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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 +181 -74
4 changed files with 181 additions and 74 deletions
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Showing only changes of commit 2d016dc085 - Show all commits

4
debug/app.ona
View File

@ -14,9 +14,13 @@ options = {
[42] = "42",
}
if pos.y > 0 do
options["foo"] = "rab"
options[42] = "24"
@print("Conditional hit!")
end
@print(options.title)
@print(options["foo"])
@print(options[42])

70
source/ona/kym.zig
View File

@ -61,6 +61,9 @@ pub const RuntimeEnv = struct {
clt,
cge,
cle,
jt: u32,
jf: u32,
};
const OpcodeList = coral.list.Stack(Opcode);
@ -265,6 +268,22 @@ pub const RuntimeEnv = struct {
}
},
.@"if" => |@"if"| {
try self.compile_expression(chunk, @"if".condition_expression);
try chunk.opcodes.push_one(.{.jf = 0});
const jump_opcode = &chunk.opcodes.values[chunk.opcodes.values.len - 1];
for (@"if".block_statements.values) |block_statement| {
try self.compile_statement(chunk, block_statement);
}
coral.debug.assert(jump_opcode.* == .jf);
coral.debug.assert(chunk.opcodes.values.len < coral.math.max_int(@typeInfo(u32).Int));
jump_opcode.jf = @intCast(chunk.opcodes.values.len);
},
.expression => |expression| try self.compile_expression(chunk, expression),
}
}
@ -288,10 +307,10 @@ pub const RuntimeEnv = struct {
}
};
fn compile(self: *Chunk, ast: Ast) RuntimeError!void {
fn compile(self: *Chunk, statements: *const Ast.Statement.List) RuntimeError!void {
var unit = CompilationUnit{};
for (ast.list_statements()) |statement| {
for (statements.values) |statement| {
try unit.compile_statement(self, statement);
}
}
@ -322,8 +341,10 @@ pub const RuntimeEnv = struct {
defer coral.debug.assert(self.env.frames.pop() != null);
for (self.opcodes.values) |opcode| {
switch (opcode) {
var opcode_cursor = @as(u32, 0);
while (opcode_cursor < self.opcodes.values.len) : (opcode_cursor += 1) {
switch (self.opcodes.values[opcode_cursor]) {
.push_nil => try self.env.locals.push_one(null),
.push_true => try self.env.locals.push_one(try self.env.new_boolean(true)),
.push_false => try self.env.locals.push_one(try self.env.new_boolean(false)),
@ -791,6 +812,29 @@ pub const RuntimeEnv = struct {
}));
},
.jf => |jf| {
const condition = (try self.pop_local()) orelse {
opcode_cursor = jf;
continue;
};
self.env.discard(condition);
if (!condition.is_truthy()) {
opcode_cursor = jf;
}
},
.jt => |jt| {
const condition = (try self.pop_local()) orelse continue;
self.env.discard(condition);
if (condition.is_truthy()) {
opcode_cursor = jt;
}
},
}
}
@ -1044,20 +1088,18 @@ pub const RuntimeEnv = struct {
defer self.allocator.deallocate(file_data);
const file_name = file_path.to_string() orelse "<script>";
var ast = Ast.make(self.allocator, file_name);
defer ast.free();
ast.parse(file_data) catch |parse_error| return switch (parse_error) {
error.BadSyntax => self.raise(error.BadSyntax, ast.error_message()),
error.OutOfMemory => error.OutOfMemory,
};
var chunk = try Chunk.make(self, file_name);
defer chunk.free();
try chunk.compile(ast);
var ast = Ast.make(self.allocator, file_name);
defer ast.free();
try chunk.compile(ast.parse(file_data) catch |parse_error| return switch (parse_error) {
error.BadSyntax => self.raise(error.BadSyntax, ast.error_message()),
error.OutOfMemory => error.OutOfMemory,
});
return chunk.execute();
}

