diff --git a/.drone.yml b/.drone.yml index 90b928b..452f163 100644 --- a/.drone.yml +++ b/.drone.yml @@ -29,18 +29,7 @@ steps: - java -jar /drone/lib/spt/org.metaborg.spt.cmd/target/org.metaborg.spt.cmd* -l . -s /drone/lib/spt/org.metaborg.meta.lang.spt -t tests - mkdir -p lib - curl -o lib/sunshine.jar -L 'http://artifacts.metaborg.org/service/local/artifact/maven/redirect?r=snapshots&g=org.metaborg&a=org.metaborg.sunshine2&v=LATEST' - - name: setup_gen - image: gcc - volumes: - - name: m2 - path: /root/.m2 - commands: - - git clone https://github.com/facebook/nailgun.git - - cd nailgun - - make - - cd ../bin - - ln -s ../nailgun/nailgun-client/target/ng . - - cd .. + - bin/fosgen tests/emit_sum.fos - name: extract_tests image: xonsh/xonsh commands: @@ -52,8 +41,7 @@ steps: path: /drone/lib - name: m2 path: /root/.m2 - commands: # Note we first make sure that fosgen is working - - bin/fosgen -d tests/emit_sum.fos + commands: - bin/generate_test_code - name: python_tests image: python:slim @@ -67,13 +55,6 @@ steps: image: haskell commands: - bin/run_tests runghc hs - - name: ocaml_tests - image: ocaml/opam - commands: - - ls -als tests/extracted - - opam init - - eval $(opam env) - - bin/run_tests ocaml ml volumes: - name: lib diff --git a/.gitignore b/.gitignore index 35e6d95..80a4a3c 100644 --- a/.gitignore +++ b/.gitignore @@ -12,16 +12,10 @@ .pydevproject -a.out - *.aterm /site -bin/ng tests/extracted/* tests/*.js tests/*.py tests/*.hs -tests/*.ml -tests/*.cmi -tests/*.cmo adhoc* diff --git a/README.md b/README.md index 0df4cba..010be66 100644 --- a/README.md +++ b/README.md @@ -8,13 +8,9 @@ dimensions. So I embarked on this project to see if I could produce as comfortable a language as possible to work in, given that I inevitably will be doing a -bunch of coding. The language will be centrally organized around the -concept of "streams" (somewhat in the spirit of -[streem](https://github.com/matz/streem) and/or -[Orc](http://orc.csres.utexas.edu/index.shtml), or to a lesser extent, -[Sisal-is](https://github.com/parsifal-47/sisal-is)). In fact all higher-type -entities will be cast in terms of streams, or in slogan form, "++f++unctions -and (binary) ++o++perators are ++str++eams" (hence the name "fostr"). +bunch of coding. The language will be +organized around (unary) ++f++unctions, (binary) ++o++perators, and +(nullary) ++str++eams, hence the name "fostr". Other guiding principles: @@ -28,9 +24,11 @@ Other guiding principles: the language design from the ground up, it can be kept both effective and natural. -* fostr code uses streams (and their specializations to functions and - operators) all the time, so they are first-class entities that are easy - to create, pass around, compose, etc. +* Code uses functions all the time. So needless to say, functions should be + first-class entities that are exceptionally easy to create, pass around, + etc. + +* And true to the name, operators and streams should be just as easy to handle. * Try to keep the constructs available as simple to reason about as possible, and practical to use. So side effects are OK, and it should be clear when diff --git a/bin/extract_tests.xsh b/bin/extract_tests.xsh index 422acb1..40ead93 100644 --- a/bin/extract_tests.xsh +++ b/bin/extract_tests.xsh @@ -13,35 +13,22 @@ DESTINATION = 'tests/extracted' # Extension for extracted files: EXT = 'fos' -# Extension for desired input: -INP = 'in' - # Extension for expectations: EXP = 'expect' for path in TEST_LIST: destdir = pf"{DESTINATION}/{path.stem}" mkdir -p @(destdir) - chmod ugo+rwx @(destdir) contents = path.read_text() tests = re.split(r'test\s*(.+?)\s*\[\[.*?\n', contents)[1:] testit = iter(tests) for name, details in zip(testit, testit): - pfm = re.search(r'\n\s*\]\][\s\S]*?parse\s*fails', details) - if pfm: continue # skip examples that don't parse - ntfm = re.search(r'\n\s*\]\].*?don.t.test', details) - if ntfm: continue # explicit skip - em = re.search(r'\n\]\]', details) + em = re.search(r'\n\s*\]\]', details) if not em: continue - example = details[:em.start()+1].replace('[[','').replace(']]','') + example = details[:em.start()+1] expath = destdir / f"{name}.{EXT}" expath.write_text(example) echo Wrote @(expath) - im = re.search(r'/\*\*\s+accepts.*?\n([\s\S]*?)\*\*/', details[em.end():]) - if im: - ipath = destdir / f"{name}.{INP}" - ipath.write_text(im[1]) - echo " ...and" @(ipath) xm = re.search(r'/\*\*\s+writes.*?\n([\s\S]*?)\*\*/', details[em.end():]) if xm: xpath = destdir / f"{name}.{EXP}" diff --git a/bin/fosgen b/bin/fosgen index b03656b..c5af48b 100755 --- a/bin/fosgen +++ b/bin/fosgen @@ -5,7 +5,6 @@ erro() { printf "%s\n" "$*" >&2; } ##### Set defaults: SUPPRESS_ERR=YES -USE_NAILGUN=YES LANGUAGE=Python ##### Extract command line options: @@ -15,23 +14,18 @@ do -h|--help) echo echo "Usage:" - echo " fosgen [-d] [-j] [-l LANGUAGE] FILE" + echo " fosgen [-d] [-l LANGUAGE] FILE" echo echo "Writes to standard output the code generated from the fostr" echo "program in FILE, targeting the specified LANGUAGE (which" echo "defaults to Python)." echo echo "The -d option writes diagnostic output to standard error." - echo "The -j option uses the Spoofax Sunshine JAR directly, rather" - echo "than via nailgun." exit ;; -d) SUPPRESS_ERR='' ;; - -j) - USE_NAILGUN='' - ;; -l) shift LANGUAGE="$1" @@ -73,17 +67,5 @@ then exec 2>/dev/null fi -if [[ $USE_NAILGUN ]] -then - if [[ $SUPPRESS_ERR ]] - then - $BINDIR/let_sun_shine - else - $BINDIR/let_sun_shine noisy - fi - $BINDIR/ng sunshine transform -p $PROJDIR -n $LANGUAGE -i $PROGRAM - exit $? -fi - java -jar $SUNJAR transform -p $PROJDIR -l $PROJDIR -l $MVN_REPO -n $LANGUAGE -i $PROGRAM exit $? diff --git a/bin/generate_test_code b/bin/generate_test_code index 0d151a8..2c443d6 100755 --- a/bin/generate_test_code +++ b/bin/generate_test_code @@ -4,7 +4,7 @@ failed=0 for dir in tests/extracted/*; do for file in $dir/*.fos; do - for language in Python Javascript Haskell OCaml; do + for language in Python Javascript Haskell; do echo bin/fosgen -l ${language%.