dblock / excalc-rs / 36185105670

98%

push

github

Add user-defined functions with recursion support

name(params) := expr defines a function (e.g. f(x) := x^2 + 1), visible
to later statements the same way a variable assignment is, and listed
alongside variables by the REPL's vars command (showing the actual
definition, not a placeholder). Functions can call themselves or each
other; arguments are evaluated in the caller's scope (proper lexical
scoping). Since the language has no if/branching construct,
self-recursive calls can't stop at a computed base case, so runaway
recursion is caught by checking actual remaining stack space on every
nested call (via the stacker crate) and failing gracefully instead of
crashing with a native stack overflow. Function names can't collide
with built-ins or pi/e, and definitions are session-only, matching
variable persistence.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

294 of 310 new or added lines in 4 files covered. (94.84%)

5779 of 5901 relevant lines covered (97.93%)

142457.11 hits per line