[0.4.10] - 2025-0x-xx

• Tested with Rley 0.9.02 and Rubocop 1.74

[0.4.09] - 2025-01-16

• Tested with MRI Ruby 3.4.1.
• Minor changes
• [NEW] Added demo folder
• [FIX] Some Rubocop 1.72.0 offences fixed.

[0.4.08] - 2022-04-09

• Refactoring of the Scanner class.

Changed

• Frontend::Scanner class: major code refactoring.

[0.4.07] - 2021-11-21

• Minor fixes; dependency towards Rubies 3+ allowed...

Fixed

• File loxxy.gemspec dependency on Ruby version relaxed to support Ruby 3+
• File resolver.rb Fixed a typo in standard Lox error message.
• File collide_with_paramaeter.lox Fixed typo in error message.
• File duplicate_local.lox Fixed typo in error message.
• File duplicate_parameter.lox Fixed typo in error message.

[0.4.06] - 2021-11-01

• Code update to cope with Rley v.0.8.08 changes

Changed

• File AST::AstBuilder some reduce_ to cope implementation change of ? quantifier
• Method AST::LoxCallExpr#initialize call to Array#flatten with argList argument
• File loxxy.gemspec dependency towards rely minimal version number is now 0.8.08
• Some spec files updated after rley changes of ?, *, + quantifiers

Removed

• File front_end/literal.rb: obsolete

[0.4.05] - 2021-10-10

• Removal of Literal class, code restyling to please Rubocop 1.22

Changed

• Class Scanner remove all dependencies to Frontend::Literal class
• File .rubocop.yml added new cops from Rubocop 1.21 and 1.22
• File parser_spec.rb use of parentheses in ambiguous expressions
• File raw_parser_spec.rb use of parentheses in ambiguous expressions
• File loxxy.gemspec forced dependency to Rley 0.8.06

[0.4.04] - 2021-09-11

• Grammar optimization (3 rules less, use of match_closest feature from Rley)

Changed

• Method Ast::AstBuilder#reduce_arguments code re-styling: use shorthand &:
• File grammar.rb use match_closest constraint from Rley to cope with dangling else statement

[0.4.02] - 2021-09-10

• Fixes inAST::AstBuilder class to cope with changes in Rley 0.8.03

Changed

• File loxxy.gemspec forced dependency to Rley 0.8.03

Fixed

• Method Ast::AstBuilder#reduce_class_naming fixed access to IDENTIFER in (LESS IDENTIFER)?
• Method Ast::AstBuilder#reduce_var_declaration fixed access to expression in (EQUAL expression)?
• Method Ast::AstBuilder#reduce_assign_exprfixed access to call in (call DOT)?
• Method Ast::AstBuilder#reduce_parametersfixed access to IDENTIFIER in (COMMA IDENTIFIER)*
• Method Ast::AstBuilder#reduce_argumentsfixed access to expression in (COMMA expression)*

[0.4.01] - 2021-08-22

• Grammar and AST::AstBuilder adapted to take profit of extended grammar notiation in Rley 0.8.01

Changed

• Class Ast::ASTBuilder removal of methods made redundant with new Rley version
• File .rubocop.yml added config for new cops
• File grammar.rb changed rules to use new extended rule syntax in Rley

[0.4.00] - 2021-05-24

• Version bump. Loxxy is capable to run the LoxLox interpreter, an interpreter written in Lox.

New

• Method BackEnd::LoxInstance#falsey? added
• Method BackEnd::LoxInstance#truthy? added

Changed

• Method BackEnd::Engine#after_variable_expr the error message Undefined variable nows gives the location of the offending variable.

• Class Ast::LoxClassStmtis now a subclass of LoxNode

• File README.md added an explanation on how to run LoxLoxinterpreter.

Fixed

• Method Ast::LoxClassStmt#initialize fixed inconsistencies in its Yard/RDoc documentation.
• Method Ast::LoxFunStmt#initialize fixed inconsistencies in its Yard/RDoc documentation.
• Method BackEnd::Engine#native_getc now returns -1 when its reaches EOF.
• Method BackEnd::Resolver#after_logical_expr was missing and this caused the lack of resultation in the second operand.