*} $file ... bin/fosgen -l $language $file if [[ $? -ne 0 ]]; then diff --git a/bin/let_sun_shine b/bin/let_sun_shine deleted file mode 100755 index cb3c67a..0000000 --- a/bin/let_sun_shine +++ /dev/null @@ -1,40 +0,0 @@ -#!/bin/bash - -# Helper for fosgen, not intended to be used directly -# With an argument, print diagnostic output - -BINDIR=$(dirname $BASH_SOURCE) - -if $BINDIR/ng sunshine --help -then - if [[ $1 ]] - then - echo "sun already shining." - fi -else - if [[ $1 ]] - then - echo "disperse the clouds." - fi - SUNJAR="$BINDIR/../lib/sunshine.jar" - PROJDIR="$BINDIR/.." - if [[ ! $MVN_REPO ]]; then - MVN_REPO="$HOME/.m2/repository" - fi - if [[ ! -d $MVN_REPO ]]; then - MVN_REPO="/root/.m2/repository" - fi - if [[ ! -d $MVN_REPO ]]; then - echo "Cannot find your Maven repository. Please set environment variable" - echo "MVN_REPO to its full path and re-run." - exit 1 - fi - if [[ $1 ]] - then - java -jar $SUNJAR server & - else - java -jar $SUNJAR server >/dev/null 2>&1 & - fi - sleep 5 - $BINDIR/ng sunshine load -l $PROJDIR -l $MVN_REPO -fi diff --git a/bin/run_tests b/bin/run_tests index da49485..90ccaa7 100755 --- a/bin/run_tests +++ b/bin/run_tests @@ -9,14 +9,8 @@ diffed=0 for dir in tests/extracted/*; do for file in $dir/*.$ext; do ((total++)) - if [[ -f ${file%.*}.in ]]; then - cat ${file%.*}.in | $command $file > $file.out - result=$? - else - $command $file > $file.out - result=$? - fi - if [[ $result -ne 0 ]]; then + $command $file > $file.out + if [[ $? -ne 0 ]]; then echo ERROR: $command $file failed. ((failed++)) else diff --git a/editor/Analysis.esv b/editor/Analysis.esv index eb3197f..0667f1e 100644 --- a/editor/Analysis.esv +++ b/editor/Analysis.esv @@ -22,4 +22,3 @@ menus action: "Show pre-analyzed AST" = debug-show-pre-analyzed (source) action: "Show analyzed AST" = debug-show-analyzed - action: "Show analyzed type" = debug-show-type diff --git a/editor/Generation.esv b/editor/Generation.esv index 9e5051c..3d71fe2 100644 --- a/editor/Generation.esv +++ b/editor/Generation.esv @@ -4,4 +4,3 @@ menus action: "Python" = to-python action: "Javascript" = to-javascript action: "Haskell" = to-haskell - action: "OCaml" = to-ocaml diff --git a/editor/Syntax.esv b/editor/Syntax.esv index 7b732a1..e8e0e23 100644 --- a/editor/Syntax.esv +++ b/editor/Syntax.esv @@ -8,7 +8,7 @@ imports language table : target/metaborg/sdf.tbl - start symbols : Start + start symbols : Ex line comment : "//" block comment : "/*" * "*/" @@ -20,7 +20,6 @@ menus action: "Format" = editor-format (source) action: "Show parsed AST" = debug-show-aterm (source) - action: "Desugar AST" = debug-desugar-fostr (source) views diff --git a/metaborg.yaml b/metaborg.yaml index 0b9c842..b1f5407 100644 --- a/metaborg.yaml +++ b/metaborg.yaml @@ -19,7 +19,6 @@ language: sdf: pretty-print: fostr sdf2table: java - jsglr-version: layout-sensitive placeholder: prefix: "$" stratego: diff --git a/mkdocs.yml b/mkdocs.yml index c2d5242..6726b34 100644 --- a/mkdocs.yml +++ b/mkdocs.yml @@ -2,14 +2,13 @@ site_name: fostr language nav: - README.md - tests/basic.md -- trans/statics.md - implementation.md plugins: - search - semiliterate: ignore_folders: [target, lib] - exclude_extensions: ['.o', '.hi', '.cmi', '.cmo'] + exclude_extensions: ['.o', '.hi'] extract_standard_markdown: terminate: theme: diff --git a/signature/TYPE.str b/signature/TYPE.str deleted file mode 120000 index 332d8ef..0000000 --- a/signature/TYPE.str +++ /dev/null @@ -1 +0,0 @@ -TYPE.stx \ No newline at end of file diff --git a/signature/TYPE.stx b/signature/TYPE.stx deleted file mode 100644 index e299f8b..0000000 --- a/signature/TYPE.stx +++ /dev/null @@ -1,7 +0,0 @@ -module signature/TYPE -signature - sorts TYPE // semantic type - constructors - INT : TYPE - STRING : TYPE - STREAM : TYPE diff --git a/statics/util.stx b/statics/util.stx deleted file mode 100644 index 7ce94e7..0000000 --- a/statics/util.stx +++ /dev/null @@ -1,7 +0,0 @@ -module statics/util -imports signature/TYPE - -rules - lastTYPE : list(TYPE) -> TYPE - lastTYPE([T]) = T. - lastTYPE([U | TS]) = lastTYPE(TS). diff --git a/syntax/fostr.sdf3 b/syntax/fostr.sdf3 index f782466..b454b2f 100644 --- a/syntax/fostr.sdf3 +++ b/syntax/fostr.sdf3 @@ -6,59 +6,30 @@ imports context-free start-symbols - Start - -lexical sorts - - STRING_LITERAL - -lexical syntax - - STRING_LITERAL = "'"~[\']*"'" + Ex context-free sorts - Start LineSeq Line OptTermEx TermExLst TermEx Ex + Ex context-free syntax - Start.TopLevel = LineSeq - - LineSeq = Line - LineSeq.Sequence = sq:Line+ {layout(align-list sq)} - - Line = OptTermEx - Line.ISequence = TermExLst OptTermEx {layout(0.first.line == 1.first.line)} - - TermExLst.Prior = TermEx+ - - OptTermEx = ex:Ex {layout(offside ex)} - OptTermEx = te:TermEx {layout(offside te)} - - TermEx.Terminate = <;> - - Ex.Int = INT - Ex.LitString = STRING_LITERAL - Ex.EscString = STRING - Ex.Stream = - Ex.Sum = < + > {left} - Ex.Concat = < ++ > {left} - Ex.Gets = [[Ex] << [Ex]] {left} - Ex.DefGets = [<<< [Ex]] - Ex.To = [[Ex] >> [Ex]] {left} - Ex.DefTo = [[Ex] >>>] - Ex.Emits = <!> - Ex.DefEmits = - - Ex = <()> {bracket} + Ex.Int = INT + Ex.Stdio = + Ex.Sum = {Ex "+"}+ + Ex.Receives = [[Ex] << [Ex]] {left} + Ex.Enters = [[Ex] >> [Ex]] {left} + Ex = <()> {bracket} context-free priorities - Ex.To - > Ex.DefTo - > {Ex.Sum Ex.Concat} - > Ex.DefGets - > Ex.Gets, + Ex.Enters + > Ex.Sum + > Ex.Receives, // prevent cycle: no singletons - LineSeq.Sequence <0> .