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#
#
# The Nim Compiler
# (c) Copyright 2012 Andreas Rumpf
#
# See the file "copying.txt", included in this
# distribution, for details about the copyright.
#
## Implements the dispatcher for the different parsers.
import
strutils, llstream, ast, astalgo, idents, lexer, options, msgs, parser,
pbraces, filters, filter_tmpl, renderer
type
TFilterKind* = enum
filtNone, filtTemplate, filtReplace, filtStrip
TParserKind* = enum
skinStandard, skinStrongSpaces, skinBraces, skinEndX
const
parserNames*: array[TParserKind, string] = ["standard", "strongspaces",
"braces", "endx"]
filterNames*: array[TFilterKind, string] = ["none", "stdtmpl", "replace",
"strip"]
type
TParsers*{.final.} = object
skin*: TParserKind
parser*: TParser
proc parseFile*(fileIdx: int32): PNode{.procvar.}
proc openParsers*(p: var TParsers, fileIdx: int32, inputstream: PLLStream)
proc closeParsers*(p: var TParsers)
proc parseAll*(p: var TParsers): PNode
proc parseTopLevelStmt*(p: var TParsers): PNode
# implements an iterator. Returns the next top-level statement or nil if end
# of stream.
# implementation
proc parseFile(fileIdx: int32): PNode =
var
p: TParsers
f: File
let filename = fileIdx.toFullPathConsiderDirty
if not open(f, filename):
rawMessage(errCannotOpenFile, filename)
return
openParsers(p, fileIdx, llStreamOpen(f))
result = parseAll(p)
closeParsers(p)
proc parseAll(p: var TParsers): PNode =
case p.skin
of skinStandard, skinStrongSpaces:
result = parser.parseAll(p.parser)
of skinBraces:
result = pbraces.parseAll(p.parser)
of skinEndX:
internalError("parser to implement")
result = ast.emptyNode
proc parseTopLevelStmt(p: var TParsers): PNode =
case p.skin
of skinStandard, skinStrongSpaces:
result = parser.parseTopLevelStmt(p.parser)
of skinBraces:
result = pbraces.parseTopLevelStmt(p.parser)
of skinEndX:
internalError("parser to implement")
result = ast.emptyNode
proc utf8Bom(s: string): int =
if (s[0] == '\xEF') and (s[1] == '\xBB') and (s[2] == '\xBF'):
result = 3
else:
result = 0
proc containsShebang(s: string, i: int): bool =
if (s[i] == '#') and (s[i + 1] == '!'):
var j = i + 2
while s[j] in Whitespace: inc(j)
result = s[j] == '/'
proc parsePipe(filename: string, inputStream: PLLStream): PNode =
result = ast.emptyNode
var s = llStreamOpen(filename, fmRead)
if s != nil:
var line = newStringOfCap(80)
discard llStreamReadLine(s, line)
var i = utf8Bom(line)
var linenumber = 1
if containsShebang(line, i):
discard llStreamReadLine(s, line)
i = 0
inc linenumber
if line[i] == '#' and line[i+1] in {'?', '!'}:
if line[i+1] == '!':
message(newLineInfo(filename, linenumber, 1),
warnDeprecated, "use '#?' instead; '#!'")
inc(i, 2)
while line[i] in Whitespace: inc(i)
var q: TParser
openParser(q, filename, llStreamOpen(substr(line, i)))
result = parser.parseAll(q)
closeParser(q)
llStreamClose(s)
proc getFilter(ident: PIdent): TFilterKind =
for i in countup(low(TFilterKind), high(TFilterKind)):
if identEq(ident, filterNames[i]):
return i
result = filtNone
proc getParser(ident: PIdent): TParserKind =
for i in countup(low(TParserKind), high(TParserKind)):
if identEq(ident, parserNames[i]):
return i
rawMessage(errInvalidDirectiveX, ident.s)
proc getCallee(n: PNode): PIdent =
if n.kind in nkCallKinds and n.sons[0].kind == nkIdent:
result = n.sons[0].ident
elif n.kind == nkIdent:
result = n.ident
else:
rawMessage(errXNotAllowedHere, renderTree(n))
proc applyFilter(p: var TParsers, n: PNode, filename: string,
stdin: PLLStream): PLLStream =
var ident = getCallee(n)
var f = getFilter(ident)
case f
of filtNone:
p.skin = getParser(ident)
result = stdin
of filtTemplate:
result = filterTmpl(stdin, filename, n)
of filtStrip:
result = filterStrip(stdin, filename, n)
of filtReplace:
result = filterReplace(stdin, filename, n)
if f != filtNone:
if hintCodeBegin in gNotes:
rawMessage(hintCodeBegin, [])
msgWriteln(result.s)
rawMessage(hintCodeEnd, [])
proc evalPipe(p: var TParsers, n: PNode, filename: string,
start: PLLStream): PLLStream =
result = start
if n.kind == nkEmpty: return
if n.kind == nkInfix and n.sons[0].kind == nkIdent and
identEq(n.sons[0].ident, "|"):
for i in countup(1, 2):
if n.sons[i].kind == nkInfix:
result = evalPipe(p, n.sons[i], filename, result)
else:
result = applyFilter(p, n.sons[i], filename, result)
elif n.kind == nkStmtList:
result = evalPipe(p, n.sons[0], filename, result)
else:
result = applyFilter(p, n, filename, result)
proc openParsers(p: var TParsers, fileIdx: int32, inputstream: PLLStream) =
var s: PLLStream
p.skin = skinStandard
let filename = fileIdx.toFullPathConsiderDirty
var pipe = parsePipe(filename, inputstream)
if pipe != nil: s = evalPipe(p, pipe, filename, inputstream)
else: s = inputstream
case p.skin
of skinStandard, skinBraces, skinEndX:
parser.openParser(p.parser, fileIdx, s, false)
of skinStrongSpaces:
parser.openParser(p.parser, fileIdx, s, true)
proc closeParsers(p: var TParsers) =
parser.closeParser(p.parser)
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