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main
...
semi_separ
23
.drone.yml
23
.drone.yml
@ -29,18 +29,7 @@ steps:
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- 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
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- mkdir -p lib
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- 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'
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- name: setup_gen
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image: gcc
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volumes:
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- name: m2
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path: /root/.m2
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commands:
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- git clone https://github.com/facebook/nailgun.git
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- cd nailgun
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- make
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- cd ../bin
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- ln -s ../nailgun/nailgun-client/target/ng .
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- cd ..
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- bin/fosgen tests/emit_sum.fos
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- name: extract_tests
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image: xonsh/xonsh
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commands:
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@ -52,8 +41,7 @@ steps:
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path: /drone/lib
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- name: m2
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path: /root/.m2
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commands: # Note we first make sure that fosgen is working
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- bin/fosgen -d tests/emit_sum.fos
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commands:
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- bin/generate_test_code
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- name: python_tests
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image: python:slim
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@ -67,13 +55,6 @@ steps:
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image: haskell
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commands:
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- bin/run_tests runghc hs
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- name: ocaml_tests
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image: ocaml/opam
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commands:
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- ls -als tests/extracted
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- opam init
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- eval $(opam env)
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- bin/run_tests ocaml ml
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volumes:
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- name: lib
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6
.gitignore
vendored
6
.gitignore
vendored
@ -12,16 +12,10 @@
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.pydevproject
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a.out
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*.aterm
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/site
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bin/ng
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tests/extracted/*
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tests/*.js
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tests/*.py
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tests/*.hs
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tests/*.ml
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tests/*.cmi
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tests/*.cmo
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adhoc*
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@ -11,8 +11,7 @@ language as possible to work in, given that I inevitably will be doing a
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bunch of coding. The language will be centrally organized around the
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concept of "streams" (somewhat in the spirit of
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[streem](https://github.com/matz/streem) and/or
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[Orc](http://orc.csres.utexas.edu/index.shtml), or to a lesser extent,
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[Sisal-is](https://github.com/parsifal-47/sisal-is)). In fact all higher-type
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[Orc](http://orc.csres.utexas.edu/index.shtml)). In fact all higher-type
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entities will be cast in terms of streams, or in slogan form, "++f++unctions
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and (binary) ++o++perators are ++str++eams" (hence the name "fostr").
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@ -13,16 +13,12 @@ DESTINATION = 'tests/extracted'
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# Extension for extracted files:
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EXT = 'fos'
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# Extension for desired input:
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INP = 'in'
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# Extension for expectations:
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EXP = 'expect'
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for path in TEST_LIST:
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destdir = pf"{DESTINATION}/{path.stem}"
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mkdir -p @(destdir)
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chmod ugo+rwx @(destdir)
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contents = path.read_text()
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tests = re.split(r'test\s*(.+?)\s*\[\[.*?\n', contents)[1:]
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testit = iter(tests)
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@ -31,17 +27,12 @@ for path in TEST_LIST:
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if pfm: continue # skip examples that don't parse
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ntfm = re.search(r'\n\s*\]\].*?don.t.test', details)
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if ntfm: continue # explicit skip
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em = re.search(r'\n\]\]', details)
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em = re.search(r'\n\s*\]\]', details)
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if not em: continue
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example = details[:em.start()+1].replace('[[','').replace(']]','')
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example = details[:em.start()+1]
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expath = destdir / f"{name}.{EXT}"
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expath.write_text(example)
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echo Wrote @(expath)
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im = re.search(r'/\*\*\s+accepts.*?\n([\s\S]*?)\*\*/', details[em.end():])
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if im:
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ipath = destdir / f"{name}.{INP}"
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ipath.write_text(im[1])
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echo " ...and" @(ipath)
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xm = re.search(r'/\*\*\s+writes.*?\n([\s\S]*?)\*\*/', details[em.end():])
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if xm:
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xpath = destdir / f"{name}.{EXP}"
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20
bin/fosgen
20
bin/fosgen
@ -5,7 +5,6 @@ erro() { printf "%s\n" "$*" >&2; }
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##### Set defaults:
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SUPPRESS_ERR=YES
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USE_NAILGUN=YES
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LANGUAGE=Python
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##### Extract command line options:
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@ -15,23 +14,18 @@ do
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-h|--help)
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echo
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echo "Usage:"
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echo " fosgen [-d] [-j] [-l LANGUAGE] FILE"
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echo " fosgen [-d] [-l LANGUAGE] FILE"
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echo
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echo "Writes to standard output the code generated from the fostr"
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echo "program in FILE, targeting the specified LANGUAGE (which"
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echo "defaults to Python)."