> Line+ = Line + Ex.Sum <0> .> {Ex "+"}+ = Ex, + + // flat: no Sum immediately in Sum: + {Ex "+"}+ = Ex <0> .> Ex.Sum, + {Ex "+"}+ = {Ex "+"}+ "+" Ex <2> .> Ex.Sum diff --git a/tests/basic.spt b/tests/basic.spt index 3d5a4a6..9b00d89 100644 --- a/tests/basic.spt +++ b/tests/basic.spt @@ -1,37 +1,20 @@ module basic language fostr -test hw1_type [[ -[[stream]] << [['Hello, world! ']] << [[3+2]] << ' times.' -]] -run get-type on #1 to STREAM() -run get-type on #2 to STRING() -run get-type on #3 to INT() -run get-type to STREAM() -/** writes -Hello, world! 5 times.**/ - /** md Title: A whirlwind tour of fostr ## Whirlwind tour -There seems only to be one way to start a tour like this. So here goes: +fostr is just in its infancy, so it's not yet even ready for +Hello, World. The best we can offer now is this little snippet +that writes the sum of the ASCII codes for 'H', 'W', and '!' to standard output: ```fostr **/ -/** md */ test hello_world [[ -<<< 'Hello, world!' -]] /* **/ -parse to TopLevel(DefGets(LitString("'Hello, world!'"))) -/** writes -Hello, world!**/ - -// Prior proto-hello-world, no longer in the tour. -test emit_sum [[ -stream << 72 + 87 + 33 -]] -parse to TopLevel(Gets(Stream(), Sum(Sum(Int("72"), Int("87")), Int("33")))) +/** md */ test emit_sum [[ +stdio << 72 + 87 + 33 +]]/* **/ parse to Receives(Stdio(), Sum([Int("72"), Int("87"), Int("33")])) /** writes 192**/ @@ -39,7 +22,7 @@ parse to TopLevel(Gets(Stream(), Sum(Sum(Int("72"), Int("87")), Int("33")))) ``` At the moment, there are only two ways to run a file containing fostr code -(you can find the above in `tests/hw.fos`). They both start by +(you can find the above in `tests/emit_sum.fos`). They both start by cloning this fostr project. Then, either: 1. Open the project in Eclipse and build it, visit your program file, @@ -52,279 +35,73 @@ cloning this fostr project. Then, either: For example, this snippet generates the following Python: ```python -{! ../tests/hw.py extract: +{! ../tests/emit_sum.py extract: start: 'Stdio\s=' !} ``` -It generates nearly identical code in -this simple example for Javascript (just with `"Hello, world!"` -in place of `r'Hello, world!'`), although it generates a different -preamble defining Stdio for each language. (Currently, Haskell and OCaml -code generation are also supported.) - -There's not much to break down in such a tiny program as this, but let's do -it. The prefix operator `<<<` could be read as "the default stream receives...", -and unsurprisingly in a main program the default stream is standard input and -output. And `'Hello, world!'` is a literal string constant; what you see is -what you get. The only detail to know is that such constants must occur -within a single line of your source file. So depending on how you -ran the program and how closely you looked at its output, -you may have noticed this program does not write a newline at the end -of its message. Nothing is ever implicitly sent to a stream. So if you want -newlines, you should switch to a (double-quoted) string that allows -the usual array of escape sequences: - -```fostr -**/ - -/** md */ test hello_esc_world [[ -<<< "Hello,\t\tworld!\n\n" -]] /* **/ -parse to TopLevel(DefGets(EscString("\"Hello,\t\tworld!\n\n\""))) -/** writes -Hello, world! - -**/ - -/** md +(which writes "192" to standard output), or this non-idiomatic, inefficient, but +working Javascript: +```javascript +{! ../tests/emit_sum.js extract: + start: '^}' +!} ``` -(We threw in two of each so you could clearly see them in the output if -you run this program.) +In either case, there's also a preamble defining Stdio that's generated. +(Haskell code generation is also currently supported.) ### Everything has a value As mentioned in the [Introduction](../README.md), everything in a fostr program (including the entire program itself) is an expression and has -a value. So what's the value of that expression above? Well, for convenience, -the value of a stream receiving an item is (generally) just the stream back -again. That way we can use the general (left-associative) -`_stream_ << _value_` operator to chain insertions into a stream: +a value. So what's the value of that expression above? Well, `stdio` is our +first example of a stream, and for convenience, the value of a stream +receiving an item is just the stream back again. The `<<` operator is also +left-associative, so that way we can chain insertions into a stream: ```fostr **/ -/** md */ test state_obvious [[ -<<< 'Two and ' << 2 << ' make ' << 2+2 << ".\n" -]] /* **/ -parse to TopLevel( - Gets(Gets(Gets(Gets(DefGets(LitString("'Two and '")),Int("2")), - LitString("' make '")),Sum(Int("2"),Int("2"))), - EscString("\".\n\""))) -/** writes -Two and 2 make 4. -**/ - -test emit_twice [[ -stream << 72 + 87 + 33 << 291 -]] -parse to TopLevel( - Gets(Gets(Stream(), Sum(Sum(Int("72"), Int("87")), Int("33"))), Int("291"))) +/** md */ test emit_twice [[ +stdio << 72 + 87 + 33 << 291 +]]/* **/ parse to Receives( + Receives(Stdio(), Sum([Int("72"), Int("87"), Int("33")])), + Int("291")) /** writes 192291**/ /** md ``` +Running this program produces a nice palindromic output: "192291". And because sometimes you want to emphasize the value and propagate that instead of the stream, you can also write these expressions "the other way" -with `>>>` for sending to the default stream or `>>` in general; these forms -(generally) return the value sent, so the following writes "824": +with `>>`; both forms return the first argument: ```fostr **/ /** md */ test enters_twice [[ -(7 + 8 >> stream + 9) >>> -]] /* **/ -parse to