[0.3.02] - 2021-05-22

• New built-in expressions getc, chr, exit and print_eeror , fixes with deeply nested returns, set expressions

New

• Class BackEnd::Engine new built-in functions getc, chr, exit, and print_error

Changed

• Class Ast::LoxSetExpr value to assign is now a distinct atrrbute instead of a subnode
• Class BackEnd::Engine two distinct stacks: one of expression evaluation, another for argument passing

Fixed

• Class BackEnd::LoxClass: in some contexts the init method returned twice 'this'.
• Method LoxFunction#call mismatch between deeply nested returns and environments

[0.3.01] - 2021-05-08

• Fix in Scanner class, added more tests in test suite.

New

• Added the new subfolder extra under test_suite. It will contain tests for non-standard features or tests not covered in standard test suite.

Fixed

• Class FrontEnd::Scanner: Couldn't correctly recognize a plus preceding directly a number literal

[0.3.00] - 2021-05-07

• Milestone: Loxxy passes all reference test suite.

Fixed

• Method BackEnd::Resolver#before_variable_expr: Standard Lox allows re-declaration of a variable at top-level scope

[0.2.06] - 2021-05-04

• Nearly passing the 'official' test suite, fixing non-compliant behavior, specialized exceptions for errors

New

• Module LoxFileTester module that hosts methods that simplify the tests of Lox source file.

Changed

• Folder test_suite vastly reorganized. Sub-folder baseline contains spec files testing the Lox files from official implementation
• Class BackEnd::Engine replaced most StandardError by Loxxy::RuntimeError exception.
• Class BackEnd::Resolver replaced most StandardError by Loxxy::RuntimeError exception.
• Method Datatype::Number#/ now handles correctly expression like 0/0 (integer divide)

Fixed

• 0/0 expression results in a ZeroDivisionError exception, in Lox this result to a NaN (Not a Number). Now, Loxxy is aligned to standard Lox
• FrontEnd::Scanner now always treats expression like -123 as the unary or binary minus operator applied to a positive number.

[0.2.05] - 2021-04-26

• Loxxy now transforms for loops into while loops (desugaring), fix in Scanner class

Changed

• Method Ast::ASTBuilder#reduce_for_stmt converts 'for' loops into 'while' loops
• Method `Ast::ASTBuilder#reduce_for_control takes care of case for(expr1;;expr2) now test expression is set to true

Fixed

• Method FrontEnd::Scanner#next_token keyword recognition was case insensitive

Removed

• Method Ast::Visitor#visitor_for_stmt
• Method BackEnd::Engine#after_for_stmt
• Method BackEnd::Resolver#before_for_stmt
• Method BackEnd::Resolver#after_for_stmt

[0.2.04] - 2021-04-25

• Loxxy passes the test suite for for statements

Fixed

• Method BackEnd::Engine#after_for_stmt now a for(;;) executes the body once; a for without test will execute forever
• Method `BackEnd::Resolver#after_for_stmt now accepts nil test expression

[0.2.03] - 2021-04-24

• Fixes for the set (field) expressions, accept methods for AST nodes are meta-programmed

New

• Module Ast::Visitee provides the define_accept method that generate accept method with meta-programming

Fixed

• Method BackEnd::Engine#before_set_expr methos method that ensure that the receiver is evaluated first, then the assigned value
• Method BackEnd::Engine#after_set_expr now pushes the value assigned to the field also onto the stack
• Class BackEnd::Engine a number of StnadardError exceptions are replaced by Loxxy::RuntimeError

[0.2.02] - 2021-04-21

• Improvements in the scanner class (escape sequence for quotes and newlines), error messages closer to jlox.

Changed

• File loxxy executable doesn't show a stack trace for scanner errors
• Class ScannerError is now a subclass of Loxxy::Error
• Class Scanner now returns a specific error message for unterminated strings
• Class Scanner error messages are closer to the ones from jlox
• Class Scanner supports now escape sequences \" for double quotes, \n for newlines
• File README.md Reshuffled some text

[0.2.01] - 2021-04-18

• Minor improvements in CLI, starting re-documenting README.md.

