[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::Function implementation of a function object.

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