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* 3344Kartik K. Agaram2016-09-123-6/+8
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* 3343Kartik K. Agaram2016-09-124-35/+54
| | | | | Reorganize layers a bit so I can add a couple of scenarios testing static dispatch *before* I add `stash` into the mix.
* 3342Kartik K. Agaram2016-09-121-1/+8
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* 3341Kartik K. Agaram2016-09-1215-35/+58
| | | | | | | Process type abbreviations in function headers. Still a couple of places where doing this causes strange errors. We'll track those down next.
* 3340Kartik K. Agaram2016-09-123-0/+0
| | | | | | | | Rename files to be consistent with my (forgotten) convention of always using underscores over hyphens. I'll leave server-socket.mu alone for now, since Stephen's hacking on it.
* 3339Kartik K. Agaram2016-09-122-1/+2
| | | | Fix a couple of failing example programs.
* 3338Kartik K. Agaram2016-09-1212-16/+41
| | | | Process type abbreviations in container definitions.
* 3337 - first use of type abbreviations: textKartik K. Agaram2016-09-1235-968/+971
| | | | | In the process I've uncover a couple of situations we don't support type abbreviations yet. They're next.
* 3336Kartik K. Agaram2016-09-111-4/+0
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* 3335Kartik K. Agaram2016-09-113-16/+26
| | | | | | | | Clean up rest of long-standing bit of ugliness. I'm growing more confident now that I can use layers to cleanly add any functionality I want. All I need is hook functions. No need to ever put '{' on their own line, or add arguments to calls.
* 3334Kartik K. Agaram2016-09-112-8/+6
| | | | Clean up one long-standing bit of ugliness.
* 3333Kartik K. Agaram2016-09-111-3/+0
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* 3332Kartik K. Agaram2016-09-111-2/+2
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* 3331Kartik K. Agaram2016-09-111-23/+26
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* 3330Kartik K. Agaram2016-09-111-0/+7
| | | | Fix CI #2: memory leaks.
* 3329Kartik K. Agaram2016-09-111-4/+4
| | | | Fix CI.
* 3328Kartik K. Agaram2016-09-111-1/+0
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* 3327Kartik K. Agaram2016-09-117-10/+9
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* 3326Kartik K. Agaram2016-09-111-0/+8
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* 3325Kartik K. Agaram2016-09-111-2/+14
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* 3324 - completely redo type abbreviationsKartik K. Agaram2016-09-115-81/+157
| | | | | | | | | | | | | | | | | | | | | | | | | The old approach with '&' and '@' modifiers turned out to be a bad idea because it introduces notions of precedence. Worse, it turns out you want different precedence rules at different times as the old test alluded: x:@number:3 # we want this to mean (address number 3) x:address:@number # we want this to mean (address array number) Instead we'll give up and focus on a single extensible mechanism that allows us to say this instead: x:@:number:3 x:address:@:number In addition it allows us to shorten other types as well: x:&:@:num type board = &:@:&:@:char # for tic-tac-toe Hmm, that last example reminds me that we don't handle abbreviations inside type abbreviation definitions so far..
* 3323 - Add simple network primitivesStephen Malina2016-09-112-0/+180
| | | | | | | | | | | | | | Includes four Mu functions: - $socket: Creates the C structure for a socket and tries to bind and listen on a user-provided port. - $accept: Returns a number pointer to a new socket session. Should be called with the result of $socket. - $read-from-socket: Read one character from the socket, passed in as a Mu number. Should only be called after calling $socket and $accept. - $close-socket: Takes two parameters, one for the result of $socket and one for the result of $accept, closing both sockets and releasing bound ports.