New

• Class Loxxy::CLIParser parser for the command-line options

Changed

• File loxxy executable now uses commad-line parsing
• File .rubocop.yml updated with new cops
• File README.md Added examples for command-line interface
• File loxxy.gemspec expanded description of gem

[0.2.00] - 2021-04-17

• Loxxy implements the complete Lox language including its object-oriented features.

New

• Class Ast::LoxSuperExpr an AST node that represents the occurrence of super in source code.
• Method Ast::ASTBuilder#reduce_class_subclassing action launched by the parser when detecting inheritance
• Method Ast::ASTBuilder#reduce_super_expr action launched by the parser when detecting the super keyword
• Method Ast::Visitor#visit_super_expr visit of an Ast::LoxSuperExpr node
• Method BackEnd::Engine#after_super_stmt does the lookup of an inherited method.
• Method BackEnd::Resolver#after_super_stmt checks for correct context for super occurrence

Changed

• Method Ast::ASTBuilder#reduce_class_decl expanded in order to support superclass
• Class Ast::LoxClassStmt added superclass attribute, expanded constructor signature.
• Method BackEnd::Engine#after_class_stmt adds an environment for super variable.
• Class BackEnd::LoxClass added superclass attribute, expanded constructor signature.
• Method BackEnd::LoxClass#find_method now does the lookup in superclass(es)
• Method BackEnd::Resolver#after_class_stmt super variable resolution
• File grammar.rb changed rules to cope with superclass name and super keyword
• File README.md updated to reflect current implementation level

[0.1.17] - 2021-04-11

• Loxxy now support custom initializer.

Changed

• Method BackEnd::Class#call updated for custom initializer.
• Class BackEnd::LoxFunction added an attribute is_initializer
• Class BackEnd::Resolver#before_return_stmt added a check that return in initializer may not return a value

Fixed

• Method BackEnd::Engine#after_call_expr now does arity checking also for initalizer.
• Method BackEnd::LoxInstance#set removed the check of field existence that prevented the creation of ... fields

[0.1.16] - 2021-04-10

• Fixed an issue in name lookup. All the this test suite is passing.

Changed

• Method BackEnd::Engine#after_var_stmt now it creates the variable and pouts it in the symbol table

Removed

• Method BackEnd::Engine#before_var_stmt it generated bug when assigning a value to a var, when that var name occurred elsewhere

[0.1.15] - 2021-04-08

• Fixed the dangling elseby tweaking the grammar rules

Changed

• Method Ast::ASTBuilder#reduce_if__else_stmt parse action specific for if with else branch

Fixed

• File grammar.rb changed rules to cope with dangling else issue

Changed

• Method Ast::ASTBuilder#reduce_if_stmt parse action for if without else branch
• File README.md removed the section about the dangling else issue.

[0.1.14] - 2021-04-05

• Loxxy now implements the 'this' keyword

New

• Class Ast::LoxThisExpr a syntax node that represents an occurrence of the this keyword
• Method Ast::ASTBuilder#reduce_this_expr parse action for this keyword
• Method Ast::Visitor#visit_this_expr visit of an Ast::LoxThisExpr node
• Method BackEnd::Engine#after_this_expr runtime action for this keyword (i.e. refers to current instance)
• Method BackEnd::LoxFunction#bind implementation of bound method

Changed

• Class BackEnd::Resolver implementing semantic actions for this keyword
• File grammar.rb added name to a syntax rule

