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Implement Control Flow Statements in Kym #37

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kayomn merged 8 commits from kym-control-flow into main 2023-08-26 00:01:25 +02:00
Conversation 0 Commits 8 Files Changed 5 +602 -606
3 changed files with 602 additions and 606 deletions
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Showing only changes of commit 0d6e5250c7 - Show all commits

16
source/ona/kym.zig
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@ -1,4 +1,4 @@
const Ast = @import("./kym/Ast.zig");
const ast = @import("./kym/ast.zig");
const coral = @import("coral");
@ -72,7 +72,7 @@ pub const RuntimeEnv = struct {
local_identifiers_buffer: [255][]const coral.io.Byte = [_][]const coral.io.Byte{""} ** 255,
local_identifiers_count: u8 = 0,
fn compile_expression(self: *CompilationUnit, chunk: *Chunk, expression: Ast.Expression) RuntimeError!void {
fn compile_expression(self: *CompilationUnit, chunk: *Chunk, expression: ast.Expression) RuntimeError!void {
const number_format = coral.utf8.DecimalFormat{
.delimiter = "_",
.positive_prefix = .none,
@ -258,7 +258,7 @@ pub const RuntimeEnv = struct {
}
}
fn compile_statement(self: *CompilationUnit, chunk: *Chunk, statement: Ast.Statement) RuntimeError!void {
fn compile_statement(self: *CompilationUnit, chunk: *Chunk, statement: ast.Statement) RuntimeError!void {
switch (statement) {
.@"return" => |@"return"| {
if (@"return".expression) |expression| {
@ -307,7 +307,7 @@ pub const RuntimeEnv = struct {
}
};
fn compile(self: *Chunk, statements: *const Ast.Statement.List) RuntimeError!void {
fn compile(self: *Chunk, statements: *const ast.StatementList) RuntimeError!void {
var unit = CompilationUnit{};
for (statements.values) |statement| {
@ -1092,12 +1092,12 @@ pub const RuntimeEnv = struct {
defer chunk.free();
var ast = Ast.make(self.allocator, file_name);
var ast_tree = ast.Tree.make(self.allocator, file_name);
defer ast.free();
defer ast_tree.free();
try chunk.compile(ast.parse(file_data) catch |parse_error| return switch (parse_error) {
error.BadSyntax => self.raise(error.BadSyntax, ast.error_message()),
try chunk.compile(ast_tree.parse(file_data) catch |parse_error| return switch (parse_error) {
error.BadSyntax => self.raise(error.BadSyntax, ast_tree.error_message()),
error.OutOfMemory => error.OutOfMemory,
});

598
source/ona/kym/Ast.zig
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@ -1,598 +0,0 @@
const coral = @import("coral");
const tokens = @import("./tokens.zig");
name: []const coral.io.Byte,
allocator: coral.io.Allocator,
arena: coral.arena.Stacking,
error_buffer: coral.list.ByteStack,
tokenizer: tokens.Tokenizer,
parsed_statements: Statement.List,
has_returned: bool,
pub const Expression = union (enum) {
nil_literal,
true_literal,
false_literal,
builtin: []const coral.io.Byte,
number_literal: []const coral.io.Byte,
string_literal: []const coral.io.Byte,
symbol_literal: []const coral.io.Byte,
table_literal: TableLiteral,
grouped_expression: *Expression,
local_get: []const coral.io.Byte,
local_set: []const coral.io.Byte,
field_get: struct {
object_expression: *Expression,
identifier: []const coral.io.Byte,
},
field_set: struct {
object_expression: *Expression,
identifier: []const coral.io.Byte,
value_expression: *Expression,
},
subscript_get: struct {
object_expression: *Expression,
subscript_expression: *Expression,
},
subscript_set: struct {
object_expression: *Expression,
subscript_expression: *Expression,
value_expression: *Expression,
},
binary_operation: struct {
operator: BinaryOperator,
lhs_expression: *Expression,
rhs_expression: *Expression,
},
unary_operation: struct {
operator: UnaryOperator,
expression: *Expression,
},
invoke: struct {
object_expression: *Expression,
argument_expressions: List,
},
pub const BinaryOperator = enum {
addition,
subtraction,
multiplication,
divsion,
equals_comparison,
greater_than_comparison,
greater_equals_comparison,
less_than_comparison,
less_equals_comparison,
fn token(self: BinaryOperator) tokens.Token {
return switch (self) {
.addition => .symbol_plus,
.subtraction => .symbol_minus,
.multiplication => .symbol_asterisk,
