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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 +149 -167
3 changed files with 149 additions and 167 deletions
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Showing only changes of commit c4916a4195 - Show all commits

31
source/ona/kym.zig
View File

@ -294,32 +294,19 @@ pub const RuntimeEnv = struct {
},
.@"if" => |@"if"| {
try self.compile_expression(chunk, @"if".then_block.condition_expression);
try self.compile_expression(chunk, @"if".condition_expression);
try chunk.opcodes.push_one(.{.jf = 0});
const then_origin_index = @as(u32, @intCast(chunk.opcodes.values.len - 1));
for (@"if".then_block.block_statements.values) |block_statement| {
for (@"if".block_statements.values) |block_statement| {
try self.compile_statement(chunk, block_statement);
}
chunk.opcodes.values[then_origin_index].jf = @intCast(chunk.opcodes.values.len - 1);
if (@"if".else_block) |else_block| {
if (else_block.condition_expression) |condition_expression| {
try self.compile_expression(chunk, condition_expression);
try chunk.opcodes.push_one(.{.jf = 0});
}
const else_origin_index = @as(u32, @intCast(chunk.opcodes.values.len - 1));
for (else_block.block_statements.values) |block_statement| {
try self.compile_statement(chunk, block_statement);
}
if (else_block.condition_expression != null) {
chunk.opcodes.values[else_origin_index].jf = @intCast(chunk.opcodes.values.len - 1);
}
if (@"if".else_statement) |else_statement| {
try self.compile_statement(chunk, else_statement.*);
}
},
@ -352,10 +339,10 @@ pub const RuntimeEnv = struct {
}
};
fn compile(self: *Chunk, statements: *const ast.StatementList) RuntimeError!void {
fn compile(self: *Chunk, statements: []const ast.Statement) RuntimeError!void {
var unit = CompilationUnit{};
for (statements.values) |statement| {
for (statements) |statement| {
try unit.compile_statement(self, statement);
}
}
@ -887,12 +874,6 @@ pub const RuntimeEnv = struct {
}
},
}
// for (self.env.locals.values) |local| {
// self.env.print(if (local) |ref| ref.typename() else "nil");
// }
// self.env.print("------------");
}
return self.pop_local();