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echo
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echo "The -d option writes diagnostic output to standard error."
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echo "The -j option uses the Spoofax Sunshine JAR directly, rather"
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echo "than via nailgun."
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exit
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;;
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-d)
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SUPPRESS_ERR=''
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;;
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-j)
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USE_NAILGUN=''
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;;
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-l)
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shift
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LANGUAGE="$1"
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@ -73,17 +67,5 @@ then
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exec 2>/dev/null
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fi
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if [[ $USE_NAILGUN ]]
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then
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if [[ $SUPPRESS_ERR ]]
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then
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$BINDIR/let_sun_shine
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else
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$BINDIR/let_sun_shine noisy
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fi
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$BINDIR/ng sunshine transform -p $PROJDIR -n $LANGUAGE -i $PROGRAM
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exit $?
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fi
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java -jar $SUNJAR transform -p $PROJDIR -l $PROJDIR -l $MVN_REPO -n $LANGUAGE -i $PROGRAM
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exit $?
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@ -4,7 +4,7 @@ failed=0
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for dir in tests/extracted/*; do
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for file in $dir/*.fos; do
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for language in Python Javascript Haskell OCaml; do
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for language in Python Javascript Haskell; do
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echo bin/fosgen -l ${language%.*} $file ...
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bin/fosgen -l $language $file
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if [[ $? -ne 0 ]]; then
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@ -1,40 +0,0 @@
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#!/bin/bash
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# Helper for fosgen, not intended to be used directly
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# With an argument, print diagnostic output
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BINDIR=$(dirname $BASH_SOURCE)
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if $BINDIR/ng sunshine --help
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then
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if [[ $1 ]]
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then
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echo "sun already shining."
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fi
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else
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if [[ $1 ]]
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then
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echo "disperse the clouds."
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fi
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SUNJAR="$BINDIR/../lib/sunshine.jar"
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PROJDIR="$BINDIR/.."
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if [[ ! $MVN_REPO ]]; then
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MVN_REPO="$HOME/.m2/repository"
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fi
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if [[ ! -d $MVN_REPO ]]; then
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MVN_REPO="/root/.m2/repository"
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fi
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if [[ ! -d $MVN_REPO ]]; then
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echo "Cannot find your Maven repository. Please set environment variable"
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echo "MVN_REPO to its full path and re-run."
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exit 1
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fi
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if [[ $1 ]]
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then
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java -jar $SUNJAR server &
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else
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java -jar $SUNJAR server >/dev/null 2>&1 &
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fi
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sleep 5
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$BINDIR/ng sunshine load -l $PROJDIR -l $MVN_REPO
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fi
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@ -9,14 +9,8 @@ diffed=0
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for dir in tests/extracted/*; do
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for file in $dir/*.$ext; do
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((total++))
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if [[ -f ${file%.*}.in ]]; then
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cat ${file%.*}.in | $command $file > $file.out
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result=$?
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else
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$command $file > $file.out
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result=$?
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fi
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if [[ $result -ne 0 ]]; then
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if [[ $? -ne 0 ]]; then
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echo ERROR: $command $file failed.