* 3322Kartik K. Agaram2016-09-111-2/+2
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* 3321Kartik K. Agaram2016-09-103-18/+34
| | | | | | | | | | | Clean up another case (after commit 3309) of premature support for shape-shifting recipes, where early layers had code without corresponding tests. One addendum to commit 3309: the proximal cause for triggering the rewrite of type_trees was that I realized to_string() and variants were lying to me while debugging; they couldn't distinguish between `(a . b)` and `((a) . b)`
* 3320Kartik K. Agaram2016-09-101-6/+14
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* 3319Kartik K. Agaram2016-09-101-2/+26
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* 3318Kartik K. Agaram2016-09-107-0/+144
| | | | Describe immutability checks in the Readme.
* 3317Kartik K. Agaram2016-09-101-4/+4
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* 3316Kartik K. Agaram2016-09-101-1/+2
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* 3315Kartik K. Agaram2016-09-1047-702/+1549
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* 3314Kartik K. Agaram2016-09-101-21/+25
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* 3313Kartik K. Agaram2016-09-103-14/+89
| | | | | | | Allow type-trees to be ordered in some consistent fashion. This could be quite inefficient since we often end up comparing the four sub-trees of the two arguments in 4 different ways. So far it isn't much of a time sink.
* 3312Kartik K. Agaram2016-09-102-4/+7
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* 3311Kartik K. Agaram2016-09-101-1/+0
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* 3310Kartik K. Agaram2016-09-101-1/+2
| | | | | Turns out the slowdown reported in 3309 was almost entirely due to commit 3305: supporting extremely small floating point numbers.
* 3309Kartik K. Agaram2016-09-0931-488/+1104
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Rip out everything to fix one failing unit test (commit 3290; type abbreviations). This commit does several things at once that I couldn't come up with a clean way to unpack: A. It moves to a new representation for type trees without changing the actual definition of the `type_tree` struct. B. It adds unit tests for our type metadata precomputation, so that errors there show up early and in a simpler setting rather than dying when we try to load Mu code. C. It fixes a bug, guarding against infinite loops when precomputing metadata for recursive shape-shifting containers. To do this it uses a dumb way of comparing type_trees, comparing their string representations instead. That is likely incredibly inefficient. Perhaps due to C, this commit has made Mu incredibly slow. Running all tests for the core and the edit/ app now takes 6.5 minutes rather than 3.5 minutes. == more notes and details I've been struggling for the past week now to back out of a bad design decision, a premature optimization from the early days: storing atoms directly in the 'value' slot of a cons cell rather than creating a special 'atom' cons cell and storing it on the 'left' slot. In other words, if a cons cell looks like this: o / | \ left val right ..then the type_tree (a b c) used to look like this (before this commit): o | \ a o | \ b o | \ c null ..rather than like this 'classic' approach to s-expressions which never mixes val and right (which is what we now have): o / \ o o | / \ a o o | / \ b o null | c The old approach made several operations more complicated, most recently the act of replacing a (possibly atom/leaf) sub-tree with another. That was the final straw that got me to realize the contortions I was going through to save a few type_tree nodes (cons cells). Switching to the new approach was hard partly because I've been using the old approach for so long and type_tree manipulations had pervaded everything. Another issue I ran into was the realization that my layers were not cleanly separated. Key parts of early layers (precomputing type metadata) existed purely for far later ones (shape-shifting types). Layers I got repeatedly stuck at: 1. the transform for precomputing type sizes (layer 30) 2. type-checks on merge instructions (layer 31) 3. the transform for precomputing address offsets in types (layer 36) 4. replace operations in supporting shape-shifting recipes (layer 55) After much thrashing I finally noticed that it wasn't the entirety of these layers that was giving me trouble, but just the type metadata precomputation, which had bugs that weren't manifesting until 30 layers later. Or, worse, when loading .mu files before any tests had had a chance to run. A common failure mode was running into types at run time that I hadn't precomputed metadata for at transform time. Digging into these bugs got me to realize that what I had before wasn't really very good, but a half-assed heuristic approach that did a whole lot of extra work precomputing