2017-11-04 01:01:59 +00:00
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|
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//: make some recipes more friendly by trying to auto-convert their ingredients to text
|
2016-03-21 00:00:48 +00:00
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|
5001 - drop the :(scenario) DSL
I've been saying for a while[1][2][3] that adding extra abstractions makes
things harder for newcomers, and adding new notations doubly so. And then
I notice this DSL in my own backyard. Makes me feel like a hypocrite.
[1] https://news.ycombinator.com/item?id=13565743#13570092
[2] https://lobste.rs/s/to8wpr/configuration_files_are_canary_warning
[3] https://lobste.rs/s/mdmcdi/little_languages_by_jon_bentley_1986#c_3miuf2
The implementation of the DSL was also highly hacky:
a) It was happening in the tangle/ tool, but was utterly unrelated to tangling
layers.
b) There were several persnickety constraints on the different kinds of
lines and the specific order they were expected in. I kept finding bugs
where the translator would silently do the wrong thing. Or the error messages
sucked, and readers may be stuck looking at the generated code to figure
out what happened. Fixing error messages would require a lot more code,
which is one of my arguments against DSLs in the first place: they may
be easy to implement, but they're hard to design to go with the grain of
the underlying platform. They require lots of iteration. Is that effort
worth prioritizing in this project?
On the other hand, the DSL did make at least some readers' life easier,
the ones who weren't immediately put off by having to learn a strange syntax.
There were fewer quotes to parse, fewer backslash escapes.
Anyway, since there are also people who dislike having to put up with strange
syntaxes, we'll call that consideration a wash and tear this DSL out.
---
This commit was sheer drudgery. Hopefully it won't need to be redone with
a new DSL because I grow sick of backslashes.
2019-03-13 01:56:55 +00:00
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|
void test_rewrite_stashes_to_text() {
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|
transform(
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"def main [\n"
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" local-scope\n"
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" n:num <- copy 34\n"
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" stash n\n"
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"]\n"
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);
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CHECK_TRACE_CONTENTS(
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"transform: {stash_2_0: (\"address\" \"array\" \"character\")} <- to-text-line {n: \"number\"}\n"
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"transform: stash {stash_2_0: (\"address\" \"array\" \"character\")}\n"
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);
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}
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void test_rewrite_traces_to_text() {
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transform(
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"def main [\n"
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" local-scope\n"
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" n:num <- copy 34\n"
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" trace 2, [app], n\n"
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"]\n"
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);
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CHECK_TRACE_CONTENTS(
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"transform: {trace_2_2: (\"address\" \"array\" \"character\")} <- to-text-line {n: \"number\"}\n"
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"transform: trace {2: \"literal\"}, {\"app\": \"literal-string\"}, {trace_2_2: (\"address\" \"array\" \"character\")}\n"
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);
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}
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2016-07-24 08:52:36 +00:00
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2016-03-21 09:53:34 +00:00
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//: special case: rewrite attempts to stash contents of most arrays to avoid
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//: passing addresses around
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5001 - drop the :(scenario) DSL
I've been saying for a while[1][2][3] that adding extra abstractions makes
things harder for newcomers, and adding new notations doubly so. And then
I notice this DSL in my own backyard. Makes me feel like a hypocrite.
[1] https://news.ycombinator.com/item?id=13565743#13570092
[2] https://lobste.rs/s/to8wpr/configuration_files_are_canary_warning
[3] https://lobste.rs/s/mdmcdi/little_languages_by_jon_bentley_1986#c_3miuf2
The implementation of the DSL was also highly hacky:
a) It was happening in the tangle/ tool, but was utterly unrelated to tangling
layers.
b) There were several persnickety constraints on the different kinds of
lines and the specific order they were expected in. I kept finding bugs
where the translator would silently do the wrong thing. Or the error messages
sucked, and readers may be stuck looking at the generated code to figure
out what happened. Fixing error messages would require a lot more code,
which is one of my arguments against DSLs in the first place: they may
be easy to implement, but they're hard to design to go with the grain of
the underlying platform. They require lots of iteration. Is that effort
worth prioritizing in this project?