.divsion => .symbol_forward_slash,
.equals_comparison => .symbol_double_equals,
.greater_than_comparison => .symbol_greater_than,
.greater_equals_comparison => .symbol_greater_equals,
.less_than_comparison => .symbol_less_than,
.less_equals_comparison => .symbol_less_equals,
};
}
};
pub const TableLiteral = coral.list.Stack(struct {
key_expression: Expression,
value_expression: Expression,
});
pub const List = coral.list.Stack(Expression);
};
const ExpressionParser = fn (self: *Self) ParseError!Expression;
pub const ParseError = error {
OutOfMemory,
BadSyntax,
};
const Self = @This();
pub const Statement = union (enum) {
@"return": struct {
expression: ?Expression,
},
@"if": struct {
condition_expression: Expression,
block_statements: List,
},
expression: Expression,
pub const List = coral.list.Stack(Statement);
};
const UnaryOperator = enum {
boolean_negation,
numeric_negation,
};
fn binary_operation_parser(
comptime parse_next: ExpressionParser,
comptime operators: []const Expression.BinaryOperator) ExpressionParser {
const BinaryOperationParser = struct {
fn parse(self: *Self) ParseError!Expression {
const allocator = self.arena.as_allocator();
var expression = try parse_next(self);
inline for (operators) |operator| {
const token = comptime operator.token();
if (self.tokenizer.token == coral.io.tag_of(token)) {
self.tokenizer.step();
if (self.tokenizer.token == .end) {
return self.report("expected other half of expression after `" ++ comptime token.text() ++ "`");
}
expression = .{
.binary_operation = .{
.operator = operator,
.lhs_expression = try coral.io.allocate_one(allocator, expression),
.rhs_expression = try coral.io.allocate_one(allocator, try parse_next(self)),
},
};
}
}
return expression;
}
};
return BinaryOperationParser.parse;
}
pub fn error_message(self: Self) []const coral.io.Byte {
return self.error_buffer.values;
}
pub fn free(self: *Self) void {
self.parsed_statements.free();
self.error_buffer.free();
self.arena.free();
}
pub fn make(allocator: coral.io.Allocator, ast_name: []const coral.io.Byte) Self {
return Self{
.arena = coral.arena.Stacking.make(allocator, 4096),
.error_buffer = coral.list.ByteStack.make(allocator),
.parsed_statements = Statement.List.make(allocator),
.tokenizer = .{.source = ""},
.allocator = allocator,
.name = ast_name,
.has_returned = false,
};
}
fn report(self: *Self, message: []const coral.io.Byte) ParseError {
coral.utf8.print_formatted(coral.list.stack_as_writer(&self.error_buffer), "{name}@{line}: {message}", .{
.name = self.name,
.line = self.tokenizer.lines_stepped,
.message = message,
}) catch return error.OutOfMemory;
return error.BadSyntax;
}
pub fn parse(self: *Self, data: []const coral.io.Byte) ParseError!*const Statement.List {
self.tokenizer = .{.source = data};
self.has_returned = false;
self.parsed_statements.free();
self.parsed_statements = try self.parse_statements();
if (self.tokenizer.token == .keyword_end) {
return self.report("unexpected `end` without matching `do` block");
}
return &self.parsed_statements;
}
const parse_additive = binary_operation_parser(parse_equality, &.{
.addition,
.subtraction,
});
const parse_comparison = binary_operation_parser(parse_term, &.{
.greater_than_comparison,
.greater_equals_comparison,
.less_than_comparison,
.less_equals_comparison
});
const parse_equality = binary_operation_parser(parse_comparison, &.{
.equals_comparison,
});
pub fn parse_expression(self: *Self) ParseError!Expression {
const allocator = self.arena.as_allocator();
const expression = try parse_additive(self);
if (self.tokenizer.token == .symbol_equals) {
self.tokenizer.skip_newlines();
if (self.tokenizer.token == .end) {
return self.report("expected assignment after `=`");
}
return switch (expression) {
.local_get => |local_get| .{.local_set = local_get},
.field_get => |field_get| .{
.field_set = .{
.object_expression = field_get.object_expression,
.identifier = field_get.identifier,
.value_expression = try coral.io.allocate_one(allocator, try self.parse_expression()),
},
},
.subscript_get => |subscript_get| .{
.subscript_set = .{
.object_expression = subscript_get.object_expression,
.subscript_expression = subscript_get.subscript_expression,