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((failed++))
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else
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@ -22,4 +22,3 @@ menus
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action: "Show pre-analyzed AST" = debug-show-pre-analyzed (source)
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action: "Show analyzed AST" = debug-show-analyzed
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action: "Show analyzed type" = debug-show-type
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@ -4,4 +4,3 @@ menus
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action: "Python" = to-python
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action: "Javascript" = to-javascript
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action: "Haskell" = to-haskell
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action: "OCaml" = to-ocaml
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@ -2,14 +2,13 @@ site_name: fostr language
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nav:
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- README.md
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- tests/basic.md
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- trans/statics.md
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- implementation.md
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plugins:
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- search
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- semiliterate:
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ignore_folders: [target, lib]
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exclude_extensions: ['.o', '.hi', '.cmi', '.cmo']
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exclude_extensions: ['.o', '.hi']
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extract_standard_markdown:
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terminate: <!-- /md -->
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theme:
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@ -1 +0,0 @@
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TYPE.stx
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@ -1,7 +0,0 @@
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module signature/TYPE
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signature
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sorts TYPE // semantic type
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constructors
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INT : TYPE
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STRING : TYPE
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STREAM : TYPE
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@ -1,7 +0,0 @@
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module statics/util
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imports signature/TYPE
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rules
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lastTYPE : list(TYPE) -> TYPE
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lastTYPE([T]) = T.
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lastTYPE([U | TS]) = lastTYPE(TS).
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@ -8,14 +8,6 @@ context-free start-symbols
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Start
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||||
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lexical sorts
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||||
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STRING_LITERAL
|
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lexical syntax
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STRING_LITERAL = "'"~[\']*"'"
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context-free sorts
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Start LineSeq Line OptTermEx TermExLst TermEx Ex
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@ -38,26 +30,17 @@ context-free syntax
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TermEx.Terminate = <<Ex>;>
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Ex.Int = INT
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Ex.LitString = STRING_LITERAL
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Ex.EscString = STRING
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Ex.Stream = <stream>
|
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Ex.Sum = <<Ex> + <Ex>> {left}
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Ex.Concat = <<Ex> ++ <Ex>> {left}
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Ex.Sum = [[Ex] + [Ex]] {left}
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Ex.Gets = [[Ex] << [Ex]] {left}
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Ex.DefGets = [<<< [Ex]]
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Ex.To = [[Ex] >> [Ex]] {left}
|
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Ex.DefTo = [[Ex] >>>]
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Ex.Emits = <<Ex>!>
|
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Ex.DefEmits = <!!>
|
||||
|
||||
Ex = <(<Ex>)> {bracket}
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|
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context-free priorities
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||||
|
||||
Ex.To
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||||
> Ex.DefTo
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> {Ex.Sum Ex.Concat}
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> Ex.DefGets
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> Ex.Sum
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> Ex.Gets,
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|
||||
// prevent cycle: no singletons
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||||
|
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207
tests/basic.spt
207
tests/basic.spt
@ -1,36 +1,20 @@
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module basic
|
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language fostr
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||||
|
||||
test hw1_type [[
|
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[[stream]] << [['Hello, world! ']] << [[3+2]] << ' times.'
|
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]]
|
||||
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
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Hello, world! 5 times.**/
|
||||
|
||||
/** md
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||||
Title: A whirlwind tour of fostr
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||||
|
||||
## 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 [[
|
||||
/** md */ test emit_sum [[
|
||||
stream << 72 + 87 + 33
|
||||
]]
|
||||
]] /* **/
|
||||
parse to TopLevel(Gets(Stream(), Sum(Sum(Int("72"), Int("87")), Int("33"))))
|
||||
/** writes
|
||||
192**/
|
||||
@ -39,7 +23,7 @@ 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,
|
||||
@ -52,70 +36,30 @@ 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
|
||||
```
|
||||
(We threw in two of each so you could clearly see them in the output if
|
||||
you run this program.)