[0.1.13] - 2021-04-05

• Loxxy now implements method calls

New

• Class Ast::LoxGetExpr a syntax node that represents a read access to an object property
• Class Ast::LoxSetExpr a syntax node that represents a write access to an object property
• Method Ast::ASTBuilder#reduce_set_expr parse action for write access to an object property
• Method Ast::ASTBuilder#reduce_get_expr parse action for read access to an object property
• Method Ast::Visitor#visit_set_expr visit of an Ast::LoxSetExpr node
• Method Ast::Visitor#visit_get_expr visit of an Ast::LoxGetExpr node
• Method BackEnd::Engine#after_set_expr runtime action for property setting
• Method BackEnd::Engine#after_get_expr runtime action for property getting
• Method BackEnd::LoxInstance#set implementation of write accessor
• Method BackEnd::LoxInstance#get implementation of read accessor
• Method BackEnd::Resolver#after_set_expr resolve action for property setting
• Method BackEnd::Resolver#after_get_expr resolve action for property getting

Changed

• Method Ast::ASTBuilder#reduce_assign_expr expanded to support write access to an object property
• Class LoxClassStmt: methods are now aggregate under the body attribute
• Class LoxFunStmt: has a new attribute is_method and inherits from Ast::LoxNode
• Method BackEnd::Engine#after_class_stmt methods are aggregated into the classes
• Method BackEnd::Engine#after_fun_stmt extension for method
• File grammar.rb added names to two syntax rules

[0.1.12] - 2021-04-03

• Intermediate version: Loxxy does instance creation (default constructor)

New

• Method BackEnd::LoxClass#call made class callable (for invoking the constructor)
• Class BackEnd::LoxInstance runtime representation of a Lox instance (object).

Changed

• Method BackEnd::Engine#after_call_expr Added Lox class as callable thing.

Fixed

• Method Ast::ASTBuilder#reduce_class_body couldn't handle properly empty classes

[0.1.11] - 2021-04-03

• Intermediate version: Loxxy does class declarations

New

• Class Ast::LoxClassStmt a syntax node that represents a class declaration
• Method Ast::ASTBuilder#reduce_class_decl creates a LoxClassStmt instance
• Method Ast::ASTBuilder#reduce_class_name
• Method Ast::ASTBuilder#reduce_reduce_class_body collect the methods of the class
• Method Ast::ASTBuilder#reduce_method_plus_more for dealing with methods
• Method Ast::ASTBuilder#reduce_method_plus_end
• Method Ast::ASTVisitor#visit_class_stmt for visiting an Ast::LoxClassStmt node
• Method Ast::LoxBlockStmt#empty? returns true if the code block is empty
• Method BackEnd::Engine#after_class_stmt
• Method BackEnd::Resolver#after_class_stmt
• Method BackEnd::Resolver#before_class_stmt
• Class BackEnd::LoxClass runtime representation of a Lox class.

Changed

• File grammar.rb refactoring of class declaration syntax rules

[0.1.10] - 2021-03-31

• Flag return statements occurring outside functions as an error

Changed

• Class BackEnd::Resolver Added attribute current_function to know whether the visited parse node is located inside a function

[0.1.09] - 2021-03-28

• Fix and test suite for return statements

CHANGED

• Loxxy reports an error when a return statement occurs in top-level scope

Fixed

• A return without explicit value genrated an exception in some cases.

[0.1.08] - 2021-03-27

• Loxxy implements variable resolving and binding as described in Chapter 11 of "Crafting Interpreters" book.

New

• Class BackEnd::Resolver implements the variable resolution (whenever a variable is in use, locate the declaration of that variable)

CHANGED

• Class Ast::Visitor changes in some method signatures
• Class BackEnd::Engine new attribute resolver that points to a BackEnd::Resolver instance
• Class BackEnd::Engine several methods dealing with variables have been adapted to take the resolver into account.

[0.1.07] - 2021-03-14

• Loxxy now supports nested functions and closures

Changed

• Method Ast::AstBuilder#reduce_call_expr now supports nested call expressions (e.g. getCallback()(); )
• Class BackEnd::Environment: added the attributes predecessor and embedding to support closures.
• Class BackeEnd::LoxFunction: added the attribute closure that is equal to the environment where the function is declared.
• Constructor BackEnd::LoxFunction#new now takes a BackEnd::Engineas its fourth parameter
• Methods BackEnd::SymbolTable#enter_environment, BackEnd::SymbolTable#leave_environment take into account closures.