.value_expression = try coral.io.allocate_one(allocator, try self.parse_expression()),
},
},
else => self.report("expected local or field on left-hand side of expression"),
};
}
return expression;
}
fn parse_factor(self: *Self) ParseError!Expression {
const allocator = self.arena.as_allocator();
var expression = @as(Expression, parse: {
switch (self.tokenizer.token) {
.symbol_paren_left => {
self.tokenizer.skip_newlines();
if (self.tokenizer.token == .end) {
return self.report("expected an expression after `(`");
}
const expression = try self.parse_expression();
if (self.tokenizer.token != .symbol_paren_right) {
return self.report("expected a closing `)` after expression");
}
self.tokenizer.skip_newlines();
break: parse .{.grouped_expression = try coral.io.allocate_one(allocator, expression)};
},
.keyword_nil => {
self.tokenizer.skip_newlines();
break: parse .nil_literal;
},
.keyword_true => {
self.tokenizer.skip_newlines();
break: parse .true_literal;
},
.keyword_false => {
self.tokenizer.skip_newlines();
break: parse .false_literal;
},
.number => |value| {
self.tokenizer.skip_newlines();
break: parse .{.number_literal = value};
},
.string => |value| {
self.tokenizer.skip_newlines();
break: parse .{.string_literal = value};
},
.identifier => |identifier| {
self.tokenizer.skip_newlines();
break: parse .{.local_get = identifier};
},
.builtin => |builtin| {
self.tokenizer.skip_newlines();
break: parse .{.builtin = builtin};
},
.symbol_brace_left => {
var table_literal = Expression.TableLiteral.make(allocator);
self.tokenizer.skip_newlines();
while (true) {
switch (self.tokenizer.token) {
.symbol_brace_right => {
self.tokenizer.skip_newlines();
break: parse .{.table_literal = table_literal};
},
.symbol_period => {
self.tokenizer.step();
const identifier = switch (self.tokenizer.token) {
.identifier => |identifier| identifier,
else => return self.report("expected identifier after `.`"),
};
self.tokenizer.skip_newlines();
if (self.tokenizer.token != .symbol_equals) {
return self.report("expected `=` after symbol");
}
self.tokenizer.skip_newlines();
try table_literal.push_one(.{
.value_expression = try self.parse_expression(),
.key_expression = .{.symbol_literal = identifier},
});
switch (self.tokenizer.token) {
.symbol_comma => self.tokenizer.skip_newlines(),
.symbol_brace_right => {
self.tokenizer.skip_newlines();
break: parse .{.table_literal = table_literal};
},
else => return self.report("expected `,` or `}` after expression"),
}
},
.symbol_bracket_left => {
self.tokenizer.step();
const subscript_expression = try self.parse_expression();
if (self.tokenizer.token != .symbol_bracket_right) {
return self.report("expected `]` after subscript expression");
}
self.tokenizer.skip_newlines();
if (self.tokenizer.token != .symbol_equals) {
return self.report("expected `=` after `]`");
}
self.tokenizer.skip_newlines();
try table_literal.push_one(.{
.value_expression = try self.parse_expression(),
.key_expression = subscript_expression,
});
switch (self.tokenizer.token) {
.symbol_comma => self.tokenizer.skip_newlines(),
.symbol_brace_right => {
self.tokenizer.skip_newlines();
break: parse .{.table_literal = table_literal};
},
else => return self.report("expected `,` or `}` after expression"),
}
},
else => return self.report("expected `}` or fields in table literal"),
}
}
},
.symbol_minus => {
self.tokenizer.skip_newlines();
if (self.tokenizer.token == .end) {
return self.report("expected expression after numeric negation (`-`)");
}
break: parse .{
.unary_operation = .{
.expression = try coral.io.allocate_one(allocator, try self.parse_factor()),
.operator = .numeric_negation,
},
};
},
.symbol_bang => {
self.tokenizer.skip_newlines();
if (self.tokenizer.token == .end) {
return self.report("expected expression after boolean negation (`!`)");
}
break: parse .{
.unary_operation = .{
.expression = try coral.io.allocate_one(allocator, try self.parse_factor()),
.operator = .boolean_negation,
},
};
},
else => return self.report("unexpected token in expression"),
}
});
while (true) {
switch (self.tokenizer.token) {
.symbol_period => {
self.tokenizer.skip_newlines();
// TODO: Remove when Zig fixes miscompilation with in-place struct re-assignment.