133
source/ona/kym/Ast.zig
View File

@ -5,9 +5,10 @@ const tokens = @import("./tokens.zig");
name: []const coral.io.Byte,
allocator: coral.io.Allocator,
arena: coral.arena.Stacking,
statements: Statement.List,
error_buffer: coral.list.ByteStack,
tokenizer: tokens.Tokenizer,
parsed_statements: Statement.List,
has_returned: bool,
pub const Expression = union (enum) {
nil_literal,
@ -108,9 +109,14 @@ pub const Statement = union (enum) {
expression: ?Expression,
},
@"if": struct {
condition_expression: Expression,
block_statements: List,
},
expression: Expression,
const List = coral.list.Stack(Statement);
pub const List = coral.list.Stack(Statement);
};
const UnaryOperator = enum {
@ -159,19 +165,20 @@ pub fn error_message(self: Self) []const coral.io.Byte {
}
pub fn free(self: *Self) void {
self.arena.free();
self.statements.free();
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),
.statements = Statement.List.make(allocator),
.parsed_statements = Statement.List.make(allocator),
.tokenizer = .{.source = ""},
.allocator = allocator,
.name = ast_name,
.has_returned = false,
};
}
@ -185,58 +192,19 @@ fn report(self: *Self, message: []const coral.io.Byte) ParseError {
return error.BadSyntax;
}
pub fn list_statements(self: Self) []const Statement {
return self.statements.values;
}
pub fn parse(self: *Self, data: []const coral.io.Byte) ParseError!void {
pub fn parse(self: *Self, data: []const coral.io.Byte) ParseError!*const Statement.List {
self.tokenizer = .{.source = data};
self.has_returned = false;
var has_returned = false;
self.parsed_statements.free();
self.tokenizer.skip_newlines();
self.parsed_statements = try self.parse_statements();
while (true) {
try self.statements.push_one(parse_statement: {
switch (self.tokenizer.token) {
.end => return,
.keyword_return => {
if (has_returned) {
return self.report("multiple returns in function scope but expected only one");
if (self.tokenizer.token == .keyword_end) {
return self.report("unexpected `end` without matching `do` block");
}
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");
}
has_returned = true;
break: parse_statement .{
.@"return" = .{
.expression = null,
},
};
},
else => {
break: parse_statement .{
.expression = try self.parse_expression()
};
},
}
});
}
return &self.parsed_statements;
}
const parse_additive = binary_operation_parser(parse_equality, &.{
@ -561,6 +529,69 @@ fn parse_factor(self: *Self) ParseError!Expression {
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,

42
source/ona/kym/tokens.zig
View File

@ -38,6 +38,9 @@ pub const Token = union(enum) {
keyword_return,
keyword_self,
keyword_const,
keyword_if,
keyword_do,
keyword_end,
pub fn text(self: Token) []const coral.io.Byte {
return switch (self) {
@ -79,6 +82,9 @@ pub const Token = union(enum) {
.keyword_true => "true",
.keyword_return => "return",
.keyword_self => "self",
.keyword_if => "if",
.keyword_do => "do",
.keyword_end => "end",
};
}
};
@ -173,9 +179,17 @@ pub const Tokenizer = struct {
}
},
'n' => {
if (coral.io.ends_with(identifier, "il")) {
self.token = .keyword_nil;
'd' => {
if (coral.io.ends_with(identifier, "o")) {
self.token = .keyword_do;
return;
}
},
'e' => {
if (coral.io.ends_with(identifier, "nd")) {
self.token = .keyword_end;
return;
}
@ -189,9 +203,17 @@ pub const Tokenizer = struct {
}
},
't' => {
if (coral.io.ends_with(identifier, "rue")) {
self.token = .keyword_true;
'i' => {
if (coral.io.ends_with(identifier, "f")) {
self.token = .keyword_if;
return;
}
},
'n' => {
if (coral.io.ends_with(identifier, "il")) {
self.token = .keyword_nil;
return;
}
@ -213,6 +235,14 @@ pub const Tokenizer = struct {
}
},
't' => {
if (coral.io.ends_with(identifier, "rue")) {
self.token = .keyword_true;
return;
}
},
else => {},
}