|
||||
(which writes "192" to standard output); it also generates identical code in
|
||||
this simple example for
|
||||
Javascript, although it generates a different preamble defining Stdio in each
|
||||
case. (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, appropriately
|
||||
enough, `stream` is our
|
||||
first example of a stream, and for convenience, the value of a stream
|
||||
receiving an item is (usually) 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 [[
|
||||
/** md */ test emit_twice [[
|
||||
stream << 72 + 87 + 33 << 291
|
||||
]]
|
||||
]] /* **/
|
||||
parse to TopLevel(
|
||||
Gets(Gets(Stream(), Sum(Sum(Int("72"), Int("87")), Int("33"))), Int("291")))
|
||||
/** writes
|
||||
@ -123,28 +67,24 @@ parse to TopLevel(
|
||||
|
||||
/** 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, so the following writes "824":
|
||||
```fostr
|
||||
**/
|
||||
|
||||
/** md */ test enters_twice [[
|
||||
(7 + 8 >> stream + 9) >>>
|
||||
(7 + 8 >> stream + 9) >> stream
|
||||
]] /* **/
|
||||
parse to TopLevel(
|
||||
DefTo(Sum(Sum(Int("7"), To(Int("8"), Stream())), Int("9"))))
|
||||
To(Sum(Sum(Int("7"), To(Int("8"), Stream())), Int("9")), Stream()))
|
||||
/** 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
|
||||
|
||||
@ -154,13 +94,13 @@ lines are indented from the start of the initial line:
|
||||
**/
|
||||
|
||||
/** md */ test receive_enter_break [[
|
||||
<<<
|
||||
stream <<
|
||||
7
|
||||
+ 8 >>>
|
||||
+ 8 >> stream
|
||||
+ 9
|
||||
]] /* **/
|
||||
parse to TopLevel(
|
||||
DefGets(Sum(Sum(Int("7"), DefTo(Int("8"))), Int("9"))))
|
||||
Gets(Stream(), Sum(Sum(Int("7"), To(Int("8"), Stream())), Int("9"))))
|
||||
/** writes
|
||||
824**/
|
||||
|
||||
@ -171,8 +111,8 @@ parse to TopLevel(
|
||||
**/
|
||||
|
||||
/** md */ test enter_receive_bad_continuation [[
|
||||
(7 + 8 >>> + 9)
|
||||
>> (<<< 9 + 2)
|
||||
(7 + 8 >> stream + 9)
|
||||
>> (stream << 9 + 2)
|
||||
]] /* **/
|
||||
parse fails
|
||||
|
||||
@ -195,17 +135,16 @@ lines are evaluated in sequence. For example, the program
|
||||
**/
|
||||
|
||||
/** md */ test emit_thrice [[
|
||||
<<< 72 + 87
|
||||
<<< 88
|
||||
stream << 72 + 87
|
||||
stream << 88
|
||||
+ 96
|
||||
99 + 12
|
||||
>>>
|
||||
|
||||
99 + 12 >>
|
||||
stream
|
||||
]] /* **/
|
||||
parse to TopLevel(Sequence([
|
||||
DefGets(Sum(Int("72"), Int("87"))),
|
||||
DefGets(Sum(Int("88"), Int("96"))),
|
||||
Sum(Int("99"), DefTo(Int("12")))
|
||||
Gets(Stream(), Sum(Int("72"), Int("87"))),
|
||||
Gets(Stream(), Sum(Int("88"), Int("96"))),
|
||||
Sum(Int("99"), To(Int("12"), Stream()))
|
||||
]))
|
||||
/** writes
|
||||
15918412**/
|
||||
@ -220,10 +159,10 @@ in sequence align at the left; e.g., the following fails to parse:
|
||||
**/
|
||||
|
||||
/** md */ test emit_thrice_bad_alignment [[
|
||||
<<< 72 + 87
|
||||
<<< 88
|
||||
stream << 72 + 87
|
||||
stream << 88
|
||||
+ 96
|
||||
99 + 12 >>>
|
||||
99 + 12 >> stream
|
||||
]] /* **/
|
||||
parse fails
|
||||
|
||||
@ -238,23 +177,23 @@ are so terminated. So the following is OK:
|
||||
**/
|
||||
|
||||
/** md */ test emit_several [[
|
||||
<<< 1 + 2; 3 >>>
|
||||
(4 + 5) >>>; stream << 6;
|
||||
<<< 7
|
||||
<<< 8
|
||||
stream << 1 + 2; 3 >> stream
|
||||
(4 + 5) >> stream; stream << 6;
|
||||
stream << 7
|
||||
stream << 8
|
||||
+ (9+10);
|
||||
11 + 12 >>>; 13 >>>
|
||||
>>>
|
||||
11 + 12 >> stream; 13 >> stream
|
||||
>> stream
|
||||
]] /* **/
|
||||
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"))))]),
|
||||
ISequence(Prior([Terminate(Gets(Stream(), Sum(Int("1"), Int("2"))))]),
|
||||
To(Int("3"), Stream())),
|
||||
ISequence(Prior([Terminate(To(Sum(Int("4"), Int("5")), Stream()))]),
|
||||
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"))))
|
||||
Gets(Stream(), Int("7")),
|
||||
Terminate(Gets(Stream(), Sum(Int("8"), Sum(Int("9"), Int("10"))))),
|
||||
ISequence(Prior([Terminate(Sum(Int("11"), To(Int("12"), Stream())))]),
|
||||
To(To(Int("13"), Stream()), Stream()))
|
||||
]))
|
||||
/** writes
|
||||
3396727121313**/
|
||||
@ -282,49 +221,3 @@ run desugar-fostr to TopLevel(Sequence([
|
||||
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.
