Represents in-progress parsing, will be converted to an Ast after completion.
//! Represents in-progress parsing, will be converted to an Ast after completion.
// This recursive descent parser must be "predictive," using only constant
// token lookahead and never backtracking.
//
// This means that whenever the parser encounters a choice it is allowed to look
// at the next k tokens in order to make that choice, where k is a fixed constant.
//
// Once the parser has made the choice, it must either succeed at parsing that sub
// expression or fail entirely and present an error to the user. The parser is never
// allowed to backtrack and make a different choice to see if that one succeeds.
//
// This ensures worst-case linear runtime rather than worst-case exponential runtime
// and requires the Zig grammar to be LL(k).
pub const Error = error{ParseError} || Allocator.Error;
gpa: Allocator,
source: []const u8,
tokens: Ast.TokenList.Slice,
tok_i: TokenIndex,
errors: std.ArrayList(AstError),
nodes: Ast.NodeList,
extra_data: std.ArrayList(u32),
scratch: std.ArrayList(Node.Index),
recover: bool,
fn tokenTag(p: *const Parse, token_index: TokenIndex) Token.Tag {
return p.tokens.items(.tag)[token_index];
}
fn tokenStart(p: *const Parse, token_index: TokenIndex) Ast.ByteOffset {
return p.tokens.items(.start)[token_index];
}
fn nodeTag(p: *const Parse, node: Node.Index) Node.Tag {
return p.nodes.items(.tag)[@backingInt(node)];
}
fn nodeMainToken(p: *const Parse, node: Node.Index) TokenIndex {
return p.nodes.items(.main_token)[@backingInt(node)];
}
fn nodeData(p: *const Parse, node: Node.Index) Node.Data {
return p.nodes.items(.data)[@backingInt(node)];
}
const SmallSpan = union(enum) {
zero_or_one: Node.OptionalIndex,
multi: Node.SubRange,
};
const Members = struct {
len: usize,
/// Must be either `.opt_node_and_opt_node` if `len <= 2` or `.extra_range` otherwise.
data: Node.Data,
trailing: bool,
fn toSpan(self: Members, p: *Parse) !Node.SubRange {
return switch (self.len) {
0 => p.listToSpan(&.{}),
1 => p.listToSpan(&.{self.data.opt_node_and_opt_node[0].unwrap().?}),
2 => p.listToSpan(&.{ self.data.opt_node_and_opt_node[0].unwrap().?, self.data.opt_node_and_opt_node[1].unwrap().? }),
else => self.data.extra_range,
};
}
};
fn listToSpan(p: *Parse, list: []const Node.Index) Allocator.Error!Node.SubRange {
try p.extra_data.appendSlice(p.gpa, @ptrCast(list));
return .{
.start = @fromBackingInt(@intCast(p.extra_data.items.len - list.len)),
.end = @fromBackingInt(@intCast(p.extra_data.items.len)),
};
}
fn addNode(p: *Parse, elem: Ast.Node) Allocator.Error!Node.Index {
const result: Node.Index = @fromBackingInt(@intCast(p.nodes.len));
try p.nodes.append(p.gpa, elem);
return result;
}
fn setNode(p: *Parse, i: usize, elem: Ast.Node) Node.Index {
p.nodes.set(i, elem);
return @fromBackingInt(@intCast(i));
}
fn reserveNode(p: *Parse, tag: Ast.Node.Tag) !usize {
try p.nodes.resize(p.gpa, p.nodes.len + 1);
p.nodes.items(.tag)[p.nodes.len - 1] = tag;
return p.nodes.len - 1;
}
fn unreserveNode(p: *Parse, node_index: usize) void {
if (p.nodes.len == node_index) {
p.nodes.resize(p.gpa, p.nodes.len - 1) catch unreachable;
} else {
// There is zombie node left in the tree, let's make it as inoffensive as possible
// (sadly there's no no-op node)
p.nodes.items(.tag)[node_index] = .unreachable_literal;
p.nodes.items(.main_token)[node_index] = p.tok_i;
}
}
fn addExtra(p: *Parse, extra: anytype) Allocator.Error!ExtraIndex {
const info = @typeInfo(@TypeOf(extra)).@"struct";
try p.extra_data.ensureUnusedCapacity(p.gpa, info.field_names.len);
const result: ExtraIndex = @fromBackingInt(@intCast(p.extra_data.items.len));
inline for (info.field_names, info.field_types) |field_name, field_type| {
const data: u32 = switch (field_type) {
Node.Index,
Node.OptionalIndex,
OptionalTokenIndex,
ExtraIndex,
=> @backingInt(@field(extra, field_name)),
TokenIndex,
=> @field(extra, field_name),
else => @compileError("unexpected field type"),
};
p.extra_data.appendAssumeCapacity(data);
}
return result;
}
fn warnExpected(p: *Parse, expected_token: Token.Tag) Error!void {
@branchHint(.cold);
try p.warnMsg(.{
.tag = .expected_token,
.token = p.tok_i,
.extra = .{ .expected_tag = expected_token },
});
}
fn warn(p: *Parse, error_tag: AstError.Tag) Error!void {
@branchHint(.cold);
try p.warnMsg(.{ .tag = error_tag, .token = p.tok_i });
}
fn warnMsg(p: *Parse, msg: Ast.Error) Error!void {
@branchHint(.cold);
switch (msg.tag) {
.expected_semi_after_decl,
.expected_semi_after_stmt,
.expected_comma_after_field,
.expected_comma_after_arg,
.expected_comma_after_param,
.expected_comma_after_initializer,
.expected_comma_after_switch_prong,
.expected_comma_after_for_operand,
.expected_comma_after_capture,
.expected_semi_or_else,
.expected_semi_or_lbrace,
.expected_token,
.expected_block,
.expected_block_or_assignment,
.expected_block_or_expr,
.expected_block_or_field,
.expected_expr,
.expected_expr_or_assignment,
.expected_fn,
.expected_inlinable,
.expected_labelable,
.expected_param_list,
.expected_prefix_expr,
.expected_primary_type_expr,
.expected_pub_item,
.expected_return_type,
.expected_suffix_op,
.expected_type_expr,
.expected_var_decl,
.expected_var_decl_or_fn,
.expected_loop_payload,
.expected_container,
=> if (msg.token != 0 and !p.tokensOnSameLine(msg.token - 1, msg.token)) {
var copy = msg;
copy.token_is_prev = true;
copy.token -= 1;
try p.errors.append(p.gpa, copy);
} else {
try p.errors.append(p.gpa, msg);
},
else => try p.errors.append(p.gpa, msg),
}
if (!p.recover) return error.ParseError;
}
fn fail(p: *Parse, tag: Ast.Error.Tag) error{ ParseError, OutOfMemory } {
@branchHint(.cold);
return p.failMsg(.{ .tag = tag, .token = p.tok_i });
}
fn failExpected(p: *Parse, expected_token: Token.Tag) error{ ParseError, OutOfMemory } {
@branchHint(.cold);
return p.failMsg(.{
.tag = .expected_token,
.token = p.tok_i,
.extra = .{ .expected_tag = expected_token },
});
}
fn failMsg(p: *Parse, msg: Ast.Error) error{ ParseError, OutOfMemory } {
@branchHint(.cold);
try p.warnMsg(msg);
return error.ParseError;
}
/// Root <- skip ContainerMembers eof
pub fn parseRoot(p: *Parse) Allocator.Error!void {
// Root node must be index 0.
p.nodes.appendAssumeCapacity(.{
.tag = .root,
.main_token = 0,
.data = undefined,
});
const root_members = p.parseContainerMembers() catch |err| switch (err) {
error.OutOfMemory => |e| return e,
error.ParseError => {
assert(p.errors.items.len > 0);
return;
},
};
const root_decls = try root_members.toSpan(p);
if (p.tokenTag(p.tok_i) != .eof) {
p.warnExpected(.eof) catch |err| switch (err) {
error.OutOfMemory => |e| return e,
error.ParseError => {
assert(p.errors.items.len > 0);
return;
},
};
}
p.nodes.items(.data)[0] = .{ .extra_range = root_decls };
}
/// Parse in ZON mode. Subset of the language.
/// TODO: set a flag in Parse struct, and honor that flag
/// by emitting compilation errors when non-zon nodes are encountered.
pub fn parseZon(p: *Parse) Allocator.Error!void {
// We must use index 0 so that 0 can be used as null elsewhere.
p.nodes.appendAssumeCapacity(.{
.tag = .root,
.main_token = 0,
.data = undefined,
});
const node_index = p.expectExpr() catch |err| switch (err) {
error.ParseError => {
assert(p.errors.items.len > 0);
return;
},
else => |e| return e,
};
if (p.tokenTag(p.tok_i) != .eof) {
p.warnExpected(.eof) catch |err| switch (err) {
error.OutOfMemory => |e| return e,
error.ParseError => {
assert(p.errors.items.len > 0);
return;
},
};
}
p.nodes.items(.data)[0] = .{ .node = node_index };
}
fn parseContainerMembers(p: *Parse) Error!Members {
const scratch_top = p.scratch.items.len;
defer p.scratch.shrinkRetainingCapacity(scratch_top);
var field_state: union(enum) {
/// No fields have been seen.
none,
/// Currently parsing fields.
seen,
/// Saw fields and then a declaration after them.
/// Payload is first token of previous declaration.
end: Node.Index,
/// There was a declaration between fields, don't report more errors.
err,
} = .none;
var last_field: TokenIndex = undefined;
// Skip container doc comments.
while (p.eatToken(.container_doc_comment)) |_| {}
var trailing = false;
while (true) {
const doc_comment = try p.eatDocComments();
sw: switch (p.tokenTag(p.tok_i)) {
.keyword_test => {
if (doc_comment) |some| {
try p.warnMsg(.{ .tag = .test_doc_comment, .token = some });
}
const maybe_test_decl_node = try p.expectTestDeclRecoverable();
if (maybe_test_decl_node) |test_decl_node| {
if (field_state == .seen) {
field_state = .{ .end = test_decl_node };
}
try p.scratch.append(p.gpa, test_decl_node);
}
trailing = false;
},
.keyword_comptime => switch (p.tokenTag(p.tok_i + 1)) {
.l_brace => {
if (doc_comment) |some| {
try p.warnMsg(.{ .tag = .comptime_doc_comment, .token = some });
}
const comptime_token = p.nextToken();
const opt_block = p.parseBlock() catch |err| switch (err) {
error.OutOfMemory => |e| return e,
error.ParseError => blk: {
p.findNextContainerMember();
break :blk null;
},
};
if (opt_block) |block| {
const comptime_node = try p.addNode(.{
.tag = .@"comptime",
.main_token = comptime_token,
.data = .{ .node = block },
});
if (field_state == .seen) {
field_state = .{ .end = comptime_node };
}
try p.scratch.append(p.gpa, comptime_node);
}
trailing = false;
},
else => {
const identifier = p.tok_i;
defer last_field = identifier;
switch (field_state) {
.none => field_state = .seen,
.err, .seen => {},
.end => |node| {
try p.warnMsg(.{
.tag = .decl_between_fields,
.token = p.nodeMainToken(node),
});
try p.warnMsg(.{
.tag = .previous_field,
.is_note = true,
.token = last_field,
});
try p.warnMsg(.{
.tag = .next_field,
.is_note = true,
.token = identifier,
});
// Continue parsing; error will be reported later.
field_state = .err;
},
}
const container_field = p.expectContainerField() catch |err| switch (err) {
error.OutOfMemory => |e| return e,
error.ParseError => {
p.findNextContainerMember();
continue;
},
};
try p.scratch.append(p.gpa, container_field);
switch (p.tokenTag(p.tok_i)) {
.comma => {
p.tok_i += 1;
trailing = true;
continue;
},
.r_brace, .eof => {
trailing = false;
break;
},
else => {},
}
// There is not allowed to be a decl after a field with no comma.
