RELEASE-NOTES.txt

STANC3 RELEASE NOTES
======================================================================

v2.27.0 (2 June 2021)
======================================================================

 - Added the `--info` argument to output a list of functions and distributions used.(#813)
 - Added `ode_ckrk` and `ode_ckrk_tol` to the Stan language.(#828)
 - Cleaned up indexing by using variadic rvalue and assign functions.(#829)
 - Fixed incorrect codegen for mixed-type array expressions.(#830)
 - Added building ARM to our infrastructure.(#832, #833)
 - Made locations_array constexpr and moved curr_statement__ to function scope.(#842, #845)
 - Added range checks.(#849, #521)
 - Consolidated the use of | in cdf functions to match lpdf/lpmf and lccdf functions. Comma version of cdf function is deprecated.(#863)
 - Adds signatures for data-only quantile functions.(#870)
 - Cleanup readability of the C++.(#871)
 - Adds vectorized versions of `fma()`.(#888)
 - Fixed optimizer crash on divide-by-zero expressions.(#891)
 - Added clearing of read/write events for global matrix_cls.(#897)
 - Added  `ode_adjoint_tol_ctl` and improved type printing with variadic ODEs.(#900)

v2.26.1 (15 February 2021)
======================================================================

- Fixed issue with not allowing user-defined _lp functions with a void return type in transformed parameters block.

v2.26.0 (26 January 2021)
======================================================================

 - Added deprecated functions warnings to regular use, and replace in canonicalizer.(#726)
 - Added a small readme for dockerfiles usage locally.(#738)
 - Added `matrix chol2inv(matrix)`.(#740)
 - Added a Github Actions job to build binaries.(#747)
 - Modified code-generation for user-defined functions to accept Eigen expressions.(#752)
 - Added OpenCL support for: bernoulli_lpmf, bernoulli_logit_lpmf, beta_lpdf, beta_proportion_lpdf, binomial_lpmf, cauchy_lpdf, chi_square_lpdf, double_exponential_lpdf, exp_mod_normal_lpdf, exponential_lpdf, frechet_lpdf, gamma_lpdf, gumbel_lpdf, inv_chi_square_lpdf, inv_gamma_lpdf, logistic_lpdf, lognormal_lpdf, neg_binomial_lpmf, neg_binomial_2_lpmf, neg_binomial_2_log_lpmf, normal_lpdf, pareto_lpdf, pareto_type_2_lpdf, poisson_lpmf, poisson_log_lpmf, rayleigh_lpdf, scaled_inv_chi_square_lpdf, skew_normal_lpdf, std_normal_lpdf, student_t_lpdf, uniform_lpdf, weibull_lpdf
 - Allowed `write_array()`, `log_prob()`, and `transform_inits()` to avoid a vector copy and read/write(#761)
 - Added the discrete_range distribution.(#763)
 - Use Eigen comma initializer to avoid copy in vector construction.(#766)
 - Allowed calling lp functions in transformed parameters block.(#767)
 - Fixed multi-dim indexing bug.(#768)
 - Moved the reported location of parsing errors closer to the problematic section.(#771)
 - Fixed a optimization bug in handling of unnormalized distributions.(#778)
 - Added profiling to the Stan language.(#794)
 - Added `linspaced_int_array()`(#796)

v2.25.0 (26 October 2020)
======================================================================

- Improved parser error message on missing semicolon in the data or parameters block.
- Expanded OpenCL (GPU) support for GLMs to now handle parameters for any argument.
- Fix parameter unconstraining bug when the constraints depend on other constrained parameters.
- "offset, "multiplier," "lower," and "upper" are no longer reserved keywords and can be used in the names of identifiers.
- Extended `elt_multiply` (`.*`) and `elt_divide` (`./`) to cases where both inputs are scalars.
- Added support for unnormalized distributions for the `target +=` sytnax.
- Changed the MIR to represent function declarations as Options.
- Variable names are now allowed that shadow math function names.
- Fixed a bug with not recognizing transformed parameters in pedantic mode
- Added vectorised binary functions:
    - bessel_first_kind
    - beta
    - binary_log_loss
    - binomial_coefficient_log
    - choose
    - falling_factorial
    - fdim
    - fmax
    - fmin
    - fmod
    - gamma_p
    - gamma_q
    - hypot
    - lbeta
    - ldexp
    - lmgamma
    - log_diff_exp
    - log_falling_factorial
    - log_inv_logit_diff
    - log_modified_bessel_first_kind
    - log_rising_factorial
    - modified_bessel_first_kind
    - modified_bessel_second_kind
    - lmultiply
    - multiply_log
    - owens_t
    - rising_factorial