|
||||
**/
|
||||
|
||||
@ -1,7 +1,7 @@
|
||||
<<< 1 + 2; 3 >>>
|
||||
(4 + 5) >>> >> stream; stream << 6;
|
||||
<<< 7 << 75
|
||||
<<< 8
|
||||
stream << 1 + 2; 3 >> stream
|
||||
(4 + 5) >> stream; stream << 6;
|
||||
stream << 7
|
||||
stream << 8
|
||||
+ (9+10);
|
||||
11 + 12 >>>; 13 >>>
|
||||
>>>
|
||||
11 + 12 >> stream; 13 >> stream
|
||||
>> stream
|
||||
|
||||
@ -1,4 +1,4 @@
|
||||
stream << 'Some numbers: '
|
||||
stream << 72 + 87
|
||||
stream << 88
|
||||
+ 96
|
||||
99 + 12 >>
|
||||
|
||||
@ -1 +0,0 @@
|
||||
<<< 'Hello, world!'
|
||||
@ -1 +0,0 @@
|
||||
<<< "Hello,\t\tworld!\n\n"
|
||||
@ -1,4 +1,5 @@
|
||||
module analysis
|
||||
|
||||
imports
|
||||
|
||||
statixruntime
|
||||
@ -50,18 +51,3 @@ rules // Debugging
|
||||
debug-show-analyzed: (sel, _, _, path, projp) -> (filename, result)
|
||||
with filename := <guarantee-extension(|"analyzed.aterm")> 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 := <stx-get-ast-analysis <+ fail-msg(|$[no analysis on node [<strip-annos;write-to-string> node]])>;
|
||||
// Gets the type of the given node (or throws an error)
|
||||
type := <stx-get-ast-type(|a) <+ fail-msg(|$[no type on node [<strip-annos;write-to-string> node]])> node
|
||||
|
||||
fail-msg(|msg) = err-msg(|$[get-type: [msg]]); fail
|
||||
|
||||
// Prints the analyzed type of a selection.
|
||||
debug-show-type: (sel, _, _, path, projp) -> (filename, result)
|
||||
with filename := <guarantee-extension(|"type.aterm")> path
|
||||
; result := <get-type> sel
|
||||
|
||||
@ -13,12 +13,10 @@ rules
|
||||
*/
|
||||
deISe: ISequence(Prior(l),x) -> Sequence(<conc>(l, [x]))
|
||||
|
||||
seqFlatten: Sequence(l) -> Sequence(<mapconcat(?Sequence(<id>) <+ ![<id>])>l)
|
||||
|
||||
defStream: DefGets(x) -> Gets(Stream(), x)
|
||||
defStream: DefTo(x) -> To(x, Stream())
|
||||
defStream: DefEmits() -> Emits(Stream())
|
||||
enList: x -> [x]
|
||||
seqFlatten: Sequence(l) -> Sequence(<mapconcat(?Sequence(<id>) <+ enList)>l)
|
||||
|
||||
strategies
|
||||
|
||||
desugar-fostr = bottomup(try(defStream <+ deISe <+ seqFlatten))
|
||||
desugar-fostr = bottomup(try(deISe <+ seqFlatten))
|
||||
|
||||
@ -6,7 +6,6 @@ imports
|
||||
pp
|
||||
outline
|
||||
analysis
|
||||
ocaml
|
||||
haskell
|
||||
javascript
|
||||
python
|
||||
|
||||
@ -1,99 +1,43 @@
|
||||
module haskell
|
||||
imports libstrategolib signatures/- signature/TYPE util analysis
|
||||
imports libstrategolib signatures/- util
|
||||
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.