// Report error but recover parser.
try p.warn(.expected_comma_after_field);
p.findNextContainerMember();
},
},
.keyword_pub,
.keyword_const,
.keyword_var,
.keyword_threadlocal,
.keyword_export,
.keyword_extern,
.keyword_inline,
.keyword_noinline,
.keyword_fn,
=> |t| {
if (t == .keyword_extern) {
switch (p.tokenTag(p.tok_i + 1)) {
.keyword_struct,
.keyword_union,
.keyword_enum,
.keyword_opaque,
=> |ct| continue :sw ct,
else => {},
}
}
if (t == .keyword_inline) {
switch (p.tokenTag(p.tok_i + 1)) {
.keyword_for,
.keyword_while,
=> |ct| continue :sw ct,
else => {},
}
}
p.tok_i += @intFromBool(t == .keyword_pub);
const opt_top_level_decl = try p.expectTopLevelDeclRecoverable();
if (opt_top_level_decl) |top_level_decl| {
if (field_state == .seen) {
field_state = .{ .end = top_level_decl };
}
try p.scratch.append(p.gpa, top_level_decl);
}
trailing = p.tokenTag(p.tok_i - 1) == .semicolon;
},
.eof, .r_brace => {
if (doc_comment) |tok| {
try p.warnMsg(.{
.tag = .unattached_doc_comment,
.token = tok,
});
}
break;
},
else => {
const c_container = p.parseCStyleContainer() catch |err| switch (err) {
error.OutOfMemory => |e| return e,
error.ParseError => false,
};
if (c_container) continue;
const identifier = p.tok_i;
defer last_field = identifier;
switch (field_state) {
.none => field_state = .seen,
.err, .seen => {},
.end => |node| {
try p.warnMsg(.{
.tag = .decl_between_fields,
.token = p.nodeMainToken(node),
});
try p.warnMsg(.{
.tag = .previous_field,
.is_note = true,
.token = last_field,
});
try p.warnMsg(.{
.tag = .next_field,
.is_note = true,
.token = identifier,
});
// Continue parsing; error will be reported later.
field_state = .err;
},
}
const container_field = p.expectContainerField() catch |err| switch (err) {
error.OutOfMemory => |e| return e,
error.ParseError => {
p.findNextContainerMember();
continue;
},
};
try p.scratch.append(p.gpa, container_field);
switch (p.tokenTag(p.tok_i)) {
.comma => {
p.tok_i += 1;
trailing = true;
continue;
},
.r_brace, .eof => {
trailing = false;
break;
},
else => {},
}
// There is not allowed to be a decl after a field with no comma.
// Report error but recover parser.
try p.warn(.expected_comma_after_field);
if (p.tokenTag(p.tok_i) == .semicolon and p.tokenTag(identifier) == .identifier) {
try p.warnMsg(.{
.tag = .var_const_decl,
.is_note = true,
.token = identifier,
});
}
p.findNextContainerMember();
continue;
},
}
}
const items = p.scratch.items[scratch_top..];
if (items.len <= 2) {
return Members{
.len = items.len,
.data = .{ .opt_node_and_opt_node = .{
if (items.len >= 1) items[0].toOptional() else .none,
if (items.len >= 2) items[1].toOptional() else .none,
} },
.trailing = trailing,
};
} else {
return Members{
.len = items.len,
.data = .{ .extra_range = try p.listToSpan(items) },
.trailing = trailing,
};
}
}
/// Attempts to find next container member by searching for certain tokens
fn findNextContainerMember(p: *Parse) void {
if (!p.recover) {
while (p.tokenTag(p.tok_i) != .eof) {
p.tok_i += 1;
}
return;
}
var level: u32 = 0;
while (true) {
const tok = p.nextToken();
switch (p.tokenTag(tok)) {
// Any of these can start a new top level declaration.
.keyword_test,
.keyword_comptime,
.keyword_pub,
.keyword_export,
.keyword_extern,
.keyword_inline,
.keyword_noinline,
.keyword_threadlocal,
.keyword_const,
.keyword_var,
.keyword_fn,
=> {
if (level == 0) {
p.tok_i -= 1;
return;
}
},
.identifier => {
if (p.tokenTag(tok + 1) == .comma and level == 0) {
p.tok_i -= 1;
return;
}
},
.comma, .semicolon => {
// this decl was likely meant to end here
if (level == 0) {
return;
}
},
.l_paren, .l_bracket, .l_brace => level += 1,
.r_paren, .r_bracket => {
if (level != 0) level -= 1;
},
.r_brace => {
if (level == 0) {
// end of container, exit
p.tok_i -= 1;
return;
}
level -= 1;
},
.eof => {
p.tok_i -= 1;
return;
},
else => {},
}
}
}
/// Attempts to find the next statement by searching for a semicolon
fn findNextStmt(p: *Parse) void {
if (!p.recover) {
while (p.tokenTag(p.tok_i) != .eof) {
p.tok_i += 1;
}
return;
}
var level: u32 = 0;
while (true) {
const tok = p.nextToken();
switch (p.tokenTag(tok)) {
.l_brace => level += 1,
.r_brace => {
if (level == 0) {
p.tok_i -= 1;
return;
}
level -= 1;
},
.semicolon => {
if (level == 0) {
return;
}
},
.eof => {
p.tok_i -= 1;
return;
},
else => {},
}
}
}
fn expectTestDecl(p: *Parse) Error!Node.Index {
const test_token = p.assertToken(.keyword_test);
const name_token: OptionalTokenIndex = switch (p.tokenTag(p.tok_i)) {
.string_literal, .identifier => .fromToken(p.nextToken()),
else => .none,
};
const block_node = try p.parseBlock() orelse return p.fail(.expected_block);
return p.addNode(.{
.tag = .test_decl,
.main_token = test_token,
.data = .{ .opt_token_and_node = .{
name_token,
block_node,
} },
});
}
fn expectTestDeclRecoverable(p: *Parse) error{OutOfMemory}!?Node.Index {
if (p.expectTestDecl()) |node| {
return node;
} else |err| switch (err) {
error.OutOfMemory => |e| return e,
error.ParseError => {
p.findNextContainerMember();
return null;
},
}
}
fn expectTopLevelDecl(p: *Parse) !?Node.Index {
const extern_export_inline_token = p.nextToken();
var is_extern: bool = false;
var expect_fn: bool = false;
var expect_var_or_fn: bool = false;
switch (p.tokenTag(extern_export_inline_token)) {
.keyword_extern => {
_ = p.eatToken(.string_literal);
is_extern = true;
expect_var_or_fn = true;
},
.keyword_export => expect_var_or_fn = true,
.keyword_inline, .keyword_noinline => expect_fn = true,
else => p.tok_i -= 1,
}
const opt_fn_proto = try p.parseFnProto();
if (opt_fn_proto) |fn_proto| {
switch (p.tokenTag(p.tok_i)) {
.semicolon => {
p.tok_i += 1;
return fn_proto;
},
.l_brace => {
if (is_extern) {
try p.warnMsg(.{ .tag = .extern_fn_body, .token = extern_export_inline_token });
return null;
}
const fn_decl_index = try p.reserveNode(.fn_decl);
errdefer p.unreserveNode(fn_decl_index);
const body_block = try p.parseBlock();
return p.setNode(fn_decl_index, .{
.tag = .fn_decl,
.main_token = p.nodeMainToken(fn_proto),
.data = .{ .node_and_node = .{
fn_proto,
body_block.?,
} },
});
},
else => {
// Since parseBlock only return error.ParseError on
// a missing '}' we can assume this function was
// supposed to end here.
try p.warn(.expected_semi_or_lbrace);
return null;
},
}
}
if (expect_fn) {
try p.warn(.expected_fn);
return error.ParseError;
}
const thread_local_token = p.eatToken(.keyword_threadlocal);
if (try p.parseGlobalVarDecl()) |var_decl| return var_decl;
if (thread_local_token != null) {
return p.fail(.expected_var_decl);
}
if (expect_var_or_fn) {
return p.fail(.expected_var_decl_or_fn);
}
return p.fail(.expected_pub_item);
}
fn expectTopLevelDeclRecoverable(p: *Parse) error{OutOfMemory}!?Node.Index {
return p.expectTopLevelDecl() catch |err| switch (err) {
error.OutOfMemory => |e| return e,
error.ParseError => {
p.findNextContainerMember();
return null;
},
};
}
fn parseFnProto(p: *Parse) !?Node.Index {
const fn_token = p.eatToken(.keyword_fn) orelse return null;
// We want the fn proto node to be before its children in the array.
const fn_proto_index = try p.reserveNode(.fn_proto);
errdefer p.unreserveNode(fn_proto_index);
_ = p.eatToken(.identifier);
const params = try p.parseParamDeclList();
const align_expr = try p.parseByteAlign();
const addrspace_expr = try p.parseAddrSpace();
const section_expr = try p.parseLinkSection();
const callconv_expr = try p.parseCallconv();
_ = p.eatToken(.bang);
const return_type_expr = try p.parseTypeExpr();
if (return_type_expr == null) {
// most likely the user forgot to specify the return type.
// Mark return type as invalid and try to continue.
try p.warn(.expected_return_type);
}
if (align_expr == null and section_expr == null and callconv_expr == null and addrspace_expr == null) {
switch (params) {
.zero_or_one => |param| return p.setNode(fn_proto_index, .{
.tag = .fn_proto_simple,
.main_token = fn_token,
.data = .{ .opt_node_and_opt_node = .{
param,
.fromOptional(return_type_expr),
} },
}),
.multi => |span| {
return p.setNode(fn_proto_index, .{
.tag = .fn_proto_multi,
.main_token = fn_token,
.data = .{ .extra_and_opt_node = .{
try p.addExtra(Node.SubRange{
.start = span.start,
.end = span.end,
}),
.fromOptional(return_type_expr),
} },
});
},
}
}
switch (params) {
.zero_or_one => |param| return p.setNode(fn_proto_index, .{
.tag = .fn_proto_one,
.main_token = fn_token,
.data = .{ .extra_and_opt_node = .{
try p.addExtra(Node.FnProtoOne{
.param = param,
.align_expr = .fromOptional(align_expr),
.addrspace_expr = .fromOptional(addrspace_expr),
.section_expr = .fromOptional(section_expr),
.callconv_expr = .fromOptional(callconv_expr),
}),
.fromOptional(return_type_expr),
} },
}),
.multi => |span| {
return p.setNode(fn_proto_index, .{
.tag = .fn_proto,
.main_token = fn_token,
.data = .{ .extra_and_opt_node = .{
try p.addExtra(Node.FnProto{
.params_start = span.start,
.params_end = span.end,
.align_expr = .fromOptional(align_expr),
.addrspace_expr = .fromOptional(addrspace_expr),
.section_expr = .fromOptional(section_expr),
.callconv_expr = .fromOptional(callconv_expr),
}),
.fromOptional(return_type_expr),
} },
});
},
}
}
fn setVarDeclInitExpr(p: *Parse, var_decl: Node.Index, init_expr: Node.OptionalIndex) void {
const init_expr_result = switch (p.nodeTag(var_decl)) {
.simple_var_decl => &p.nodes.items(.data)[@backingInt(var_decl)].opt_node_and_opt_node[1],
.aligned_var_decl => &p.nodes.items(.data)[@backingInt(var_decl)].node_and_opt_node[1],
.local_var_decl, .global_var_decl => &p.nodes.items(.data)[@backingInt(var_decl)].extra_and_opt_node[1],
else => unreachable,
};
init_expr_result.* = init_expr;
}
/// Returns a `*_var_decl` node with its rhs (init expression) initialized to .none.