TopLevel( - DefTo(Sum(Sum(Int("7"), To(Int("8"), Stream())), Int("9")))) +(7 + 8 >> stdio + 9) >> stdio +]]/* **/ parse to + Enters(Sum([Int("7"), Enters(Int("8"), Stdio()), Int("9")]), Stdio()) /** writes 824**/ -/** md -``` -Two things are worth noting here: the default stream can always be referred to -directly via the identifier `stream`, and the precedences of `<<` and `>>` are -different so that generally full expressions go to a stream with `<<` but -just individual terms are sent with `>>`. - -### Layout in fostr - -Expressions may be laid out onto multiple lines, as long as all continuation -lines are indented from the start of the initial line: -```fostr -**/ - -/** md */ test receive_enter_break [[ -<<< - 7 - + 8 >>> - + 9 -]] /* **/ -parse to TopLevel( - DefGets(Sum(Sum(Int("7"), DefTo(Int("8"))), Int("9")))) -/** writes -824**/ - -/** md -``` -(So for example you will get a parse error with something like this:) -```fostr -**/ - -/** md */ test enter_receive_bad_continuation [[ -(7 + 8 >>> + 9) ->> (<<< 9 + 2) -]] /* **/ -parse fails - /* Extra tests not in the tour */ + +test receive_enter [[ +stdio << (7 + 8 >> stdio + 9) +]]/* **/ parse to + Receives(Stdio(), Sum([Int("7"), Enters(Int("8"), Stdio()), Int("9")])) +/** writes +824**/ + test enter_receive [[ -(7 + 8 >> stream + 9) >> (stream << 9 + 2) -]] /* **/ -parse to TopLevel( - To(Sum(Sum(Int("7"),To(Int("8"),Stream())),Int("9")), - Gets(Stream(),Sum(Int("9"),Int("2"))))) +(7 + 8 >> stdio + 9) >> (stdio << 9 + 2) +]]/* **/ parse to + Enters(Sum([Int("7"),Enters(Int("8"),Stdio()),Int("9")]), + Receives(Stdio(),Sum([Int("9"),Int("2")]))) /** writes 81124**/ /** md ``` - -Of course, fostr programs are not limited to one line; expressions on successive -lines are evaluated in sequence. For example, the program -```fostr -**/ - -/** md */ test emit_thrice [[ - <<< 72 + 87 - <<< 88 - + 96 - 99 + 12 - >>> - -]] /* **/ -parse to TopLevel(Sequence([ - DefGets(Sum(Int("72"), Int("87"))), - DefGets(Sum(Int("88"), Int("96"))), - Sum(Int("99"), DefTo(Int("12"))) -])) -/** writes -15918412**/ - -/** md -``` - -will write 15918412. The fostr parser enforces that successive expressions -in sequence align at the left; e.g., the following fails to parse: - -```fostr -**/ - -/** md */ test emit_thrice_bad_alignment [[ - <<< 72 + 87 -<<< 88 - + 96 - 99 + 12 >>> -]] /* **/ -parse fails - -/** md -``` - -Note you can optionally terminate an expression in a sequence with a semicolon, -and you may place multiple expressions on a single line if the earlier one(s) -are so terminated. So the following is OK: - -```fostr -**/ - -/** md */ test emit_several [[ - <<< 1 + 2; 3 >>> - (4 + 5) >>>; stream << 6; - <<< 7 - <<< 8 - + (9+10); - 11 + 12 >>>; 13 >>> - >>> -]] /* **/ -parse to TopLevel(Sequence([ - ISequence(Prior([Terminate(DefGets(Sum(Int("1"), Int("2"))))]), - DefTo(Int("3"))), - ISequence(Prior([Terminate(DefTo(Sum(Int("4"), Int("5"))))]), - Terminate(Gets(Stream(), Int("6")))), - DefGets(Int("7")), - Terminate(DefGets(Sum(Int("8"), Sum(Int("9"), Int("10"))))), - ISequence(Prior([Terminate(Sum(Int("11"), DefTo(Int("12"))))]), - DefTo(DefTo(Int("13")))) -])) -/** writes -3396727121313**/ - -/** md -``` -**/ - -test emit_several_desugar [[ - stream << 1 + 2; 3 >> stream - (4 + 5) >> stream; stream << 6; - stream << 7 - stream << 8 - + (9+10); - 11 + 12 >> stream; 13 >> stream - >> stream -]] /* don't test */ -run desugar-fostr to TopLevel(Sequence([ - Terminate(Gets(Stream(), Sum(Int("1"), Int("2")))), - To(Int("3"), Stream()), - Terminate(To(Sum(Int("4"), Int("5")), Stream())), - Terminate(Gets(Stream(), Int("6"))), - Gets(Stream(), Int("7")), - Terminate(Gets(Stream(), Sum(Int("8"), Sum(Int("9"), Int("10"))))), - Terminate(Sum(Int("11"), To(Int("12"), Stream()))), - To(To(Int("13"), Stream()), Stream()) -])) - -test emit_several_default [[ -<<< 1 + 2; 3 >>> -(4 + 5) >>> >> stream; stream << 6; -<<< 7 << 75 -<<< 8 - + (9+10); -11 + 12 >>>; 13 >>> - >>> -]] parse succeeds -/** writes -3399677527121313**/ - -/** md -### Streams are bidirectional - -So far we have only sent items to a stream. But we can extract them from -streams as well, with the `!` postfix operator. `!!` all by itself abbreviates -`stream!`, i.e., extraction from the standard stream. For example, - -```fostr -**/ - -/** md */ test custom_hw [[ -<<< "What is your name?\n" -<<< 'Hello, ' ++ !! -]] /* **/ -parse to TopLevel(Sequence([ - DefGets(EscString("\"What is your name?\n\"")), - DefGets(Concat(LitString("'Hello, '"),DefEmits())) -])) -/** accepts -Kilroy -**/ -/** writes -What is your name? -Hello, Kilroy -**/ - -/** md -``` - -queries users for their name and then writes a customized greeting. It also -illustrates the use of `++` for string concatenation, as opposed to `+` for -(numerical) addition. **/ diff --git a/tests/emit_several.fos b/tests/emit_several.fos deleted file mode 100644 index e7cbac5..0000000 --- a/tests/emit_several.fos +++ /dev/null @@ -1,7 +0,0 @@ -<<< 1 + 2; 3 >>> -(4 + 5) >>> >> stream; stream << 6; -<<< 7 << 75 -<<< 8 - + (9+10); -11 + 12 >>>; 13 >>> - >>> diff --git a/tests/emit_sum.fos b/tests/emit_sum.fos index 8826edb..8dfe808 100644 --- a/tests/emit_sum.fos +++ b/tests/emit_sum.fos @@ -1 +1 @@ -stream << 72 + 87 + 33 +stdio << 72 + 87 + 33 diff --git a/tests/emit_thrice.fos b/tests/emit_thrice.fos deleted file mode 100644 index 232e2be..0000000 --- a/tests/emit_thrice.fos +++ /dev/null @@ -1,5 +0,0 @@ - stream << 'Some numbers: ' - stream << 88 - + 96 - 99 + 12 >> - stream diff --git a/tests/hw.fos b/tests/hw.fos deleted file mode 100644 index 19eade4..0000000 --- a/tests/hw.fos +++ /dev/null @@ -1 +0,0 @@ -<<< 'Hello, world!' diff --git a/tests/hw2.fos b/tests/hw2.fos deleted file mode 100644 index c177d31..0000000 --- a/tests/hw2.fos +++ /dev/null @@ -1 +0,0 @@ -<<< "Hello,\t\tworld!