|
||||
|
||||
Finally, at the toplevel we emit the result of <Preactions>() before
|
||||
returning the final value.
|
||||
/* 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
|
||||
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")
|
||||
|
||||
main = do
|
||||
[<Preactions>()]return [val]]
|
||||
[p]return [c]]
|
||||
|
||||
hs: (_, Stream()) -> "StdIO"
|
||||
hs: (_, Int(x)) -> x
|
||||
hs: (_, LitString(x)) -> <haskLitString>x
|
||||
hs: (_, EscString(x)) -> x
|
||||
hs: (_, Sum(x, y)) -> $[([x] + [y])]
|
||||
hs: (_, Concat(x, y)) -> $[([x] ++ [y])]
|
||||
hs: Stream() -> ("StdIO", "")
|
||||
hs: Int(x) -> (x, "")
|
||||
hs: Sum( (c, p), (d, q)) -> ($[([c] + [d])], <conc-strings>(p,q))
|
||||
|
||||
hs: (Gets(_, xn), Gets(s, x)) -> v
|
||||
with v := <newname>"_fostr_get"
|
||||
; <add-preactions>[$[[v] <- [<hs_gets>(s, xn, x)]]]
|
||||
hs: (To(xn, _), To(x, s)) -> v
|
||||
with v := <newname>"_fostr_to"
|
||||
; <add-preactions>[$[let [v] = [x]], <hs_gets>(s, xn, v)]
|
||||
hs: Gets((c, p), (d, q)) -> <hsget>(c,d,<conc-strings>(p,q),<newname>"fosgt")
|
||||
hsget: (s, x, p, v) -> (v, <concat-strings>[p, $[[v] <- [s] `gets` [x]],
|
||||
"\n"])
|
||||
|
||||
hs_gets: (s, xn, x ) -> $[[s] [<hs_getOp>xn] [x]]
|
||||
hs_getOp = get-type; (?STRING() < !"`getsStr`" + !"`gets`")
|
||||
hs: To( (c, p), (d, q)) -> <hsto>(c,d,<conc-strings>(p,q),<newname>"fosto")
|
||||
hsto: (x, s, p, v) -> (v, <concat-strings>[p, $[let [v] = [x]], "\n",
|
||||
$[[s] `gets` [v]], "\n"])
|
||||
|
||||
hs: (_, Emits(s)) -> v
|
||||
with v := <newname>"_fostr_emitted"
|
||||
; <add-preactions>[$[[v] <- emit [s]]]
|
||||
|
||||
hs: (_, Terminate(x)) -> $[[x];;]
|
||||
hs: (_, Sequence(l)) -> <last>l
|
||||
/* One drawback of using paramorphism is we have to handle lists
|
||||
explicitly:
|
||||
*/
|
||||
hs: (_, []) -> []
|
||||
hs: (_, [x | xs]) -> [x | xs]
|
||||
|
||||
/* Another drawback of using paramorphism is at the very leaves we have
|
||||
to undouble the tuple:
|
||||
*/
|
||||
hs: (x, x) -> x where <is-string>x
|
||||
|
||||
/* Characters we need to escape in Haskell string constants */
|
||||
Hascape: ['\t' | cs ] -> ['\', 't' | cs ]
|
||||
/* I think I can just use ASCII constants for characters... */
|
||||
Hascape: [ 0 | cs ] -> ['\', '0' | cs ]
|
||||
Hascape: [ 7 | cs ] -> ['\', 'a' | cs ] // Alert
|
||||
Hascape: [ 8 | cs ] -> ['\', 'b' | cs ] // Backspace
|
||||
Hascape: [ 11 | cs ] -> ['\', 'v' | cs ] // Vertical tab
|
||||
Hascape: [ 12 | cs ] -> ['\', 'f' | cs ] // Form feed
|
||||
hs: Terminate((c,p)) -> ($[[c];;], p)
|
||||
hs: Sequence(l) -> (<last; Fst>l, <map(Snd); concat-strings>l)
|
||||
|
||||
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 := <conc-strings>(<Preactions>(), <lines>)
|
||||
; rules(Preactions: () -> newp)
|
||||
haskell = bottomup(try(hs))
|
||||
|
||||