fn parseVarDeclProto(p: *Parse) !?Node.Index {
const mut_token = p.eatToken(.keyword_const) orelse
p.eatToken(.keyword_var) orelse
return null;
_ = try p.expectToken(.identifier);
const opt_type_node = if (p.eatToken(.colon) == null) null else try p.expectTypeExpr();
const opt_align_node = try p.parseByteAlign();
const opt_addrspace_node = try p.parseAddrSpace();
const opt_section_node = try p.parseLinkSection();
if (opt_section_node == null and opt_addrspace_node == null) {
const align_node = opt_align_node orelse {
return try p.addNode(.{
.tag = .simple_var_decl,
.main_token = mut_token,
.data = .{
.opt_node_and_opt_node = .{
.fromOptional(opt_type_node),
.none, // set later with `setVarDeclInitExpr
},
},
});
};
const type_node = opt_type_node orelse {
return try p.addNode(.{
.tag = .aligned_var_decl,
.main_token = mut_token,
.data = .{
.node_and_opt_node = .{
align_node,
.none, // set later with `setVarDeclInitExpr
},
},
});
};
return try p.addNode(.{
.tag = .local_var_decl,
.main_token = mut_token,
.data = .{
.extra_and_opt_node = .{
try p.addExtra(Node.LocalVarDecl{
.type_node = type_node,
.align_node = align_node,
}),
.none, // set later with `setVarDeclInitExpr
},
},
});
} else {
return try p.addNode(.{
.tag = .global_var_decl,
.main_token = mut_token,
.data = .{
.extra_and_opt_node = .{
try p.addExtra(Node.GlobalVarDecl{
.type_node = .fromOptional(opt_type_node),
.align_node = .fromOptional(opt_align_node),
.addrspace_node = .fromOptional(opt_addrspace_node),
.section_node = .fromOptional(opt_section_node),
}),
.none, // set later with `setVarDeclInitExpr
},
},
});
}
}
fn parseGlobalVarDecl(p: *Parse) !?Node.Index {
const var_decl = try p.parseVarDeclProto() orelse return null;
const init_node: ?Node.Index = switch (p.tokenTag(p.tok_i)) {
.equal_equal => blk: {
try p.warn(.wrong_equal_var_decl);
p.tok_i += 1;
break :blk try p.expectExpr();
},
.equal => blk: {
p.tok_i += 1;
break :blk try p.expectExpr();
},
else => null,
};
p.setVarDeclInitExpr(var_decl, .fromOptional(init_node));
try p.expectSemicolon(.expected_semi_after_decl, false);
return var_decl;
}
fn expectContainerField(p: *Parse) !Node.Index {
_ = p.eatToken(.keyword_comptime);
const main_token = p.tok_i;
_ = p.eatTokens(&.{ .identifier, .colon });
const type_expr = try p.expectTypeExpr();
const align_expr = try p.parseByteAlign();
const value_expr = if (p.eatToken(.equal) == null) null else try p.expectExpr();
if (align_expr == null) {
return p.addNode(.{
.tag = .container_field_init,
.main_token = main_token,
.data = .{ .node_and_opt_node = .{
type_expr,
.fromOptional(value_expr),
} },
});
} else if (value_expr == null) {
return p.addNode(.{
.tag = .container_field_align,
.main_token = main_token,
.data = .{ .node_and_node = .{
type_expr,
align_expr.?,
} },
});
} else {
return p.addNode(.{
.tag = .container_field,
.main_token = main_token,
.data = .{ .node_and_extra = .{
type_expr,
try p.addExtra(Node.ContainerField{
.align_expr = align_expr.?,
.value_expr = value_expr.?,
}),
} },
});
}
}
fn expectStatement(p: *Parse, is_block_level: bool) Error!Node.Index {
if (p.eatToken(.keyword_comptime)) |comptime_token| {
const opt_block_expr = try p.parseBlockExpr();
if (opt_block_expr) |block_expr| {
return p.addNode(.{
.tag = .@"comptime",
.main_token = comptime_token,
.data = .{ .node = block_expr },
});
}
if (is_block_level) {
return p.expectVarAssignStatement(comptime_token);
} else {
const assign = try p.expectAssignExpr();
try p.expectSemicolon(.expected_semi_after_stmt, true);
if (p.nodeTag(assign) != .assign_destructure) {
return p.addNode(.{
.tag = .@"comptime",
.main_token = comptime_token,
.data = .{ .node = assign },
});
} else {
return assign;
}
}
}
switch (p.tokenTag(p.tok_i)) {
.keyword_nosuspend => {
return p.addNode(.{
.tag = .@"nosuspend",
.main_token = p.nextToken(),
.data = .{ .node = try p.expectBlockExprStatement() },
});
},
.keyword_suspend => {
const token = p.nextToken();
const block_expr = try p.expectBlockExprStatement();
return p.addNode(.{
.tag = .@"suspend",
.main_token = token,
.data = .{ .node = block_expr },
});
},
.keyword_defer => if (is_block_level) return p.addNode(.{
.tag = .@"defer",
.main_token = p.nextToken(),
.data = .{ .node = try p.expectBlockExprStatement() },
}),
.keyword_errdefer => if (is_block_level) return p.addNode(.{
.tag = .@"errdefer",
.main_token = p.nextToken(),
.data = .{ .node = try p.expectBlockExprStatement() },
}),
.keyword_if => return p.expectIfStatement(),
.keyword_enum, .keyword_struct, .keyword_union => {
const identifier = p.tok_i + 1;
if (try p.parseCStyleContainer()) {
// Return something so that `expectStatement` is happy.
return p.addNode(.{
.tag = .identifier,
.main_token = identifier,
.data = undefined,
});
}
},
else => {},
}
if (try p.parseLabeledStatement()) |labeled_statement| return labeled_statement;
if (is_block_level) {
return p.expectVarAssignStatement(null);
} else {
const assign = try p.expectAssignExpr();
try p.expectSemicolon(.expected_semi_after_stmt, true);
return assign;
}
}
fn expectVarAssignStatement(p: *Parse, comptime_token: ?TokenIndex) !Node.Index {
const scratch_top = p.scratch.items.len;
defer p.scratch.shrinkRetainingCapacity(scratch_top);
while (true) {
const opt_var_decl_proto = try p.parseVarDeclProto();
if (opt_var_decl_proto) |var_decl| {
try p.scratch.append(p.gpa, var_decl);
} else {
const expr = try p.parseExpr() orelse {
if (p.scratch.items.len == scratch_top) {
// We parsed nothing
return p.fail(.expected_statement);
} else {
// We've had at least one LHS, but had a bad comma
return p.fail(.expected_expr_or_var_decl);
}
};
try p.scratch.append(p.gpa, expr);
}
_ = p.eatToken(.comma) orelse break;
}
const lhs_count = p.scratch.items.len - scratch_top;
assert(lhs_count > 0);
const equal_token = p.eatToken(.equal) orelse eql: {
if (lhs_count > 1) {
// Definitely a destructure, so allow recovering from ==
if (p.eatToken(.equal_equal)) |tok| {
try p.warnMsg(.{ .tag = .wrong_equal_var_decl, .token = tok });
break :eql tok;
}
return p.failExpected(.equal);
}
const lhs = p.scratch.items[scratch_top];
switch (p.nodeTag(lhs)) {
.global_var_decl, .local_var_decl, .simple_var_decl, .aligned_var_decl => {
// Definitely a var decl, so allow recovering from ==
if (p.eatToken(.equal_equal)) |tok| {
try p.warnMsg(.{ .tag = .wrong_equal_var_decl, .token = tok });
break :eql tok;
}
return p.failExpected(.equal);
},
else => {},
}
const expr = try p.finishAssignExpr(lhs);
try p.expectSemicolon(.expected_semi_after_stmt, true);
if (comptime_token) |t| {
return p.addNode(.{
.tag = .@"comptime",
.main_token = t,
.data = .{ .node = expr },
});
} else {
return expr;
}
};
const rhs = try p.expectExpr();
try p.expectSemicolon(.expected_semi_after_stmt, true);
if (lhs_count == 1) {
const lhs = p.scratch.items[scratch_top];
switch (p.nodeTag(lhs)) {
.simple_var_decl, .aligned_var_decl, .local_var_decl, .global_var_decl => {
p.setVarDeclInitExpr(lhs, rhs.toOptional());
// Don't need to wrap in comptime
return lhs;
},
else => {},
}
const expr = try p.addNode(.{
.tag = .assign,
.main_token = equal_token,
.data = .{ .node_and_node = .{
lhs,
rhs,
} },
});
if (comptime_token) |t| {
return p.addNode(.{
.tag = .@"comptime",
.main_token = t,
.data = .{ .node = expr },
});
} else {
return expr;
}
}
// An actual destructure! No need for any `comptime` wrapper here.
const extra_start: ExtraIndex = @fromBackingInt(@intCast(p.extra_data.items.len));
try p.extra_data.ensureUnusedCapacity(p.gpa, lhs_count + 1);
p.extra_data.appendAssumeCapacity(@intCast(lhs_count));
p.extra_data.appendSliceAssumeCapacity(@ptrCast(p.scratch.items[scratch_top..]));
return p.addNode(.{
.tag = .assign_destructure,
.main_token = equal_token,
.data = .{ .extra_and_node = .{
extra_start,
rhs,
} },
});
}
/// If a parse error occurs, reports an error, but then finds the next statement
/// and returns that one instead. If a parse error occurs but there is no following
/// statement, returns null.
fn expectStatementRecoverable(p: *Parse) Error!?Node.Index {
while (true) {
return p.expectStatement(true) catch |err| switch (err) {
error.OutOfMemory => |e| return e,
error.ParseError => {
p.findNextStmt(); // Try to skip to the next statement.
switch (p.tokenTag(p.tok_i)) {
.r_brace => return null,
.eof => return error.ParseError,
else => continue,
}
},
};
}
}
fn expectIfStatement(p: *Parse) !Node.Index {
const if_token = p.assertToken(.keyword_if);
_ = try p.expectToken(.l_paren);
const condition = try p.expectExpr();
_ = try p.expectToken(.r_paren);
_ = try p.parsePtrPayload();
// TODO propose to change the syntax so that semicolons are always required
// inside if statements, even if there is an `else`.
var else_required = false;
const then_expr = blk: {
const block_expr = try p.parseBlockExpr();
if (block_expr) |block| break :blk block;
const assign_expr = try p.parseAssignExpr() orelse {
return p.fail(.expected_block_or_assignment);
};
if (p.eatToken(.semicolon)) |_| {
return p.addNode(.{
.tag = .if_simple,
.main_token = if_token,
.data = .{ .node_and_node = .{
condition,
assign_expr,
} },
});
}
else_required = true;
break :blk assign_expr;
};
_ = p.eatToken(.keyword_else) orelse {
if (else_required) {
try p.warn(.expected_semi_or_else);
}
return p.addNode(.{
.tag = .if_simple,
.main_token = if_token,
.data = .{ .node_and_node = .{
condition,
then_expr,
} },
});
};
_ = try p.parsePayload();
const else_expr = try p.expectStatement(false);
return p.addNode(.{
.tag = .@"if",
.main_token = if_token,
.data = .{ .node_and_extra = .{
condition,
try p.addExtra(Node.If{
.then_expr = then_expr,
.else_expr = else_expr,
}),
} },
});
}
fn parseLabeledStatement(p: *Parse) !?Node.Index {
const opt_label_token = p.parseBlockLabel();
if (try p.parseBlock()) |block| return block;
if (try p.parseLoopStatement()) |loop_stmt| return loop_stmt;
if (try p.parseSwitchExpr(opt_label_token != null)) |switch_expr| return switch_expr;
const label_token = opt_label_token orelse return null;
const after_colon = p.tok_i;
// Don't bother trying to give a better error message if recovery is disabled.
// This avoids a possible stack overflow in e.g. parseTypeExpr() when fuzzing.
if (p.recover) {
if (try p.parseTypeExpr()) |_| {
const a = try p.parseByteAlign();
const b = try p.parseAddrSpace();
const c = try p.parseLinkSection();
const d = if (p.eatToken(.equal) == null) null else try p.expectExpr();
if (a != null or b != null or c != null or d != null) {
return p.failMsg(.{ .tag = .expected_var_const, .token = label_token });
}
}
}
return p.failMsg(.{ .tag = .expected_labelable, .token = after_colon });
}
fn parseLoopStatement(p: *Parse) !?Node.Index {
const inline_token = p.eatToken(.keyword_inline);
if (try p.parseForStatement()) |for_statement| return for_statement;
if (try p.parseWhileStatement()) |while_statement| return while_statement;
if (inline_token == null) return null;
// If we've seen "inline", there should have been a "for" or "while"
return p.fail(.expected_inlinable);
}
fn parseForStatement(p: *Parse) !?Node.Index {
const for_token = p.eatToken(.keyword_for) orelse return null;
const scratch_top = p.scratch.items.len;
defer p.scratch.shrinkRetainingCapacity(scratch_top);
const inputs = try p.forPrefix();
var else_required = false;
var seen_semicolon = false;
const then_expr = blk: {
const block_expr = try p.parseBlockExpr();
if (block_expr) |block| break :blk block;
const assign_expr = try p.parseAssignExpr() orelse {
return p.fail(.expected_block_or_assignment);
};
if (p.eatToken(.semicolon)) |_| {
seen_semicolon = true;
break :blk assign_expr;
}
else_required = true;
break :blk assign_expr;
};
var has_else = false;
if (!seen_semicolon and p.eatToken(.keyword_else) != null) {
try p.scratch.append(p.gpa, then_expr);
const else_stmt = try p.expectStatement(false);
try p.scratch.append(p.gpa, else_stmt);
has_else = true;
} else if (inputs == 1) {
if (else_required) try p.warn(.expected_semi_or_else);
return try p.addNode(.{
.tag = .for_simple,
.main_token = for_token,
.data = .{ .node_and_node = .{
p.scratch.items[scratch_top],
then_expr,
} },
});
} else {
if (else_required) try p.warn(.expected_semi_or_else);
try p.scratch.append(p.gpa, then_expr);
}
return try p.addNode(.{
.tag = .@"for",
.main_token = for_token,
.data = .{ .@"for" = .{
(try p.listToSpan(p.scratch.items[scratch_top..])).start,
.{ .inputs = @intCast(inputs), .has_else = has_else },
} },
});
}
fn parseWhileStatement(p: *Parse) !?Node.Index {
const while_token = p.eatToken(.keyword_while) orelse return null;
_ = try p.expectToken(.l_paren);
const condition = try p.expectExpr();
_ = try p.expectToken(.r_paren);
_ = try p.parsePtrPayload();
const cont_expr = try p.parseWhileContinueExpr();
// TODO propose to change the syntax so that semicolons are always required
// inside while statements, even if there is an `else`.
