lang0/0-lang0py/lang0py.py

import os
import sys

def eq(a, b):
    return a == b

def emit(string):
    sys.stdout.write(string)
    sys.stdout.flush()

def trace(header, value):
    if os.environ.get('TRACE'):
        sys.stderr.write(f'{header}={value!r}\n')

eof = chr(0)
eol = chr(10)
quote = chr(34)
PEEK = None
LINE = 1

def peek():
    global PEEK

    if PEEK is None:
        char = sys.stdin.read(1)
        trace('char', char)
        if not char:
            PEEK = eof
        else:
            PEEK = char

    return PEEK

peek()

def skip():
    global LINE
    global PEEK

    if eol == PEEK:
        LINE += 1

    PEEK = None

def __check(func, args: list[str], msg: list[str]) -> None:
    result = func(*args)
    if result:
        return

    sys.stderr.write(' '.join(msg) + '\n')
    sys.stderr.flush()
    exit(1)

def intinc(a: str) -> str:
    if not a:
        return "1"

    return str(int(a) + 1)

MAPSTORE = {}

def mapclear(mapname: str) -> str:
    MAPSTORE.pop(mapname)
    return ""

def mapgetkey(mapname: str, key: str, default: str) -> str:
    return MAPSTORE.get(mapname, {}).get(key, default)

def mapsetkey(mapname: str, key: str, value: str) -> str:
    MAPSTORE.setdefault(mapname, {})
    MAPSTORE[mapname][key] = value
    return ""

def registerid(id: str) -> str:
    idname = mapgetkey("REGISTERID", id, "")
    if idname:
        return idname
    newidx = mapgetkey("REGISTERID", "__len__", "0")
    idname = "identifier" + newidx
    mapsetkey("REGISTERID", id, idname)
    newlen = intinc(newidx)
    mapsetkey("REGISTERID", "__len__", newlen)
    return idname

def emitln(data):
    emit(data)
    emit(eol)

def lexident():
    word = ''
    while True:
        char = peek()

        if char < 'a' or char > 'z':
            break

        word += char
        skip()

    return word

def skipchar(char):
    global LINE
    assert char == peek(), (LINE, char, peek())
    skip()

def parseconststring():
    skipchar(quote)
    emit(quote)

    escaped = False
    while True:
        char = peek()
        if char == eof:
            break
        if char == quote:
            break

        emit(char)

        skip()

    skipchar(quote)
    emit(quote)

def parseexprvarref():
    varname = lexident()
    varid = registerid(varname)
    emit(varid)

def parseexprcall():
    funcname = lexident()
    __check(mapgetkey, ["FUNCREG", funcname, ""], ["Function", funcname, "does not exist"])
    funcid = registerid(funcname)
    emit(funcid)
    emit('(')

    first = True
    while ' ' == peek():
        skip()
        if not first:
            emit(', ')
        if quote == peek():
            parseconststring()
        else:
            parseexprvarref()
        first = False

    emit(')')

def parsestatdeclare(indent):
    skipchar(' ')
    var = lexident()
    skipchar(eol)

def parsestatset(indent):
    skipchar(' ')
    varname = lexident()
    varid = registerid(varname)
    skipchar(' ')

    emit('    ' * indent)
    emit(varid)
    emit(' = ')

    parseconststring()

    emit(eol)
    skipchar(eol)

def parsestatcalc(indent):
    skipchar(' ')
    varname = lexident()
    varid = registerid(varname)
    skipchar(' ')

    emit('    ' * indent)
    emit(varid)
    emit(' = ')

    parseexprcall()

    emit(eol)
    skipchar(eol)

def parsestatif(indent):
    skipchar(' ')
    emit('    ' * indent)
    emit('if ')
    parseexprvarref()
    emitln(':')
    skipchar(eol)

    parseblock(indent + 1)

def parsestatforever(indent):
    emit('    ' * indent)
    emitln('while True:')
    skipchar(eol)

    parseblock(indent + 1)

def parsestatbreak(indent):
    emit('    ' * indent)
    emitln('break')
    skipchar(eol)