const unnecessary_temp = try coral.io.allocate_one(allocator, expression);
expression = .{
.field_get = .{
.identifier = switch (self.tokenizer.token) {
.identifier => |field_identifier| field_identifier,
else => return self.report("expected identifier after `.`"),
},
.object_expression = unnecessary_temp,
},
};
self.tokenizer.skip_newlines();
},
.symbol_bracket_left => {
self.tokenizer.skip_newlines();
// TODO: Remove when Zig fixes miscompilation with in-place struct re-assignment.
const unnecessary_temp = try coral.io.allocate_one(allocator, expression);
expression = .{
.subscript_get = .{
.subscript_expression = try coral.io.allocate_one(allocator, try self.parse_expression()),
.object_expression = unnecessary_temp,
},
};
if (self.tokenizer.token != .symbol_bracket_right) {
return self.report("expected `]` subscript expression");
}
self.tokenizer.skip_newlines();
},
.symbol_paren_left => {
var argument_expressions = Expression.List.make(allocator);
while (true) {
self.tokenizer.skip_newlines();
switch (self.tokenizer.token) {
.symbol_paren_right => break,
else => {
try argument_expressions.push_one(try self.parse_expression());
switch (self.tokenizer.token) {
.symbol_comma => continue,
.symbol_paren_right => break,
else => return self.report("expected `,` or `)` after function argument expression"),
}
},
}
}
self.tokenizer.skip_newlines();
// TODO: Remove when Zig fixes miscompilation with in-place struct re-assignment.
const unnecessary_temp = try coral.io.allocate_one(allocator, expression);
expression = .{
.invoke = .{
.argument_expressions = argument_expressions,
.object_expression = unnecessary_temp,
},
};
},
else => break,
}
}
return expression;
}
fn parse_statements(self: *Self) ParseError!Statement.List {
var statements = Statement.List.make(self.arena.as_allocator());
self.tokenizer.skip_newlines();
while (true) {
try statements.push_one(parse_statement: {
switch (self.tokenizer.token) {
.end, .keyword_end => return statements,
.keyword_return => {
if (self.has_returned) {
return self.report("multiple returns in function scope but expected only one");
}
self.tokenizer.step();
if (self.tokenizer.token != .end and self.tokenizer.token != .newline) {
break: parse_statement .{.@"return" = .{.expression = try self.parse_expression()}};
}
if (self.tokenizer.token != .end and self.tokenizer.token != .newline) {
return self.report("expected end or newline after return statement");
}
self.has_returned = true;
break: parse_statement .{.@"return" = .{.expression = null}};
},
.keyword_if => {
self.tokenizer.step();
const condition_expression = try self.parse_expression();
if (self.tokenizer.token != .keyword_do) {
return self.report("expected `do` block after if statement");
}
self.tokenizer.step();
const if_statement = Statement{
.@"if" = .{
.block_statements = try self.parse_statements(),
.condition_expression = condition_expression,
},
};
if (self.tokenizer.token != .keyword_end) {
return self.report("expected `end` after block");
}
self.tokenizer.skip_newlines();
break: parse_statement if_statement;
},
else => break: parse_statement .{.expression = try self.parse_expression()},
}
});
}
}
const parse_term = binary_operation_parser(parse_factor, &.{
.multiplication,
.divsion,
});

594
source/ona/kym/ast.zig Normal file
View File

@ -0,0 +1,594 @@
const coral = @import("coral");
const tokens = @import("./tokens.zig");
pub const BinaryOperator = enum {
addition,
subtraction,
multiplication,
divsion,
equals_comparison,
greater_than_comparison,
greater_equals_comparison,
less_than_comparison,
less_equals_comparison,
fn builder(comptime build_next: ExpressionBuilder, comptime operators: []const BinaryOperator) ExpressionBuilder {
const Builder = struct {
fn build(self: *Tree) ParseError!Expression {
const allocator = self.arena.as_allocator();
var expression = try build_next(self);
inline for (operators) |operator| {
const token = @as(tokens.Token, switch (operator) {
.addition => .symbol_plus,
.subtraction => .symbol_minus,
.multiplication => .symbol_asterisk,
.divsion => .symbol_forward_slash,
.equals_comparison => .symbol_double_equals,
.greater_than_comparison => .symbol_greater_than,
.greater_equals_comparison => .symbol_greater_equals,
.less_than_comparison => .symbol_less_than,
.less_equals_comparison => .symbol_less_equals,
});