var else_required = false;
const then_expr = blk: {
const block_expr = try p.parseBlockExpr();
if (block_expr) |block| break :blk block;
const assign_expr = try p.parseAssignExpr() orelse {
return p.fail(.expected_block_or_assignment);
};
if (p.eatToken(.semicolon)) |_| {
if (cont_expr == null) {
return try p.addNode(.{
.tag = .while_simple,
.main_token = while_token,
.data = .{ .node_and_node = .{
condition,
assign_expr,
} },
});
} else {
return try p.addNode(.{
.tag = .while_cont,
.main_token = while_token,
.data = .{ .node_and_extra = .{
condition,
try p.addExtra(Node.WhileCont{
.cont_expr = cont_expr.?,
.then_expr = assign_expr,
}),
} },
});
}
}
else_required = true;
break :blk assign_expr;
};
_ = p.eatToken(.keyword_else) orelse {
if (else_required) {
try p.warn(.expected_semi_or_else);
}
if (cont_expr == null) {
return try p.addNode(.{
.tag = .while_simple,
.main_token = while_token,
.data = .{ .node_and_node = .{
condition,
then_expr,
} },
});
} else {
return try p.addNode(.{
.tag = .while_cont,
.main_token = while_token,
.data = .{ .node_and_extra = .{
condition,
try p.addExtra(Node.WhileCont{
.cont_expr = cont_expr.?,
.then_expr = then_expr,
}),
} },
});
}
};
_ = try p.parsePayload();
const else_expr = try p.expectStatement(false);
return try p.addNode(.{
.tag = .@"while",
.main_token = while_token,
.data = .{ .node_and_extra = .{
condition,
try p.addExtra(Node.While{
.cont_expr = .fromOptional(cont_expr),
.then_expr = then_expr,
.else_expr = else_expr,
}),
} },
});
}
fn parseBlockExprStatement(p: *Parse) !?Node.Index {
const block_expr = try p.parseBlockExpr();
if (block_expr) |expr| return expr;
const assign_expr = try p.parseAssignExpr();
if (assign_expr) |expr| {
try p.expectSemicolon(.expected_semi_after_stmt, true);
return expr;
}
return null;
}
fn expectBlockExprStatement(p: *Parse) !Node.Index {
return try p.parseBlockExprStatement() orelse return p.fail(.expected_block_or_expr);
}
fn parseBlockExpr(p: *Parse) Error!?Node.Index {
switch (p.tokenTag(p.tok_i)) {
.identifier => {
if (p.tokenTag(p.tok_i + 1) == .colon and
p.tokenTag(p.tok_i + 2) == .l_brace)
{
p.tok_i += 2;
return p.parseBlock();
} else {
return null;
}
},
.l_brace => return p.parseBlock(),
else => return null,
}
}
fn parseAssignExpr(p: *Parse) !?Node.Index {
const expr = try p.parseExpr() orelse return null;
return try p.finishAssignExpr(expr);
}
fn parseSingleAssignExpr(p: *Parse) !?Node.Index {
const lhs = try p.parseExpr() orelse return null;
const tag = assignOpNode(p.tokenTag(p.tok_i)) orelse return lhs;
return try p.addNode(.{
.tag = tag,
.main_token = p.nextToken(),
.data = .{ .node_and_node = .{
lhs,
try p.expectExpr(),
} },
});
}
fn finishAssignExpr(p: *Parse, lhs: Node.Index) !Node.Index {
const tok = p.tokenTag(p.tok_i);
if (tok == .comma) return p.finishAssignDestructureExpr(lhs);
const tag = assignOpNode(tok) orelse return lhs;
return p.addNode(.{
.tag = tag,
.main_token = p.nextToken(),
.data = .{ .node_and_node = .{
lhs,
try p.expectExpr(),
} },
});
}
fn assignOpNode(tok: Token.Tag) ?Node.Tag {
return switch (tok) {
.asterisk_equal => .assign_mul,
.slash_equal => .assign_div,
.percent_equal => .assign_mod,
.plus_equal => .assign_add,
.minus_equal => .assign_sub,
.angle_bracket_angle_bracket_left_equal => .assign_shl,
.angle_bracket_angle_bracket_left_pipe_equal => .assign_shl_sat,
.angle_bracket_angle_bracket_right_equal => .assign_shr,
.ampersand_equal => .assign_bit_and,
.caret_equal => .assign_bit_xor,
.pipe_equal => .assign_bit_or,
.asterisk_percent_equal => .assign_mul_wrap,
.plus_percent_equal => .assign_add_wrap,
.minus_percent_equal => .assign_sub_wrap,
.asterisk_pipe_equal => .assign_mul_sat,
.plus_pipe_equal => .assign_add_sat,
.minus_pipe_equal => .assign_sub_sat,
.equal => .assign,
else => null,
};
}
fn finishAssignDestructureExpr(p: *Parse, first_lhs: Node.Index) !Node.Index {
const scratch_top = p.scratch.items.len;
defer p.scratch.shrinkRetainingCapacity(scratch_top);
try p.scratch.append(p.gpa, first_lhs);
while (p.eatToken(.comma)) |_| {
const expr = try p.expectExpr();
try p.scratch.append(p.gpa, expr);
}
const equal_token = try p.expectToken(.equal);
const rhs = try p.expectExpr();
const lhs_count = p.scratch.items.len - scratch_top;
assert(lhs_count > 1); // we already had first_lhs, and must have at least one more lvalue
const extra_start: ExtraIndex = @fromBackingInt(@intCast(p.extra_data.items.len));
try p.extra_data.ensureUnusedCapacity(p.gpa, lhs_count + 1);
p.extra_data.appendAssumeCapacity(@intCast(lhs_count));
p.extra_data.appendSliceAssumeCapacity(@ptrCast(p.scratch.items[scratch_top..]));
return p.addNode(.{
.tag = .assign_destructure,
.main_token = equal_token,
.data = .{ .extra_and_node = .{
extra_start,
rhs,
} },
});
}
fn expectSingleAssignExpr(p: *Parse) !Node.Index {
return try p.parseSingleAssignExpr() orelse return p.fail(.expected_expr_or_assignment);
}
fn expectAssignExpr(p: *Parse) !Node.Index {
return try p.parseAssignExpr() orelse return p.fail(.expected_expr_or_assignment);
}
fn parseExpr(p: *Parse) Error!?Node.Index {
return p.parseExprPrecedence(0);
}
fn expectExpr(p: *Parse) Error!Node.Index {
return try p.parseExpr() orelse return p.fail(.expected_expr);
}
const Assoc = enum {
left,
none,
};
const OperInfo = struct {
prec: i8,
tag: Node.Tag,
assoc: Assoc = Assoc.left,
};
// A table of binary operator information. Higher precedence numbers are
// stickier. All operators at the same precedence level should have the same
// associativity.
const operTable = std.enums.directEnumArrayDefault(Token.Tag, OperInfo, .{ .prec = -1, .tag = Node.Tag.root }, 0, .{
.keyword_or = .{ .prec = 10, .tag = .bool_or },
.keyword_and = .{ .prec = 20, .tag = .bool_and },
.equal_equal = .{ .prec = 30, .tag = .equal_equal, .assoc = Assoc.none },
.bang_equal = .{ .prec = 30, .tag = .bang_equal, .assoc = Assoc.none },
.angle_bracket_left = .{ .prec = 30, .tag = .less_than, .assoc = Assoc.none },
.angle_bracket_right = .{ .prec = 30, .tag = .greater_than, .assoc = Assoc.none },
.angle_bracket_left_equal = .{ .prec = 30, .tag = .less_or_equal, .assoc = Assoc.none },
.angle_bracket_right_equal = .{ .prec = 30, .tag = .greater_or_equal, .assoc = Assoc.none },
.ampersand = .{ .prec = 40, .tag = .bit_and },
.caret = .{ .prec = 40, .tag = .bit_xor },
.pipe = .{ .prec = 40, .tag = .bit_or },
.keyword_orelse = .{ .prec = 40, .tag = .@"orelse" },
.keyword_catch = .{ .prec = 40, .tag = .@"catch" },
.angle_bracket_angle_bracket_left = .{ .prec = 50, .tag = .shl },
.angle_bracket_angle_bracket_left_pipe = .{ .prec = 50, .tag = .shl_sat },
.angle_bracket_angle_bracket_right = .{ .prec = 50, .tag = .shr },
.plus = .{ .prec = 60, .tag = .add },
.minus = .{ .prec = 60, .tag = .sub },
.plus_plus = .{ .prec = 60, .tag = .array_cat },
.plus_percent = .{ .prec = 60, .tag = .add_wrap },
.minus_percent = .{ .prec = 60, .tag = .sub_wrap },
.plus_pipe = .{ .prec = 60, .tag = .add_sat },
.minus_pipe = .{ .prec = 60, .tag = .sub_sat },
.pipe_pipe = .{ .prec = 70, .tag = .merge_error_sets },
.asterisk = .{ .prec = 70, .tag = .mul },
.slash = .{ .prec = 70, .tag = .div },
.percent = .{ .prec = 70, .tag = .mod },
.asterisk_percent = .{ .prec = 70, .tag = .mul_wrap },
.asterisk_pipe = .{ .prec = 70, .tag = .mul_sat },
});
fn parseExprPrecedence(p: *Parse, min_prec: i32) Error!?Node.Index {
assert(min_prec >= 0);
var node = try p.parsePrefixExpr() orelse return null;
var banned_prec: i8 = -1;
while (true) {
const tok_tag = p.tokenTag(p.tok_i);
const info = operTable[@as(usize, @intCast(@backingInt(tok_tag)))];
if (info.prec < min_prec) {
break;
}
if (info.prec == banned_prec) {
return p.fail(.chained_comparison_operators);
}
const oper_token = p.nextToken();
// Special-case handling for "catch"
if (tok_tag == .keyword_catch) {
_ = try p.parsePayload();
}
// Check for whitespace error before parsing the rhs to facilitate fuzzing.
// Consider the case where there is a mismatched whitespace error but the rhs
// expression triggers stack overflow when parsing is attempted. In this case
// we want to return with an error rather than crashing on stack overflow.