On the other hand, the DSL did make at least some readers' life easier,
the ones who weren't immediately put off by having to learn a strange syntax.
There were fewer quotes to parse, fewer backslash escapes.
Anyway, since there are also people who dislike having to put up with strange
syntaxes, we'll call that consideration a wash and tear this DSL out.
---
This commit was sheer drudgery. Hopefully it won't need to be redone with
a new DSL because I grow sick of backslashes.
2019-03-13 01:56:55 +00:00
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void test_rewrite_stashes_of_arrays() {
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transform(
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"def main [\n"
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" local-scope\n"
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" n:&:@:num <- new number:type, 3\n"
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" stash *n\n"
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"]\n"
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);
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CHECK_TRACE_CONTENTS(
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"transform: {stash_2_0: (\"address\" \"array\" \"character\")} <- array-to-text-line {n: (\"address\" \"array\" \"number\")}\n"
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"transform: stash {stash_2_0: (\"address\" \"array\" \"character\")}\n"
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);
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}
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void test_ignore_stashes_of_static_arrays() {
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transform(
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"def main [\n"
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" local-scope\n"
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" n:@:num:3 <- create-array\n"
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" stash n\n"
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"]\n"
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);
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CHECK_TRACE_CONTENTS(
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"transform: stash {n: (\"array\" \"number\" \"3\")}\n"
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);
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}
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void test_rewrite_stashes_of_recipe_header_products() {
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transform(
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"container foo [\n"
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" x:num\n"
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"]\n"
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"def bar -> x:foo [\n"
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" local-scope\n"
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" load-ingredients\n"
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" x <- merge 34\n"
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" stash x\n"
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"]\n"
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);
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CHECK_TRACE_CONTENTS(
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"transform: stash {stash_2_0: (\"address\" \"array\" \"character\")}\n"
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);
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}
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2016-07-24 22:04:41 +00:00
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//: misplaced; should be in instruction inserting/deleting transforms, but has
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//: prerequisites: deduce_types_from_header and check_or_set_types_by_name
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:(after "Transform.push_back(deduce_types_from_header)")
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2016-10-22 19:16:02 +00:00
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Transform.push_back(convert_ingredients_to_text); // idempotent
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2016-03-21 00:00:48 +00:00
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:(code)
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2016-10-22 23:10:23 +00:00
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void convert_ingredients_to_text(const recipe_ordinal r) {
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2016-03-21 00:00:48 +00:00
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recipe& caller = get(Recipe, r);
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2019-02-25 08:17:46 +00:00
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trace(101, "transform") << "--- convert some ingredients to text in recipe " << caller.name << end();
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2016-03-21 00:00:48 +00:00
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// in recipes without named locations, 'stash' is still not extensible
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if (contains_numeric_locations(caller)) return;
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2016-09-15 18:48:01 +00:00
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convert_ingredients_to_text(caller);
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2016-03-21 00:00:48 +00:00
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}
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2016-09-15 18:48:01 +00:00
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void convert_ingredients_to_text(recipe& caller) {
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2016-03-21 00:00:48 +00:00
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vector<instruction> new_instructions;
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2016-10-20 05:10:35 +00:00
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for (int i = 0; i < SIZE(caller.steps); ++i) {
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2016-03-21 00:00:48 +00:00
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instruction& inst = caller.steps.at(i);
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2016-09-15 20:46:13 +00:00
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// all these cases are getting hairy. how can we make this extensible?