\n\n" diff --git a/trans/analysis.str b/trans/analysis.str index e0c22ef..a28f21a 100644 --- a/trans/analysis.str +++ b/trans/analysis.str @@ -1,4 +1,5 @@ module analysis + imports statixruntime @@ -8,7 +9,6 @@ imports injections/- libspoofax/term/origin - desugar rules // Analysis @@ -19,9 +19,8 @@ rules // Analysis // multi-file analysis // editor-analyze = stx-editor-analyze(pre-analyze, post-analyze|"statics", "projectOk", "fileOk") - pre-analyze = desugar-fostr - ; origin-track-forced(explicate-injections-fostr-Start) - post-analyze = origin-track-forced(implicate-injections-fostr-Start) + pre-analyze = origin-track-forced(explicate-injections-fostr-Ex) + post-analyze = origin-track-forced(implicate-injections-fostr-Ex) rules // Editor Services @@ -32,36 +31,16 @@ rules // Editor Services rules // Debugging // Prints the abstract syntax ATerm of a selection. - debug-show-aterm: (sel, _, _, path, projp) -> (filename, result) + debug-show-aterm: (selected, _, _, path, project-path) -> (filename, result) with filename := path - ; result := sel - - // Prints the desugared abstract syntax ATerm of a selection. - debug-desugar-fostr: (sel, _, _, path, projp) -> (filename, result) - with filename := path - ; result := sel + ; result := selected // Prints the pre-analyzed abstract syntax ATerm of a selection. - debug-show-pre-analyzed: (sel, _, _, path, projp) -> (filename, result) + debug-show-pre-analyzed: (selected, _, _, path, project-path) -> (filename, result) with filename := path - ; result := sel + ; result := selected // Prints the analyzed annotated abstract syntax ATerm of a selection. - debug-show-analyzed: (sel, _, _, path, projp) -> (filename, result) + debug-show-analyzed: (selected, _, _, path, project-path) -> (filename, result) with filename := path - ; result := sel - - // Extract the type assigned to a node by Statix - get-type: node -> type - where - // Assigns variable a to be the result of the Statix analysis of the entire program (or throws an error) - a := node]])>; - // Gets the type of the given node (or throws an error) - type := node]])> node - - fail-msg(|msg) = err-msg(|$[get-type: [msg]]); fail - - // Prints the analyzed type of a selection. - debug-show-type: (sel, _, _, path, projp) -> (filename, result) - with filename := path - ; result := sel + ; result := selected diff --git a/trans/desugar.str b/trans/desugar.str deleted file mode 100644 index b22ebd8..0000000 --- a/trans/desugar.str +++ /dev/null @@ -1,24 +0,0 @@ -module desugar -imports libstrategolib signatures/- - -rules - /* ISequence() and Prior() are just noise for more expressions in sequence, - put in to get the layout rules right. So we remove them and collapse - all occurrence of them into one big Sequence() call on a list. - - This is slightly tricky because there might not be any Sequence() call - at the top level, but yet an ISequence(). So we do it in two passes, - first converting ISequence()s to Sequence()s, and then collapsing - Sequence()s. - */ - deISe: ISequence(Prior(l),x) -> Sequence((l, [x])) - - seqFlatten: Sequence(l) -> Sequence() <+ ![])>l) - - defStream: DefGets(x) -> Gets(Stream(), x) - defStream: DefTo(x) -> To(x, Stream()) - defStream: DefEmits() -> Emits(Stream()) - -strategies - - desugar-fostr = bottomup(try(defStream <+ deISe <+ seqFlatten)) diff --git a/trans/fostr.str b/trans/fostr.str index 91194d6..d9a585a 100644 --- a/trans/fostr.str +++ b/trans/fostr.str @@ -6,7 +6,6 @@ imports pp outline analysis - ocaml haskell javascript python diff --git a/trans/haskell.str b/trans/haskell.str index 0e0eb15..028a7bd 100644 --- a/trans/haskell.str +++ b/trans/haskell.str @@ -1,99 +1,49 @@ module haskell -imports libstrategolib signatures/- signature/TYPE util analysis -rules - /* Approach: - A) We will define a local transformation taking a term with value strings - at each child to a value string for the node. - B) We will append IO actions needed to set up for the value progressively - to a Preactions rule (mapping () to the list of actions). There will - be a utility `add-preaction` to append a new clause to value of this - rule. - C) We will use bottomup-para to traverse the full AST with the - transformation from A so that we have access to the original expression - (and can get the Statix-associated type when we need to). - Hence the transformation in (A) must actually take a pair of - an (original) term and a term with value strings at each child, - and be certain to return a value string. +imports libstrategolib signatures/- util - Finally, at the toplevel we emit the result of () before - returning the final value. +signature + constructors + TopLevel: Ex -> Ex + +rules + /* Approach: Generate code from the bottom up. + At every node, we create a pair of the implementation and + necessary preamble of IO actions. + We concatenate preambles as we go up. + Finally, at the toplevel we emit the preamble before returning the + final value. */ - hs: (_, TopLevel(val)) -> $[-- Preamble from fostr - import System.IO + hs: TopLevel((c,p)) -> $[import System.IO data IOStream = StdIO - -- Danger: These currently assume the stream is StdIO - gets :: Show b => a -> b -> IO a - gets s d = do + stdio :: IO IOStream + stdio = return StdIO + + receives :: Show b => IO a -> b -> IO a + receives s d = do + temp <- s putStr(show d) - return s - - getsStr :: a -> String -> IO a - getsStr s d = do - putStr(d) - return s - - emit s = do - l <- getLine - return (l ++ "\n") + return temp main = do - [()]return [val]] + [p]return [c]] - hs: (_, Stream()) -> "StdIO" - hs: (_, Int(x)) -> x - hs: (_, LitString(x)) -> x - hs: (_, EscString(x)) -> x - hs: (_, Sum(x, y)) -> $[([x] + [y])] - hs: (_, Concat(x, y)) -> $[([x] ++ [y])] + hs: Stdio() -> ("stdio", "") + hs: Int(x) -> (x, "") + hs: Sum((c,p)) -> ($[sum [c]], p) + hs: Receives((c, p), (d, s)) -> ($[[c] `receives` [d]], (p,s)) + hs: Enters((c, p), (d, s)) -> (c,d,(p,s),"fos") - hs: (Gets(_, xn), Gets(s, x)) -> v - with v := "_fostr_get" - ; [$[[v] <- [(s, xn, x)]]] - hs: (To(xn, _), To(x, s)) -> v - with v := "_fostr_to" - ; [$[let [v] = [x]], (s, xn, v)] + hsenter: (x, s, p, v) -> (v, [$[[p]let [v] = [x]], "\n", + $[[s] `receives` [v]], "\n"]) - hs_gets: (s, xn, x ) -> $[[s] [xn] [x]] - hs_getOp = get-type; (?STRING() < !"