{
const tok_len = tok_tag.lexeme().?.len;
if (p.tokenStart(oper_token) + tok_len >= p.source.len) {
try p.warn(.expected_expr);
return node;
}
const char_before = p.source[p.tokenStart(oper_token) - 1];
const char_after = p.source[p.tokenStart(oper_token) + tok_len];
if (tok_tag == .ampersand and char_after == '&') {
// without types we don't know if '&&' was intended as 'bitwise_and address_of', or a c-style logical_and
// The best the parser can do is recommend changing it to 'and' or ' & &'
try p.warnMsg(.{ .tag = .invalid_ampersand_ampersand, .token = oper_token });
} else if (std.ascii.isWhitespace(char_before) != std.ascii.isWhitespace(char_after)) {
try p.warnMsg(.{ .tag = .mismatched_binary_op_whitespace, .token = oper_token });
}
}
const rhs = try p.parseExprPrecedence(info.prec + 1) orelse {
try p.warn(.expected_expr);
return node;
};
node = try p.addNode(.{
.tag = info.tag,
.main_token = oper_token,
.data = .{ .node_and_node = .{ node, rhs } },
});
if (info.assoc == Assoc.none) {
banned_prec = info.prec;
}
}
return node;
}
fn parsePrefixExpr(p: *Parse) Error!?Node.Index {
const tag: Node.Tag = switch (p.tokenTag(p.tok_i)) {
.bang => .bool_not,
.minus => .negation,
.tilde => .bit_not,
.minus_percent => .negation_wrap,
.ampersand => .address_of,
.keyword_try => .@"try",
else => return p.parsePrimaryExpr(),
};
return try p.addNode(.{
.tag = tag,
.main_token = p.nextToken(),
.data = .{ .node = try p.expectPrefixExpr() },
});
}
fn expectPrefixExpr(p: *Parse) Error!Node.Index {
return try p.parsePrefixExpr() orelse return p.fail(.expected_prefix_expr);
}
fn parseTypeExpr(p: *Parse) Error!?Node.Index {
switch (p.tokenTag(p.tok_i)) {
.question_mark => return try p.addNode(.{
.tag = .optional_type,
.main_token = p.nextToken(),
.data = .{ .node = try p.expectTypeExpr() },
}),
.keyword_anyframe => switch (p.tokenTag(p.tok_i + 1)) {
.arrow => return try p.addNode(.{
.tag = .anyframe_type,
.main_token = p.nextToken(),
.data = .{ .token_and_node = .{
p.nextToken(),
try p.expectTypeExpr(),
} },
}),
else => return try p.parseErrorUnionExpr(),
},
.asterisk => {
const asterisk = p.nextToken();
const mods = try p.parsePtrModifiers(.bit_align);
const elem_type = try p.expectTypeExpr();
if (mods.bit_range_start != .none) {
return try p.addNode(.{
.tag = .ptr_type_bit_range,
.main_token = asterisk,
.data = .{ .extra_and_node = .{
try p.addExtra(Node.PtrTypeBitRange{
.sentinel = .none,
.align_node = mods.align_node.unwrap().?,
.addrspace_node = mods.addrspace_node,
.bit_range_start = mods.bit_range_start.unwrap().?,
.bit_range_end = mods.bit_range_end.unwrap().?,
}),
elem_type,
} },
});
} else if (mods.addrspace_node != .none) {
return try p.addNode(.{
.tag = .ptr_type,
.main_token = asterisk,
.data = .{ .extra_and_node = .{
try p.addExtra(Node.PtrType{
.sentinel = .none,
.align_node = mods.align_node,
.addrspace_node = mods.addrspace_node,
}),
elem_type,
} },
});
} else {
return try p.addNode(.{
.tag = .ptr_type_aligned,
.main_token = asterisk,
.data = .{ .opt_node_and_node = .{
mods.align_node,
elem_type,
} },
});
}
},
.l_bracket => switch (p.tokenTag(p.tok_i + 1)) {
.asterisk => {
const l_bracket = p.nextToken();
_ = p.nextToken();
var sentinel: ?Node.Index = null;
if (p.eatToken(.identifier)) |ident| {
const ident_slice = p.source[p.tokenStart(ident)..p.tokenStart(ident + 1)];
if (!std.mem.eql(u8, std.mem.trimEnd(u8, ident_slice, &std.ascii.whitespace), "c")) {
p.tok_i -= 1;
}
} else if (p.eatToken(.colon)) |_| {
sentinel = try p.expectExpr();
}
_ = try p.expectToken(.r_bracket);
const mods = try p.parsePtrModifiers(.byte_align);
const elem_type = try p.expectTypeExpr();
if (sentinel == null and mods.addrspace_node == .none) {
return try p.addNode(.{
.tag = .ptr_type_aligned,
.main_token = l_bracket,
.data = .{ .opt_node_and_node = .{
mods.align_node,
elem_type,
} },
});
} else if (mods.align_node == .none and mods.addrspace_node == .none) {
return try p.addNode(.{
.tag = .ptr_type_sentinel,
.main_token = l_bracket,
.data = .{ .opt_node_and_node = .{
.fromOptional(sentinel),
elem_type,
} },
});
} else {
return try p.addNode(.{
.tag = .ptr_type,
.main_token = l_bracket,
.data = .{ .extra_and_node = .{
try p.addExtra(Node.PtrType{
.sentinel = .fromOptional(sentinel),
.align_node = mods.align_node,
.addrspace_node = mods.addrspace_node,
}),
elem_type,
} },
});
}
},
else => {
const lbracket = p.nextToken();
const len_expr = try p.parseExpr();
const sentinel: ?Node.Index = if (p.eatToken(.colon)) |_|
try p.expectExpr()
else
null;
_ = try p.expectToken(.r_bracket);
if (len_expr == null) {
const mods = try p.parsePtrModifiers(.byte_align);
const elem_type = try p.expectTypeExpr();
if (sentinel == null and mods.addrspace_node == .none) {
return try p.addNode(.{
.tag = .ptr_type_aligned,
.main_token = lbracket,
.data = .{ .opt_node_and_node = .{
mods.align_node,
elem_type,
} },
});
} else if (mods.align_node == .none and mods.addrspace_node == .none) {
return try p.addNode(.{
.tag = .ptr_type_sentinel,
.main_token = lbracket,
.data = .{ .opt_node_and_node = .{
.fromOptional(sentinel),
elem_type,
} },
});
} else {
return try p.addNode(.{
.tag = .ptr_type,
.main_token = lbracket,
.data = .{ .extra_and_node = .{
try p.addExtra(Node.PtrType{
.sentinel = .fromOptional(sentinel),
.align_node = mods.align_node,
.addrspace_node = mods.addrspace_node,
}),
elem_type,
} },
});
}
} else {
switch (p.tokenTag(p.tok_i)) {
.keyword_align,
.keyword_const,
.keyword_volatile,
.keyword_allowzero,
.keyword_addrspace,
=> return p.fail(.ptr_mod_on_array_child_type),
else => {},
}
const elem_type = try p.expectTypeExpr();
if (sentinel == null) {
return try p.addNode(.{
.tag = .array_type,
.main_token = lbracket,
.data = .{ .node_and_node = .{
len_expr.?,
elem_type,
} },
});
} else {
return try p.addNode(.{
.tag = .array_type_sentinel,
.main_token = lbracket,
.data = .{ .node_and_extra = .{
len_expr.?,
try p.addExtra(Node.ArrayTypeSentinel{
.sentinel = sentinel.?,
.elem_type = elem_type,
}),
} },
});
}
}
},
},
else => return p.parseErrorUnionExpr(),
}
}
fn expectTypeExpr(p: *Parse) Error!Node.Index {
return try p.parseTypeExpr() orelse return p.fail(.expected_type_expr);
}
fn parsePrimaryExpr(p: *Parse) !?Node.Index {
switch (p.tokenTag(p.tok_i)) {
.keyword_asm => return try p.expectAsmExpr(),
.keyword_if => return try p.expectIf(expectExpr),
.keyword_break => {
return try p.addNode(.{
.tag = .@"break",
.main_token = p.nextToken(),
.data = .{ .opt_token_and_opt_node = .{
try p.parseBreakLabel(),
.fromOptional(try p.parseExpr()),
} },
});
},
.keyword_continue => {
return try p.addNode(.{
.tag = .@"continue",
.main_token = p.nextToken(),
.data = .{ .opt_token_and_opt_node = .{
try p.parseBreakLabel(),
.fromOptional(try p.parseExpr()),
} },
});
},
.keyword_comptime => {
return try p.addNode(.{
.tag = .@"comptime",
.main_token = p.nextToken(),
.data = .{ .node = try p.expectExpr() },
});
},
.keyword_nosuspend => {
return try p.addNode(.{
.tag = .@"nosuspend",
.main_token = p.nextToken(),
.data = .{ .node = try p.expectExpr() },
});
},
.keyword_resume => {
return try p.addNode(.{
.tag = .@"resume",
.main_token = p.nextToken(),
.data = .{ .node = try p.expectExpr() },
});
},
.keyword_return => {
return try p.addNode(.{
.tag = .@"return",
.main_token = p.nextToken(),
.data = .{ .opt_node = .fromOptional(try p.parseExpr()) },
});
},
.identifier => {
if (p.tokenTag(p.tok_i + 1) == .colon) {
switch (p.tokenTag(p.tok_i + 2)) {
.keyword_inline => {
p.tok_i += 3;
switch (p.tokenTag(p.tok_i)) {
.keyword_for => return try p.expectFor(expectExpr),
.keyword_while => return try p.expectWhileExpr(),
else => return p.fail(.expected_inlinable),
}
},
.keyword_for => {
p.tok_i += 2;
return try p.expectFor(expectExpr);
},
.keyword_while => {
p.tok_i += 2;
return try p.expectWhileExpr();
},
else => return try p.parseCurlySuffixExpr(),
}
} else {
return try p.parseCurlySuffixExpr();
}
},
.keyword_inline => {
p.tok_i += 1;
switch (p.tokenTag(p.tok_i)) {
.keyword_for => return try p.expectFor(expectExpr),
.keyword_while => return try p.expectWhileExpr(),
else => return p.fail(.expected_inlinable),
}
},
.keyword_for => return try p.expectFor(expectExpr),
.keyword_while => return try p.expectWhileExpr(),
.l_brace => return try p.parseBlock(),
else => return try p.parseCurlySuffixExpr(),
}
}
fn parseBlock(p: *Parse) !?Node.Index {
const lbrace = p.eatToken(.l_brace) orelse return null;
const scratch_top = p.scratch.items.len;
defer p.scratch.shrinkRetainingCapacity(scratch_top);
while (true) {
if (p.tokenTag(p.tok_i) == .r_brace) break;
const statement = try p.expectStatementRecoverable() orelse break;
try p.scratch.append(p.gpa, statement);
}
_ = try p.expectToken(.r_brace);
const statements = p.scratch.items[scratch_top..];
const semicolon = statements.len != 0 and (p.tokenTag(p.tok_i - 2)) == .semicolon;
if (statements.len <= 2) {
return try p.addNode(.{
.tag = if (semicolon) .block_two_semicolon else .block_two,
.main_token = lbrace,
.data = .{ .opt_node_and_opt_node = .{
if (statements.len >= 1) statements[0].toOptional() else .none,
if (statements.len >= 2) statements[1].toOptional() else .none,
} },
});
} else {
return try p.addNode(.{
.tag = if (semicolon) .block_semicolon else .block,
.main_token = lbrace,
.data = .{ .extra_range = try p.listToSpan(statements) },
});
}
}
fn forPrefix(p: *Parse) Error!usize {
const start = p.scratch.items.len;
_ = try p.expectToken(.l_paren);
while (true) {
var input = try p.expectExpr();
if (p.eatToken(.ellipsis2)) |ellipsis| {
input = try p.addNode(.{
.tag = .for_range,
.main_token = ellipsis,
.data = .{ .node_and_opt_node = .{
input,
.fromOptional(try p.parseExpr()),
} },
});
}
try p.scratch.append(p.gpa, input);
switch (p.tokenTag(p.tok_i)) {
.comma => p.tok_i += 1,
.r_paren => {
p.tok_i += 1;
break;
},
.colon, .r_brace, .r_bracket => return p.failExpected(.r_paren),
// Likely just a missing comma; give error but continue parsing.
else => try p.warn(.expected_comma_after_for_operand),
}
if (p.eatToken(.r_paren)) |_| break;
}
const inputs = p.scratch.items.len - start;
_ = p.eatToken(.pipe) orelse {
try p.warn(.expected_loop_payload);
return inputs;
};
while (true) {
_ = p.eatToken(.asterisk);
_ = try p.expectToken(.identifier);
switch (p.tokenTag(p.tok_i)) {
.comma => p.tok_i += 1,
.pipe => {
p.tok_i += 1;
break;
},
// Likely just a missing comma; give error but continue parsing.
else => try p.warn(.expected_comma_after_capture),
}
if (p.eatToken(.pipe)) |_| break;
}
return inputs;
}
fn expectWhileExpr(p: *Parse) !Node.Index {
const while_token = p.assertToken(.keyword_while);
_ = try p.expectToken(.l_paren);
const condition = try p.expectExpr();
_ = try p.expectToken(.r_paren);
_ = try p.parsePtrPayload();
const cont_expr = try p.parseWhileContinueExpr();
const then_expr = try p.expectExpr();
_ = p.eatToken(.keyword_else) orelse {
if (cont_expr == null) {
return try p.addNode(.{
.tag = .while_simple,
.main_token = while_token,
.data = .{ .node_and_node = .{
condition,
then_expr,
} },
});
} else {
return try p.addNode(.{
.tag = .while_cont,
.main_token = while_token,
.data = .{ .node_and_extra = .{
condition,
try p.addExtra(Node.WhileCont{
.cont_expr = cont_expr.?,
.then_expr = then_expr,
}),
} },
});
}
};
_ = try p.parsePayload();
const else_expr = try p.expectExpr();
return try p.addNode(.{
.tag = .@"while",
.main_token = while_token,
.data = .{ .node_and_extra = .{
condition,
try p.addExtra(Node.While{
.cont_expr = .fromOptional(cont_expr),
.then_expr = then_expr,
.else_expr = else_expr,
}),
} },
});
}
fn parseCurlySuffixExpr(p: *Parse) !?Node.Index {
const lhs = try p.parseTypeExpr() orelse return null;
const lbrace = p.eatToken(.l_brace) orelse return lhs;
// If there are 0 or 1 items, we can use ArrayInitOne/StructInitOne;
// otherwise we use the full ArrayInit/StructInit.
const scratch_top = p.scratch.items.len;
defer p.scratch.shrinkRetainingCapacity(scratch_top);
const opt_field_init = try p.parseFieldInit();
if (opt_field_init) |field_init| {
try p.scratch.append(p.gpa, field_init);
while (true) {
switch (p.tokenTag(p.tok_i)) {
.comma => p.tok_i += 1,
.r_brace => {
p.tok_i += 1;
break;
},
.colon, .r_paren, .r_bracket => return p.failExpected(.r_brace),
// Likely just a missing comma; give error but continue parsing.
else => try p.warn(.expected_comma_after_initializer),
}
if (p.eatToken(.r_brace)) |_| break;
const next = try p.expectFieldInit();
try p.scratch.append(p.gpa, next);
}
const comma = (p.tokenTag(p.tok_i - 2)) == .comma;
const inits = p.scratch.items[scratch_top..];
std.debug.assert(inits.len != 0);
if (inits.len <= 1) {
return try p.addNode(.{
.tag = if (comma) .struct_init_one_comma else .struct_init_one,
.main_token = lbrace,
.data = .{ .node_and_opt_node = .{
lhs,
inits[0].toOptional(),
} },
});
} else {
return try p.addNode(.{
.tag = if (comma) .struct_init_comma else .struct_init,
.main_token = lbrace,
.data = .{ .node_and_extra = .{
lhs,
try p.addExtra(try p.listToSpan(inits)),
} },
});
}
}
while (true) {
if (p.eatToken(.r_brace)) |_| break;
const elem_init = try p.expectExpr();
try p.scratch.append(p.gpa, elem_init);
switch (p.tokenTag(p.tok_i)) {
.comma => p.tok_i += 1,
.r_brace => {
p.tok_i += 1;
break;
},
.colon, .r_paren, .r_bracket => return p.failExpected(.r_brace),
// Likely just a missing comma; give error but continue parsing.