Fixed

• Method Ast::AstBuilder#after_var_stmt now takes into account the value from the top of stack

[0.1.06] - 2021-03-06

• Parameters/arguments checks in function declaration and call

Changed

• Method Ast::AstBuilder#reduce_call_arglist raises a Loxxy::RuntimeError when more than 255 arguments are used.

• Method BackEnd::Engine#after_call_expr raises a Loxxy::RuntimeError when argument count doesn't match the arity of function.

• Class BackEnd::Function renamed to LoxFunction

[0.1.05] - 2021-03-05

• Test for Fibbonacci recursive function is now passing.

Fixed

• Method BackEnd::Function#call a call doesn't no more generate of TWO scopes

[0.1.04] - 2021-02-28

Added

• Class Ast::LoxReturnStmt a node that represents a return statement
• Method Ast::ASTBuilder#reduce_return_stmt
• Method Ast::ASTVisitor#visit_return_stmt for visiting an Ast::LoxReturnStmt node
• Method BackEnd::Engine#after_return_stmt to handle return statement
• Method BackEnd::Function#! implementing the logical negation of a function (as value).
• Test suite for logical operators (in project repository)
• Test suite for block code
• Test suite for call and function declaration (initial)

Changed

• Method BackEnd::Engine#after_call_expr now generate a catch and throw events

[0.1.03] - 2021-02-26

• Runtime argument checking for arithmetic and comparison operators

Added

• Test suite for arithmetic and comparison operators (in project repository)
• Class BackEnd::UnaryOperator: runtime argument validation
• Class BackEnd::BinaryOperator: runtime argument validation

Changed

• File console renamed to loxxy. Very basic command-line interface.
• Custom exception classes
• File README.md updated list of supported Lox keywords.

[0.1.02] - 2021-02-21

• Function definition and call documented in README.md

Changed

• File README.md updated description of function definition and function call.

Fixed

• Method BackEnd::Engine#after_print_stmt now handles of empty stack or nil data.
• Method BackEnd::Engine#after_call_expr was pushing one spurious item onto data stack.

[0.1.01] - 2021-02-20

Fixed

• Fixed most offences for Rubocop.

[0.1.00] - 2021-02-20

• Version number bumped, Loxxy supports function definitions

Added

• Class Ast::LoxFunStmt a node that represents a function declaration
• Method Ast::ASTBuilder#reduce_fun_decl
• Method Ast::ASTBuilder#reduce_function creates a LoxFunStmt instance
• Method Ast::ASTBuilder#reduce_parameters_plus_more for dealing with function parameters
• Method Ast::ASTBuilder#reduce_parameters_plus_end
• Method Ast::ASTVisitor#visit_fun_stmt for visiting an Ast::LoxFunStmt node
• Method Ast::LoxBlockStmt#empty? returns true if the code block is empty
• Method BackEnd::Engine#after_fun_stmt
• Method BackEnd::NativeFunction#call
• Method BackEnd::NativeFunction#to_str
• Method BackEnd::LoxFunction runtime representation of a Lox function.

Changed

• Method BackEnd::Engine#after_call_expr

Fixed

• Fixed inconsistencies in documentation comments.

[0.0.28] - 2021-02-15

• The interpreter implements function calls (to a native function).

Added

• Class Ast::LoxCallExpr a node that represents a function call expression
• Method Ast::ASTBuilder#reduce_call_expr
• Method Ast::ASTBuilder#reduce_refinement_plus_end
• Method Ast::ASTBuilder#reduce_call_arglist creates a LoxCallExpr node
• Method Ast::ASTBuilder#reduce_arguments_plus_more builds the function argument array
• Method Ast::ASTVisitor#visit_call_expr for visiting an Ast::LoxCallExpr node
• Method BackEnd::Engine#after_call_exprimplements the evaluation of a function call.
• Method BackEnd::Engine#after_for_stmt implements most of the for control flow

[0.0.27] - 2021-01-24

• The interpreter implements while loops.