def parsestatreturn(indent):
    emit('    ' * indent)
    emit('return ')
    if ' ' == peek():
        skip()
        if quote == peek():
            parseconststring()
        else:
            parseexprvarref()
    emit(eol)
    skipchar(eol)

def parsestatcheck(indent):
    skipchar(' ')
    emit('    ' * indent)
    emit('__check(')

    funcname = lexident()
    funcid = registerid(funcname)
    trace("funcid", funcid)
    emit(funcid)
    emit(', [')
    notfirst = False

    while True:
        skipchar(' ')

        if ':' == peek():
            break

        if notfirst:
            emit(', ')

        if quote == peek():
            parseconststring()
        else:
            parseexprvarref()

        notfirst = True

    skipchar(':')

    emit('], [')
    notfirst = False

    while True:
        skipchar(' ')

        if notfirst:
            emit(', ')

        if quote == peek():
            parseconststring()
        else:
            parseexprvarref()

        if eol == peek():
            break
        notfirst = True
    emitln('])')

def parsestattrace(indent):
    skipchar(' ')
    emit('    ' * indent)
    emit('trace("')

    varname = lexident()
    varid = registerid(varname)
    skipchar(eol)

    emit(varname)
    emit('", ')
    emit(varid)
    emitln(')')

def parsestat(indent):
    call = lexident()
    trace('call', call)

    if call == "declare":
        parsestatdeclare(indent)
        return

    if call == "set":
        parsestatset(indent)
        return

    if call == "calc":
        parsestatcalc(indent)
        return

    if call == "if":
        parsestatif(indent)
        return

    if call == "forever":
        parsestatforever(indent)
        return

    if call == "break":
        parsestatbreak(indent)
        return

    if call == "return":
        parsestatreturn(indent)
        return

    if call == "check":
        parsestatcheck(indent)
        return

    if call == "trace":
        parsestattrace(indent)
        return

    funcid = registerid(call)

    emit('    ' * indent)
    emit(funcid)
    emit('(')

    first = True
    while ' ' == peek():
        skip()
        if not first:
            emit(", ")
        if '"' == peek():
            parseconststring()
        else:
            parseexprvarref()
        first = False

    skipchar(eol)

    emitln(')')

def parseblock(indent):
    while True:
        while eol == peek():
            skip()

        for _ in range(indent - 1):
            skipchar('\t')

        if '/' == peek():
            skip()
            skipchar(eol)
            break

        skipchar('\t')

        parsestat(indent)

def parsefunc():
    funcname = lexident()
    funcid = registerid(funcname)
    mapsetkey("FUNCREG", funcname, "1")

    trace('funcname', funcname)
    emit('def ')
    emit(funcid)
    emit('(')

    first = True
    while ' ' == peek():
        skip()
        varname = lexident()
        varid = registerid(varname)
        if not first:
            emit(", ")
        emit(varid)
        first = False

    if '/' == peek():
        # Ahead declaration
        skipchar('/')
        skipchar(eol)
        emitln("):")
        emitln("    pass # ahead declaration")
        emit(eol)
        return

    skipchar(':')
    skipchar(eol)

    emit('): # ')
    emitln(funcname)

    parseblock(1)

    emit(eol)

