diff options
Diffstat (limited to 'src/algebra/net.spad.pamphlet')
| -rw-r--r-- | src/algebra/net.spad.pamphlet | 94 |
1 files changed, 42 insertions, 52 deletions
diff --git a/src/algebra/net.spad.pamphlet b/src/algebra/net.spad.pamphlet index 05d15354..4f2ded2a 100644 --- a/src/algebra/net.spad.pamphlet +++ b/src/algebra/net.spad.pamphlet @@ -37,25 +37,24 @@ Conduit(): Category == with ++ Description: ++ This category describes input byte stream conduits. InputByteConduit(): Category == Conduit with - readByteIfCan!: % -> SingleInteger - ++ readByteIfCan!(cond) attempts to read a byte from the + readByte!: % -> Maybe Byte + ++ readByte!(cond) attempts to read a byte from the ++ input conduit `cond'. Returns the read byte if successful, - ++ otherwise return -1. - ++ Note: Ideally, the return value should have been of type - ++ Maybe Byte; but that would have implied allocating - ++ a cons cell for every read attempt, which is overkill. - readBytes!: (%,ByteBuffer) -> SingleInteger + ++ otherwise \spad{nothing}. + readBytes!: (%,ByteBuffer) -> NonNegativeInteger ++ readBytes!(c,b) reads byte sequences from conduit `c' into ++ the byte buffer `b'. The actual number of bytes written ++ is returned, and the length of `b' is set to that amount. add readBytes!(cond,buf) == - count: NonNegativeInteger := 0 - b : SingleInteger - while count < capacity buf and ((b := readByteIfCan! cond) >= 0) repeat - qsetelt!(buf,count,b : Byte) - count := count + 1 - setLength!(buf,count)::SingleInteger + count := 0@NonNegativeInteger + while count < capacity buf repeat + case readByte! cond is + b@Byte => + qsetelt!(buf,count,b) + count := count + 1 + otherwise => break + setLength!(buf,count) @ @@ -69,22 +68,19 @@ InputByteConduit(): Category == Conduit with ++ Description: ++ This category describes output byte stream conduits. OutputByteConduit(): Category == Conduit with - writeByteIfCan!: (%,Byte) -> SingleInteger - ++ writeByteIfCan!(c,b) attempts to write the byte `b' on + writeByte!: (%,Byte) -> Maybe Byte + ++ writeByte!(c,b) attempts to write the byte `b' on ++ the conduit `c'. Returns the written byte if successful, - ++ otherwise, returns -1. - ++ Note: Ideally, the return value should have been of type - ++ Maybe Byte; but that would have implied allocating - ++ a cons cell for every write attempt, which is overkill. - writeBytes!: (%,ByteBuffer) -> SingleInteger + ++ otherwise, returns \spad{nothing}. + writeBytes!: (%,ByteBuffer) -> NonNegativeInteger ++ writeBytes!(c,b) write bytes from buffer `b' ++ onto the conduit `c'. The actual number of written ++ bytes is returned. add writeBytes!(cond,buf) == - count: SingleInteger := 0 + count := 0@NonNegativeInteger while count < capacity buf and - writeByteIfCan!(cond,qelt(buf,count)) >= 0 repeat + writeByte!(cond,qelt(buf,count)) case Byte repeat count := count + 1 count @@ -143,10 +139,10 @@ InputBinaryFile(): Public == Private where per [openBinaryFile(f,input$IOMode)$Lisp,f::FileName,false] isOpen? ifile == not null? rep(ifile).stream - readByteIfCan! ifile == + readByte! ifile == isOpen? ifile => - b: SingleInteger := readByteFromFile(rep(ifile).stream)$Lisp - if b < 0@SingleInteger then + b: Maybe Byte := readByteFromFile(rep(ifile).stream)$Lisp + if b case nothing then rep(ifile).eof := true b error "file is not open" @@ -165,7 +161,6 @@ InputBinaryFile(): Public == Private where position!(ifile,p) == isOpen? ifile => FILE_-POSITION(rep(ifile).stream,p)$Lisp - p error "file is not open" coerce(ifile: %): OutputForm == rep(ifile).filename::OutputForm @@ -200,7 +195,7 @@ OutputBinaryFile(): Public == Private where per [openBinaryFile(f,output$IOMode)$Lisp,f::FileName] isOpen? ifile == not null? rep(ifile).stream - writeByteIfCan!(ifile,b) == + writeByte!(ifile,b) == isOpen? ifile => writeByteToFile(rep(ifile).stream,b)$Lisp error "file is not open" close! ifile == @@ -338,50 +333,45 @@ InetClientStreamSocket(): Public == Private where Public == Join(NetworkClientSocket IP4Address, CoercibleTo OutputForm) with connectTo: (Hostname, PortNumber) -> Maybe % Private == add - -- we hope that a small integer is OK on all platform Host == Union(IP4Address,Hostname) - Rep == Record(%host: Host, %port: PortNumber, %sock: SingleInteger) + -- we hope that a small integer is OK on all platforms + Rep == Record(%host: Host, %port: PortNumber, %sock: Maybe SingleInteger) connectTo(ip: IP4Address, p: PortNumber) == - s: SingleInteger := connectToHostAndPort(ip,4,p)$Lisp - s = -1::SingleInteger => nothing + s: Maybe SingleInteger := connectToHostAndPort(ip,4,p)$Lisp + s case nothing => nothing just per [ip::Host,p,s] connectTo(h: Hostname, p: PortNumber) == (ip := resolve(h)$IP4Address) case nothing => nothing - s: SingleInteger := connectToHostAndPort(ip@IP4Address,4,p)$Lisp - s = -1::SingleInteger => nothing + s: Maybe SingleInteger := connectToHostAndPort(ip@IP4Address,4,p)$Lisp + s case nothing => nothing just per [h::Host,p,s] isConnected? s == - rep(s).%sock ~= -1::SingleInteger + rep(s).%sock case SingleInteger readBytes!(x,b) == - n: SingleInteger := + not isConnected? x => error "socket is not connected" + n: NonNegativeInteger := readFromStreamSocket(rep(x).%sock,b, capacity b)$Lisp - if n <= 0 then close! x - else setLength!(b,n : NonNegativeInteger) - n - readByteIfCan! x == - r: SingleInteger := readByteFromStreamSocket(rep(x).%sock)$Lisp - if r < 0 then close! x - r + setLength!(b,n) + + readByte! x == + not isConnected? x => error "socket is not connected" + readByteFromStreamSocket(rep(x).%sock)$Lisp writeBytes!(x,b) == - n: SingleInteger := - writeToStreamSocket(rep(x).%sock,b, capacity b)$Lisp - if n <= 0 then close! x - else setLength!(b,n : NonNegativeInteger) - n + not isConnected? x => error "socket is not connected" + writeToStreamSocket(rep(x).%sock,b, #b)$Lisp - writeByteIfCan!(x,b) == - r: SingleInteger := writeByteToStreamSocket(rep(x).%sock,b)$Lisp - if r < 0 then close! x - r + writeByte!(x,b) == + not isConnected? x => error "socket is not connected" + writeByteToStreamSocket(rep(x).%sock,b)$Lisp close! x == closeSocket(rep(x).%sock)$Lisp - rep(x).%sock := -1::SingleInteger + rep(x).%sock := nothing x coerce(x: %): OutputForm == |