`getsStr`" + !"`gets`") - - hs: (_, Emits(s)) -> v - with v := "_fostr_emitted" - ; [$[[v] <- emit [s]]] - - hs: (_, Terminate(x)) -> $[[x];;] - hs: (_, Sequence(l)) -> l - /* One drawback of using paramorphism is we have to handle lists - explicitly: - */ - hs: (_, []) -> [] - hs: (_, [x | xs]) -> [x | xs] - - /* Another drawback of using paramorphism is at the very leaves we have - to undouble the tuple: - */ - hs: (x, x) -> x where x - - /* Characters we need to escape in Haskell string constants */ - Hascape: ['\t' | cs ] -> ['\', 't' | cs ] - /* I think I can just use ASCII constants for characters... */ - Hascape: [ 0 | cs ] -> ['\', '0' | cs ] - Hascape: [ 7 | cs ] -> ['\', 'a' | cs ] // Alert - Hascape: [ 8 | cs ] -> ['\', 'b' | cs ] // Backspace - Hascape: [ 11 | cs ] -> ['\', 'v' | cs ] // Vertical tab - Hascape: [ 12 | cs ] -> ['\', 'f' | cs ] // Form feed + hslist: x -> (x, x) + brack: x -> $<[]> strategies - haskLitString = un-single-quote - ; string-as-chars(escape-chars(Escape <+ Hascape)) - ; double-quote - - haskell = rules(Preactions: () -> ""); bottomup-para(try(hs)) - - /* See "Approach" at top of file */ - add-preactions = newp := ((), ) - ; rules(Preactions: () -> newp) + // wrap expression in a toplevel and then apply code generation + haskell = !TopLevel(); bottomup(try(hs <+ hslist)) // Interface haskell code generation with editor services and file system to-haskell: (selected, _, _, path, project-path) -> (filename, result) diff --git a/trans/javascript.str b/trans/javascript.str index 9b596ad..398c29e 100644 --- a/trans/javascript.str +++ b/trans/javascript.str @@ -1,60 +1,31 @@ module javascript imports libstrategolib signatures/- util +signature + constructors + TopLevel: Ex -> Ex + rules - js: TopLevel(x) -> $[// Fostr preamble - const _fostr_readline = require('readline'); - const _fostr_events = require('events'); - const _fostr_rl = _fostr_readline.createInterface({input: process.stdin}); - const Stdio = { - gets: v => { process.stdout.write(String(v)); return Stdio; }, - emit: async () => { - const [line] = await _fostr_events.once(_fostr_rl, 'line'); - return line + "\n"; } + js: TopLevel(x) -> $[const Stdio = { + receives: v => { process.stdout.write(String(v)); return Stdio; }, } - function to(data, strm) { - strm.gets(data); + function forwards(data, strm) { + strm.receives(data); return data; } + [x]] - const _fostr_body = async () => { - // End of preamble + js: Stdio() -> $[Stdio] + js: Int(x) -> x + js: Sum(x) -> $[[x].reduce((v,w) => v+w)] + js: Receives(x, y) -> $[[x].receives([y])] + js: Enters(x, y) -> $[forwards([x],[y])] - [x] - - // Fostr coda - _fostr_rl.close() - } - _fostr_body(); - ] - with line := "[line]" - - js: Stream() -> $[Stdio] - js: Int(x) -> x - js: LitString(x) -> x - js: EscString(x) -> x - js: Sum(x, y) -> $[[x] + [y]] - js: Concat(x, y) -> $[[x] + [y]] - js: Gets(x, y) -> $[[x].gets([y])] - js: To(x, y) -> $[to([x],[y])] - js: Emits(x) -> $[(await [x].emit())] - js: Terminate(x) -> x - js: Sequence(l) -> l - - /* Characters we need to escape in Javascript string constants */ - Jscape: ['\t' | cs ] -> ['\', 't' | cs ] - /* I think I can just use ASCII constants for characters... */ - Jscape: [ 0 | cs ] -> ['\', '0' | cs ] - Jscape: [ 8 | cs ] -> ['\', 'b' | cs ] // Backspace - Jscape: [ 11 | cs ] -> ['\', 'v' | cs ] // Vertical tab - Jscape: [ 12 | cs ] -> ['\', 'f' | cs ] // Form feed + jslist: x -> $<[<x>]> strategies - javaLitString = un-single-quote - ; string-as-chars(escape-chars(Escape <+ Jscape)) - ; single-quote - - javascript = bottomup(try(js)) + // wrap expression in a toplevel, then generate code from bottom up + javascript = !TopLevel(); bottomup(try(js <+ jslist)) // Interface javascript code generation with editor services and file system to-javascript: (selected, _, _, path, project-path) -> (filename, result) diff --git a/trans/ocaml.str b/trans/ocaml.str deleted file mode 100644 index 049dbf4..0000000 --- a/trans/ocaml.str +++ /dev/null @@ -1,66 +0,0 @@ -module ocaml -imports libstrategolib signatures/- util signature/TYPE analysis - -/* Note will use bottomup-para to traverse the full AST so that - we have access to the original expression (and can get the - Statix-associated type when we need to). - - This means that every one of our local rules must take a pair - of an original term and a term with every child replaced by - its generated code. - */ - -rules - ml: (_, TopLevel(x)) -> $[(* fostr preamble *) - type stream = { getS: string -> stream; emitS: unit -> string } - let rec stdio = { - getS = (fun s -> print_string s; stdio); - emitS = (fun () -> (read_line ()) ^ "\n"); - };; - (* End of preamble *) - - [x]] - - ml: (_, Stream()) -> $[stdio] - ml: (_, Int(x)) -> x - ml: (_, LitString(x)) -> $[{|[x]|}] - ml: (_, EscString(x)) -> x - ml: (_, Sum(x, y)) -> $[[x] + [y]] - ml: (_, Concat(x, y)) -> $[[x] ^ [y]] - - ml: (Gets(_,yn), Gets(x, y)) - -> $[([x]).getS ([(yn,y)])] - ml: (To(xn,_), To(x, y)) - -> $[let _fto = ([x]) in (ignore (([y]).getS ([(xn,"_fto")])); _fto)] - ml: (_, Emits(s)) -> $[[s].emitS ()] - - ml: (_, Terminate(x)) -> x - ml: (_, Sequence(l)) -> l - - ml_seq: [x] -> x - ml_seq: [x | xs ] -> $[ignore ([x]); -[xs]] - - /* One drawback of using paramorphism is we have to handle lists - explicitly: - */ - ml: (_, []) -> [] - ml: (_, [x | xs]) -> [x | xs] - - /* Another drawback of using paramorphism is at the very leaves we have - to undouble the tuple: - */ - ml: (x, x) -> x where x - - ml_str: (node, code) -> $[[node]([code])] - -strategies - - ml_string_cast = get-type; (?INT() < !"string_of_int" + !"") - - ocaml = bottomup-para(try(ml)) - - // Interface ocaml code generation with editor services and file system - to-ocaml: (selected, _, _, path, project-path) -> (filename, result) - with filename := path - ; result := selected diff --git a/trans/python.str b/trans/python.str index f42b1cb..85b845b 100644 --- a/trans/python.str +++ b/trans/python.str @@ -1,38 +1,35 @@ module python imports libstrategolib signatures/- util + +signature + constructors + TopLevel: Ex -> Ex + rules - py: TopLevel(x) -> $[## Fostr preamble - import sys + py: TopLevel(x) -> $[import sys class StdioC: - def gets(self, v): + def receives(self, v): print(v, file=sys.stdout, end='') return self - def emit(self): - return input() + "\n" # Python inconsistently strips when using input - def to(data,strm): - strm.gets(data) + def forwards(data,strm): + strm.receives(data) return data Stdio = StdioC() - ## End of preamble - [x]] - py: Stream() -> $[Stdio] - py: Int(x) -> x - py: LitString(x) -> $[r[x]] - py: EscString(x) -> x - py: Sum(x,y) -> $[[x] + [y]] - py: Concat(x,y) -> $[[x] + [y]] - py: Gets(x, y) -> $[[x].gets([y])] - py: To(x, y) -> $[to([x],[y])] - py: Emits(x) -> $[[x].emit()] - py: Terminate(x) -> $[[x];] - py: Sequence(l) -> l + py: Stdio() -> $[Stdio] + py: Int(x) -> x + py: Sum(x) -> $[sum([x])] + py: Receives(x, y) -> $[[x].receives([y])] + py: Enters(x, y) -> $[forwards([x],[y])] + + pylist: x -> $<[<x>]> strategies - python = bottomup(try(py)) + // wrap with a toplevel, then generate code from the bottom up + python = !TopLevel(); bottomup(try(py <+ pylist)) // Interface python code generation with editor services and file system to-python: (selected, _, _, path, project-path) -> (filename, result) diff --git a/trans/statics.stx b/trans/statics.stx index ce99bf7..fcd0c7f 100644 --- a/trans/statics.stx +++ b/trans/statics.stx @@ -1,267 +1,16 @@ module statics imports signatures/fostr-sig -imports signature/TYPE -imports statics/util -/** md -Title: Adding Program Analysis with Statix - -## Development of fostr static analysis - -This section is more documentation of Spoofax in general and Statix -in particular than of fostr itself, but is being maintained here in case -it could be either helpful to someone getting started with Statix or -helpful in understanding how the static characteristics of fostr were designed. - -As mentioned in the [Overview](../README.md), I don't like to program and a -corollary of that is never to use a facility unless/until there's a need for -it. So the first few rudimentary passes at fostr simply declared every program -to be "OK" from the point of view of Statix: -```statix -{! "\git docs/statix_start:trans/statics.stx" extract: - start: programOk - stop: (.*TopLevel.*) -!} -``` - -Then I reached the point at which the grammar was basically just -```SDF3 -// Start.TopLevel = -// Seq = -// Seq.Sequence = sq:Ex+ {layout(align-list sq)} -// Ex.Terminated = <;> -{! "\git docs/statix_start:syntax/fostr.sdf3" extract: - start: TermEx.Terminate - stop: (.*bracket.*) -!} -``` -(The first four clauses are in comments because they approximate fostr's -grammar; it actually uses a few more sorts for sequences of -expressions, to achieve fostr's exact layout rules. Also note that the parsing -of literal strings later evolved to include the surrounding single quotes, -because the rule above implicitly allows layout between the quotes and the -string contents, creating ambiguity.) - -This was the first point at which there were two different types that might -need to be written to standard output (Int and String), and although of course -the dynamically-typed Python and Javascript code generated dealt with both fine, -the Haskell code needed to differ depending on the -type of the item written (and I hadn't even started OCaml code generation at -that point since I knew it would be hopeless without statically typing fostr -programs). - -So it was time to bite the bullet and add type checking via Statix to fostr. -The first step was to replace the simple assertion that any TopLevel -is OK with a constraint that its Seq must type properly, and an assignment of -that type to the top level node: -```statix -programOk(tl@TopLevel(seq)) :- {T} - type_Seq(seq) == T, - @tl.type := T. -``` -Of course, for this to even parse, we must have a definition of `type_Seq`: -```statix -{! ../signature/TYPE.stx extract: {start: module, stop: rules} !