else => try p.warn(.expected_comma_after_initializer),
}
}
const comma = (p.tokenTag(p.tok_i - 2)) == .comma;
const inits = p.scratch.items[scratch_top..];
switch (inits.len) {
0 => return try p.addNode(.{
.tag = .struct_init_one,
.main_token = lbrace,
.data = .{ .node_and_opt_node = .{
lhs,
.none,
} },
}),
1 => return try p.addNode(.{
.tag = if (comma) .array_init_one_comma else .array_init_one,
.main_token = lbrace,
.data = .{ .node_and_node = .{
lhs,
inits[0],
} },
}),
else => return try p.addNode(.{
.tag = if (comma) .array_init_comma else .array_init,
.main_token = lbrace,
.data = .{ .node_and_extra = .{
lhs,
try p.addExtra(try p.listToSpan(inits)),
} },
}),
}
}
fn parseErrorUnionExpr(p: *Parse) !?Node.Index {
const suffix_expr = try p.parseSuffixExpr() orelse return null;
const bang = p.eatToken(.bang) orelse return suffix_expr;
return try p.addNode(.{
.tag = .error_union,
.main_token = bang,
.data = .{ .node_and_node = .{
suffix_expr,
try p.expectTypeExpr(),
} },
});
}
fn parseSuffixExpr(p: *Parse) !?Node.Index {
var res = try p.parsePrimaryTypeExpr() orelse return null;
while (try p.parseSuffixOp(res)) |suffix_op| {
res = suffix_op;
}
return res;
}
fn parsePrimaryTypeExpr(p: *Parse) !?Node.Index {
switch (p.tokenTag(p.tok_i)) {
.char_literal => return try p.addNode(.{
.tag = .char_literal,
.main_token = p.nextToken(),
.data = undefined,
}),
.number_literal => return try p.addNode(.{
.tag = .number_literal,
.main_token = p.nextToken(),
.data = undefined,
}),
.keyword_unreachable => return try p.addNode(.{
.tag = .unreachable_literal,
.main_token = p.nextToken(),
.data = undefined,
}),
.keyword_anyframe => return try p.addNode(.{
.tag = .anyframe_literal,
.main_token = p.nextToken(),
.data = undefined,
}),
.string_literal => {
const main_token = p.nextToken();
return try p.addNode(.{
.tag = .string_literal,
.main_token = main_token,
.data = undefined,
});
},
.builtin => return try p.expectBuiltinCall(),
.keyword_fn => return (try p.parseFnProto()).?,
.keyword_if => return try p.expectIf(expectTypeExpr),
.keyword_switch => return try p.expectSwitchExpr(false),
.keyword_extern,
.keyword_packed,
=> {
p.tok_i += 1;
return try p.expectContainerDeclAuto();
},
.keyword_struct,
.keyword_opaque,
.keyword_enum,
.keyword_union,
=> return try p.expectContainerDeclAuto(),
.keyword_comptime => return try p.addNode(.{
.tag = .@"comptime",
.main_token = p.nextToken(),
.data = .{ .node = try p.expectTypeExpr() },
}),
.multiline_string_literal_line => {
const first_line = p.nextToken();
while (p.tokenTag(p.tok_i) == .multiline_string_literal_line) {
p.tok_i += 1;
}
return try p.addNode(.{
.tag = .multiline_string_literal,
.main_token = first_line,
.data = .{ .token_and_token = .{
first_line,
p.tok_i - 1,
} },
});
},
.identifier => switch (p.tokenTag(p.tok_i + 1)) {
.colon => switch (p.tokenTag(p.tok_i + 2)) {
.keyword_inline => {
p.tok_i += 3;
switch (p.tokenTag(p.tok_i)) {
.keyword_for => return try p.expectFor(expectTypeExpr),
.keyword_while => return try p.expectWhileTypeExpr(),
else => return p.fail(.expected_inlinable),
}
},
.keyword_for => {
p.tok_i += 2;
return try p.expectFor(expectTypeExpr);
},
.keyword_while => {
p.tok_i += 2;
return try p.expectWhileTypeExpr();
},
.keyword_switch => {
p.tok_i += 2;
return try p.expectSwitchExpr(true);
},
.l_brace => {
p.tok_i += 2;
return (try p.parseBlock()).?;
},
else => return try p.addNode(.{
.tag = .identifier,
.main_token = p.nextToken(),
.data = undefined,
}),
},
else => return try p.addNode(.{
.tag = .identifier,
.main_token = p.nextToken(),
.data = undefined,
}),
},
.keyword_inline => {
p.tok_i += 1;
switch (p.tokenTag(p.tok_i)) {
.keyword_for => return try p.expectFor(expectTypeExpr),
.keyword_while => return try p.expectWhileTypeExpr(),
else => return p.fail(.expected_inlinable),
}
},
.keyword_for => return try p.expectFor(expectTypeExpr),
.keyword_while => return try p.expectWhileTypeExpr(),
.period => switch (p.tokenTag(p.tok_i + 1)) {
.identifier => {
p.tok_i += 1;
return try p.addNode(.{
.tag = .enum_literal,
.main_token = p.nextToken(), // identifier
.data = undefined,
});
},
.l_brace => {
const lbrace = p.tok_i + 1;
p.tok_i = lbrace + 1;
// If there are 0, 1, or 2 items, we can use ArrayInitDotTwo/StructInitDotTwo;
// otherwise we use the full ArrayInitDot/StructInitDot.
const scratch_top = p.scratch.items.len;
defer p.scratch.shrinkRetainingCapacity(scratch_top);
const opt_field_init = try p.parseFieldInit();
if (opt_field_init) |field_init| {
try p.scratch.append(p.gpa, field_init);
while (true) {
switch (p.tokenTag(p.tok_i)) {
.comma => p.tok_i += 1,
.r_brace => {
p.tok_i += 1;
break;
},
.colon, .r_paren, .r_bracket => return p.failExpected(.r_brace),
// Likely just a missing comma; give error but continue parsing.
else => try p.warn(.expected_comma_after_initializer),
}
if (p.eatToken(.r_brace)) |_| break;
const next = try p.expectFieldInit();
try p.scratch.append(p.gpa, next);
}
const comma = (p.tokenTag(p.tok_i - 2)) == .comma;
const inits = p.scratch.items[scratch_top..];
std.debug.assert(inits.len != 0);
if (inits.len <= 2) {
return try p.addNode(.{
.tag = if (comma) .struct_init_dot_two_comma else .struct_init_dot_two,
.main_token = lbrace,
.data = .{ .opt_node_and_opt_node = .{
if (inits.len >= 1) .fromOptional(inits[0]) else .none,
if (inits.len >= 2) .fromOptional(inits[1]) else .none,
} },
});
} else {
return try p.addNode(.{
.tag = if (comma) .struct_init_dot_comma else .struct_init_dot,
.main_token = lbrace,
.data = .{ .extra_range = try p.listToSpan(inits) },
});
}
}
while (true) {
if (p.eatToken(.r_brace)) |_| break;
const elem_init = try p.expectExpr();
try p.scratch.append(p.gpa, elem_init);
switch (p.tokenTag(p.tok_i)) {
.comma => p.tok_i += 1,
.r_brace => {
p.tok_i += 1;
break;
},
.colon, .r_paren, .r_bracket => return p.failExpected(.r_brace),
// Likely just a missing comma; give error but continue parsing.
else => try p.warn(.expected_comma_after_initializer),
}
}
const comma = (p.tokenTag(p.tok_i - 2)) == .comma;
const inits = p.scratch.items[scratch_top..];
if (inits.len <= 2) {
return try p.addNode(.{
.tag = if (inits.len == 0)
.struct_init_dot_two
else if (comma) .array_init_dot_two_comma else .array_init_dot_two,
.main_token = lbrace,
.data = .{ .opt_node_and_opt_node = .{
if (inits.len >= 1) inits[0].toOptional() else .none,
if (inits.len >= 2) inits[1].toOptional() else .none,
} },
});
} else {
return try p.addNode(.{
.tag = if (comma) .array_init_dot_comma else .array_init_dot,
.main_token = lbrace,
.data = .{ .extra_range = try p.listToSpan(inits) },
});
}
},
else => return null,
},
.keyword_error => switch (p.tokenTag(p.tok_i + 1)) {
.l_brace => {
const error_token = p.tok_i;
p.tok_i += 2;
while (true) {
if (p.eatToken(.r_brace)) |_| break;
_ = try p.eatDocComments();
_ = try p.expectToken(.identifier);
switch (p.tokenTag(p.tok_i)) {
.comma => p.tok_i += 1,
.r_brace => {
p.tok_i += 1;
break;
},
.colon, .r_paren, .r_bracket => return p.failExpected(.r_brace),
// Likely just a missing comma; give error but continue parsing.
else => try p.warn(.expected_comma_after_field),
}
}
return try p.addNode(.{
.tag = .error_set_decl,
.main_token = error_token,
.data = .{
.token_and_token = .{
error_token + 1, // lbrace
p.tok_i - 1, // rbrace
},
},
});
},
else => {
const main_token = p.nextToken();
_ = try p.expectToken(.period);
_ = try p.expectToken(.identifier);
return try p.addNode(.{
.tag = .error_value,
.main_token = main_token,
.data = undefined,
});
},
},
.l_paren => return try p.addNode(.{
.tag = .grouped_expression,
.main_token = p.nextToken(),
.data = .{ .node_and_token = .{
try p.expectExpr(),
try p.expectToken(.r_paren),
} },
}),
else => return null,
}
}
fn expectPrimaryTypeExpr(p: *Parse) !Node.Index {
return try p.parsePrimaryTypeExpr() orelse return p.fail(.expected_primary_type_expr);
}
fn expectWhileTypeExpr(p: *Parse) !Node.Index {
const while_token = p.assertToken(.keyword_while);
_ = try p.expectToken(.l_paren);
const condition = try p.expectExpr();
_ = try p.expectToken(.r_paren);
_ = try p.parsePtrPayload();
const cont_expr = try p.parseWhileContinueExpr();
const then_expr = try p.expectTypeExpr();
_ = p.eatToken(.keyword_else) orelse {
if (cont_expr == null) {
return try p.addNode(.{
.tag = .while_simple,
.main_token = while_token,
.data = .{ .node_and_node = .{
condition,
then_expr,
} },
});
} else {
return try p.addNode(.{
.tag = .while_cont,
.main_token = while_token,
.data = .{ .node_and_extra = .{
condition,
try p.addExtra(Node.WhileCont{
.cont_expr = cont_expr.?,
.then_expr = then_expr,
}),
} },
});
}
};
_ = try p.parsePayload();
const else_expr = try p.expectTypeExpr();
return try p.addNode(.{
.tag = .@"while",
.main_token = while_token,
.data = .{ .node_and_extra = .{
condition,
try p.addExtra(Node.While{
.cont_expr = .fromOptional(cont_expr),
.then_expr = then_expr,
.else_expr = else_expr,
}),
} },
});
}
fn parseSwitchExpr(p: *Parse, is_labeled: bool) !?Node.Index {
const switch_token = p.eatToken(.keyword_switch) orelse return null;
return try p.expectSwitchSuffix(if (is_labeled) switch_token - 2 else switch_token);
}
fn expectSwitchExpr(p: *Parse, is_labeled: bool) !Node.Index {
const switch_token = p.assertToken(.keyword_switch);
return try p.expectSwitchSuffix(if (is_labeled) switch_token - 2 else switch_token);
}
fn expectSwitchSuffix(p: *Parse, main_token: TokenIndex) !Node.Index {
_ = try p.expectToken(.l_paren);
const expr_node = try p.expectExpr();
_ = try p.expectToken(.r_paren);
_ = try p.expectToken(.l_brace);
const cases = try p.parseSwitchProngList();
const trailing_comma = p.tokenTag(p.tok_i - 1) == .comma;
_ = try p.expectToken(.r_brace);
return p.addNode(.{
.tag = if (trailing_comma) .switch_comma else .@"switch",
.main_token = main_token,
.data = .{ .node_and_extra = .{
expr_node,
try p.addExtra(Node.SubRange{
.start = cases.start,
.end = cases.end,
}),
} },
});
}
fn expectAsmExpr(p: *Parse) !Node.Index {
const asm_token = p.assertToken(.keyword_asm);
_ = p.eatToken(.keyword_volatile);
_ = try p.expectToken(.l_paren);
const template = try p.expectExpr();
if (p.eatToken(.r_paren)) |rparen| {
return p.addNode(.{
.tag = .asm_simple,
.main_token = asm_token,
.data = .{ .node_and_token = .{
template,
rparen,
} },
});
}
_ = try p.expectToken(.colon);
const scratch_top = p.scratch.items.len;
defer p.scratch.shrinkRetainingCapacity(scratch_top);
while (true) {
const output_item = try p.parseAsmOutputItem() orelse break;
try p.scratch.append(p.gpa, output_item);
switch (p.tokenTag(p.tok_i)) {
.comma => p.tok_i += 1,
// All possible delimiters.