Added

• Class Ast::LoxForStmt a node that represents a for statement
• Method Ast::ASTBuilder#reduce_for_stmt
• Method Ast::ASTBuilder#reduce_for_control creates an Ast::LoxForStmt node
• Method Ast::ASTVisitor#visit_for_stmt for visiting an Ast::LoxWhileStmt node
• Method BackEnd::Engine#before_for_stmt builds a new environment for the loop variable
• Method BackEnd::Engine#after_for_stmt implements most of the for control flow

Changed

• File README.md updated.

[0.0.26] - 2021-01-22

• The interpreter implements while loops.

Added

• Class Ast::LoxWhileStmt a node that represents a while statement
• Method Ast::ASTBuilder#reduce_while_stmt creates an Ast::LoxWhileStmt node
• Method Ast::ASTVisitor#visit_while_stmt for visiting an Ast::LoxWhileStmt node
• Method BackEnd::Engine#after_while_stmt implements the while looping structure

Changed

• File README.md updated.

[0.0.25] - 2021-01-21

• The interpreter implements blocks of code.

Added

• Class Ast::LoxBlockStmt a node that represents a block of code
• Method Ast::ASTBuilder#reduce_block_stmt creates an Ast::LoxBlockStmt node
• Method Ast::ASTVisitor#visit_block_stmt for visiting an Ast::LoxBlockStmt node
• Method BackEnd::Engine#before_block_stmt creates an new enclosed Environment
• Method BackEnd::Engine#after_block_stmt close enclosed Environment and make parent Environment the current one

Changed

• File README.md updated.

[0.0.24] - 2021-01-20

• The interpreter implements the assignment of variables.

Added

• Class Ast::LoxAssignExpr a node that represents the assignment of a value to a variable
• Method Ast::ASTBuilder#reduce_assign_expr creates an Ast::LoxAssignExpr node
• Method Ast::ASTVisitor#visit_assign_expr for visiting an Ast::LoxAssignExpr node
• Method BackEnd::Engine#after_assign_expr implementation of the assignment
• Method BackEnd::Variable#assign to assign a value to a variable

[0.0.23] - 2021-01-20

• Fix for variables without explicit initialization.

Added

• Method Ast::ASTVisitor#visit_builtin for visiting Datatype::BuiltinDatatype value.
• Method BackEnd::Engine#before_visit_builtin push the data value onto the stack.

Fixed

• Method Ast::LoxVarStmt#initialize: in case no explicit value provided then use Datatype::Nil.instanceinstead of Ruby nil

[0.0.22] - 2021-01-17

• The interpreter can retrieve the value of a variable.

Added

• Method Ast::ASTBuilder#declaration_plus_more and Ast::ASTBuilder#declaration_plus_end to allow multiple expressions/statements
• Method Ast::ASTBuilder#reduce_var_expression creates an Ast::LoxVariableExpr node
• Method Ast::ASTVisitor#visit_var_expr for visiting Ast::LoxVariableExpr nodes
• Class Ast::LoxSeqDecl a node that represents a sequence of declarations/statements
• Class Ast::LoxVarExpr a node that represents a variable occurrence in an expression
• Method Engine::after_variable_expr: retrieve the value of variable with given name

Changed

• Method Ast::ASTBuilder#reduce_lox_program to support multiple statements/declarations
• File README.md updated.

[0.0.21] - 2021-01-16

• The interpreter supports the declaration global variables.

Added

• Class BackEnd::Entry, mixin module for objects put in the symbol table
• Class BackEnd::Environment that keeps track of variables in a given context.
• Class BackEnd::SymbolTable that keeps track of environments.
• Class BackEnd::Variable internal representation of a Lox variable
• Method Ast::ASTBuilder#reduce_var_declaration and Ast::ASTBuilder#reduce_var_declaration
• Method Ast::ASTVisitor#visit_var_stmt for visiting LoxVarStmt nodes
• Attribute Engine::symbol_tablefor keeping track of variables
• Method Engine::after_var_stmt for the implementation of variable declarations

[0.0.20] - 2021-01-15

• The interpreter supports the if ... else statement.

