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Diffstat (limited to 'compiler/parser.nim')
| -rw-r--r-- | compiler/parser.nim | 2590 |
1 files changed, 2590 insertions, 0 deletions
diff --git a/compiler/parser.nim b/compiler/parser.nim new file mode 100644 index 000000000..747505097 --- /dev/null +++ b/compiler/parser.nim @@ -0,0 +1,2590 @@ +# +# +# The Nim Compiler +# (c) Copyright 2015 Andreas Rumpf +# +# See the file "copying.txt", included in this +# distribution, for details about the copyright. +# + +# This module implements the parser of the standard Nim syntax. +# The parser strictly reflects the grammar ("doc/grammar.txt"); however +# it uses several helper routines to keep the parser small. A special +# efficient algorithm is used for the precedence levels. The parser here can +# be seen as a refinement of the grammar, as it specifies how the AST is built +# from the grammar and how comments belong to the AST. + + +# In fact the grammar is generated from this file: +when isMainModule or defined(nimTestGrammar): + # Leave a note in grammar.txt that it is generated: + #| # This file is generated by compiler/parser.nim. + import std/pegs + when defined(nimPreviewSlimSystem): + import std/syncio + + proc writeGrammarFile(x: string) = + var outp = open(x, fmWrite) + for line in lines("compiler/parser.nim"): + if line =~ peg" \s* '#| ' {.*}": + outp.write matches[0], "\L" + outp.close + + when defined(nimTestGrammar): + import std/os + from ../testament/lib/stdtest/specialpaths import buildDir + const newGrammarText = buildDir / "grammar.txt" + + if not dirExists(buildDir): + createDir(buildDir) + + writeGrammarFile(newGrammarText) + + proc checkSameGrammar*() = + doAssert sameFileContent(newGrammarText, "doc/grammar.txt"), + "execute 'nim r compiler/parser.nim' to keep grammar.txt up-to-date" + else: + writeGrammarFile("doc/grammar.txt") + import ".." / tools / grammar_nanny + checkGrammarFile() + +import + llstream, lexer, idents, msgs, options, lineinfos, + pathutils + +when not defined(nimCustomAst): + import ast +else: + import plugins / customast + +import std/strutils + +when defined(nimpretty): + import layouter + +when defined(nimPreviewSlimSystem): + import std/assertions + +type + Parser* = object # A Parser object represents a file that + # is being parsed + currInd: int # current indentation level + firstTok: bool # Has the first token been read? + hasProgress: bool # some while loop requires progress ensurance + lex*: Lexer # The lexer that is used for parsing + tok*: Token # The current token + lineStartPrevious*: int + lineNumberPrevious*: int + bufposPrevious*: int + inPragma*: int # Pragma level + inSemiStmtList*: int + when not defined(nimCustomAst): + emptyNode: PNode + when defined(nimpretty): + em*: Emitter + + SymbolMode = enum + smNormal, smAllowNil, smAfterDot + + PrimaryMode = enum + pmNormal, pmTypeDesc, pmTypeDef, pmTrySimple + +when defined(nimCustomAst): + # For the `customast` version we cannot share nodes, not even empty nodes: + template emptyNode(p: Parser): PNode = newNode(nkEmpty) + +# helpers for the other parsers +proc isOperator*(tok: Token): bool +proc getTok*(p: var Parser) +proc parMessage*(p: Parser, msg: TMsgKind, arg: string = "") +proc skipComment*(p: var Parser, node: PNode) +proc newNodeP*(kind: TNodeKind, p: Parser): PNode +proc newIntNodeP*(kind: TNodeKind, intVal: BiggestInt, p: Parser): PNode +proc newFloatNodeP*(kind: TNodeKind, floatVal: BiggestFloat, p: Parser): PNode +proc newStrNodeP*(kind: TNodeKind, strVal: sink string, p: Parser): PNode +proc newIdentNodeP*(ident: PIdent, p: Parser): PNode +proc expectIdentOrKeyw*(p: Parser) +proc expectIdent*(p: Parser) +proc parLineInfo*(p: Parser): TLineInfo +proc eat*(p: var Parser, tokType: TokType) +proc skipInd*(p: var Parser) +proc optPar*(p: var Parser) +proc optInd*(p: var Parser, n: PNode) +proc indAndComment*(p: var Parser, n: PNode, maybeMissEquals = false) +proc setBaseFlags*(n: PNode, base: NumericalBase) +proc parseSymbol*(p: var Parser, mode = smNormal): PNode +proc parseTry(p: var Parser; isExpr: bool): PNode +proc parseCase(p: var Parser): PNode +proc parseStmtPragma(p: var Parser): PNode +proc parsePragma(p: var Parser): PNode +proc postExprBlocks(p: var Parser, x: PNode): PNode +proc parseExprStmt(p: var Parser): PNode +proc parseBlock(p: var Parser): PNode +proc primary(p: var Parser, mode: PrimaryMode): PNode +proc simpleExprAux(p: var Parser, limit: int, mode: PrimaryMode): PNode + +# implementation + +template prettySection(body) = + when defined(nimpretty): beginSection(p.em) + body + when defined(nimpretty): endSection(p.em) + +proc getTok(p: var Parser) = + ## Get the next token from the parser's lexer, and store it in the parser's + ## `tok` member. + p.lineNumberPrevious = p.lex.lineNumber + p.lineStartPrevious = p.lex.lineStart + p.bufposPrevious = p.lex.bufpos + rawGetTok(p.lex, p.tok) + p.hasProgress = true + when defined(nimpretty): + emitTok(p.em, p.lex, p.tok) + # skip the additional tokens that nimpretty needs but the parser has no + # interest in: + while p.tok.tokType == tkComment: + rawGetTok(p.lex, p.tok) + emitTok(p.em, p.lex, p.tok) + +proc openParser*(p: var Parser, fileIdx: FileIndex, inputStream: PLLStream, + cache: IdentCache; config: ConfigRef) = + ## Open a parser, using the given arguments to set up its internal state. + ## + reset(p.tok) + openLexer(p.lex, fileIdx, inputStream, cache, config) + when defined(nimpretty): + openEmitter(p.em, cache, config, fileIdx) + getTok(p) # read the first token + p.firstTok = true + when not defined(nimCustomAst): + p.emptyNode = newNode(nkEmpty) + +proc openParser*(p: var Parser, filename: AbsoluteFile, inputStream: PLLStream, + cache: IdentCache; config: ConfigRef) = + openParser(p, fileInfoIdx(config, filename), inputStream, cache, config) + +proc closeParser*(p: var Parser) = + ## Close a parser, freeing up its resources. + closeLexer(p.lex) + +proc parMessage(p: Parser, msg: TMsgKind, arg = "") = + ## Produce and emit the parser message `arg` to output. + lexMessageTok(p.lex, msg, p.tok, arg) + +proc parMessage(p: Parser, msg: string, tok: Token) = + ## Produce and emit a parser message to output about the token `tok` + parMessage(p, errGenerated, msg % prettyTok(tok)) + +proc parMessage(p: Parser, arg: string) = + ## Produce and emit the parser message `arg` to output. + lexMessageTok(p.lex, errGenerated, p.tok, arg) + +template withInd(p, body: untyped) = + let oldInd = p.currInd + p.currInd = p.tok.indent + body + p.currInd = oldInd + +template newlineWasSplitting(p: var Parser) = + when defined(nimpretty): + layouter.newlineWasSplitting(p.em) + +template realInd(p): bool = p.tok.indent > p.currInd +template sameInd(p): bool = p.tok.indent == p.currInd +template sameOrNoInd(p): bool = p.tok.indent == p.currInd or p.tok.indent < 0 + +proc validInd(p: var Parser): bool {.inline.