.colon, .r_paren, .r_brace, .r_bracket => break,
// Likely just a missing comma; give error but continue parsing.
else => try p.warnExpected(.comma),
}
}
const clobbers: Node.OptionalIndex = if (p.eatToken(.colon)) |_| clobbers: {
while (true) {
const input_item = try p.parseAsmInputItem() orelse break;
try p.scratch.append(p.gpa, input_item);
switch (p.tokenTag(p.tok_i)) {
.comma => p.tok_i += 1,
// All possible delimiters.
.colon, .r_paren, .r_brace, .r_bracket => break,
// Likely just a missing comma; give error but continue parsing.
else => try p.warnExpected(.comma),
}
}
_ = p.eatToken(.colon) orelse break :clobbers .none;
break :clobbers (try p.expectExpr()).toOptional();
} else .none;
const rparen = try p.expectToken(.r_paren);
const span = try p.listToSpan(p.scratch.items[scratch_top..]);
return p.addNode(.{
.tag = .@"asm",
.main_token = asm_token,
.data = .{ .node_and_extra = .{
template,
try p.addExtra(Node.Asm{
.items_start = span.start,
.items_end = span.end,
.clobbers = clobbers,
.rparen = rparen,
}),
} },
});
}
fn parseAsmOutputItem(p: *Parse) !?Node.Index {
_ = p.eatToken(.l_bracket) orelse return null;
const identifier = try p.expectToken(.identifier);
_ = try p.expectToken(.r_bracket);
_ = try p.expectToken(.string_literal);
_ = try p.expectToken(.l_paren);
const type_expr: Node.OptionalIndex = blk: {
if (p.eatToken(.arrow)) |_| {
break :blk .fromOptional(try p.expectTypeExpr());
} else {
_ = try p.expectToken(.identifier);
break :blk .none;
}
};
const rparen = try p.expectToken(.r_paren);
return try p.addNode(.{
.tag = .asm_output,
.main_token = identifier,
.data = .{ .opt_node_and_token = .{
type_expr,
rparen,
} },
});
}
fn parseAsmInputItem(p: *Parse) !?Node.Index {
_ = p.eatToken(.l_bracket) orelse return null;
const identifier = try p.expectToken(.identifier);
_ = try p.expectToken(.r_bracket);
_ = try p.expectToken(.string_literal);
_ = try p.expectToken(.l_paren);
const expr = try p.expectExpr();
const rparen = try p.expectToken(.r_paren);
return try p.addNode(.{
.tag = .asm_input,
.main_token = identifier,
.data = .{ .node_and_token = .{
expr,
rparen,
} },
});
}
fn parseBreakLabel(p: *Parse) Error!OptionalTokenIndex {
return if (p.eatTokens(&.{ .colon, .identifier })) |i| .fromToken(i + 1) else .none;
}
fn parseBlockLabel(p: *Parse) ?TokenIndex {
return p.eatTokens(&.{ .identifier, .colon });
}
fn parseFieldInit(p: *Parse) !?Node.Index {
if (p.eatTokens(&.{ .period, .identifier, .equal })) |_| {
return try p.expectExpr();
}
return null;
}
fn expectFieldInit(p: *Parse) !Node.Index {
if (p.eatTokens(&.{ .period, .identifier, .equal })) |_| {
return try p.expectExpr();
}
return p.fail(.expected_initializer);
}
fn parseWhileContinueExpr(p: *Parse) !?Node.Index {
_ = p.eatToken(.colon) orelse return null;
_ = try p.expectToken(.l_paren);
const node = try p.parseAssignExpr() orelse return p.fail(.expected_expr_or_assignment);
_ = try p.expectToken(.r_paren);
return node;
}
fn parseLinkSection(p: *Parse) !?Node.Index {
_ = p.eatToken(.keyword_linksection) orelse return null;
_ = try p.expectToken(.l_paren);
const expr_node = try p.expectExpr();
_ = try p.expectToken(.r_paren);
return expr_node;
}
fn parseCallconv(p: *Parse) !?Node.Index {
_ = p.eatToken(.keyword_callconv) orelse return null;
_ = try p.expectToken(.l_paren);
const expr_node = try p.expectExpr();
_ = try p.expectToken(.r_paren);
return expr_node;
}
fn parseAddrSpace(p: *Parse) !?Node.Index {
_ = p.eatToken(.keyword_addrspace) orelse return null;
_ = try p.expectToken(.l_paren);
const expr_node = try p.expectExpr();
_ = try p.expectToken(.r_paren);
return expr_node;
}
/// This function can return null nodes and then still return nodes afterwards,
/// such as in the case of anytype and `...`. Caller must look for rparen to find
/// out when there are no more param decls left.
fn expectParamDecl(p: *Parse) !?Node.Index {
_ = try p.eatDocComments();
switch (p.tokenTag(p.tok_i)) {
.keyword_noalias, .keyword_comptime => p.tok_i += 1,
.ellipsis3 => {
p.tok_i += 1;
return null;
},
else => {},
}
_ = p.eatTokens(&.{ .identifier, .colon });
if (p.eatToken(.keyword_anytype)) |_| {
return null;
} else {
return try p.expectTypeExpr();
}
}
fn parsePayload(p: *Parse) Error!OptionalTokenIndex {
_ = p.eatToken(.pipe) orelse return .none;
const identifier = try p.expectToken(.identifier);
_ = try p.expectToken(.pipe);
return .fromToken(identifier);
}
fn parsePtrPayload(p: *Parse) Error!OptionalTokenIndex {
_ = p.eatToken(.pipe) orelse return .none;
_ = p.eatToken(.asterisk);
const identifier = try p.expectToken(.identifier);
_ = try p.expectToken(.pipe);
return .fromToken(identifier);
}
/// Returns the first identifier token, if any.
fn parsePtrIndexPayload(p: *Parse) Error!OptionalTokenIndex {
_ = p.eatToken(.pipe) orelse return .none;
_ = p.eatToken(.asterisk);
const identifier = try p.expectToken(.identifier);
if (p.eatToken(.comma) != null) {
_ = try p.expectToken(.identifier);
}
_ = try p.expectToken(.pipe);
return .fromToken(identifier);
}
fn parseSwitchProng(p: *Parse) !?Node.Index {
const scratch_top = p.scratch.items.len;
defer p.scratch.shrinkRetainingCapacity(scratch_top);
const is_inline = p.eatToken(.keyword_inline) != null;
if (p.eatToken(.keyword_else) == null) {
while (true) {
const item = try p.parseSwitchItem() orelse break;
try p.scratch.append(p.gpa, item);
if (p.eatToken(.comma) == null) break;
}
if (scratch_top == p.scratch.items.len) {
if (is_inline) p.tok_i -= 1;
return null;
}
}
const arrow_token = try p.expectToken(.equal_angle_bracket_right);
_ = try p.parsePtrIndexPayload();
const items = p.scratch.items[scratch_top..];
if (items.len <= 1) {
return try p.addNode(.{
.tag = if (is_inline) .switch_case_inline_one else .switch_case_one,
.main_token = arrow_token,
.data = .{ .opt_node_and_node = .{
if (items.len >= 1) items[0].toOptional() else .none,
try p.expectSingleAssignExpr(),
} },
});
} else {
return try p.addNode(.{
.tag = if (is_inline) .switch_case_inline else .switch_case,
.main_token = arrow_token,
.data = .{ .extra_and_node = .{
try p.addExtra(try p.listToSpan(items)),
try p.expectSingleAssignExpr(),
} },
});
}
}
fn parseSwitchItem(p: *Parse) !?Node.Index {
const expr = try p.parseExpr() orelse return null;
if (p.eatToken(.ellipsis3)) |token| {
return try p.addNode(.{
.tag = .switch_range,
.main_token = token,
.data = .{ .node_and_node = .{
expr,
try p.expectExpr(),
} },
});
}
return expr;
}
/// The following invariant will hold:
/// - `(bit_range_start == .none) == (bit_range_end == .none)`
/// - `bit_range_start != .none` implies `align_node != .none`
/// - `bit_range_end != .none` implies `align_node != .none`
const PtrModifiers = struct {
align_node: Node.OptionalIndex,
addrspace_node: Node.OptionalIndex,
bit_range_start: Node.OptionalIndex,
bit_range_end: Node.OptionalIndex,
};
fn parsePtrModifiers(p: *Parse, align_type: enum { bit_align, byte_align }) !PtrModifiers {
var result: PtrModifiers = .{
.align_node = .none,
.addrspace_node = .none,
.bit_range_start = .none,
.bit_range_end = .none,
};
while (true) {
switch (p.tokenTag(p.tok_i)) {
.keyword_align => {
if (result.align_node != .none) {
try p.warn(.extra_align_qualifier);
}
p.tok_i += 1;
_ = try p.expectToken(.l_paren);
result.align_node = (try p.expectExpr()).toOptional();
if (p.eatToken(.colon)) |colon| {
if (align_type == .byte_align) {
try p.warnMsg(.{ .tag = .invalid_bit_range, .token = colon });
}
result.bit_range_start = (try p.expectExpr()).toOptional();
_ = try p.expectToken(.colon);
result.bit_range_end = (try p.expectExpr()).toOptional();
}
_ = try p.expectToken(.r_paren);
},
.keyword_addrspace => {
if (result.addrspace_node != .none) {
try p.warn(.extra_addrspace_qualifier);
}
result.addrspace_node = .fromOptional(try p.parseAddrSpace());
},
.keyword_allowzero,
.keyword_const,
.keyword_volatile,
=> p.tok_i += 1,
else => return result,
}
}
}
fn parseSuffixOp(p: *Parse, lhs: Node.Index) !?Node.Index {
switch (p.tokenTag(p.tok_i)) {
.l_bracket => {
const lbracket = p.nextToken();
const index_expr = try p.expectExpr();
if (p.eatToken(.ellipsis2)) |_| {
const opt_end_expr = try p.parseExpr();
if (p.eatToken(.colon)) |_| {
const sentinel = try p.expectExpr();
_ = try p.expectToken(.r_bracket);
return try p.addNode(.{
.tag = .slice_sentinel,
.main_token = lbracket,
.data = .{ .node_and_extra = .{
lhs,
try p.addExtra(Node.SliceSentinel{
.start = index_expr,
.end = .fromOptional(opt_end_expr),
.sentinel = sentinel,
}),
} },
});
}
_ = try p.expectToken(.r_bracket);
const end_expr = opt_end_expr orelse {
return try p.addNode(.{
.tag = .slice_open,
.main_token = lbracket,
.data = .{ .node_and_node = .{
lhs,
index_expr,
} },
});
};
return try p.addNode(.{
.tag = .slice,
.main_token = lbracket,
.data = .{ .node_and_extra = .{
lhs,
try p.addExtra(Node.Slice{
.start = index_expr,
.end = end_expr,
}),
} },
});
}
_ = try p.expectToken(.r_bracket);
return try p.addNode(.{
.tag = .array_access,
.main_token = lbracket,
.data = .{ .node_and_node = .{
lhs,
index_expr,
} },
});
},
.period_asterisk => return try p.addNode(.{
.tag = .deref,
.main_token = p.nextToken(),
.data = .{ .node = lhs },
}),
.period => switch (p.tokenTag(p.tok_i + 1)) {
.identifier => return try p.addNode(.{
.tag = .field_access,
.main_token = p.nextToken(),
.data = .{ .node_and_token = .{
lhs,
p.nextToken(),
} },
}),
.question_mark => return try p.addNode(.{
.tag = .unwrap_optional,
.main_token = p.nextToken(),
.data = .{ .node_and_token = .{
lhs,
p.nextToken(),
} },
}),
.l_brace => {
// this a misplaced `.{`, handle the error somewhere else
return null;
},
else => {
p.tok_i += 1;
try p.warn(.expected_suffix_op);
return null;
},
},
.l_paren => {
const lparen = p.nextToken();
const scratch_top = p.scratch.items.len;
defer p.scratch.shrinkRetainingCapacity(scratch_top);
while (true) {
if (p.eatToken(.r_paren)) |_| break;
const param = try p.expectExpr();
try p.scratch.append(p.gpa, param);
switch (p.tokenTag(p.tok_i)) {
.comma => p.tok_i += 1,
.r_paren => {
p.tok_i += 1;
break;
},
.colon, .r_brace, .r_bracket => return p.failExpected(.r_paren),
// Likely just a missing comma; give error but continue parsing.
else => try p.warn(.expected_comma_after_arg),
}
}
const comma = (p.tokenTag(p.tok_i - 2)) == .comma;
const params = p.scratch.items[scratch_top..];
switch (params.len) {
0, 1 => return try p.addNode(.{
.tag = if (comma) .call_one_comma else .call_one,
.main_token = lparen,
.data = .{ .node_and_opt_node = .{
lhs,
if (params.len >= 1) .fromOptional(params[0]) else .none,
} },
}),
else => return try p.addNode(.{
.tag = if (comma) .call_comma else .call,
.main_token = lparen,
.data = .{ .node_and_extra = .{
lhs,
try p.addExtra(try p.listToSpan(params)),
} },
}),
}
},
else => return null,
}
}
/// Caller must have already verified the first token.