} -**/ - -// see docs/implementation.md for detail on how to switch to multi-file analysis +// see docs/implementation.md for details on how to switch to multi-file analysis rules // single-file entry point - programOk : Start + programOk : Ex - /** md -rules - type_Seq : Seq -> TYPE -``` - **/ - - type_LineSeq : LineSeq -> TYPE - - programOk(tl@TopLevel(seq)) :- {T} - type_LineSeq(seq) == T, - @tl.type := T. - - /** md -Now to type a Seq, we look to the syntax, and see that there are two -possibilities for what it might be: just an Ex, or a Sequence(_) of a -list of 'Ex's. For the first, Statix does not allow one sort to simply -"become" another, but the Spoofax infrastructure automatically inserts -"injection" constructors for us, in this case one named Ex2Seq. So the -first rule for `type_Seq` is straightforward: - -```statix - type_Seq(s@Ex2Seq(e)) = T : - - type_Ex(e) == T, - @s.type := T. -``` -where of course type_Ex needs its own declaration analogous to the above. - **/ - - type_Line : Line -> TYPE - - type_LineSeq(ls@Line2LineSeq(l)) = T :- - type_Line(l) == T, - @ls.type := T. - - /** md - -The other (and in fact more typical) rule for `type_Seq`, when it actually -consists of a sequence of expressions, is a bit more involved. Fortunately -Statix provides a primitive for mapping over a list, so we can proceed as -follows: -```statix - types_Exs maps type_Ex(list(*)) = list(*) - type_Seq(s@Sequence(l)) = T :- {lt} - types_Exs(l) == lt, - lastTYPE(lt) == T, - @s.type := T. -``` -Here `lastTYPE` is a function that extracts the last TYPE from a list. -Unless/until Statix develops some sort of standard library, it must be -hand-defined, as done in "statics/util.stx" like so: -```statix -{! ../statics/util.stx extract: {start: lastTYPE} !} -``` - **/ - - types_Lines maps type_Line(list(*)) = list(*) - - type_LineSeq(ls@Sequence(l)) = T :- {lt} - types_Lines(l) == lt, - lastTYPE(lt) == T, - @ls.type := T. - - type_OptTermEx : OptTermEx -> TYPE - - type_Line(l@OptTermEx2Line(ote)) = T :- - type_OptTermEx(ote) == T, - @l.type := T. - - type_Ex : Ex -> TYPE - type_TermEx : TermEx -> TYPE - - type_OptTermEx(ote@Ex2OptTermEx(e)) = T :- - type_Ex(e) == T, - @ote.type := T. - - type_OptTermEx(ote@TermEx2OptTermEx(te)) = T :- - type_TermEx(te) == T, - @ote.type := T. - - /** md - -This brings us to the syntax rules for the basic expressions themselves, -which comprise almost all of the remaining fostr language constructs. -But first a mechanism suggested by Ivo Wilms to avoid repeating the node -type annotation in every rule: -```statix - **/ - - /** md */ - ty_Ex : Ex -> TYPE - - type_Ex(e) = ty@ty_Ex(e) :- - @e.type := ty. - /* **/ - - /** md -``` -At this stage in fostr's development, there was no difference between a -terminated and unterminated expression, so the typing rule for that -constructor was trivial: -```statix - ty_Ex(Terminated(e)) = ty_Ex(e). -``` - **/ - - type_TermEx(te@Terminate(e)) = T :- - type_Ex(e) == T, - @te.type := T. - - /** md - -Now typing literals is straightforward: -```statix -{! "\git docs/statix_works:trans/statics.stx" extract: - start: '(.*ty_Ex.Int.*\s*)' - stop: '/. ../' -!} -``` - **/ - - ty_Ex(Int(_)) = INT(). - ty_Ex(LitString(_)) = STRING(). - ty_Ex(EscString(_)) = STRING(). - ty_Ex(e@Stream()) = STREAM(). - - /** md - -Finally we get to the binary operators, and here we use the pattern found in -recent versions of the -"[chicago](https://github.com/MetaBorgCube/statix-sandbox/tree/master/chicago)" -example language and in the Fall 2020 TU-Delft class lecture on -[Name Binding and Name Resolution](https://tudelft-cs4200-2020.github.io/lectures/2020/09/24/lecture5/). -This pattern lets us specify error messages. - -```statix - **/ - - /** md */ - ty_Ex(Sum(e1, e2)) = INT() :- - type_Ex(e1) == INT() | error $[Expression [e1] not an Int in sum.]@e1, - type_Ex(e2) == INT() | error $[Expression [e2] not an Int in sum.]@e2. - - ty_Ex(Gets(e1, e2)) = STREAM() :- {T} - type_Ex(e1) == STREAM() | error $[Only Streams may receive items.]@e1, - type_Ex(e2) == T. - - ty_Ex(To(e1, e2)) = T :- - type_Ex(e1) == T, - type_Ex(e2) == STREAM() | error $[Items may only be sent to Streams.]@e2. - /* **/ - - ty_Ex(Concat(e1, e2)) = STRING() :- - type_Ex(e1) == STRING() | error $[Expression [e1] not String in concat.]@e1, - type_Ex(e2) == STRING() | error $[Expression [e2] not String in concat.]@e2. - - ty_Ex(Emits(e)) = STRING() :- // At the moment, only stream is stdio - type_Ex(e) == STREAM() | error $[Only Streams may emit items.]@e. - - /** md -``` - -### Using type annotations in transformation - -At this point, Statix properly types all of the valid programs of the very -rudimentary language defined by the grammar above. But the proximate purpose -for implementing this typing was to aid Haskell code generation. So how -do we actually use the assigned types in a Stratego transformation? - -Statix provides a Stratego api that includes, among other items, strategies -`stx-get-ast-analysis` and `stx-get-ast-type(|analysis)` that provide access -to the assigned types. However, it's easiest to use the information via -a wrapper like this, essentially lifted from the "chicago" language project: -```stratego -{! analysis.str extract: - start: Extract.the.type -terminate: Prints.the.analyzed.type -!} -``` - -Now `get_type` run on a node of the analyzed AST produces the assigned `TYPE` -(as an ATerm in the constructors of sort TYPE in Statix). - -Thus, you can select on the assigned type, as in the strategy to select -the correct Haskell operator to use to send an item to standard output: -```stratego -{! haskell.str extract: - start: '(.*hs_getOp.=.*)' - stop: \s -!} -``` - **/ + programOk(Sum(_)). + programOk(Receives(_,_)). + programOk(Enters(_,_)). rules // multi-file entry point @@ -269,6 +18,6 @@ rules // multi-file entry point projectOk(s). - fileOk : scope * Start + fileOk : scope * Ex - fileOk(s, TopLevel(_)). + fileOk(s, Receives(_,_)). diff --git a/trans/util.str b/trans/util.str index 78b4ab8..eee9663 100644 --- a/trans/util.str +++ b/trans/util.str @@ -3,7 +3,7 @@ imports libstrategolib rules join(|infix) : [] -> "" - join(|infix) : [x | xs] -> (x, xs) + join(|infix) : [x | xs] -> $[[x][xs]] prejoin(|infix) : [] -> "" - prejoin(|infix) : [x | xs] -> [infix,x,xs] + prejoin(|infix) : [x | xs] -> $[[infix][x][xs]]