} = + result = p.tok.indent < 0 or p.tok.indent > p.currInd + +proc rawSkipComment(p: var Parser, node: PNode) = + if p.tok.tokType == tkComment: + if node != nil: + var rhs = node.comment + when defined(nimpretty): + if p.tok.commentOffsetB > p.tok.commentOffsetA: + rhs.add fileSection(p.lex.config, p.lex.fileIdx, p.tok.commentOffsetA, p.tok.commentOffsetB) + else: + rhs.add p.tok.literal + else: + rhs.add p.tok.literal + node.comment = move rhs + else: + parMessage(p, errInternal, "skipComment") + getTok(p) + +proc skipComment(p: var Parser, node: PNode) = + if p.tok.indent < 0: rawSkipComment(p, node) + +proc flexComment(p: var Parser, node: PNode) = + if p.tok.indent < 0 or realInd(p): rawSkipComment(p, node) + +const + errInvalidIndentation = "invalid indentation" + errIdentifierExpected = "identifier expected, but got '$1'" + errExprExpected = "expression expected, but found '$1'" + +proc skipInd(p: var Parser) = + if p.tok.indent >= 0: + if not realInd(p): parMessage(p, errInvalidIndentation) + +proc optPar(p: var Parser) = + if p.tok.indent >= 0: + if p.tok.indent < p.currInd: parMessage(p, errInvalidIndentation) + +proc optInd(p: var Parser, n: PNode) = + skipComment(p, n) + skipInd(p) + +proc getTokNoInd(p: var Parser) = + getTok(p) + if p.tok.indent >= 0: parMessage(p, errInvalidIndentation) + +proc expectIdentOrKeyw(p: Parser) = + if p.tok.tokType != tkSymbol and not isKeyword(p.tok.tokType): + lexMessage(p.lex, errGenerated, errIdentifierExpected % prettyTok(p.tok)) + +proc expectIdent(p: Parser) = + if p.tok.tokType != tkSymbol: + lexMessage(p.lex, errGenerated, errIdentifierExpected % prettyTok(p.tok)) + +proc eat(p: var Parser, tokType: TokType) = + ## Move the parser to the next token if the current token is of type + ## `tokType`, otherwise error. + if p.tok.tokType == tokType: + getTok(p) + else: + lexMessage(p.lex, errGenerated, + "expected: '" & $tokType & "', but got: '" & prettyTok(p.tok) & "'") + +proc parLineInfo(p: Parser): TLineInfo = + ## Retrieve the line information associated with the parser's current state. + result = getLineInfo(p.lex, p.tok) + +proc indAndComment(p: var Parser, n: PNode, maybeMissEquals = false) = + if p.tok.indent > p.currInd: + if p.tok.tokType == tkComment: rawSkipComment(p, n) + elif maybeMissEquals: + let col = p.bufposPrevious - p.lineStartPrevious + var info = newLineInfo(p.lex.fileIdx, p.lineNumberPrevious, col) + parMessage(p, "invalid indentation, maybe you forgot a '=' at $1 ?" % [p.lex.config$info]) + else: parMessage(p, errInvalidIndentation) + else: + skipComment(p, n) + +proc newNodeP(kind: TNodeKind, p: Parser): PNode = + result = newNode(kind, parLineInfo(p)) + +proc newIntNodeP(kind: TNodeKind, intVal: BiggestInt, p: Parser): PNode = + result = newAtom(kind, intVal, parLineInfo(p)) + +proc newFloatNodeP(kind: TNodeKind, floatVal: BiggestFloat, + p: Parser): PNode = + result = newAtom(kind, floatVal, parLineInfo(p)) + +proc newStrNodeP(kind: TNodeKind, strVal: sink string, p: Parser): PNode = + result = newAtom(kind, strVal, parLineInfo(p)) + +proc newIdentNodeP(ident: PIdent, p: Parser): PNode = + result = newAtom(ident, parLineInfo(p)) + +proc parseExpr(p: var Parser): PNode +proc parseStmt(p: var Parser): PNode +proc parseTypeDesc(p: var Parser, fullExpr = false): PNode +proc parseTypeDefValue(p: var Parser): PNode +proc parseParamList(p: var Parser, retColon = true): PNode + +proc isSigilLike(tok: Token): bool {.inline.