v2.33.0 (5 September 2023)

• Added tuple types to the language (#1100)
• The following deprecations have been turned into errors this version:
  • The old array syntax, e.g. int arr[5];. Use array[5] int arr; instead.
  • Distribution functions ending in _log. Use either _lpdf or _lpmf.
  • The functions binomial_coefficient_log, multiply_log, and cov_exp_quad. Use lchoose, lmultiply, and gp_exp_quad_cov respectively.
  • The if_else function. Use the ternary operator cond ? true_value : false_value
  • Use of CDFs with a , between the first and second argument. Use a |.
  • Comments beginning with #. Use //.
  • Use of <- for assignment. Use =.
  • The increment_log_prob function. Use the target += statement.
  • The get_lp() function. Use target().
  • The use of nested multi-indices on the left hand side of an assignment statement.
    For this version, these can all be automatically updated with the --canonicalize=deprecations argument to the autoformatter. This is not guaranteed to work for versions following this one.
    Additionally, the following identifiers are now reserved words: array, offset, multiplier, lower, and upper.
    (#1287)
• Exposed vectorized signatures for log_sum_exp (#1344)
• Exposed new functions qr, qr_thin, eigendecompose_sym, eigendecompose, complex_schur_decompose, svd, and csr_extract. (#1346)
• Added a log_prob_impl specialization specifically for reverse mode to improve code generation (#1327)
• Fixed an issue where returning array literals could produce the wrong types in C++. (#1335)
• Fixed an issue with leading zeroes in real literals like 0E0 (#1336)
• Fixed a bug with type promotion in the arguments to user-defined distributions generating bad C++. (#1338)
• Fixed optimization logic for deducing whether mixes of scalars, data matrices, and autodiff matrices can be promoted to SoA (#1347)
• Fixed an issue with the partial evaluator crashing on statements containing a mod-by-zero. (#1351)
• --filename-in-msg now also affects the name of the file shown in runtime exceptions. Useful for interfaces which use mangled or temporary names during compilation. (#1339)
• Improved error message provided when the wrong return type is returned from a function.
  Return statements now follow the same type promotion rules as assignment and function argument passing.
  The typechecker now allows infinite loops (while (1) without an internal break) to be the end of a returning function. Previously, an (unreachable) return statement was needed following the loop.
  (#1341)
• Improved error messages for unsupported type in reduce_sum (#1332)
• Improved error messages when using a reserved word as a variable name. (#1343)

v2.33.0-rc1 (22 August 2023)

Tagging v2.33.0-rc1

v2.32.2 (15 May 2023)

• Fixed an issue in Stan, see release notes.

v2.32.1 (2 May 2023)

• The shapes and sizes of parameter initial values are now checked against the specified sizes in the model before being read in, matching the existing behavior for data. (#1316)
  Note: This change may cause existing code which worked "by accident" to raise new errors about mismatches between the model's declarations and the provided initialization.
• Errors in transform_inits should now properly highlight the location in the original Stan program. (#1318)
• Fixed an issue where the --debug-generate-inits debug flag would fail badly if parameter sizes depended on data (#1319)

v2.32.0 (20 April 2023)

• Syntax removals scheduled for this version have been pushed back to 2.33. We still recommend updating your Stan models as you are able. As a reminder, deprecated syntax which will be removed in minor versions can as a rule be updated automatically using find-and-replace tools or the Stan compiler's auto-formatting abilities. (#1303)
• The deprecated --include_paths and --allow_undefined arguments have been removed, use --include-paths and --allow-undefined. (#1303)
• Recursive user-defined functions no longer need forward declarations. (#1277)
• Added overloads to eigenvalues and eigenvectors which accept a complex matrix as input. (#1282)
• Fixed an issue where profile blocks could generate uncompilable C++ when used with --O1. (#1281)
• Fixed an issue where the compiler would generate uncompilable C++ when a matrix expression featured mixed types of elements. (#1292)
• Fixed an issue where a user-defined-function expecting real arguments could be passed an integer and exhibit integer behavior like truncating division. (#1296)
• Fixed an issue where external functions could not be used in higher-order functions without the end-user supplying an implementation of our functor structs. (#1298)
• Fixed a bug in transform_inits for models which used complex types (#1305)
• Improved the error shown when an #included file cannot be found to list the paths it searched on. (#1273)
• Improved --filename-in-msg for the command line version of stanc. Errors now use the requested name, not just warnings. (#1274)
• Refactored how C++ is code-generated in the compiler. (#1233)
• Added tests for various parts of the C++ backend which weren't previously tested, and added a --debug-lir flag to print out the C++ representation in a s-expression. (#1276)
• Updated code generate of get_param_names (#1245)
• Switched to std::endl instead of '\n' to end prints. (#1301)
• Added a new function unconstrain_array to the generated code. This is currently not exposed. (#1305)
• Added a --debug-generate-inits flag to stanc which behaves like --debug-generate-data but for declarations in the parameters block. (#1306)
• Sped up some code which is critical to parsing. (#1302)

v2.32.0-rc1 (10 April 2023)

Run make format, dune promote

v2.31.0 (21 November 2022)