if (self.tokenizer.token == coral.io.tag_of(token)) {
self.tokenizer.step();
if (self.tokenizer.token == .end) {
return self.report(
"expected other half of expression after `" ++
comptime token.text() ++
"`");
}
expression = .{
.binary_operation = .{
.operator = operator,
.lhs_expression = try coral.io.allocate_one(allocator, expression),
.rhs_expression = try coral.io.allocate_one(allocator, try build_next(self)),
},
};
}
}
return expression;
}
};
return Builder.build;
}
};
pub const Expression = union (enum) {
nil_literal,
true_literal,
false_literal,
builtin: []const coral.io.Byte,
number_literal: []const coral.io.Byte,
string_literal: []const coral.io.Byte,
symbol_literal: []const coral.io.Byte,
table_literal: TableLiteral,
grouped_expression: *Expression,
local_get: []const coral.io.Byte,
local_set: []const coral.io.Byte,
field_get: struct {
object_expression: *Expression,
identifier: []const coral.io.Byte,
},
field_set: struct {
object_expression: *Expression,
identifier: []const coral.io.Byte,
value_expression: *Expression,
},
subscript_get: struct {
object_expression: *Expression,
subscript_expression: *Expression,
},
subscript_set: struct {
object_expression: *Expression,
subscript_expression: *Expression,
value_expression: *Expression,
},
binary_operation: struct {
operator: BinaryOperator,
lhs_expression: *Expression,
rhs_expression: *Expression,
},
unary_operation: struct {
operator: UnaryOperator,
expression: *Expression,
},
invoke: struct {
object_expression: *Expression,
argument_expressions: ExpressionList,
},
pub const TableLiteral = coral.list.Stack(struct {
key_expression: Expression,
value_expression: Expression,
});
};
const ExpressionBuilder = fn (self: *Tree) ParseError!Expression;
pub const ExpressionList = coral.list.Stack(Expression);
pub const ParseError = error {
OutOfMemory,
BadSyntax,
};
pub const Statement = union (enum) {
@"return": struct {
expression: ?Expression,
},
@"if": struct {
condition_expression: Expression,
block_statements: StatementList,
},
expression: Expression,
};
pub const StatementList = coral.list.Stack(Statement);
pub const Tree = struct {
name: []const coral.io.Byte,
allocator: coral.io.Allocator,
arena: coral.arena.Stacking,
error_buffer: coral.list.ByteStack,
tokenizer: tokens.Tokenizer,
parsed_statements: StatementList,
has_returned: bool,
pub fn error_message(self: Tree) []const coral.io.Byte {
return self.error_buffer.values;
}
pub fn free(self: *Tree) void {
self.parsed_statements.free();
self.error_buffer.free();
self.arena.free();
}
pub fn make(allocator: coral.io.Allocator, ast_name: []const coral.io.Byte) Tree {
return .{
.arena = coral.arena.Stacking.make(allocator, 4096),
.error_buffer = coral.list.ByteStack.make(allocator),
.parsed_statements = StatementList.make(allocator),
.tokenizer = .{.source = ""},
.allocator = allocator,
.name = ast_name,
.has_returned = false,
};
}
pub fn parse(self: *Tree, data: []const coral.io.Byte) ParseError!*const StatementList {
self.tokenizer = .{.source = data};
self.has_returned = false;
self.parsed_statements.free();
self.parsed_statements = try self.parse_statements();
if (self.tokenizer.token == .keyword_end) {
return self.report("unexpected `end` without matching `do` block");
}
return &self.parsed_statements;
}
const parse_additive = BinaryOperator.builder(parse_equality, &.{
.addition,
.subtraction,
});
const parse_comparison = BinaryOperator.builder(parse_term, &.{
.greater_than_comparison,
.greater_equals_comparison,
.less_than_comparison,
.less_equals_comparison
});
const parse_equality = BinaryOperator.builder(parse_comparison, &.{
.equals_comparison,
});
pub fn parse_expression(self: *Tree) ParseError!Expression {
const allocator = self.arena.as_allocator();
const expression = try self.parse_additive();
if (self.tokenizer.token == .symbol_equals) {
self.tokenizer.skip_newlines();
if (self.tokenizer.token == .end) {
return self.report("expected assignment after `=`");
}
return switch (expression) {
.local_get => |local_get| .{.local_set = local_get},
.field_get => |field_get| .{
.field_set = .{
.object_expression = field_get.object_expression,
.identifier = field_get.identifier,
.value_expression = try coral.io.allocate_one(allocator, try self.parse_expression()),
},
},
.subscript_get => |subscript_get| .{
.subscript_set = .{