Code contributions were made by @andrjohns @nhuurre @rok-cesnovar @rybern and @seantalts 

v2.24.1 (11 August 2020)
======================================================================

Bugfixes:

- added using std::pow to generated code
- fixed code generation for pow()
- added data quantifier to linspaced_* signatures
- fixed code generation for empty matrices

v2.24.0 (28 July 2020)
======================================================================

New functions: 
   `algebra_solver_newton`

   `matrix hmm_hidden_state_prob(matrix, matrix, vector)`
   `int[] hmm_latent_rng(matrix, matrix, vector)`
   `real hmm_marginal(matrix, matrix, vector)`
    
   `T lambert_w0(T)`, for any T
   `T lambert_w1(T)`, for any T
    
   `matrix matrix_power(matrix, int)`
   
   `real multinomial_logit_log(int[], vector)`
   `real multinomial_logit_lpmf(int[], vector)`
   `int[] multinomial_logit_rng(vector, int)`
    
   `ode_adams`, `ode_adams_tol`
   `ode_bdf`, `ode_bdf_tol`
   `ode_rk45`, `ode_rk45_tol`

   `T pow(int, T)`
   `T pow(real, T)`
   `T pow(T, int)`
   `T pow(T, real) `
    (previously only real pow(real, real) was available)

   `T reverse(T)`, where T is vector, row_vector or an array of any type
   
   `matrix identity_matrix(int)`
   `real[] linspaced_array(int, real, real); row_vector linspaced_row_vector(int, real, real); vector linspaced_vector(int, real, real)`
   `int[] one_hot_int_array(int, int); real[] one_hot_array(int, int); row_vector one_hot_row_vector(int, int); vector one_hot_vector(int, int)`
   `int[] ones_int_array(int); real[] ones_array(int); row_vector ones_row_vector(int); vector ones_vector(int)`
   `vector uniform_simplex(int)`
   `int[] zeros_int_array(int); real[] zeros_array(int); row_vector zeros_row_vector(int); vector zeros_vector(int)`


New features:

- pedantic mode
- experimental optimization mode
- new integer division operator `%/%`
- non-scalar values are now allowed in lower, upper, offset and multiplier
- integrate_ode_* functions are now deprecated
- data-only restricted functions now work with parameters in generated quantities
- improved out-of-bounds messages for vectors, matrices
- added checks for invalid literals
- `--allow_undefined` and `--include_paths` are deprecated in favor of `--allow-undefined` and `--include-paths`
- cleaned up the generated model C++ code: model is now final, using statements instead of typedef, better use of inline, use of `.clear()` instead of `.resize(0)`, remove unnecessary functions
- cleaned up the OCaml code: better use of helper functions, removed duplicate functions, better exception messages, replace imperative code for handling Stan Math signatures
- size expressions for parameters and generated quantities are now only evaluated once
- better handle model names that are not C++ friendly (start with numbers, have non-alphanumeric characters)

Bugfixes:
- changed the loop index type to int to prevent issues when using it in expressions with signed numbers
- integer arrays now initialize to the smallest representable integer
- var arrays initialize with a prebuilt dummy var, to not creat new varis
- all map_rect calls are registered when using MPI
- _lpdf/_lpmf functions are now used instead of *_log when generating code for the tilde statements
- single argument distribution do not require the vertical bar anymore (e.g. std_normal_lpdf(x|))
- fixed a bug that caused tilde statements to conflict with userdef functions
- rng functions are no longer allowed in size declarations
- fixed the _lpdf functor struct so that UDF with _log and int argument now compile
- fixed array literal type-checking 
- fixed the error messages for missing input (line number is now displayed properly)
- fixed indexing in transform_init()
- fixed emitting generated quantities only (for gq_writer)
- fixed debug data generator for constrained matrix types and added array value bounds