} = + result = tok.tokType == tkOpr and tok.ident.s[0] == '@' + +proc isRightAssociative(tok: Token): bool {.inline.} = + ## Determines whether the token is right assocative. + result = tok.tokType == tkOpr and tok.ident.s[0] == '^' + # or (tok.ident.s.len > 1 and tok.ident.s[^1] == '>') + +proc isUnary(tok: Token): bool = + ## Check if the given token is a unary operator + tok.tokType in {tkOpr, tkDotDot} and + tok.spacing == {tsLeading} + +proc checkBinary(p: Parser) {.inline.} = + ## Check if the current parser token is a binary operator. + # we don't check '..' here as that's too annoying + if p.tok.tokType == tkOpr: + if p.tok.spacing == {tsTrailing}: + parMessage(p, warnInconsistentSpacing, prettyTok(p.tok)) + +#| module = complexOrSimpleStmt ^* (';' / IND{=}) +#| +#| comma = ',' COMMENT? +#| semicolon = ';' COMMENT? +#| colon = ':' COMMENT? +#| colcom = ':' COMMENT? +#| +#| operator = OP0 | OP1 | OP2 | OP3 | OP4 | OP5 | OP6 | OP7 | OP8 | OP9 +#| | 'or' | 'xor' | 'and' +#| | 'is' | 'isnot' | 'in' | 'notin' | 'of' | 'as' | 'from' +#| | 'div' | 'mod' | 'shl' | 'shr' | 'not' | '..' +#| +#| prefixOperator = operator +#| +#| optInd = COMMENT? IND? +#| optPar = (IND{>} | IND{=})? +#| +#| simpleExpr = arrowExpr (OP0 optInd arrowExpr)* pragma? +#| arrowExpr = assignExpr (OP1 optInd assignExpr)* +#| assignExpr = orExpr (OP2 optInd orExpr)* +#| orExpr = andExpr (OP3 optInd andExpr)* +#| andExpr = cmpExpr (OP4 optInd cmpExpr)* +#| cmpExpr = sliceExpr (OP5 optInd sliceExpr)* +#| sliceExpr = ampExpr (OP6 optInd ampExpr)* +#| ampExpr = plusExpr (OP7 optInd plusExpr)* +#| plusExpr = mulExpr (OP8 optInd mulExpr)* +#| mulExpr = dollarExpr (OP9 optInd dollarExpr)* +#| dollarExpr = primary (OP10 optInd primary)* + +proc isOperator(tok: Token): bool = + #| operatorB = OP0 | OP1 | OP2 | OP3 | OP4 | OP5 | OP6 | OP7 | OP8 | OP9 | + #| 'div' | 'mod' | 'shl' | 'shr' | 'in' | 'notin' | + #| 'is' | 'isnot' | 'not' | 'of' | 'as' | 'from' | '..' | 'and' | 'or' | 'xor' + tok.tokType in {tkOpr, tkDiv, tkMod, tkShl, tkShr, tkIn, tkNotin, tkIs, + tkIsnot, tkNot, tkOf, tkAs, tkFrom, tkDotDot, tkAnd, + tkOr, tkXor} + +proc colcom(p: var Parser, n: PNode) = + eat(p, tkColon) + skipComment(p, n) + +const tkBuiltInMagics = {tkType, tkStatic, tkAddr} + +template setEndInfo() = + when defined(nimsuggest): + result.endInfo = TLineInfo(fileIndex: p.lex.fileIdx, + line: p.lex.previousTokenEnd.line, + col: p.lex.previousTokenEnd.col) + +proc parseSymbol(p: var Parser, mode = smNormal): PNode = + #| symbol = '`' (KEYW|IDENT|literal|(operator|'('|')'|'['|']'|'{'|'}'|'=')+)+ '`' + #| | IDENT | 'addr' | 'type' | 'static' + #| symbolOrKeyword = symbol | KEYW + case p.tok.tokType + of tkSymbol: + result = newIdentNodeP(p.tok.ident, p) + getTok(p) + of tokKeywordLow..tokKeywordHigh: + if p.tok.tokType in tkBuiltInMagics or mode == smAfterDot: + # for backwards compatibility these 2 are always valid: + result = newIdentNodeP(p.tok.ident, p) + getTok(p) + elif p.tok.tokType == tkNil and mode == smAllowNil: + result = newNodeP(nkNilLit, p) + getTok(p) + else: + parMessage(p, errIdentifierExpected, p.tok) + result = p.emptyNode + of tkAccent: + result = newNodeP(nkAccQuoted, p) + getTok(p) + # progress guaranteed + while true: + case p.tok.tokType + of tkAccent: + if not result.hasSon: + parMessage(p, errIdentifierExpected, p.tok) + break + of tkOpr, tkDot, tkDotDot, tkEquals, tkParLe..tkParDotRi: + let lineinfo = parLineInfo(p) + var accm = "" + while p.tok.tokType in {tkOpr, tkDot, tkDotDot, tkEquals, + tkParLe..tkParDotRi}: + accm.add($p.tok) + getTok(p) + let node = newAtom(p.lex.cache.getIdent(accm), lineinfo) + result.add(node) + of tokKeywordLow..tokKeywordHigh, tkSymbol, tkIntLit..tkCustomLit: + result.add(newIdentNodeP(p.lex.cache.getIdent($p.tok), p)) + getTok(p) + else: + parMessage(p, errIdentifierExpected, p.tok) + break + eat(p, tkAccent) + else: + parMessage(p, errIdentifierExpected, p.tok) + # BUGFIX: We must consume a token here to prevent endless loops! + # But: this really sucks for idetools and keywords, so we don't do it + # if it is a keyword: + #if not isKeyword(p.tok.tokType): getTok(p) + result = p.emptyNode + setEndInfo() + +proc equals(p: var Parser, a: PNode): PNode = + if p.tok.tokType == tkEquals: + result = newNodeP(nkExprEqExpr, p) + getTok(p) + #optInd(p, result) + result.add(a) + result.add(parseExpr(p)) + else: + result = a + +proc colonOrEquals(p: var Parser, a: PNode): PNode = + if p.tok.tokType == tkColon: + result = newNodeP(nkExprColonExpr, p) + getTok(p) + newlineWasSplitting(p) + #optInd(p, result) + result.add(a) + result.add(parseExpr(p)) + else: + result = equals(p, a) + +proc exprColonEqExpr(p: var Parser): PNode = + #| exprColonEqExpr = expr ((':'|'=') expr + #| / doBlock extraPostExprBlock*)? + var a = parseExpr(p) + if p.tok.tokType == tkDo: + result = postExprBlocks(p, a) + else: + result = colonOrEquals(p, a) + +proc exprEqExpr(p: var Parser): PNode = + #| exprEqExpr = expr ('=' expr + #| / doBlock extraPostExprBlock*)? + var a = parseExpr(p) + if p.tok.tokType == tkDo: + result = postExprBlocks(p, a) + else: + result = equals(p, a) + +proc exprList(p: var Parser, endTok: TokType, result: PNode) = + #| exprList = expr ^+ comma + when defined(nimpretty): + inc p.em.doIndentMore + getTok(p) + optInd(p, result) + # progress guaranteed + var a = parseExpr(p) + result.add(a) + while (p.tok.tokType != endTok) and (p.tok.tokType != tkEof): + if p.tok.tokType != tkComma: break + getTok(p) + optInd(p, a) + var a = parseExpr(p) + result.add(a) + when defined(nimpretty): + dec p.em.doIndentMore + +proc optionalExprList(p: var Parser, endTok: TokType, result: PNode) = + #| optionalExprList = expr ^* comma + when defined(nimpretty): + inc p.em.doIndentMore + getTok(p) + optInd(p, result) + # progress guaranteed + while (p.tok.tokType != endTok) and (p.tok.tokType != tkEof): + var a = parseExpr(p) + result.add(a) + if p.tok.tokType != tkComma: break + getTok(p) + optInd(p, a) + when defined(nimpretty): + dec p.em.doIndentMore + +proc exprColonEqExprListAux(p: var Parser, endTok: TokType, result: PNode) = + assert(endTok in {tkCurlyRi, tkCurlyDotRi, tkBracketRi, tkParRi}) + getTok(p) + flexComment(p, result) + optPar(p) + # progress guaranteed + while p.tok.tokType != endTok and p.tok.tokType != tkEof: + var a = exprColonEqExpr(p) + result.add(a) + if p.tok.tokType != tkComma: break + elif result.kind == nkPar: + result.transitionSonsKind(nkTupleConstr) + getTok(p) + skipComment(p, a) + optPar(p) + eat(p, endTok) + +proc exprColonEqExprList(p: var Parser, kind: TNodeKind, + endTok: TokType): PNode = + #| exprColonEqExprList = exprColonEqExpr (comma exprColonEqExpr)* (comma)? + result = newNodeP(kind, p) + exprColonEqExprListAux(p, endTok, result) + +proc dotExpr(p: var Parser, a: PNode): PNode = + var info = p.parLineInfo + getTok(p) + result = newNode(nkDotExpr, info) + optInd(p, result) + result.add(a) + result.add(parseSymbol(p, smAfterDot)) + if