def emitheader():
    emitln("import os")
    emitln("import sys")
    emitln("")
    emitln("def __eq(a, b):")
    emitln("    return a == b")
    emitln("")
    emitln("def __lt(a, b):")
    emitln("    return a[0] < b[0]")
    emitln("")
    emitln("def __addstringchar(a, b):")
    emitln("    return a + b[0]")
    emitln("")
    emitln("def __emit(string):")
    emitln("    sys.stdout.write(string)")
    emitln("    sys.stdout.flush()")
    emitln("")
    emitln("def trace(header, value):")
    emitln("    if os.environ.get('TRACE'):")
    emitln("        sys.stderr.write(f'{header}={value!r}\\n')")
    emitln("")
    emitln("__EOF = chr(0)")
    emitln("__EOL = chr(10)")
    emitln("__QUOTE = chr(34)")
    emitln("")
    emitln("STDINCOLNO = 0")
    emitln("STDINLINENO = 1")
    emitln("STDINPEEK = None")
    emitln("")
    emitln("def _readchar():")
    emitln("    char = sys.stdin.read(1)")
    emitln("    trace('char', char)")
    emitln("    if not char:")
    emitln("        return __EOF")
    emitln("    return char")
    emitln("")
    emitln("def __peek():")
    emitln("    return STDINPEEK")
    emitln("")
    emitln("def __skip():")
    emitln("    global STDINCOLNO")
    emitln("    global STDINLINENO")
    emitln("    global STDINPEEK")
    emitln("    if __EOL == STDINPEEK:")
    emitln("        STDINLINENO += 1")
    emitln("        STDINCOLNO = 0")
    emitln("    STDINCOLNO += 1")
    emitln("    STDINPEEK = _readchar()")
    emitln("")
    emitln("def __stdinlineno():")
    emitln("    global STDINLINENO")
    emitln("    return str(STDINLINENO)")
    emitln("")
    emitln("def __stdincolno():")
    emitln("    global STDINCOLNO")
    emitln("    return str(STDINCOLNO)")
    emitln("")
    emitln("__skip()")
    emitln("")
    emitln("MAPSTORE = {}")
    emitln("")
    emitln("def mapclear(mapname: str) -> str:")
    emitln("    MAPSTORE.pop(mapname)")
    emitln("    return ''")
    emitln("")
    emitln("def mapgetkey(mapname: str, key: str, default: str) -> str:")
    emitln("    return MAPSTORE.get(mapname, {}).get(key, default)")
    emitln("")
    emitln("def mapsetkey(mapname: str, key: str, value: str) -> str:")
    emitln("    MAPSTORE.setdefault(mapname, {})")
    emitln("    MAPSTORE[mapname][key] = value")
    emitln("    return ''")
    emitln("")
    emitln("def __not(a: str) -> str:")
    emitln("    if a:")
    emitln("        return ''")
    emitln("    return '1'")
    emitln("")
    emitln("def __check(func, args: list[str], msg: list[str]) -> None:")
    emitln("    result = func(*args)")
    emitln("    if result:")
    emitln("        return")
    emitln("")
    emitln("    sys.stderr.write(' '.join(msg) + '\\n')")
    emitln("    sys.stderr.flush()")
    emitln("    exit(1)")

def emitfooter():
    mainname = registerid("main")
    emitln("if __name__ == '__main__':")
    emit("    ")
    emit(mainname)
    emitln("()")

def main():
    emitheader()

    # Standard library constants
    mapsetkey("REGISTERID", "eof", "__EOF")
    mapsetkey("REGISTERID", "eol", "__EOL")
    mapsetkey("REGISTERID", "quote", "__QUOTE")

    # Standard library functions
    mapsetkey("FUNCREG", "addstringchar", "1")
    mapsetkey("REGISTERID", "addstringchar", "__addstringchar")
    mapsetkey("FUNCREG", "emit", "1")
    mapsetkey("REGISTERID", "emit", "__emit")
    mapsetkey("FUNCREG", "eq", "1")
    mapsetkey("REGISTERID", "eq", "__eq")
    mapsetkey("FUNCREG", "lt", "1")
    mapsetkey("REGISTERID", "lt", "__lt")
    mapsetkey("FUNCREG", "not", "1")
    mapsetkey("REGISTERID", "not", "__not")
    mapsetkey("FUNCREG", "mapclear", "1")
    mapsetkey("FUNCREG", "mapgetkey", "1")
    mapsetkey("FUNCREG", "mapsetkey", "1")
    mapsetkey("FUNCREG", "peek", "1")
    mapsetkey("REGISTERID", "peek", "__peek")
    mapsetkey("FUNCREG", "skip", "1")
    mapsetkey("REGISTERID", "skip", "__skip")
    mapsetkey("FUNCREG", "stdincolno", "1")
    mapsetkey("REGISTERID", "stdincolno", "__stdincolno")
    mapsetkey("FUNCREG", "stdinlineno", "1")
    mapsetkey("REGISTERID", "stdinlineno", "__stdinlineno")

    while True:
        if eof == peek():
            break

        while eol == peek():
            skip()

        parsefunc()
    emitfooter()

if __name__ == '__main__':
    main()