From 435aa61fe41ef18bdbe62aebb9c070e1936d7fe0 Mon Sep 17 00:00:00 2001
From: lisyarus <lisyarus@gmail.com>
Date: Wed, 17 Dec 2025 15:46:51 +0300
Subject: [PATCH] Implement array types & array values

---
 libs/ast/include/pslang/ast/array.hpp         |  21 +++
 libs/ast/include/pslang/ast/expression.hpp    |   5 +-
 libs/ast/include/pslang/ast/print.hpp         |   2 +
 libs/ast/source/print.cpp                     |  18 +++
 .../include/pslang/interpreter/value.hpp      |  12 +-
 .../include/pslang/interpreter/value_fwd.hpp  |  12 ++
 libs/interpreter/source/eval.cpp              | 140 +++++++++++++++++-
 libs/interpreter/source/value.cpp             |  17 +++
 libs/parser/CMakeLists.txt                    |   2 +-
 libs/parser/rules/pslang.l                    |   2 +
 libs/parser/rules/pslang.y                    |  26 +++-
 libs/type/include/pslang/type/array.hpp       |  21 +++
 libs/type/include/pslang/type/type.hpp        |   6 +-
 libs/type/include/pslang/type/type_fwd.hpp    |   1 +
 libs/type/source/print.cpp                    |   6 +
 15 files changed, 273 insertions(+), 18 deletions(-)
 create mode 100644 libs/ast/include/pslang/ast/array.hpp
 create mode 100644 libs/interpreter/include/pslang/interpreter/value_fwd.hpp
 create mode 100644 libs/type/include/pslang/type/array.hpp

diff --git a/libs/ast/include/pslang/ast/array.hpp b/libs/ast/include/pslang/ast/array.hpp
new file mode 100644
index 0000000..05e9b89
--- /dev/null
+++ b/libs/ast/include/pslang/ast/array.hpp
@@ -0,0 +1,21 @@
+#pragma once
+
+#include <pslang/ast/expression_fwd.hpp>
+
+#include <vector>
+
+namespace pslang::ast
+{
+
+	struct array
+	{
+		std::vector<expression_ptr> elements;
+	};
+
+	struct array_access
+	{
+		expression_ptr array;
+		expression_ptr index;
+	};
+
+}
diff --git a/libs/ast/include/pslang/ast/expression.hpp b/libs/ast/include/pslang/ast/expression.hpp
index b23db1e..3b82150 100644
--- a/libs/ast/include/pslang/ast/expression.hpp
+++ b/libs/ast/include/pslang/ast/expression.hpp
@@ -5,6 +5,7 @@
 #include <pslang/ast/operation.hpp>
 #include <pslang/ast/cast.hpp>
 #include <pslang/ast/function.hpp>
+#include <pslang/ast/array.hpp>
 #include <pslang/ast/expression_fwd.hpp>
 
 namespace pslang::ast
@@ -29,7 +30,9 @@ namespace pslang::ast
 		unary_operation,
 		binary_operation,
 		cast_operation,
-		function_call
+		function_call,
+		array,
+		array_access
 	>;
 
 	struct expression
diff --git a/libs/ast/include/pslang/ast/print.hpp b/libs/ast/include/pslang/ast/print.hpp
index 2cfbc8b..cb3eada 100644
--- a/libs/ast/include/pslang/ast/print.hpp
+++ b/libs/ast/include/pslang/ast/print.hpp
@@ -30,6 +30,8 @@ namespace pslang::ast
 	void print(std::ostream & out, binary_operation const & node, print_options const & options = {});
 	void print(std::ostream & out, cast_operation const & node, print_options const & options = {});
 	void print(std::ostream & out, function_call const & node, print_options const & options = {});
+	void print(std::ostream & out, array const & node, print_options const & options = {});
+	void print(std::ostream & out, array_access const & node, print_options const & options = {});
 	void print(std::ostream & out, expression_ptr const & node, print_options const & options = {});
 	void print(std::ostream & out, assignment const & node, print_options const & options = {});
 	void print(std::ostream & out, variable_declaration const & node, print_options const & options = {});
diff --git a/libs/ast/source/print.cpp b/libs/ast/source/print.cpp
index 187dfac..71e4587 100644
--- a/libs/ast/source/print.cpp
+++ b/libs/ast/source/print.cpp
@@ -152,6 +152,24 @@ namespace pslang::ast
 			print(out, argument, child(options));
 	}
 