283
source/ona/kym/ast.zig
View File

@ -118,9 +118,11 @@ pub const Expression = union (enum) {
invoke: struct {
object_expression: *Expression,
argument_expressions: ExpressionList,
argument_expressions: List,
},
const List = coral.list.Stack(Expression);
const TableLiteral = coral.list.Stack(struct {
key_expression: Expression,
value_expression: Expression,
@ -129,8 +131,6 @@ pub const Expression = union (enum) {
const ExpressionBuilder = fn (self: *Tree) ParseError!Expression;
pub const ExpressionList = coral.list.Stack(Expression);
pub const ParseError = error {
OutOfMemory,
BadSyntax,
@ -140,33 +140,29 @@ pub const Statement = union (enum) {
@"return": ?Expression,
@"if": struct {
then_block: ConditionalBlock,
else_block: ?struct {
condition_expression: ?Expression,
block_statements: StatementList,
},
condition_expression: Expression,
block_statements: List,
else_statement: ?*Statement,
},
@"while": ConditionalBlock,
block: StatementList,
@"while": struct {
condition_expression: Expression,
block_statements: List,
},
block: List,
expression: Expression,
const ConditionalBlock = struct {
condition_expression: Expression,
block_statements: StatementList,
};
const List = coral.list.Stack(Statement);
};
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,
parsed_statements: Statement.List,
has_returned: bool,
pub fn error_message(self: Tree) []const coral.io.Byte {
@ -183,7 +179,7 @@ pub const Tree = struct {
return .{
.arena = coral.arena.Stacking.make(allocator, 4096),
.error_buffer = coral.list.ByteStack.make(allocator),
.parsed_statements = StatementList.make(allocator),
.parsed_statements = Statement.List.make(allocator),
.tokenizer = .{.source = ""},
.allocator = allocator,
.name = ast_name,
@ -191,19 +187,19 @@ pub const Tree = struct {
};
}
pub fn parse(self: *Tree, data: []const coral.io.Byte) ParseError!*const StatementList {
pub fn parse(self: *Tree, data: []const coral.io.Byte) ParseError![]const Statement {
self.free();
self.tokenizer = .{.source = data};
self.has_returned = false;
self.parsed_statements.free();
self.tokenizer.skip_newlines();
self.parsed_statements = try self.parse_statements();
if (self.tokenizer.token == .keyword_end) {
return self.report("unexpected `end` without matching `do` block");
while (self.tokenizer.token != .end) {
try self.parsed_statements.push_one(try self.parse_statement());
}
return &self.parsed_statements;
return self.parsed_statements.values;
}
const parse_additive = BinaryOperator.builder(parse_equality, &.{
@ -211,6 +207,74 @@ pub const Tree = struct {
.subtraction,
});
fn parse_branch(self: *Tree) ParseError!Statement {
const allocator = self.arena.as_allocator();
defer self.tokenizer.skip_newlines();
self.tokenizer.step();
const condition_expression = try self.parse_expression();
if (self.tokenizer.token != .symbol_colon) {
return self.report("expected `:` after `if` statement condition");
}
var statements = Statement.List.make(allocator);
self.tokenizer.skip_newlines();
while (true) {
switch (self.tokenizer.token) {
.keyword_end => {
return .{
.@"if" = .{
.condition_expression = condition_expression,
.block_statements = statements,
.else_statement = null,
},
};
},
.keyword_else => {
self.tokenizer.step();
if (self.tokenizer.token != .symbol_colon) {
return self.report("expected `:` after `if` statement condition");
}
var else_statements = Statement.List.make(allocator);
self.tokenizer.skip_newlines();
while (self.tokenizer.token != .keyword_end) {
try else_statements.push_one(try self.parse_statement());
}
return .{
.@"if" = .{
.else_statement = try coral.io.allocate_one(allocator, Statement{.block = else_statements}),
.condition_expression = condition_expression,
.block_statements = statements,
},
};
},
.keyword_elif => {
return .{
.@"if" = .{
.else_statement = try coral.io.allocate_one(allocator, try self.parse_branch()),
.condition_expression = condition_expression,
.block_statements = statements,
},
};
},
else => try statements.push_one(try self.parse_statement()),
}
}
}
const parse_comparison = BinaryOperator.builder(parse_term, &.{
.greater_than_comparison,
.greater_equals_comparison,
@ -493,7 +557,7 @@ pub const Tree = struct {
},
.symbol_paren_left => {
var argument_expressions = ExpressionList.make(allocator);
var argument_expressions = Expression.List.make(allocator);
while (true) {
self.tokenizer.skip_newlines();
@ -533,124 +597,61 @@ pub const Tree = struct {
return expression;
}
fn parse_statements(self: *Tree) ParseError!StatementList {
fn parse_statement(self: *Tree) ParseError!Statement {
const allocator = self.arena.as_allocator();
var statements = StatementList.make(allocator);
self.tokenizer.skip_newlines();
switch (self.tokenizer.token) {
.keyword_return => {
defer self.tokenizer.skip_newlines();
while (true) {
try statements.push_one(parse_statement: {
switch (self.tokenizer.token) {
.end, .keyword_end, .keyword_else, .keyword_elif => 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" = 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" = null};
},
.keyword_while => {
self.tokenizer.step();
const condition_expression = try self.parse_expression();
if (self.tokenizer.token != .symbol_colon) {
return self.report("expected `:` after `while` statement");
}
const while_statement = Statement{
.@"while" = .{
.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 while_statement;
},
.keyword_if => {
self.tokenizer.step();
const then_condition_expression = try self.parse_expression();
if (self.tokenizer.token != .symbol_colon) {
return self.report("expected `:` after `if` statement condition");
}
var if_statement = Statement{
.@"if" = .{
.then_block = .{
.block_statements = try self.parse_statements(),
.condition_expression = then_condition_expression,
},
.else_block = null,
},
};
switch (self.tokenizer.token) {
.keyword_end => {},
.keyword_else => {
self.tokenizer.step();
if (self.tokenizer.token != .symbol_colon) {
return self.report("expected newline after `else` statement");
}
if_statement.@"if".else_block = .{
.condition_expression = null,
.block_statements = try self.parse_statements(),
};
},
.keyword_elif => {
self.tokenizer.step();
const else_condition_expression = try self.parse_expression();
if (self.tokenizer.token != .symbol_colon) {
return self.report("expected newline after `elif` statement condition");
}
if_statement.@"if".else_block = .{
.condition_expression = else_condition_expression,
.block_statements = try self.parse_statements(),
};
},
else => return self.report("expected closing `end`, `elif`, or `else` statement on if block"),
}
self.tokenizer.skip_newlines();
break: parse_statement if_statement;
},
else => break: parse_statement .{.expression = try self.parse_expression()},
if (self.has_returned) {
return self.report("multiple returns in lambda scope but expected only one");
}
});
self.tokenizer.step();
if (self.tokenizer.token != .end and self.tokenizer.token != .newline) {
return .{.@"return" = 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;
return .{.@"return" = null};
},
.keyword_while => {
defer self.tokenizer.skip_newlines();
self.tokenizer.step();
const condition_expression = try self.parse_expression();
if (self.tokenizer.token != .symbol_colon) {
return self.report("expected `:` after `while` statement");
}
var statements = Statement.List.make(allocator);
self.tokenizer.skip_newlines();
while (self.tokenizer.token != .keyword_end) {
try statements.push_one(try self.parse_statement());
}
return .{
.@"while" = .{
.block_statements = statements,
.condition_expression = condition_expression,
},
};
},
.keyword_if => return self.parse_branch(),
else => return .{.expression = try self.parse_expression()},
}
}

2
source/ona/kym/tokens.zig
View File

@ -98,7 +98,7 @@ pub const Token = union(enum) {
pub const Tokenizer = struct {
source: []const coral.io.Byte,
lines_stepped: usize = 1,
token: Token = .end,
token: Token = .newline,
pub fn skip_newlines(self: *Tokenizer) void {
self.step();