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2016-03-21 00:00:48 +00:00
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if (inst.name == "stash") {
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2016-10-20 05:10:35 +00:00
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for (int j = 0; j < SIZE(inst.ingredients); ++j) {
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2016-09-17 06:52:15 +00:00
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if (is_literal_text(inst.ingredients.at(j))) continue;
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2016-03-21 00:00:48 +00:00
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ostringstream ingredient_name;
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2016-04-24 18:54:30 +00:00
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ingredient_name << "stash_" << i << '_' << j << ":address:array:character";
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2016-09-15 18:48:01 +00:00
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convert_ingredient_to_text(inst.ingredients.at(j), new_instructions, ingredient_name.str());
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2016-07-24 08:52:36 +00:00
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}
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}
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else if (inst.name == "trace") {
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2016-10-20 05:10:35 +00:00
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for (int j = /*skip*/2; j < SIZE(inst.ingredients); ++j) {
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2016-09-17 06:52:15 +00:00
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if (is_literal_text(inst.ingredients.at(j))) continue;
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2016-07-24 08:52:36 +00:00
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ostringstream ingredient_name;
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ingredient_name << "trace_" << i << '_' << j << ":address:array:character";
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2016-09-15 18:48:01 +00:00
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convert_ingredient_to_text(inst.ingredients.at(j), new_instructions, ingredient_name.str());
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2016-03-21 00:00:48 +00:00
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}
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}
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2017-02-07 08:25:27 +00:00
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else if (inst.name_before_rewrite == "append") {
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2016-09-15 20:46:13 +00:00
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// override only variants that try to append to a string
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// Beware: this hack restricts how much 'append' can be overridden. Any
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// new variants that match:
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// append _:text, ___
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// will never ever get used.
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2016-09-17 06:52:15 +00:00
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if (is_literal_text(inst.ingredients.at(0)) || is_mu_text(inst.ingredients.at(0))) {
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2016-11-26 06:17:39 +00:00
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for (int j = /*skip base*/1; j < SIZE(inst.ingredients); ++j) {
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2016-09-15 20:46:13 +00:00
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ostringstream ingredient_name;
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ingredient_name << "append_" << i << '_' << j << ":address:array:character";
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convert_ingredient_to_text(inst.ingredients.at(j), new_instructions, ingredient_name.str());
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}
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}
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}
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2019-02-25 08:17:46 +00:00
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trace(103, "transform") << to_string(inst) << end();
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2016-03-21 00:00:48 +00:00
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new_instructions.push_back(inst);
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}
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caller.steps.swap(new_instructions);
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}
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2016-03-21 00:04:52 +00:00
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2016-07-24 08:52:36 +00:00
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// add an instruction to convert reagent 'r' to text in list 'out', then
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// replace r with converted text
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2016-09-15 18:48:01 +00:00
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void convert_ingredient_to_text(reagent& r, vector<instruction>& out, const string& tmp_var) {
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2016-07-24 08:52:36 +00:00
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if (!r.type) return; // error; will be handled elsewhere
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2016-09-17 06:52:15 +00:00
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|
if (is_mu_text(r)) return;
|
2016-07-24 08:52:36 +00:00
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// don't try to extend static arrays
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|
if (is_static_array(r)) return;
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|
instruction def;
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|
if (is_lookup_of_address_of_array(r)) {
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2017-02-07 08:07:16 +00:00
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|
def.name = "array-to-text-line";
|
2016-07-24 08:52:36 +00:00
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reagent/*copy*/ tmp = r;
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drop_one_lookup(tmp);
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def.ingredients.push_back(tmp);
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}
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else {
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2017-02-07 08:07:16 +00:00
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def.name = "to-text-line";
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2016-07-24 08:52:36 +00:00
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def.ingredients.push_back(r);
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}
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def.products.push_back(reagent(tmp_var));
|
2019-02-25 08:17:46 +00:00
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|
trace(103, "transform") << to_string(def) << end();
|
2016-07-24 08:52:36 +00:00
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|
out.push_back(def);
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|
r.clear(); // reclaim old memory
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r = reagent(tmp_var);
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}
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|
2016-05-06 07:46:39 +00:00
|
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|
bool is_lookup_of_address_of_array(reagent/*copy*/ x) {
|
3309
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.