+	void print(std::ostream & out, array const & node, print_options const & options)
+	{
+		put_indent(out, options);
+		out << "array";
+		newline(out);
+		for (auto const & element : node.elements)
+			print(out, element, child(options));
+	}
+
+	void print(std::ostream & out, array_access const & node, print_options const & options)
+	{
+		put_indent(out, options);
+		out << "array access";
+		newline(out);
+		print(out, node.array, child(options));
+		print(out, node.index, child(options));
+	}
+
 	void print(std::ostream & out, expression_ptr const & node, print_options const & options)
 	{
 		std::visit([&](auto const & value){ print(out, value, options); }, *node);
diff --git a/libs/interpreter/include/pslang/interpreter/value.hpp b/libs/interpreter/include/pslang/interpreter/value.hpp
index a980aa5..33bf59f 100644
--- a/libs/interpreter/include/pslang/interpreter/value.hpp
+++ b/libs/interpreter/include/pslang/interpreter/value.hpp
@@ -1,10 +1,12 @@
 #pragma once
 
 #include <pslang/type/type.hpp>
+#include <pslang/interpreter/value_fwd.hpp>
 
 #include <cstdint>
 #include <variant>
 #include <iostream>
+#include <vector>
 
 namespace pslang::interpreter
 {
@@ -53,9 +55,17 @@ namespace pslang::interpreter
 		using primitive_value_impl::primitive_value_impl;
 	};
 
+	struct array_value
+	{
+		// Can't infer type from elements in case of zero-sized array
+		type::type_ptr element_type;
+		std::vector<value_ptr> elements;
+	};
+
 	using value_impl = std::variant<
 		unit_value,
-		primitive_value
+		primitive_value,
+		array_value
 	>;
 
 	struct value
diff --git a/libs/interpreter/include/pslang/interpreter/value_fwd.hpp b/libs/interpreter/include/pslang/interpreter/value_fwd.hpp
new file mode 100644
index 0000000..7b18a6f
--- /dev/null
+++ b/libs/interpreter/include/pslang/interpreter/value_fwd.hpp
@@ -0,0 +1,12 @@
+#pragma once
+
+#include <memory>
+
+namespace pslang::interpreter
+{
+
+	struct value;
+
+	using value_ptr = std::shared_ptr<value>;
+
+}
diff --git a/libs/interpreter/source/eval.cpp b/libs/interpreter/source/eval.cpp
index 25d6a43..e392380 100644
--- a/libs/interpreter/source/eval.cpp
+++ b/libs/interpreter/source/eval.cpp
@@ -5,6 +5,7 @@
 #include <pslang/type/print.hpp>
 
 #include <sstream>
+#include <optional>
 
 namespace pslang::interpreter
 {
@@ -102,12 +103,14 @@ namespace pslang::interpreter
 			throw std::runtime_error("Identifier \"" + identifier.name + "\" is not defined");
 		}
 
-		value unary_operation_impl(ast::unary_operation_type type, unit_value const &)
+		template <typename Value>
+		value unary_operation_impl(ast::unary_operation_type type, Value const & value)
 		{
 			std::ostringstream os;
 			os << "Cannot apply unary operator \"";
 			print(os, type);
-			os << "\" to a value of type unit";
+			os << "\" to a value of type ";
+			type::print(os, type_of(value));
 			throw std::runtime_error(os.str());
 		}
 
@@ -260,12 +263,15 @@ namespace pslang::interpreter
 			throw std::runtime_error(os.str());
 		}
 
-		value binary_operation_impl_same_type(ast::binary_operation_type type, unit_value const &, value const & arg2)
+		template <typename Value>
+		value binary_operation_impl_same_type(ast::binary_operation_type type, Value const & arg1, value const & arg2)
 		{
 			std::ostringstream os;
 			os << "Cannot apply binary operator \"";
 			print(os, type);
-			os << "\" to values of type unit and ";
+			os << "\" to values of type ";
+			type::print(os, type_of(arg1));
+			os << " and ";
 			type::print(os, type_of(arg2));
 			throw std::runtime_error(os.str());
 		}
@@ -311,6 +317,14 @@ namespace pslang::interpreter
 			throw std::runtime_error("Cannot cast unit type to anything");
 		}
 