.object_expression = subscript_get.object_expression,
.subscript_expression = subscript_get.subscript_expression,
.value_expression = try coral.io.allocate_one(allocator, try self.parse_expression()),
},
},
else => self.report("expected local or field on left-hand side of expression"),
};
}
return expression;
}
fn parse_factor(self: *Tree) ParseError!Expression {
const allocator = self.arena.as_allocator();
var expression = @as(Expression, parse: {
switch (self.tokenizer.token) {
.symbol_paren_left => {
self.tokenizer.skip_newlines();
if (self.tokenizer.token == .end) {
return self.report("expected an expression after `(`");
}
const expression = try self.parse_expression();
if (self.tokenizer.token != .symbol_paren_right) {
return self.report("expected a closing `)` after expression");
}
self.tokenizer.skip_newlines();
break: parse .{.grouped_expression = try coral.io.allocate_one(allocator, expression)};
},
.keyword_nil => {
self.tokenizer.skip_newlines();
break: parse .nil_literal;
},
.keyword_true => {
self.tokenizer.skip_newlines();
break: parse .true_literal;
},
.keyword_false => {
self.tokenizer.skip_newlines();
break: parse .false_literal;
},
.number => |value| {
self.tokenizer.skip_newlines();
break: parse .{.number_literal = value};
},
.string => |value| {
self.tokenizer.skip_newlines();
break: parse .{.string_literal = value};
},
.identifier => |identifier| {
self.tokenizer.skip_newlines();
break: parse .{.local_get = identifier};
},
.builtin => |builtin| {
self.tokenizer.skip_newlines();
break: parse .{.builtin = builtin};
},
.symbol_brace_left => {
var table_literal = Expression.TableLiteral.make(allocator);
self.tokenizer.skip_newlines();
while (true) {
switch (self.tokenizer.token) {
.symbol_brace_right => {
self.tokenizer.skip_newlines();
break: parse .{.table_literal = table_literal};
},
.symbol_period => {
self.tokenizer.step();
const identifier = switch (self.tokenizer.token) {
.identifier => |identifier| identifier,
else => return self.report("expected identifier after `.`"),
};
self.tokenizer.skip_newlines();
if (self.tokenizer.token != .symbol_equals) {
return self.report("expected `=` after symbol");
}
self.tokenizer.skip_newlines();
try table_literal.push_one(.{
.value_expression = try self.parse_expression(),
.key_expression = .{.symbol_literal = identifier},
});
switch (self.tokenizer.token) {
.symbol_comma => self.tokenizer.skip_newlines(),
.symbol_brace_right => {
self.tokenizer.skip_newlines();
break: parse .{.table_literal = table_literal};
},
else => return self.report("expected `,` or `}` after expression"),
}
},
.symbol_bracket_left => {
self.tokenizer.step();
const subscript_expression = try self.parse_expression();
if (self.tokenizer.token != .symbol_bracket_right) {
return self.report("expected `]` after subscript expression");
}
self.tokenizer.skip_newlines();
if (self.tokenizer.token != .symbol_equals) {
return self.report("expected `=` after `]`");
}
self.tokenizer.skip_newlines();
try table_literal.push_one(.{
.value_expression = try self.parse_expression(),
.key_expression = subscript_expression,
});
switch (self.tokenizer.token) {
.symbol_comma => self.tokenizer.skip_newlines(),
.symbol_brace_right => {
self.tokenizer.skip_newlines();
break: parse .{.table_literal = table_literal};
},
else => return self.report("expected `,` or `}` after expression"),
}
},
else => return self.report("expected `}` or fields in table literal"),
}
}
},
.symbol_minus => {
self.tokenizer.skip_newlines();
if (self.tokenizer.token == .end) {
return self.report("expected expression after numeric negation (`-`)");
}
break: parse .{
.unary_operation = .{
.expression = try coral.io.allocate_one(allocator, try self.parse_factor()),
.operator = .numeric_negation,
},
};
},
.symbol_bang => {
self.tokenizer.skip_newlines();
if (self.tokenizer.token == .end) {
return self.report("expected expression after boolean negation (`!`)");
}
break: parse .{
.unary_operation = .{
.expression = try coral.io.allocate_one(allocator, try self.parse_factor()),
.operator = .boolean_negation,
},
};
},
else => return self.report("unexpected token in expression"),
}
});
while (true) {
switch (self.tokenizer.token) {
.symbol_period => {
self.tokenizer.skip_newlines();
// TODO: Remove when Zig fixes miscompilation with in-place struct re-assignment.