• Improved the error message for bad multiple declarations. (#1239)
• Fixed a bug where using a C++ reserved word as a name in certain situations would prevent compilation. (#1243)
• Build binaries in parallel on Jenkins. (#1244)
• Added functions complex_schur_decompose_t() and complex_schur_decompose_u() implementing the complex-valued Schur decomposition for matrices.(#1247)
• Vectorized the conj function for complex types.(#1253)
• CI change, build backwards-compatible Mac executables on flatiron mac. (#1255)
• Improved the error generated when a function is re-declared, or when a function is not given a definition. (#1256)
• print and reject will now be listed as functions in stanc --infos output. (#1257)
• Added quantile functions (inverse-CDFs) std_normal_qf and std_normal_log_qf. std_normal_qf is a synonym for inv_Phi, and std_normal_log_qf is the same but with the input on the log-scale.(#1258)
• Fix using reject() with container types. (#1261)
• Vectorized sampling statements can now be used with the truncation syntax T[ , ](#1263)
• Functions which return integer types are considered as "data" for purposes of data-only arguments.(#1265)
• The negation operator - can now accept arrays, e.g. array[N] int foo = {...}; print(-foo);(#1266)
• Exposes algebraic functions with a variadic arguments, using the following four functions: solve_powell, solve_powell_tol, solve_newton and solve_newton_tol. Relevant changes to Stan-math are already merged.(#1268)

v2.31.0-rc1 (8 November 2022)

Tagging v2.31.0-rc1

v2.30.1 (27 July 2022)

• Improved the pedantic mode warning for parameters without priors. The message now highlights when it is safe to ignore it.
• Fixed a bug in the memory pattern optimization where a for loop generated for the function inliner would prevent detection of for loops higher in the control flow graph.
• Fixed an issue with the function inliner when a function local variable had the same name as a variable in the calling scope.
• Fixed an issue where recursive functions which called themselves with a slice of their arguments would lead to infinite template expansion in C++ compilation.
• Fixed a bug in stanc.js where the stanc flags were not listed correctly in the generated C++.
• The imaginary components of complex vectors and matrices are now initialized to NaN to match the real component and behaviour of non-complex vectors and matrices.

v2.30.0 (1 July 2022)

Complex:

• Added complex containers: complex_matrix, complex_vector, and complex_row_vector with basic arithmetic support. (#1133)
• Fixed indexing of a complex container to return the correct type. (#1158)
• Added many common linear algebra functions and container operations for complex types. (#1166)
• Fixed an issue reading in complex_matrix in the data block. (#1168)
• Added vectorized signatures for get_real and get_imag, e.g. get_real(complex_matrix) => matrix. (#1169)
• Added fft, inv_fft, fft2, and inv_fft2 to the language. (#1170)
• pow (and subsequently the ^ operator) now have overloads for complex containers. (#1186)
• to_complex is now vectorized. This means signatures like to_complex(matrix, matrix) => complex_matrix are now available. (#1208)
• Added signatures for addition, subtraction and division which mix scalars and complex vector types, broadcasting the scalar as appropriate. (#1212)
• Added svd_U, svd_V, singular_values, eigenvalues_sym, and eigenvectors_sym for complex inputs. (#1212)

New functions:

• Added L1 and L2 norms. (#1140)
• Added log_determinant_spd which is faster when the input matrix is known to be symmetric and positive definite. (#1178)
• Added wishart_cholesky_lpdf and wishart_cholesky_rng distribution functions. (#1188)
• Added multi_student_t_cholesky_lpdf and multi_student_t_cholesky_rng distribution functions. (#1197)
• Added inv_wishart_cholesky_lpdf and inv_wishart_cholesky_rng distribution functions. (#1202)
• Exposes inv_inc_beta. (#1211)

Misc:

• Re-enabled function inlining optimizations at O1. (#1097)
• Modified the optimizer to turn statements like 3 + 4i into to_complex(3,4) directly. (#1112)
• Added cumulative_sum(Vector/RowVector) for var<Matrix> types. (#1152)
• Improved compile times by accumulating all template requirements into a single require_all_t on user defined functions. (#1157)
• The --info and --debug-generate-data commands now use the Yojson library for it's output. (#1161, #1175)
• Bugfixed for output values in write_array that should be NaN. (#1165)
• --dump-stan-math-signatures now prints an entire signature on one line, no matter how long it is. (#1167)
• Fix --debug-generate-data for ordered vector data types. (#1173)
• Exposed an overload for cumulative_sum which takes and returns an array of integers. (#1174)
• The javascript interface (stancjs) now generates errors which look more like stanc3's by pointing out where in the supplied code the error occurred. (#1177)
• Cleaned up the internal structuring of modules in the compiler. (#1179)
• Cleaned up code for pretty printing the Middle Intermediate Representation (MIR). (#1180)
• Added --debug-mem-patterns flag, which will print out the memory type of variables (either Array of Structs or the more efficient Struct of Arrays pattern) when optimization is enabled. (#1185)
• Allowed the adding of new distributions without requiring them to support deprecated suffixes. (#1191)
• Added eigenvectors and eigenvalues functions which return the complex-valued eigenvectors or eigenvalues of a real (asymmetrix) matrix. (#1192)
• abs is now vectorized for container types. fabs is now deprecated, as all usages can be replaced with abs thanks to array promotion rules. (#1195)
• Made installing the developer tools for the Stanc repository an interactive script with error handling. (#1200)
• Internally clean up how variable declarations are represented. (#1203)
• Simplified internal representations in the compiler. (#1204)
• The pretty-printer now preserves multiple declarations in one line like int a, b; rather than splitting them into two declarations. (#1207)
• Declarations are now allowed in places they previously would not parse, such as the only statement in the body of an if statement. (#1207)
• ./, / .*, and * now have consistent behavior with scalar arguments. (#1209)