source-academy / py-slang / 39113123161

88%

push

github

full e-stepper: the core of the engine, and the decisions for it (first slice of #557) (#578)

* full e-stepper: the core of the engine (values, operators, scoping, the machine, a text trace), and the decisions for it in the design note

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

* full e-stepper: fix the five findings of the Codex review

- a subscript assignment evaluates the right-hand side before the object and the index
- an augmented subscript assignment reads the element before it evaluates the right-hand side
- invalid nonlocal and global declarations are reported before anything runs
- a free variable search stops at an enclosing function that declares the name global
- huge ints compare correctly with infinities

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

* full e-stepper: declaration order, code point order of strings, and a note on is

- global and nonlocal after a use or an assignment of the name are reported before anything runs
- strings compare by code point, as Python does
- the design note says that is on numbers and strings compares values

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

* full e-stepper: oversized ranges, duplicate parameters, and bindings of statements that do not run yet

- a range longer than an index is an OverflowError (list, len, min, +=); one longer than 10 million is a MemoryError instead of being built
- a duplicate parameter name is a SyntaxError before anything runs
- unpacking, imports, classes, with, except clauses and del decide which names are local, even though the engine does not run them yet

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

* full e-stepper: huge ints in traces, long appends, powers with infinite exponents, repeat counts

- a trace shows an int of more than 4300 digits in short form; only str, repr and print refuse it
- appending or repeating long lists no longer spreads them into push
- float powers follow the C library for inf... (continued)

6933 of 8361 branches covered (82.92%)

Branch coverage included in aggregate %.

1390 of 1433 new or added lines in 11 files covered. (97.0%)

14312 of 15864 relevant lines covered (90.22%)

236335.38 hits per line