Added

• Class Ast::LoxItStmt, AST node specific for if else statements
• Method Ast::ASTBuilder#reduce_if_stmt as semantic action for if ... else
• Method Ast::ASTVisitor#visit_if_stmt for visiting LoxIfStmt nodes
• Method Engine::after_if_stmt implementation of the control flow

[0.0.19] - 2021-01-14

• The interpreter supports expressions between parentheses (grouping).

Added

• Class Ast::LoxLogicalExpr
• Method Ast::ASTBuilder#reduce_grouping_expr as semantic action for grouping expression
• Method Ast::ASTVisitor#visit_grouping_expr for visiting grouping expressions
• Method Engine::after_grouping_exprfor the evaluation of grouping expressions

Changed

• File grammar.rb rules for if ... else were given names in order to activate semantic actions.
• File README.md updated with little if ... else documentation.

[0.0.18] - 2021-01-13

• The interpreter can evaluate and, orexpressions.

Added

• Class Ast::LoxLogicalExpr
• Method Ast::ASTBuilder#reduce_logical_expr for the semantic action require for and, or
• Method Ast::ASTVisitor#visit_logical_expr for visiting logical expressions
• Method Backend::Engine#after_logical_expr implements the evaluation of the logical expressions

[0.0.17] - 2021-01-12

• The interpreter can evaluate all arithmetic and comparison operations.
• It implements ==, != and the unary operations !, -

Added

• Class Ast::LoxUnaryExpr
• Method Ast::ASTBuilder#reduce_unary_expr to support the evaluation of ! and `-@
• Method Ast::ASTVisitor#visit_unnary_expr for visiting unary expressions
• Method Backend::Engine#after_unary_expr evaluating an unary expression
• In class Datatype::BuiltinDatatype the methods falsey?, truthy?, !, !=
• In class Datatype::Numberthe methods <, <=, ´>´, >= and -@

Changed

• File README.md updated.

[0.0.16] - 2021-01-11

• The interpreter can evaluate product and division of two numbers.
• It also implements equality == and inequality != operators

Added

• Method Datatype::False#== for equality testing
• Method Datatype::False#!= for inequality testing
• Method Datatype::LXString#== for equality testing
• Method Datatype::LXString#!= for inequality testing
• Method Datatype::Nil#== for equality testing
• Method Datatype::Nil#!= for inequality testing
• Method Datatype::Number#== for equality testing
• Method Datatype::Number#!= for inequality testing
• Method Datatype::Number#* for multiply operator
• Method Datatype::Number#/ for divide operator
• Method Datatype::True#== for equality testing
• Method Datatype::True#!= for inequality testing

Changed

• Method BackEnd::Engine#after_binary_expr to allow *, /, ==, != operators
• File README.md updated for the newly implemented operators

[0.0.15] - 2021-01-11

• The interpreter can evaluate substraction between two numbers.

Added

• Method Datatype::Number#- implementing the subtraction operation

Changed

• File README.md minor editorial changes.
• File lx_string_spec.rb Added test for string concatenation
• File number_spec.rb Added tests for addition and subtraction operations
• File interpreter_spec.rb Added tests for subtraction operation

[0.0.14] - 2021-01-10

• The interpreter can evaluate addition of numbers and string concatenation

Added

• Method Ast::ASTVisitor#visit_binary_expr for visiting binary expressions
• Method Ast::LoxBinaryExpr#accept for visitor pattern
• Method BackEnd::Engine#after_binary_expr to trigger execution of binary operator
• Boolean class hierarchy: added methos true? and false? to ease spec test writing
• Method Datatype::LXString#+ implementation of the string concatenation
• Method Datatype::Number#+ implementation of the addition of numbers

Changed

• File interpreter_spec.rb Added tests for addition operation and string concatenation

[0.0.13] - 2021-01-10

• The interpreter can evaluate directly simple literals.

Changed

• Class AST::ASTBuilder added reduce_exprStmt to support the evaluation of literals.
• File README.md added one more example.
• File parser_spec.rb Updated the tests to reflect the change in the AST.
• File interpreter_spec.rb Added a test for literal expression.