2016-09-10 01:32:52 +00:00
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|
|
if (x.type->atom) return false;
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|
|
|
if (x.type->left->name != "address") return false;
|
2016-03-21 09:53:34 +00:00
|
|
|
if (!canonize_type(x)) return false;
|
3309
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.
2016-09-10 01:32:52 +00:00
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return is_mu_array(x);
|
2016-03-21 09:53:34 +00:00
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|
}
|
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|
2016-05-06 07:46:39 +00:00
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bool is_static_array(const reagent& x) {
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2016-04-14 05:16:24 +00:00
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// no canonize_type()
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3309
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.
2016-09-10 01:32:52 +00:00
|
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return !x.type->atom && x.type->left->atom && x.type->left->name == "array";
|
2016-04-14 05:16:24 +00:00
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}
|
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4089
Clean up how we reclaim local scopes.
It used to work like this (commit 3216):
1. Update refcounts of products after every instruction, EXCEPT:
a) when instruction is a non-primitive and the callee starts with
'local-scope' (because it's already not decremented in 'return')
OR:
b) when instruction is primitive 'next-ingredient' or
'next-ingredient-without-typechecking', and its result is saved to a
variable in the default space (because it's already incremented at
the time of the call)
2. If a function starts with 'local-scope', force it to be reclaimed
before each return. However, since locals may be returned, *very
carefully* don't reclaim those. (See the logic in the old `escaping`
and `should_update_refcount` functions.)
However, this approach had issues. We needed two separate commands for
'local-scope' (reclaim locals on exit) and 'new-default-space'
(programmer takes charge of reclaiming locals). The hard-coded
reclamation duplicated refcounting logic. In addition to adding
complexity, this implementation failed to work if a function overwrites
default-space after setting up a local-scope (the old default-space is
leaked). It also fails in the presence of continuations. Calling a
continuation more than once was guaranteed to corrupt memory (commit
3986).
After this commit, reclaiming local scopes now works like this:
Update refcounts of products for every PRIMITIVE instruction.
For non-primitive instructions, all the work happens in the `return`
instruction:
increment refcount of ingredients to `return`
(unless -- one last bit of ugliness -- they aren't saved in the
caller)
decrement the refcount of the default-space
use existing infrastructure for reclaiming as necessary
if reclaiming default-space, first decrement refcount of each
local
again, use existing infrastructure for reclaiming as necessary
This commit (finally!) completes the bulk[1] of step 2 of the plan in
commit 3991. It was very hard until I gave up trying to tweak the
existing implementation and just test-drove layer 43 from scratch.
[1] There's still potential for memory corruption if we abuse
`default-space`. I should probably try to add warnings about that at
some point (todo in layer 45).
2017-10-23 06:14:19 +00:00
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//: Supporting 'append' above requires remembering what name an instruction
|
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//: had before any rewrites or transforms.
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:(before "End instruction Fields")
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string name_before_rewrite;
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:(before "End instruction Clear")
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name_before_rewrite.clear();
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:(before "End next_instruction(curr)")
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curr->name_before_rewrite = curr->name;
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5001 - drop the :(scenario) DSL
I've been saying for a while[1][2][3] that adding extra abstractions makes
things harder for newcomers, and adding new notations doubly so. And then
I notice this DSL in my own backyard. Makes me feel like a hypocrite.
[1] https://news.ycombinator.com/item?id=13565743#13570092
[2] https://lobste.rs/s/to8wpr/configuration_files_are_canary_warning
[3] https://lobste.rs/s/mdmcdi/little_languages_by_jon_bentley_1986#c_3miuf2
The implementation of the DSL was also highly hacky:
a) It was happening in the tangle/ tool, but was utterly unrelated to tangling
layers.
b) There were several persnickety constraints on the different kinds of
lines and the specific order they were expected in. I kept finding bugs
where the translator would silently do the wrong thing. Or the error messages
sucked, and readers may be stuck looking at the generated code to figure
out what happened. Fixing error messages would require a lot more code,
which is one of my arguments against DSLs in the first place: they may
be easy to implement, but they're hard to design to go with the grain of
the underlying platform. They require lots of iteration. Is that effort
worth prioritizing in this project?