const unnecessary_temp = try coral.io.allocate_one(allocator, expression);
expression = .{
.field_get = .{
.identifier = switch (self.tokenizer.token) {
.identifier => |field_identifier| field_identifier,
else => return self.report("expected identifier after `.`"),
},
.object_expression = unnecessary_temp,
},
};
self.tokenizer.skip_newlines();
},
.symbol_bracket_left => {
self.tokenizer.skip_newlines();
// TODO: Remove when Zig fixes miscompilation with in-place struct re-assignment.
const unnecessary_temp = try coral.io.allocate_one(allocator, expression);
expression = .{
.subscript_get = .{
.subscript_expression = try coral.io.allocate_one(allocator, try self.parse_expression()),
.object_expression = unnecessary_temp,
},
};
if (self.tokenizer.token != .symbol_bracket_right) {
return self.report("expected `]` subscript expression");
}
self.tokenizer.skip_newlines();
},
.symbol_paren_left => {
var argument_expressions = ExpressionList.make(allocator);
while (true) {
self.tokenizer.skip_newlines();
switch (self.tokenizer.token) {
.symbol_paren_right => break,
else => {
try argument_expressions.push_one(try self.parse_expression());
switch (self.tokenizer.token) {
.symbol_comma => continue,
.symbol_paren_right => break,
else => return self.report("expected `,` or `)` after function argument expression"),
}
},
}
}
self.tokenizer.skip_newlines();
// TODO: Remove when Zig fixes miscompilation with in-place struct re-assignment.
const unnecessary_temp = try coral.io.allocate_one(allocator, expression);
expression = .{
.invoke = .{
.argument_expressions = argument_expressions,
.object_expression = unnecessary_temp,
},
};
},
else => break,
}
}
return expression;
}
fn parse_statements(self: *Tree) ParseError!StatementList {
var statements = StatementList.make(self.arena.as_allocator());
self.tokenizer.skip_newlines();
while (true) {
try statements.push_one(parse_statement: {
switch (self.tokenizer.token) {
.end, .keyword_end => return statements,
.keyword_return => {
if (self.has_returned) {
return self.report("multiple returns in function scope but expected only one");
}
self.tokenizer.step();
if (self.tokenizer.token != .end and self.tokenizer.token != .newline) {
break: parse_statement .{.@"return" = .{.expression = try self.parse_expression()}};
}
if (self.tokenizer.token != .end and self.tokenizer.token != .newline) {
return self.report("expected end or newline after return statement");
}
self.has_returned = true;
break: parse_statement .{.@"return" = .{.expression = null}};
},
.keyword_if => {
self.tokenizer.step();
const condition_expression = try self.parse_expression();
if (self.tokenizer.token != .keyword_do) {
return self.report("expected `do` block after if statement");
}
self.tokenizer.step();
const if_statement = Statement{
.@"if" = .{
.block_statements = try self.parse_statements(),
.condition_expression = condition_expression,
},
};
if (self.tokenizer.token != .keyword_end) {
return self.report("expected `end` after block");
}
self.tokenizer.skip_newlines();
break: parse_statement if_statement;
},
else => break: parse_statement .{.expression = try self.parse_expression()},
}
});
}
}
const parse_term = BinaryOperator.builder(parse_factor, &.{
.multiplication,
.divsion,
});
fn report(self: *Tree, message: []const coral.io.Byte) ParseError {
coral.utf8.print_formatted(coral.list.stack_as_writer(&self.error_buffer), "{name}@{line}: {message}", .{
.name = self.name,
.line = self.tokenizer.lines_stepped,
.message = message,
}) catch return error.OutOfMemory;
return error.BadSyntax;
}
};
pub const UnaryOperator = enum {
boolean_negation,
numeric_negation,
};