+		value cast_impl(array_value const & value, type::type const & type)
+		{
+			if (type::equal(type, type_of(value)))
+				return value;
+
+			throw std::runtime_error("Cannot cast array type to anything");
+		}
+
 		template <typename T>
 		value cast_impl(primitive_value_base<T> const & value, type::unit_type const &)
 		{
@@ -421,6 +435,124 @@ namespace pslang::interpreter
 			throw std::runtime_error("Function \"" + function_call.name + "\" is not defined");
 		}
 
+		value eval_impl(context & context, ast::array const & array)
+		{
+			if (array.elements.empty())
+				throw std::runtime_error("Internal error: array ast node cannot have zero elements");
+
+			type::type_ptr element_type;
+			std::vector<value_ptr> elements;
+			for (std::size_t i = 0; i < array.elements.size(); ++i)
+			{
+				auto element = std::make_unique<value>(eval(context, array.elements[i]));
+				if (i == 0)
+					element_type = std::make_unique<type::type>(type_of(*element));
+				else
+				{
+					auto new_type = type_of(*element);
+					if (!type::equal(*element_type, new_type))
+					{
+						std::ostringstream os;
+						os << "Error forming array: inferred element type is ";
+						type::print(os, *element_type);
+						os << " but element #" << i << " type is ";
+						type::print(os, new_type);
+						throw std::runtime_error(os.str());
+					}
+				}
+
+				elements.push_back(std::move(element));
+			}
+
+			return array_value{.element_type = std::move(element_type), .elements = std::move(elements)};
+		}
+
+		value eval_impl(context & context, ast::array_access const & array_access)
+		{
+			auto array = eval(context, array_access.array);
+			auto index = eval(context, array_access.index);
+
+			if (auto avalue = std::get_if<array_value>(&array))
+			{
+				std::optional<std::uint64_t> index_unsigned;
+				std::optional<std::int64_t> index_signed;
+
+				if (auto pvalue = std::get_if<primitive_value>(&index))
+				{
+					if (auto i8 = std::get_if<i8_value>(pvalue))
+					{
+						index_signed = i8->value;
+					}
+					else if (auto u8 = std::get_if<u8_value>(pvalue))
+					{
+						index_unsigned = u8->value;
+					}
+					else if (auto i16 = std::get_if<i16_value>(pvalue))
+					{
+						index_signed = i16->value;
+					}
+					else if (auto u16 = std::get_if<u16_value>(pvalue))
+					{
+						index_unsigned = u16->value;
+					}
+					else if (auto i32 = std::get_if<i32_value>(pvalue))
+					{
+						index_signed = i32->value;
+					}
+					else if (auto u32 = std::get_if<u32_value>(pvalue))
+					{
+						index_unsigned = u32->value;
+					}
+					else if (auto i64 = std::get_if<i64_value>(pvalue))
+					{
+						index_signed = i64->value;
+					}
+					else if (auto u64 = std::get_if<u64_value>(pvalue))
+					{
+						index_unsigned = u64->value;
+					}
+				}
+
+				if (!index_signed && !index_unsigned)
+				{
+					std::ostringstream os;
+					os << "Cannot index into an array with an expression of type ";
+					type::print(os, type_of(index));
+					throw std::runtime_error(os.str());
+				}
+
+				std::uint64_t final_index;
+
+				if (index_unsigned)
+				{
+					if (*index_unsigned >= avalue->elements.size())
+					{
+						std::ostringstream os;
+						os << "Array index " << *index_unsigned << " out of bounds " << avalue->elements.size();
+						throw std::runtime_error(os.str());
+					}
+					final_index = *index_unsigned;
+				}
+				else // if (index_signed)
+				{
+					if (*index_signed < 0 || *index_signed >= avalue->elements.size())
+					{
+						std::ostringstream os;
+						os << "Array index " << *index_signed << " out of bounds " << avalue->elements.size();
+						throw std::runtime_error(os.str());
+					}
+					final_index = *index_signed;
+				}
+
+				return *avalue->elements[final_index];
+			}
+
+			std::ostringstream os;
+			os << "Cannot index into a non-array of type ";
+			type::print(os, type_of(array));
+			throw std::runtime_error(os.str());
+		}
+
 		value eval_impl(context & context, ast::expression_ptr const & expression)
 		{
 			return std::visit([&](auto const & expression){ return eval_impl(context, expression); }, *expression);
diff --git a/libs/interpreter/source/value.cpp b/libs/interpreter/source/value.cpp
index dad9e92..8a566b1 100644
--- a/libs/interpreter/source/value.cpp
+++ b/libs/interpreter/source/value.cpp
@@ -24,6 +24,11 @@ namespace pslang::interpreter
 			return std::visit([](auto const & value){ return type_of_impl(value); }, value);
 		}
 