On the other hand, the DSL did make at least some readers' life easier,
the ones who weren't immediately put off by having to learn a strange syntax.
There were fewer quotes to parse, fewer backslash escapes.
Anyway, since there are also people who dislike having to put up with strange
syntaxes, we'll call that consideration a wash and tear this DSL out.
---
This commit was sheer drudgery. Hopefully it won't need to be redone with
a new DSL because I grow sick of backslashes.
2019-03-13 01:56:55 +00:00
|
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|
:(code)
|
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|
void test_append_other_types_to_text() {
|
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|
run(
|
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|
"def main [\n"
|
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" local-scope\n"
|
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" n:num <- copy 11\n"
|
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|
" c:char <- copy 111/o\n"
|
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" a:text <- append [abc], 10, n, c\n"
|
|
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" expected:text <- new [abc1011o]\n"
|
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" 10:bool/raw <- equal a, expected\n"
|
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|
"]\n"
|
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|
|
);
|
|
|
|
}
|
2016-09-15 20:46:13 +00:00
|
|
|
|
2016-03-21 00:04:52 +00:00
|
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|
//: Make sure that the new system is strictly better than just the 'stash'
|
|
|
|
//: primitive by itself.
|
|
|
|
|
5001 - drop the :(scenario) DSL
I've been saying for a while[1][2][3] that adding extra abstractions makes
things harder for newcomers, and adding new notations doubly so. And then
I notice this DSL in my own backyard. Makes me feel like a hypocrite.
[1] https://news.ycombinator.com/item?id=13565743#13570092
[2] https://lobste.rs/s/to8wpr/configuration_files_are_canary_warning
[3] https://lobste.rs/s/mdmcdi/little_languages_by_jon_bentley_1986#c_3miuf2
The implementation of the DSL was also highly hacky:
a) It was happening in the tangle/ tool, but was utterly unrelated to tangling
layers.
b) There were several persnickety constraints on the different kinds of
lines and the specific order they were expected in. I kept finding bugs
where the translator would silently do the wrong thing. Or the error messages
sucked, and readers may be stuck looking at the generated code to figure
out what happened. Fixing error messages would require a lot more code,
which is one of my arguments against DSLs in the first place: they may
be easy to implement, but they're hard to design to go with the grain of
the underlying platform. They require lots of iteration. Is that effort
worth prioritizing in this project?
On the other hand, the DSL did make at least some readers' life easier,
the ones who weren't immediately put off by having to learn a strange syntax.
There were fewer quotes to parse, fewer backslash escapes.
Anyway, since there are also people who dislike having to put up with strange
syntaxes, we'll call that consideration a wash and tear this DSL out.
---
This commit was sheer drudgery. Hopefully it won't need to be redone with
a new DSL because I grow sick of backslashes.
2019-03-13 01:56:55 +00:00
|
|
|
void test_rewrite_stash_continues_to_fall_back_to_default_implementation() {
|
|
|
|
run(
|
|
|
|
// type without a to-text implementation
|
|
|
|
"container foo [\n"
|
|
|
|
" x:num\n"
|
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|
|
" y:num\n"
|
|
|
|
"]\n"
|
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|
|
"def main [\n"
|
|
|
|
" local-scope\n"
|
|
|
|
" x:foo <- merge 34, 35\n"
|
|
|
|
" stash x\n"
|
|
|
|
"]\n"
|
|
|
|
);
|
|
|
|
CHECK_TRACE_CONTENTS(
|
|
|
|
"app: 34 35\n"
|
|
|
|
);
|
|
|
|
}
|