$Version¶

Status: Stable

documented, exercised by the test suite and/or worked examples, with no known limitations recorded.

Description¶

$Version

gives a string describing the version of Mathilda, including the versions of the libraries it was built against.

Examples (4)¶

Every input below was run against the current Mathilda build and its output recorded.

Basic examples (2)¶

In[1]:= $VersionNumber
Out[1]= 0.46

In[2]:= $Version
Out[2]= "Mathilda 0.460 (GCC 16.1.0, GMP 6.3.0, MPFR 4.2.2, FLINT 3.6.0, ECM 7.0.7, Raylib 5.5, Accelerate, Readline)"

Applications (2)¶

A descriptive string, not a number

In[3]:= StringQ[$Version]
Out[3]= True

Its head is String

In[4]:= Head[$Version]
Out[4]= String

Implementation notes¶

What it is / where defined. $Version is a read-only system constant, bound as an OwnValue in system_constants_init (src/core.c) via register_system_constant("$Version", expr_new_string(mathilda_version())) and then marked ATTR_PROTECTED. Its value is an EXPR_STRING.

Its value. The string is produced by mathilda_version() (src/version.c) and assembled entirely at compile time: "Mathilda " MATHILDA_VERSION_STRING " (<compiler>, GMP ..., MPFR ..., FLINT ..., ...)". MATHILDA_VERSION_STRING lives in src/version.h as the textual twin of MATHILDA_VERSION_NUMBER (the two are kept in sync by hand), and the library versions come from each library's own preprocessor macros — so the string names exactly what this binary was linked against. The pointer refers to static storage and is never freed.

Evaluation behaviour. Being an OwnValue, $Version evaluates to its string in a single step and, being Protected, cannot be reassigned. The exact text changes every release, so a stable check queries it structurally (StringQ[$Version]) rather than against a literal.

Attributes: Protected.

References¶

See also: $VersionNumber, Real

The descriptive string is assembled in src/version.c from MATHILDA_VERSION_STRING (src/version.h) and each linked library's own version macros.
Source: src/core.c
Specification: docs/spec/builtins/expression-information.md

Notes & additional examples¶

Notes¶

$Version is a read-only Protected OwnValue holding a descriptive string, e.g. "Mathilda 0.266 (<compiler>, GMP ..., MPFR ..., FLINT ..., ...)", assembled at compile time from MATHILDA_VERSION_STRING and each linked library's own version macros — so it names exactly what this binary was built against. The numeric release is $VersionNumber.

The exact text changes every release, so the examples check it structurally rather than against a literal.