lix -

Age	Commit message (Collapse)	Author
2022-04-26	Don't pass Symbol by reference	Eelco Dolstra
	Since Symbol is just an integer, passing it by const reference is never advantageous.
2022-04-25	rename SymbolIdx -> Symbol, Symbol -> SymbolStr	pennae
	after #6218 `Symbol` no longer confers a uniqueness invariant on the string it wraps, it is now possible to create multiple symbols that compare equal but whose string contents have different addresses. this guarantee is now only provided by `SymbolIdx`, leaving `Symbol` only as a string wrapper that knows about the intricacies of how symbols need to be formatted for output. this change renames `SymbolIdx` to `Symbol` to restore the previous semantics of `Symbol` to that name. we also keep the wrapper type and rename it to `SymbolStr` instead of returning plain strings from lookups into the symbol table because symbols are formatted for output in many places. theoretically we do not need `SymbolStr`, only a function that formats a string for output as a symbol, but having to wrap every symbol that appears in a message into eg `formatSymbol()` is error-prone and inconvient.
2022-04-21	store Symbols in a table as well, like positions	pennae
	this slightly increases the amount of memory used for any given symbol, but this increase is more than made up for if the symbol is referenced more than once in the EvalState that holds it. on average every symbol should be referenced at least twice (once to introduce a binding, once to use it), so we expect no increase in memory on average. symbol tables are limited to 2³² entries like position tables, and similar arguments apply to why overflow is not likely: 2³² symbols would require as many string instances (at 24 bytes each) and map entries (at 24 bytes or more each, assuming that the map holds on average at most one item per bucket as the docs say). a full symbol table would require at least 192GB of memory just for symbols, which is well out of reach. (an ofborg eval of nixpks today creates less than a million symbols!)
2022-04-21	replace most Pos objects/ptrs with indexes into a position table	pennae
	Pos objects are somewhat wasteful as they duplicate the origin file name and input type for each object. on files that produce more than one Pos when parsed this a sizeable waste of memory (one pointer per Pos). the same goes for ptr<Pos> on 64 bit machines: parsing enough source to require 8 bytes to locate a position would need at least 8GB of input and 64GB of expression memory. it's not likely that we'll hit that any time soon, so we can use a uint32_t index to locate positions instead.
2022-01-04	Remove EvalState::mkAttrs()	Eelco Dolstra

2022-01-04	Move empty attrset optimisation	Eelco Dolstra

2022-01-04	Ensure that attrsets are sorted	Eelco Dolstra
	Previously you had to remember to call value->attrs->sort() after populating value->attrs. Now there is a BindingsBuilder helper that wraps Bindings and ensures that sort() is called before you can use it.
2020-12-18	Replace Value type setters with mk* functions	Silvan Mosberger
	Move clearValue inside Value mkInt instead of setInt mkBool instead of setBool mkString instead of setString mkPath instead of setPath mkNull instead of setNull mkAttrs instead of setAttrs mkList instead of setList* mkThunk instead of setThunk mkApp instead of setApp mkLambda instead of setLambda mkBlackhole instead of setBlackhole mkPrimOp instead of setPrimOp mkPrimOpApp instead of setPrimOpApp mkExternal instead of setExternal mkFloat instead of setFloat Add note that the static mk* function should be removed eventually
2020-12-12	Introduce Value type setters and make use of them	Silvan Mosberger

2020-03-24	EvalState::allocAttr(): Add convenience method	Eelco Dolstra
	(cherry picked from commit c02da997570ac0d9b595d787bea8cb5a4e3cc1f5)
2018-06-12	Remove duplicate definition of allocBytes()	Eelco Dolstra

2018-05-02	Fix some random -Wconversion warnings	Eelco Dolstra

2018-02-17	libexpr: Rely on Boehm returning zeroed memory in EvalState::allocEnv()	Tuomas Tynkkynen
	Boehm guarantees that memory returned by GC_malloc() is zeroed, so take advantage of that.
2015-07-23	Optimize empty sets	Eelco Dolstra
	This reduces the number of Bindings allocations by about 10%.
2015-07-14	Move attribute set data structures into their own header file.	Nicolas B. Pierron
	This modification moves Attr and Bindings structures into their own header file which is dedicated to the attribute set representation. The goal of to isolate pieces of code which are related to the attribute set representation. Thus future modifications of the attribute set representation will only have to modify these files, and not every other file across the evaluator.