c.2: various improvememts, fix new tests

[asarhaddon]

• Define MalType as a pointer type, instead of an alias for a struct. It is now possible to declare it constant.
• Use macros to avoid lots of code duplication.
• Avoid redundant tests when possible.
• Avoid implicit signed/unsigned conversions.
• Use the const modifier whenever possible.
• Move private forward declarations from .h to .c, and forward declarations on the top of the .c.

Makefile:
enable more warnings avoid recompiling each .o for each step fix .PHONY usage

core.c:
Link mal_list/vector/hash_map directly to make_*. Move mal_readline from stepA (reallocate with GC).

• • • /: exactly two arguments. =: without memory allocation, stop comparing functions and closures. Stop assuming that nil contains a valid list(first/rest/get). throw: the argument should never be an exception. vec: refuse maps. seq: fix allocation of single character-strings.

core.h:
Represent the namespace as a static array instead of a linked list.

list:

• Avoid reversals, either by modifying the last link or simply by inserting elements in the right order,
• Avoid void*, the benefit of genericity here is small compared to the benefits of type checking.
• Store a pointer to nil as default metadata, instead of NULL.

env:

• Implement with binary trees. This is easy for a mutable structure, and helps a lot the performance of accessing REPL keys.
• move repeated calls to env_set to steps.

maps:

• Check type of map keys.
• Remove the confusing in-place mutations.

printer:
Replace most string allocations with idiomatic printf-style specifiers.

reader:
Rewrite without intermediate tokenizer. Propagate more errors. Merge list/vector/hasmap handling.

run:
does not need bash.

steps:

• reduce diff between steps.
• Add an env_apply helper, reducing duplication.
• Merge regularise_parameters into eval_fnstar (propagating errors was a burden compared to the benefit).
• Use the same function for eval_vector, eval_hashmap and apply arguments. Return an error directly, not a list containing an error.
• Rewrite quasiquote, fixing some misplaced unquotes.
• Clarify return value of TCO helpers.
• Report errors during startup.

types:

• Try to merge type selection and value extraction, for concision and safety.
• In the union, use one name per type (mal_string/keyword/symbol were confused in several places anyway).
• Represent atoms as a double pointer, and macros with a type.
• Prefer enums to macros.
• Represent function parameters as a static array instead of a linked list.

[asarhaddon]

Reducing the allocations has no visible effect on performances. On the other hand, the change of implementation for the REPL environment multiplies the performance score by 4.