metadata for utterly meaningless types like `((address number) 3)` which just happened to be part of a larger type like `(array (address number) 3)`. So, I redid it all. I switched the representation of types (because the old representation made unit tests difficult to retrofit) and added unit tests to the metadata precomputation. I also made layer 30 only do the minimal metadata precomputation it needs for the concepts introduced until then. In the process, I also made the precomputation more correct than before, and added hooks in the right place so that I could augment the logic when I introduced shape-shifting containers. == lessons learned There's several levels of hygiene when it comes to layers: 1. Every layer introduces precisely what it needs and in the simplest way possible. If I was building an app until just that layer, nothing would seem over-engineered. 2. Some layers are fore-shadowing features in future layers. Sometimes this is ok. For example, layer 10 foreshadows containers and arrays and so on without actually supporting them. That is a net win because it lets me lay out the core of Mu's data structures out in one place. But if the fore-shadowing gets too complex things get nasty. Not least because it can be hard to write unit tests for features before you provide the plumbing to visualize and manipulate them. 3. A layer is introducing features that are tested only in later layers. 4. A layer is introducing features with tests that are invalidated in later layers. (This I knew from early on to be an obviously horrendous idea.) Summary: avoid Level 2 (foreshadowing layers) as much as possible. Tolerate it indefinitely for small things where the code stays simple over time, but become strict again when things start to get more complex. Level 3 is mostly a net lose, but sometimes it can be expedient (a real case of the usually grossly over-applied term "technical debt"), and it's better than the conventional baseline of no layers and no scenarios. Just clean it up as soon as possible. Definitely avoid layer 4 at any time. == minor lessons Avoid unit tests for trivial things, write scenarios in context as much as possible. But within those margins unit tests are fine. Just introduce them before any scenarios (commit 3297). Reorganizing layers can be easy. Just merge layers for starters! Punt on resplitting them in some new way until you've gotten them to work. This is the wisdom of Refactoring: small steps. What made it hard was not wanting to merge *everything* between layer 30 and 55. The eventual insight was realizing I just need to move those two full-strength transforms and nothing else.
* 3308Kartik K. Agaram2016-09-091-55/+11
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* 3307Kartik K. Agaram2016-09-093-5/+10
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* 3306 - better error messages when mixing up screen/consoleKartik K. Agaram2016-09-081-0/+38
| | | | Thanks Ella Couch for finding this.
* 3305 - show all available precision in numbersKartik K. Agaram2016-09-082-1/+3
| | | | | | | | | | | | | | | Thanks Ella Couch for pointing out that Mu was lying when debugging small numbers. def main [ local-scope x:number <- copy 1 { x <- divide x, 2 $print x, 10/newline loop # until SIGFPE } ]
* 3304Kartik K. Agaram2016-09-072-6/+6
| | | | | | Highlight a couple of places where it turns out that we're flying by the seat of our pants with heuristics, and we don't really understand how to precompute metadata for a program's types.
* 3303Kartik K. Agaram2016-09-071-1/+1
| | | | Correction for syntax highlighting.
* 3302Kartik K. Agaram2016-09-072-2/+2
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* 3301Kartik K. Agaram2016-09-061-5/+5
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* 3300Kartik K. Agaram2016-09-062-1/+4
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* 3299Kartik K. Agaram2016-09-051-1/+1
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* 3298Kartik K. Agaram2016-09-051-15/+0
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* 3297 - run unit tests before scenariosKartik K. Agaram2016-09-052-0/+20
| | | | | | | | | | | | | | I've been putting up for some time with the tension between wanting to show scenarios at the top of the layer even if I want to *run* any unit tests of sub-components introduced within the layer before them. Turned out to be an easy fix. We don't have very many of these, and the unit tests in the early layers don't compete with any scenarios, so I don't need to mess with them. But this is a key tool in my toolkit, to be able to decouple presentation order from run order for tests. Though now the separate compilation units are again unbalanced; sigh.
* 3296Kartik K. Agaram2016-09-041-1/+1
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* 3295Kartik K. Agaram2016-09-041-1/+1
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