. - mu - Soul of a tiny new machine. More thorough tests → More comprehensible and rewrite-friendly software → More resilient society.

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author	Kartik Agaram <vc@akkartik.com>	2021-06-26 08:39:05 -0700
committer	Kartik Agaram <vc@akkartik.com>	2021-06-26 08:39:05 -0700
commit	f7a7db83eff079d0494ded92fd73403d23a55538 (patch)
tree	eb0b73c5dc76261ee1495dab7680169aaa7805f9 /html/ex4.mu.html
parent	718fd031f9e7a60f092c830ed547f5e461fb66ec (diff)
download	mu-f7a7db83eff079d0494ded92fd73403d23a55538.tar.gz

Drop some long-obsolete tooling. I no longer use iTerm2.

Diffstat (limited to 'html/ex4.mu.html')

0 files changed, 0 insertions, 0 deletions

# Wrappers around file system primitives that take a 'resources' object and # are thus easier to test. # # - start-reading - asynchronously open a file, returning a channel source for # receiving the results # - start-writing - asynchronously open a file, returning a channel sink for # the data to write # - slurp - synchronously read from a file # - dump - synchronously write to a file container resources [ lock:bool data:&:@:resource ] container resource [ name:text contents:text ] def start-reading resources:&:resources, filename:text -> contents:&:source:char, error?:bool [ local-scope load-inputs error? <- copy false { break-unless resources # fake file system contents, error? <- start-reading-from-fake-resource resources, filename return } # real file system file:num <- $open-file-for-reading filename return-unless file, null/no-contents, true/error contents:&:source:char, sink:&:sink:char <- new-channel 30 start-running receive-from-file file, sink ] def slurp resources:&:resources, filename:text -> contents:text, error?:bool [ local-scope load-inputs source:&:source:char, error?:bool <- start-reading resources, filename return-if error?, null/no-contents buf:&:buffer:char <- new-buffer 30/capacity { c:char, done?:bool, source <- read source break-if done? buf <- append buf, c loop } contents <- buffer-to-array buf ] def start-reading-from-fake-resource resources:&:resources, resource:text -> contents:&:source:char, error?:bool [ local-scope load-inputs error? <- copy false i:num <- copy 0 data:&:@:resource <- get *resources, data:offset len:num <- length *data { done?:bool <- greater-or-equal i, len break-if done? tmp:resource <- index *data, i i <- add i, 1 curr-resource:text <- get tmp, name:offset found?:bool <- equal resource, curr-resource loop-unless found? contents:&:source:char, sink:&:sink:char <- new-channel 30 curr-contents:text <- get tmp, contents:offset start-running receive-from-text curr-contents, sink return } return null/no-such-resource, true/error-found ] def receive-from-file file:num, sink:&:sink:char -> sink:&:sink:char [ local-scope load-inputs { c:char, eof?:bool <- $read-from-file file break-if eof? sink <- write sink, c loop } sink <- close sink file <- $close-file file ] def receive-from-text contents:text, sink:&:sink:char -> sink:&:sink:char [ local-scope load-inputs i:num <- copy 0 len:num <- length *contents { done?:bool <- greater-or-equal i, len break-if done? c:char <- index *contents, i sink <- write sink, c i <- add i, 1 loop } sink <- close sink ] def start-writing resources:&:resources, filename:text -> sink:&:sink:char, routine-id:num, error?:bool [ local-scope load-inputs error? <- copy false source:&:source:char, sink:&:sink:char <- new-channel 30 { break-unless resources # fake file system routine-id <- start-running transmit-to-fake-resource resources, filename, source return } # real file system file:num <- $open-file-for-writing filename return-unless file, null/sink, 0/routine-id, true/error { break-if file msg:text <- append [no such file: ] filename assert file, msg } routine-id <- start-running transmit-to-file file, source ] def dump resources:&:resources, filename:text, contents:text -> resources:&:resources, error?:bool [ local-scope load-inputs # todo: really create an empty file return-unless contents, resources, false/no-error sink-file:&:sink:char, write-routine:num, error?:bool <- start-writing resources, filename return-if error? i:num <- copy 0 len:num <- length *contents { done?:bool <- greater-or-equal i, len break-if done? c:char <- index *contents, i sink-file <- write sink-file, c i <- add i, 1 loop } close sink-file # make sure to wait for the file to be actually written to disk # (Mu practices structured concurrency: http://250bpm.com/blog:71) wait-for-routine write-routine ] def transmit-to-file file:num, source:&:source:char -> source:&:source:char [ local-scope load-inputs { c:char, done?:bool, source <- read source break-if done? $write-to-file file, c loop } file <- $close-file file ] def transmit-to-fake-resource resources:&:resources, filename:text, source:&:source:char -> resources:&:resources, source:&:source:char [ local-scope load-inputs lock:location <- get-location *resources, lock:offset wait-for-reset-then-set lock # compute new file contents buf:&:buffer:char <- new-buffer 30 { c:char, done?:bool, source <- read source break-if done? buf <- append buf, c loop } contents:text <- buffer-to-array buf new-resource:resource <- merge filename, contents # write to resources curr-filename:text <- copy null data:&:@:resource <- get *resources, data:offset # replace file contents if it already exists i:num <- copy 0 len:num <- length *data { done?:bool <- greater-or-equal i, len break-if done? tmp:resource <- index *data, i curr-filename <- get tmp, name:offset found?:bool <- equal filename, curr-filename { break-unless found? put-index *data, i, new-resource jump +unlock-and-exit } i <- add i, 1 loop } # if file didn't already exist, make room for it new-len:num <- add len, 1 new-data:&:@:resource <- new resource:type, new-len put *resources, data:offset, new-data # copy over old files i:num <- copy 0 { done?:bool <- greater-or-equal i, len break-if done? tmp:resource <- index *data, i put-index *new-data, i, tmp } # write new file put-index *new-data, len, new-resource +unlock-and-exit reset lock ]


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