if (text[i] == '&') {
const entity_end = 1 + (mem.indexOfScalarPos(u8, text, i, ';') orelse return error.InvalidEntity);
str[j] = try unescapeEntity(text[i..entity_end]);
i = entity_end;
} else {
str[j] = text[i];
i += 1;
}
}
return alloc.shrink(str, j);
}
test "dupeAndUnescape" {
var arena = std.heap.ArenaAllocator.init(testing.allocator);
defer arena.deinit();
var alloc = &arena.allocator;
testing.expectEqualSlices(u8, "test", try dupeAndUnescape(alloc, "test"));
testing.expectEqualSlices(u8, "a<b&c>d\"e'f<", try dupeAndUnescape(alloc, "a&lt;b&amp;c&gt;d&quot;e&apos;f&lt;"));
testing.expectError(error.InvalidEntity, dupeAndUnescape(alloc, "python&"));
testing.expectError(error.InvalidEntity, dupeAndUnescape(alloc, "python&&"));
testing.expectError(error.InvalidEntity, dupeAndUnescape(alloc, "python&test;"));
testing.expectError(error.InvalidEntity, dupeAndUnescape(alloc, "python&boa"));
}
test "Top level comments" {
var arena = std.heap.ArenaAllocator.init(testing.allocator);
defer arena.deinit();
var alloc = &arena.allocator;
const doc = try parse(alloc, "<?xml version='aa'?><!--comment--><python color='green'/><!--another comment-->");
testing.expectEqualSlices(u8, "python", doc.root.tag);
}