Fixed

• File loxxy.rb: shorthand method lox_true referenced the ... false object (oops).

[0.0.12] - 2021-01-09

• Initial interpreter capable of evaluating a tiny subset of Lox language.

Added

• Class AST::LoxNoopExpr
• Class AST::LoxPrintStmt
• Class BackEnd::Engine implementation of the print statement logic
• Class Interpreter

Changed

• Class Ast::ASTVisitor Added visit method
• File README.md added Hello world example.

[0.0.11] - 2021-01-08

• AST node generation for logical expression (and, or).

Changed

• Class AST::ASTBuilder added reduce_ methods for logical operations.
• File grammar.rbadded name to logical expression rules
• File README.md added gem version and license badges, expanded roadmap section.

Fixed

• File grammar.rb: a rule had incomplete non-terminal name conjunct_ in its lhs.

[0.0.10] - 2021-01-08

• AST node generation for equality expression.

Changed

• Class AST::ASTBuilder refactoring and added reduce_ methods for equality operations.
• File grammar.rbadded name to equality rules
• File README.md added gem version and license badges, expanded roadmap section.

Fixed

• File grammar.rb: a rule had still the discarded non-terminal equalityTest_star in its lhs.

[0.0.9] - 2021-01-07

• AST node generation for comparison expression.

Changed

• Class AST::ASTBuilder added reduce_ methods for comparison operations.
• File grammar.rbadded name to comparison rules

[0.0.8] - 2021-01-07

• AST node generation for arithmetic operations of number literals.

Changed

• Class AST::ASTBuilder added reduce_ methods for arithmetic operations.
• File grammar.rbadded name to arithmetic rules

Fixed

• File grammar.rb: second rule for factor had a missing member in rhs.

[0.0.7] - 2021-01-06

• Lox grammar reworked, initial AST classes created.

Added

• Class Parser this one generates AST's (Abstract Syntax Tree)
• Class AST::ASTVisitor draft initial implementation.
• Class AST::BinaryExpr draft initial implementation.
• Class AST::LoxCompoundExpr draft initial implementation.
• Class AST::LiteralExpr draft initial implementation.
• Class AST::LoxNode draft initial implementation.

Changed

• File spec_helper.rb: removed Bundler dependency
• Class AST::ASTBuilder added initial reduce_ methods.
• File README.md Removed example with AST generation since this is in flux.

[0.0.6] - 2021-01-03

• First iteration of a parser with AST generation.

Added

• Class Parser this one generates AST's (Abstract Syntax Tree)
• Class AST::ASTBuilder default code to generate an AST.

Changed

• File spec_helper.rb: removed Bundler dependency
• File README.md Added example with AST visualization.

Fixed

• File grammar.rb ensure that the constant Grammar is created once only.

[0.0.5] - 2021-01-02

• Improved example in README.md, code re-styling to please Rubocop 1.7

Changed

• Code re-styling to please Rubocop 1.7
• File README.md Improved example with better parse tree visualization.

[0.0.4] - 2021-01-01

• A first parser implementation able to parse Lox source code.

Added

• Method LXString::== equality operator.

Changed

• class Parser renamed to RawParser
• File README.md Added an example showing the use of RawParser class.

[0.0.3] - 2020-12-29

• Scanner can recognize strings and nil tokens ### Added
• class Datatype::Nil for representing nil tokens in Lox
• class Datatype::LXString for representing Lox strings

Changed

• Method BuilinDatatype::validated_value now accepts the input value as is.
• Frontend::Scanner updated code to recognize strings and nil
• File scanner_spec.rb Added tests for strings, nil scanning

[0.0.2] - 2020-12-28

• Scanner can recognize keywords, boolean and numbers ### Added
• Datatype module and classes

Changed

• Frontend::Scanner updated code to recognize booleans and numbers
• File scanner_spec.rb Added tests for keywords, booleans and number scanning
• File README.md fixed a couple of typos.

[0.0.1] - 2020-12-27

Added

• Initial Github commit