fn expectContainerDeclAuto(p: *Parse) !Node.Index {
const main_token = p.nextToken();
const arg_expr = switch (p.tokenTag(main_token)) {
.keyword_opaque => null,
.keyword_struct, .keyword_enum => blk: {
if (p.eatToken(.l_paren)) |_| {
const expr = try p.expectExpr();
_ = try p.expectToken(.r_paren);
break :blk expr;
} else {
break :blk null;
}
},
.keyword_union => blk: {
if (p.eatToken(.l_paren)) |_| {
if (p.eatToken(.keyword_enum)) |_| {
if (p.eatToken(.l_paren)) |_| {
const enum_tag_expr = try p.expectExpr();
_ = try p.expectToken(.r_paren);
_ = try p.expectToken(.r_paren);
_ = try p.expectToken(.l_brace);
const members = try p.parseContainerMembers();
const members_span = try members.toSpan(p);
_ = try p.expectToken(.r_brace);
return try p.addNode(.{
.tag = switch (members.trailing) {
true => .tagged_union_enum_tag_trailing,
false => .tagged_union_enum_tag,
},
.main_token = main_token,
.data = .{ .node_and_extra = .{
enum_tag_expr,
try p.addExtra(members_span),
} },
});
} else {
_ = try p.expectToken(.r_paren);
_ = try p.expectToken(.l_brace);
const members = try p.parseContainerMembers();
_ = try p.expectToken(.r_brace);
if (members.len <= 2) {
return try p.addNode(.{
.tag = switch (members.trailing) {
true => .tagged_union_two_trailing,
false => .tagged_union_two,
},
.main_token = main_token,
.data = members.data,
});
} else {
const span = try members.toSpan(p);
return try p.addNode(.{
.tag = switch (members.trailing) {
true => .tagged_union_trailing,
false => .tagged_union,
},
.main_token = main_token,
.data = .{ .extra_range = span },
});
}
}
} else {
const expr = try p.expectExpr();
_ = try p.expectToken(.r_paren);
break :blk expr;
}
} else {
break :blk null;
}
},
else => {
p.tok_i -= 1;
return p.fail(.expected_container);
},
};
_ = try p.expectToken(.l_brace);
const members = try p.parseContainerMembers();
_ = try p.expectToken(.r_brace);
if (arg_expr == null) {
if (members.len <= 2) {
return try p.addNode(.{
.tag = switch (members.trailing) {
true => .container_decl_two_trailing,
false => .container_decl_two,
},
.main_token = main_token,
.data = members.data,
});
} else {
const span = try members.toSpan(p);
return try p.addNode(.{
.tag = switch (members.trailing) {
true => .container_decl_trailing,
false => .container_decl,
},
.main_token = main_token,
.data = .{ .extra_range = span },
});
}
} else {
const span = try members.toSpan(p);
return try p.addNode(.{
.tag = switch (members.trailing) {
true => .container_decl_arg_trailing,
false => .container_decl_arg,
},
.main_token = main_token,
.data = .{ .node_and_extra = .{
arg_expr.?,
try p.addExtra(Node.SubRange{
.start = span.start,
.end = span.end,
}),
} },
});
}
}
/// Give a helpful error message for those transitioning from
/// C's 'struct Foo {};' to Zig's 'const Foo = struct {};'.
fn parseCStyleContainer(p: *Parse) Error!bool {
if (!p.recover) return false;
const main_token = p.tok_i;
switch (p.tokenTag(p.tok_i)) {
.keyword_enum, .keyword_union, .keyword_struct => {},
else => return false,
}
const identifier = p.tok_i + 1;
if (p.tokenTag(identifier) != .identifier) return false;
p.tok_i += 2;
try p.warnMsg(.{
.tag = .c_style_container,
.token = identifier,
.extra = .{ .expected_tag = p.tokenTag(main_token) },
});
try p.warnMsg(.{
.tag = .zig_style_container,
.is_note = true,
.token = identifier,
.extra = .{ .expected_tag = p.tokenTag(main_token) },
});
_ = try p.expectToken(.l_brace);
_ = try p.parseContainerMembers();
_ = try p.expectToken(.r_brace);
try p.expectSemicolon(.expected_semi_after_decl, true);
return true;
}
/// Holds temporary data until we are ready to construct the full ContainerDecl AST node.
fn parseByteAlign(p: *Parse) !?Node.Index {
_ = p.eatToken(.keyword_align) orelse return null;
_ = try p.expectToken(.l_paren);
const expr = try p.expectExpr();
_ = try p.expectToken(.r_paren);
return expr;
}
fn parseSwitchProngList(p: *Parse) !Node.SubRange {
const scratch_top = p.scratch.items.len;
defer p.scratch.shrinkRetainingCapacity(scratch_top);
while (true) {
const item = try parseSwitchProng(p) orelse break;
try p.scratch.append(p.gpa, item);
switch (p.tokenTag(p.tok_i)) {
.comma => p.tok_i += 1,
// All possible delimiters.
.colon, .r_paren, .r_brace, .r_bracket => break,
// Likely just a missing comma; give error but continue parsing.
else => try p.warn(.expected_comma_after_switch_prong),
}
}
return p.listToSpan(p.scratch.items[scratch_top..]);
}
fn parseParamDeclList(p: *Parse) !SmallSpan {
_ = try p.expectToken(.l_paren);
const scratch_top = p.scratch.items.len;
defer p.scratch.shrinkRetainingCapacity(scratch_top);
var varargs: enum { none, seen, err } = .none;
while (true) {
if (p.eatToken(.r_paren)) |_| break;
if (varargs == .seen) {
try p.warnMsg(.{ .tag = .varargs_nonfinal, .token = p.tok_i });
varargs = .err;
}
const opt_param = try p.expectParamDecl();
if (opt_param) |param| {
try p.scratch.append(p.gpa, param);
} else if (p.tokenTag(p.tok_i - 1) == .ellipsis3) {
if (varargs == .none) varargs = .seen;
}
switch (p.tokenTag(p.tok_i)) {
.comma => p.tok_i += 1,
.r_paren => {
p.tok_i += 1;
break;
},
.colon, .r_brace, .r_bracket => return p.failExpected(.r_paren),
// Likely just a missing comma; give error but continue parsing.
else => try p.warn(.expected_comma_after_param),
}
}
const params = p.scratch.items[scratch_top..];
return switch (params.len) {
0 => .{ .zero_or_one = .none },
1 => .{ .zero_or_one = params[0].toOptional() },
else => .{ .multi = try p.listToSpan(params) },
};
}
fn expectBuiltinCall(p: *Parse) !Node.Index {
const builtin_token = p.assertToken(.builtin);
_ = p.eatToken(.l_paren) orelse {
try p.warn(.expected_param_list);
// Pretend this was an identifier so we can continue parsing.
return p.addNode(.{
.tag = .identifier,
.main_token = builtin_token,
.data = undefined,
});
};
const scratch_top = p.scratch.items.len;
defer p.scratch.shrinkRetainingCapacity(scratch_top);
while (true) {
if (p.eatToken(.r_paren)) |_| break;
const param = try p.expectExpr();
try p.scratch.append(p.gpa, param);
switch (p.tokenTag(p.tok_i)) {
.comma => p.tok_i += 1,
.r_paren => {
p.tok_i += 1;
break;
},
// Likely just a missing comma; give error but continue parsing.
else => try p.warn(.expected_comma_after_arg),
}
}
const comma = (p.tokenTag(p.tok_i - 2)) == .comma;
const params = p.scratch.items[scratch_top..];
if (params.len <= 2) {
return p.addNode(.{
.tag = if (comma) .builtin_call_two_comma else .builtin_call_two,
.main_token = builtin_token,
.data = .{ .opt_node_and_opt_node = .{
if (params.len >= 1) .fromOptional(params[0]) else .none,
if (params.len >= 2) .fromOptional(params[1]) else .none,
} },
});
} else {
const span = try p.listToSpan(params);
return p.addNode(.{
.tag = if (comma) .builtin_call_comma else .builtin_call,
.main_token = builtin_token,
.data = .{ .extra_range = span },
});
}
}
fn expectIf(p: *Parse, comptime bodyParseFn: fn (p: *Parse) Error!Node.Index) !Node.Index {
const if_token = p.assertToken(.keyword_if);
_ = try p.expectToken(.l_paren);
const condition = try p.expectExpr();
_ = try p.expectToken(.r_paren);
_ = try p.parsePtrPayload();
const then_expr = try bodyParseFn(p);
_ = p.eatToken(.keyword_else) orelse return try p.addNode(.{
.tag = .if_simple,
.main_token = if_token,
.data = .{ .node_and_node = .{
condition,
then_expr,
} },
});
_ = try p.parsePayload();
const else_expr = try bodyParseFn(p);
return try p.addNode(.{
.tag = .@"if",
.main_token = if_token,
.data = .{ .node_and_extra = .{
condition,
try p.addExtra(Node.If{
.then_expr = then_expr,
.else_expr = else_expr,
}),
} },
});
}
fn expectFor(p: *Parse, comptime bodyParseFn: fn (p: *Parse) Error!Node.Index) !Node.Index {
const for_token = p.assertToken(.keyword_for);
const scratch_top = p.scratch.items.len;
defer p.scratch.shrinkRetainingCapacity(scratch_top);
const inputs = try p.forPrefix();
const then_expr = try bodyParseFn(p);
var has_else = false;
if (p.eatToken(.keyword_else)) |_| {
try p.scratch.append(p.gpa, then_expr);
const else_expr = try bodyParseFn(p);
try p.scratch.append(p.gpa, else_expr);
has_else = true;
} else if (inputs == 1) {
return try p.addNode(.{
.tag = .for_simple,
.main_token = for_token,
.data = .{ .node_and_node = .{
p.scratch.items[scratch_top],
then_expr,
} },
});
} else {
try p.scratch.append(p.gpa, then_expr);
}
return try p.addNode(.{
.tag = .@"for",
.main_token = for_token,
.data = .{ .@"for" = .{
(try p.listToSpan(p.scratch.items[scratch_top..])).start,
.{ .inputs = @intCast(inputs), .has_else = has_else },
} },
});
}
/// Skips over doc comment tokens. Returns the first one, if any.
fn eatDocComments(p: *Parse) Error!?TokenIndex {
if (p.eatToken(.doc_comment)) |tok| {
var first_line = tok;
if (tok > 0 and tokensOnSameLine(p, tok - 1, tok)) {
try p.warnMsg(.{
.tag = .same_line_doc_comment,
.token = tok,
});
first_line = p.eatToken(.doc_comment) orelse return null;
}
while (p.eatToken(.doc_comment)) |_| {}
return first_line;
}
return null;
}
fn tokensOnSameLine(p: *Parse, token1: TokenIndex, token2: TokenIndex) bool {
return std.mem.findScalar(u8, p.source[p.tokenStart(token1)..p.tokenStart(token2)], '\n') == null;
}
fn eatToken(p: *Parse, tag: Token.Tag) ?TokenIndex {
return if (p.tokenTag(p.tok_i) == tag) p.nextToken() else null;
}
fn eatTokens(p: *Parse, tags: []const Token.Tag) ?TokenIndex {
const available_tags = p.tokens.items(.tag)[p.tok_i..];
if (!std.mem.startsWith(Token.Tag, available_tags, tags)) return null;
const result = p.tok_i;
p.tok_i += @intCast(tags.len);
return result;
}
fn assertToken(p: *Parse, tag: Token.Tag) TokenIndex {
const token = p.nextToken();
assert(p.tokenTag(token) == tag);
return token;
}
fn expectToken(p: *Parse, tag: Token.Tag) Error!TokenIndex {
if (p.tokenTag(p.tok_i) != tag) {
return p.failMsg(.{
.tag = .expected_token,
.token = p.tok_i,
.extra = .{ .expected_tag = tag },
});
}
return p.nextToken();
}
fn expectSemicolon(p: *Parse, error_tag: AstError.Tag, recoverable: bool) Error!void {
if (p.tokenTag(p.tok_i) == .semicolon) {
_ = p.nextToken();
return;
}
try p.warn(error_tag);
if (!recoverable or !p.recover) return error.ParseError;
}
fn nextToken(p: *Parse) TokenIndex {
const result = p.tok_i;
p.tok_i += 1;
return result;
}
const Parse = @This();
const std = @import("../std.zig");
const assert = std.debug.assert;
const Allocator = std.mem.Allocator;
const Ast = std.zig.Ast;
const Node = Ast.Node;
const AstError = Ast.Error;
const TokenIndex = Ast.TokenIndex;
const OptionalTokenIndex = Ast.OptionalTokenIndex;
const ExtraIndex = Ast.ExtraIndex;
const Token = std.zig.Token;
test {
_ = @import("parser_test.zig");
}