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Diffstat (limited to 'compiler/llstream.nim')
| -rw-r--r-- | compiler/llstream.nim | 218 |
1 files changed, 218 insertions, 0 deletions
diff --git a/compiler/llstream.nim b/compiler/llstream.nim new file mode 100644 index 000000000..cc8148483 --- /dev/null +++ b/compiler/llstream.nim @@ -0,0 +1,218 @@ +# +# +# The Nim Compiler +# (c) Copyright 2012 Andreas Rumpf +# +# See the file "copying.txt", included in this +# distribution, for details about the copyright. +# + +## Low-level streams for high performance. + +import + pathutils + +when defined(nimPreviewSlimSystem): + import std/syncio + +# support `useGnuReadline`, `useLinenoise` for backwards compatibility +const hasRstdin = (defined(nimUseLinenoise) or defined(useLinenoise) or defined(useGnuReadline)) and + not defined(windows) + +when hasRstdin: import std/rdstdin + +type + TLLRepl* = proc (s: PLLStream, buf: pointer, bufLen: int): int + OnPrompt* = proc() {.closure.} + TLLStreamKind* = enum # enum of different stream implementations + llsNone, # null stream: reading and writing has no effect + llsString, # stream encapsulates a string + llsFile, # stream encapsulates a file + llsStdIn # stream encapsulates stdin + TLLStream* = object of RootObj + kind*: TLLStreamKind # accessible for low-level access (lexbase uses this) + f*: File + s*: string + rd*, wr*: int # for string streams + lineOffset*: int # for fake stdin line numbers + repl*: TLLRepl # gives stdin control to clients + onPrompt*: OnPrompt + + PLLStream* = ref TLLStream + +proc llStreamOpen*(data: sink string): PLLStream = + PLLStream(kind: llsString, s: data) + +proc llStreamOpen*(f: File): PLLStream = + PLLStream(kind: llsFile, f: f) + +proc llStreamOpen*(filename: AbsoluteFile, mode: FileMode): PLLStream = + result = PLLStream(kind: llsFile) + if not open(result.f, filename.string, mode): result = nil + +proc llStreamOpen*(): PLLStream = + PLLStream(kind: llsNone) + +proc llReadFromStdin(s: PLLStream, buf: pointer, bufLen: int): int +proc llStreamOpenStdIn*(r: TLLRepl = llReadFromStdin, onPrompt: OnPrompt = nil): PLLStream = + PLLStream(kind: llsStdIn, s: "", lineOffset: -1, repl: r, onPrompt: onPrompt) + +proc llStreamClose*(s: PLLStream) = + case s.kind + of llsNone, llsString, llsStdIn: + discard + of llsFile: + close(s.f) + +when not declared(readLineFromStdin): + # fallback implementation: + proc readLineFromStdin(prompt: string, line: var string): bool = + stdout.write(prompt) + stdout.flushFile() + result = readLine(stdin, line) + if not result: + stdout.write("\n") + quit(0) + +proc endsWith*(x: string, s: set[char]): bool = + var i = x.len-1 + while i >= 0 and x[i] == ' ': dec(i) + if i >= 0 and x[i] in s: + result = true + else: + result = false + +const + LineContinuationOprs = {'+', '-', '*', '/', '\\', '<', '>', '!', '?', '^', + '|', '%', '&', '$', '@', '~', ','} + AdditionalLineContinuationOprs = {'#', ':', '='} + +proc endsWithOpr*(x: string): bool = + result = x.endsWith(LineContinuationOprs) + +proc continueLine(line: string, inTripleString: bool): bool {.inline.} = + result = inTripleString or line.len > 0 and ( + line[0] == ' ' or + line.endsWith(LineContinuationOprs+AdditionalLineContinuationOprs)) + +proc countTriples(s: string): int = + result = 0 + var i = 0 + while i+2 < s.len: + if s[i] == '"' and s[i+1] == '"' and s[i+2] == '"': + inc result + inc i, 2 + inc i + +proc llReadFromStdin(s: PLLStream, buf: pointer, bufLen: int): int = + s.s = "" + s.rd = 0 + var line = newStringOfCap(120) + var triples = 0 + while readLineFromStdin(if s.s.len == 0: ">>> " else: "... ", line): + s.s.add(line) + s.s.add("\n") + inc triples, countTriples(line) + if not continueLine(line, (triples and 1) == 1): break + inc(s.lineOffset) + result = min(bufLen, s.s.len - s.rd) + if result > 0: + copyMem(buf, addr(s.s[s.rd]), result) + inc(s.rd, result) + +proc llStreamRead*(s: PLLStream, buf: pointer, bufLen: int): int = + case s.kind + of llsNone: + result = 0 + of llsString: + result = min(bufLen, s.s.len - s.rd) + if result > 0: + copyMem(buf, addr(s.s[0 + s.rd]), result) + inc(s.rd, result) + of llsFile: + result = readBuffer(s.f, buf, bufLen) + of llsStdIn: + if s.onPrompt!=nil: s.onPrompt() + result = s.repl(s, buf, bufLen) + +proc llStreamReadLine*(s: PLLStream, line: var string): bool = + setLen(line, 0) + case s.kind + of llsNone: + result = true + of llsString: + while s.rd < s.s.len: + case s.s[s.rd] + of '\r': + inc(s.rd) + if s.s[s.rd] == '\n': inc(s.rd) + break + of '\n': + inc(s.rd) + break + else: + line.add(s.s[s.rd]) + inc(s.rd) + result = line.len > 0 or s.rd < s.s.len + of llsFile: + result = readLine(s.f, line) + of llsStdIn: + result = readLine(stdin, line) + +proc llStreamWrite*(s: PLLStream, data: string) = + case s.kind + of llsNone, llsStdIn: + discard + of llsString: + s.s.add(data) + inc(s.wr, data.len) + of llsFile: + write(s.f, data) + +proc llStreamWriteln*(s: PLLStream, data: string) = + llStreamWrite(s, data) + llStreamWrite(s, "\n") + +proc llStreamWrite*(s: PLLStream, data: char) = + var c: char + case s.kind + of llsNone, llsStdIn: + discard + of llsString: + s.s.add(data) + inc(s.wr) + of llsFile: + c = data + discard writeBuffer(s.f, addr(c), sizeof(c)) + +proc llStreamWrite*(s: PLLStream, buf: pointer, buflen: int) = + case s.kind + of llsNone, llsStdIn: + discard + of llsString: + if buflen > 0: + setLen(s.s, s.s.len + buflen) + copyMem(addr(s.s[0 + s.wr]), buf, buflen) + inc(s.wr, buflen) + of llsFile: + discard writeBuffer(s.f, buf, buflen) + +proc llStreamReadAll*(s: PLLStream): string = + const + bufSize = 2048 + case s.kind + of llsNone, llsStdIn: + result = "" + of llsString: + if s.rd == 0: result = s.s + else: result = substr(s.s, s.rd) + s.rd = s.s.len + of llsFile: + result = newString(bufSize) + var bytes = readBuffer(s.f, addr(result[0]), bufSize) + var i = bytes + while bytes == bufSize: + setLen(result, i + bufSize) + bytes = readBuffer(s.f, addr(result[i + 0]), bufSize) + inc(i, bytes) + setLen(result, i) |