+		type::type type_of_impl(array_value const & value)
+		{
+			return type::array_type{.element_type = value.element_type, .size = value.elements.size()};
+		}
+
 		type::type type_of_impl(value const & value)
 		{
 			return std::visit([](auto const & value){ return type_of_impl(value); }, value);
@@ -68,6 +73,18 @@ namespace pslang::interpreter
 			std::visit([&](auto const & value){ return print_impl(out, value); }, value);
 		}
 
+		void print_impl(std::ostream & out, array_value const & value)
+		{
+			out << "[";
+			for (std::size_t i = 0; i < value.elements.size(); ++i)
+			{
+				if (i > 0)
+					out << ", ";
+				print(out, *value.elements[i]);
+			}
+			out << "]";
+		}
+
 		void print_impl(std::ostream & out, value const & value)
 		{
 			std::visit([&](auto const & value){ return print_impl(out, value); }, value);
diff --git a/libs/parser/CMakeLists.txt b/libs/parser/CMakeLists.txt
index e8ed47b..e48f5ce 100644
--- a/libs/parser/CMakeLists.txt
+++ b/libs/parser/CMakeLists.txt
@@ -24,7 +24,7 @@ bison_target(
 	${PSLANG_PARSER_RULES_FILE}
 	${PSLANG_PARSER_SOURCE_FILE}
 	DEFINES_FILE ${PSLANG_PARSER_HEADER_FILE}
-	COMPILE_FLAGS -Wcounterexamples
+	# COMPILE_FLAGS -Wcounterexamples
 )
 
 add_flex_bison_dependency(generate-pslang-lexer generate-pslang-parser)
diff --git a/libs/parser/rules/pslang.l b/libs/parser/rules/pslang.l
index 9d7b33e..a154a27 100644
--- a/libs/parser/rules/pslang.l
+++ b/libs/parser/rules/pslang.l
@@ -55,6 +55,8 @@ f64  { return bp::make_f64(ctx.location); }
 ","  { return bp::make_comma(ctx.location); }
 "("  { return bp::make_lparen(ctx.location); }
 ")"  { return bp::make_rparen(ctx.location); }
+"["  { return bp::make_lbracket(ctx.location); }
+"]"  { return bp::make_rbracket(ctx.location); }
 "+"  { return bp::make_plus(ctx.location); }
 "-"  { return bp::make_minus(ctx.location); }
 "*"  { return bp::make_asterisk(ctx.location); }
diff --git a/libs/parser/rules/pslang.y b/libs/parser/rules/pslang.y
index ec3ae24..7dc449d 100644
--- a/libs/parser/rules/pslang.y
+++ b/libs/parser/rules/pslang.y
@@ -78,6 +78,8 @@ template <typename T>
 %token comma ","
 %token lparen "("
 %token rparen ")"
+%token lbracket "["
+%token rbracket "]"
 %token plus "+"
 %token minus "-"
 %token asterisk "*"
@@ -156,9 +158,10 @@ template <typename T>
 %type <ast::expression> sum_expression
 %type <ast::expression> mult_expression
 %type <ast::expression> not_expression
+%type <ast::expression> postfix_expression
 %type <ast::expression> base_expression
-%type <std::vector<ast::expression_ptr>> function_call_argument_list
-%type <std::vector<ast::expression_ptr>> nonempty_function_call_argument_list
+%type <std::vector<ast::expression_ptr>> comma_separated_expression_list
+%type <std::vector<ast::expression_ptr>> nonempty_comma_separated_expression_list
 %type <ast::expression> literal
 
 %%
@@ -220,6 +223,7 @@ variable_keyword
 type_expression
 : unit { $$ = type::type(type::unit_type{}); }
 | primitive_type { $$ = type::type($1); }
+| type_expression lbracket lit_i32 rbracket { $$ = type::array_type{std::make_unique<type::type>($1), std::stoull($3)}; }
 ;
 
 primitive_type
@@ -281,25 +285,31 @@ mult_expression
 ;
 