// Interface haskell code generation with editor services and file system
|
||||
to-haskell: (selected, _, _, path, project-path) -> (filename, result)
|
||||
|
||||
@ -2,57 +2,24 @@ module javascript
|
||||
imports libstrategolib signatures/- util
|
||||
|
||||
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 = {
|
||||
js: TopLevel(x) -> $[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"; }
|
||||
}
|
||||
function to(data, strm) {
|
||||
strm.gets(data);
|
||||
return data;
|
||||
}
|
||||
|
||||
const _fostr_body = async () => {
|
||||
// End of preamble
|
||||
|
||||
[x]
|
||||
|
||||
// Fostr coda
|
||||
_fostr_rl.close()
|
||||
}
|
||||
_fostr_body();
|
||||
]
|
||||
with line := "[line]"
|
||||
[x]]
|
||||
|
||||
js: Stream() -> $[Stdio]
|
||||
js: Int(x) -> x
|
||||
js: LitString(x) -> <javaLitString>x
|
||||
js: EscString(x) -> x
|
||||
js: Sum(x, y) -> $[[x] + [y]]
|
||||
js: Concat(x, y) -> $[[x] + [y]]
|
||||
js: Sum(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) -> <join(|";\n")>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
|
||||
|
||||
strategies
|
||||
javaLitString = un-single-quote
|
||||
; string-as-chars(escape-chars(Escape <+ Jscape))
|
||||
; single-quote
|
||||
|
||||
javascript = bottomup(try(js))
|
||||
|
||||
|
||||
@ -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)) -> $[{|[<un-single-quote>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 ([<ml_str>(yn,y)])]
|
||||
ml: (To(xn,_), To(x, y))
|
||||
-> $[let _fto = ([x]) in (ignore (([y]).getS ([<ml_str>(xn,"_fto")])); _fto)]
|
||||
ml: (_, Emits(s)) -> $[[s].emitS ()]
|
||||
|
||||
ml: (_, Terminate(x)) -> x
|
||||
ml: (_, Sequence(l)) -> <ml_seq>l
|
||||
|
||||
ml_seq: [x] -> x
|
||||
ml_seq: [x | xs ] -> $[ignore ([x]);
|
||||
[<ml_seq>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 <is-string>x
|
||||
|
||||
ml_str: (node, code) -> $[[<ml_string_cast>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 := <guarantee-extension(|"ml")> path
|
||||
; result := <ocaml> selected
|
||||
@ -2,31 +2,22 @@ module python
|
||||
imports libstrategolib signatures/- util
|
||||
rules
|
||||
|
||||
py: TopLevel(x) -> $[## Fostr preamble
|
||||
import sys
|
||||
py: TopLevel(x) -> $[import sys
|
||||
class StdioC:
|
||||
def gets(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)
|
||||
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) -> <join(|"\n")>l
|
||||
|
||||
|
||||
@ -1,267 +1,14 @@
|
||||
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 = <Ex>
|
||||
// Seq.Sequence = sq:Ex+ {layout(align-list sq)}
|
||||
// Ex.Terminated = <<Ex>;>
|
||||
{! "\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
|
||||
|
||||
/** 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(TopLevel(_)).
|
||||
|
||||
rules // multi-file entry point
|
||||
|
||||
|
||||
Loading…
Reference in New Issue
Block a user