 not_expression
+: postfix_expression
+| exclamation postfix_expression { $$ = ast::unary_operation{ast::unary_operation_type::logical_not, std::make_unique<ast::expression>($2) }; }
+;
+
+postfix_expression
 : base_expression
-| exclamation base_expression { $$ = ast::unary_operation{ast::unary_operation_type::logical_not, std::make_unique<ast::expression>($2) }; }
+| postfix_expression lbracket expression rbracket { $$ = ast::array_access{std::make_unique<ast::expression>($1), std::make_unique<ast::expression>($3)}; }
 ;
 
 base_expression
 : literal
 | name { $$ = ast::identifier{$1}; }
 | lparen expression rparen { $$ = $2; }
-| name lparen function_call_argument_list rparen { $$ = ast::function_call{$1, $3}; }
+| name lparen comma_separated_expression_list rparen { $$ = ast::function_call{$1, $3}; }
+| lbracket nonempty_comma_separated_expression_list rbracket { $$ = ast::array{$2}; }
 ;
 
-function_call_argument_list
+comma_separated_expression_list
 : %empty { std::vector<ast::expression_ptr> tmp; $$ = std::move(tmp); }
-| nonempty_function_call_argument_list
+| nonempty_comma_separated_expression_list
 ;
 
-nonempty_function_call_argument_list
+nonempty_comma_separated_expression_list
 : expression { std::vector<ast::expression_ptr> tmp; tmp.push_back(std::make_unique<ast::expression>($1)); $$ = std::move(tmp); }
-| nonempty_function_call_argument_list comma expression { auto tmp = $1; tmp.push_back(std::make_unique<ast::expression>($3)); $$ = std::move(tmp); }
+| nonempty_comma_separated_expression_list comma expression { auto tmp = $1; tmp.push_back(std::make_unique<ast::expression>($3)); $$ = std::move(tmp); }
 ;
 
 literal
diff --git a/libs/type/include/pslang/type/array.hpp b/libs/type/include/pslang/type/array.hpp
new file mode 100644
index 0000000..b51c695
--- /dev/null
+++ b/libs/type/include/pslang/type/array.hpp
@@ -0,0 +1,21 @@
+#pragma once
+
+#include <pslang/type/type_fwd.hpp>
+
+#include <cstdint>
+
+namespace pslang::type
+{
+
+	struct array_type
+	{
+		type_ptr element_type;
+		std::uint64_t size;
+	};
+
+	inline bool operator == (array_type const & t1, array_type const & t2)
+	{
+		return equal(*t1.element_type, *t2.element_type) && (t1.size == t2.size);
+	}
+
+}
diff --git a/libs/type/include/pslang/type/type.hpp b/libs/type/include/pslang/type/type.hpp
index fb9dd19..3232bdf 100644
--- a/libs/type/include/pslang/type/type.hpp
+++ b/libs/type/include/pslang/type/type.hpp
@@ -2,6 +2,7 @@
 
 #include <pslang/type/unit.hpp>
 #include <pslang/type/primitive.hpp>
+#include <pslang/type/array.hpp>
 #include <pslang/type/type_fwd.hpp>
 
 #include <variant>
@@ -11,7 +12,8 @@ namespace pslang::type
 
 	using type_impl = std::variant<
 		unit_type,
-		primitive_type
+		primitive_type,
+		array_type
 	>;
 
 	struct type
@@ -20,6 +22,4 @@ namespace pslang::type
 		using type_impl::type_impl;
 	};
 
-	bool equal(type const & t1, type const & t2);
-
 }
diff --git a/libs/type/include/pslang/type/type_fwd.hpp b/libs/type/include/pslang/type/type_fwd.hpp
index 07b7084..e844f2d 100644
--- a/libs/type/include/pslang/type/type_fwd.hpp
+++ b/libs/type/include/pslang/type/type_fwd.hpp
@@ -9,4 +9,5 @@ namespace pslang::type
 
 	using type_ptr = std::shared_ptr<type>;
 
+	bool equal(type const & t1, type const & t2);
 }
diff --git a/libs/type/source/print.cpp b/libs/type/source/print.cpp
index cc67923..f08e164 100644
--- a/libs/type/source/print.cpp
+++ b/libs/type/source/print.cpp
@@ -72,6 +72,12 @@ namespace pslang::type
 			std::visit([&](auto const & value){ print_impl(out, value); }, type);
 		}
 
+		void print_impl(std::ostream & out, array_type const & type)
+		{
+			print(out, *type.element_type);
+			out << "[" << type.size << "]";
+		}
+
 		void print_impl(std::ostream & out, type const & type)
 		{
 			std::visit([&](auto const & value){ print_impl(out, value); }, type);