p.tok.tokType == tkBracketLeColon and tsLeading notin p.tok.spacing: + var x = newNode(nkBracketExpr, p.parLineInfo) + # rewrite 'x.y[:z]()' to 'y[z](x)' + x.add result.secondSon + exprList(p, tkBracketRi, x) + eat(p, tkBracketRi) + var y = newNode(nkCall, p.parLineInfo) + y.add x + y.add result.firstSon + if p.tok.tokType == tkParLe and tsLeading notin p.tok.spacing: + exprColonEqExprListAux(p, tkParRi, y) + result = y + +proc dotLikeExpr(p: var Parser, a: PNode): PNode = + var info = p.parLineInfo + result = newNode(nkInfix, info) + optInd(p, result) + var opNode = newIdentNodeP(p.tok.ident, p) + getTok(p) + result.add(opNode) + result.add(a) + result.add(parseSymbol(p, smAfterDot)) + +proc qualifiedIdent(p: var Parser): PNode = + #| qualifiedIdent = symbol ('.' optInd symbolOrKeyword)? + result = parseSymbol(p) + if p.tok.tokType == tkDot: result = dotExpr(p, result) + +proc setOrTableConstr(p: var Parser): PNode = + #| setOrTableConstr = '{' ((exprColonEqExpr comma)* | ':' ) '}' + result = newNodeP(nkCurly, p) + getTok(p) # skip '{' + optInd(p, result) + if p.tok.tokType == tkColon: + getTok(p) # skip ':' + result.transitionSonsKind(nkTableConstr) + else: + # progress guaranteed + while p.tok.tokType notin {tkCurlyRi, tkEof}: + var a = exprColonEqExpr(p) + if a.kind == nkExprColonExpr: result.transitionSonsKind(nkTableConstr) + result.add(a) + if p.tok.tokType != tkComma: break + getTok(p) + skipComment(p, a) + optPar(p) + eat(p, tkCurlyRi) # skip '}' + +proc parseCast(p: var Parser): PNode = + #| castExpr = 'cast' ('[' optInd typeDesc optPar ']' '(' optInd expr optPar ')') / + # ('(' optInd exprColonEqExpr optPar ')') + result = newNodeP(nkCast, p) + getTok(p) + if p.tok.tokType == tkBracketLe: + getTok(p) + optInd(p, result) + result.add(parseTypeDesc(p)) + optPar(p) + eat(p, tkBracketRi) + eat(p, tkParLe) + optInd(p, result) + result.add(parseExpr(p)) + else: + result.add p.emptyNode + eat(p, tkParLe) + optInd(p, result) + result.add(exprColonEqExpr(p)) + optPar(p) + eat(p, tkParRi) + setEndInfo() + +template setNodeFlag(n: PNode; f: untyped) = + when defined(nimCustomAst): + discard + else: + incl n.flags, f + +proc setBaseFlags(n: PNode, base: NumericalBase) = + case base + of base10: discard + of base2: setNodeFlag(n, nfBase2) + of base8: setNodeFlag(n, nfBase8) + of base16: setNodeFlag(n, nfBase16) + +proc parseGStrLit(p: var Parser, a: PNode): PNode = + case p.tok.tokType + of tkGStrLit: + result = newNodeP(nkCallStrLit, p) + result.add(a) + result.add(newStrNodeP(nkRStrLit, p.tok.literal, p)) + getTok(p) + of tkGTripleStrLit: + result = newNodeP(nkCallStrLit, p) + result.add(a) + result.add(newStrNodeP(nkTripleStrLit, p.tok.literal, p)) + getTok(p) + else: + result = a + setEndInfo() + +proc complexOrSimpleStmt(p: var Parser): PNode +proc simpleExpr(p: var Parser, mode = pmNormal): PNode +proc parseIfOrWhenExpr(p: var Parser, kind: TNodeKind): PNode + +proc semiStmtList(p: var Parser, result: PNode) = + inc p.inSemiStmtList + withInd(p): + # Be lenient with the first stmt/expr + let a = case p.tok.tokType + of tkIf: parseIfOrWhenExpr(p, nkIfStmt) + of tkWhen: parseIfOrWhenExpr(p, nkWhenStmt) + else: complexOrSimpleStmt(p) + result.add a + + while p.tok.tokType != tkEof: + if p.tok.tokType == tkSemiColon: + getTok(p) + if p.tok.tokType == tkParRi: + break + elif not (sameInd(p) or realInd(p)): + parMessage(p, errInvalidIndentation) + let a = complexOrSimpleStmt(p) + if a.kind == nkEmpty: + parMessage(p, errExprExpected, p.tok) + getTok(p) + else: + result.add a + dec p.inSemiStmtList + result.transitionSonsKind(nkStmtListExpr) + +proc parsePar(p: var Parser): PNode = + #| parKeyw = 'discard' | 'include' | 'if' | 'while' | 'case' | 'try' + #| | 'finally' | 'except' | 'for' | 'block' | 'const' | 'let' + #| | 'when' | 'var' | 'mixin' + #| par = '(' optInd + #| ( &parKeyw (ifExpr / complexOrSimpleStmt) ^+ ';' + #| | ';' (ifExpr / complexOrSimpleStmt) ^+ ';' + #| | pragmaStmt + #| | simpleExpr ( (doBlock extraPostExprBlock*) + #| | ('=' expr (';' (ifExpr / complexOrSimpleStmt) ^+ ';' )? ) + #| | (':' expr (',' exprColonEqExpr ^+ ',' )? ) ) ) + #| optPar ')' + # + # unfortunately it's ambiguous: (expr: expr) vs (exprStmt); however a + # leading ';' could be used to enforce a 'stmt' context ... + result = newNodeP(nkPar, p) + getTok(p) + optInd(p, result) + flexComment(p, result) + if p.tok.tokType in {tkDiscard, tkInclude, tkIf, tkWhile, tkCase, + tkTry, tkDefer, tkFinally, tkExcept, tkBlock, + tkConst, tkLet, tkWhen, tkVar, tkFor, + tkMixin}: + # XXX 'bind' used to be an expression, so we exclude it here; + # tests/reject/tbind2 fails otherwise. + semiStmtList(p, result) + elif p.tok.tokType == tkSemiColon: + # '(;' enforces 'stmt' context: + getTok(p) + optInd(p, result) + semiStmtList(p, result) + elif p.tok.tokType == tkCurlyDotLe: + result.add(parseStmtPragma(p)) + elif p.tok.tokType == tkParRi: + # Empty tuple '()' + result.transitionSonsKind(nkTupleConstr) + else: + var a = simpleExpr(p) + if p.tok.tokType == tkDo: + result = postExprBlocks(p, a) + elif p.tok.tokType == tkEquals: + # special case: allow assignments + let asgn = newNodeP(nkAsgn, p) + getTok(p) + optInd(p, result) + let b = parseExpr(p) + asgn.add a + asgn.add b + result.add(asgn) + if p.tok.tokType == tkSemiColon: + semiStmtList(p, result) + elif p.tok.tokType == tkSemiColon: + # stmt context: + result.add(a) + semiStmtList(p, result) + else: + a = colonOrEquals(p, a) + if a.kind == nkExprColonExpr: + result.transitionSonsKind(nkTupleConstr) + result.add(a) + if p.tok.tokType == tkComma: + getTok(p) + skipComment(p, a) + # (1,) produces a tuple expression: + result.transitionSonsKind(nkTupleConstr) + # progress guaranteed + while p.tok.tokType != tkParRi and p.tok.tokType != tkEof: + var a = exprColonEqExpr(p) + result.add(a) + if p.tok.tokType != tkComma: break + getTok(p) + skipComment(p, a) + optPar(p) + eat(p, tkParRi) + setEndInfo() + +proc identOrLiteral(p: var Parser, mode: PrimaryMode): PNode = + #| literal = | INT_LIT | INT8_LIT | INT16_LIT | INT32_LIT | INT64_LIT + #| | UINT_LIT | UINT8_LIT | UINT16_LIT | UINT32_LIT | UINT64_LIT + #| | FLOAT_LIT | FLOAT32_LIT | FLOAT64_LIT + #| | STR_LIT | RSTR_LIT | TRIPLESTR_LIT + #| | CHAR_LIT | CUSTOM_NUMERIC_LIT + #| | NIL + #| generalizedLit = GENERALIZED_STR_LIT | GENERALIZED_TRIPLESTR_LIT + #| identOrLiteral = generalizedLit | symbol | literal + #| | par | arrayConstr | setOrTableConstr | tupleConstr + #| | castExpr + #| tupleConstr = '(' optInd (exprColonEqExpr comma?)* optPar ')' + #| arrayConstr = '[' optInd (exprColonEqExpr comma?)* optPar ']' + case p.tok.tokType + of tkSymbol, tkBuiltInMagics, tkOut: + result = newIdentNodeP(p.tok.ident, p) + getTok(p) + result = parseGStrLit(p, result) + of tkAccent: + result = parseSymbol(p) # literals + of tkIntLit: + result = newIntNodeP(nkIntLit, p.tok.iNumber, p) + setBaseFlags(result, p.tok.base) + getTok(p) + of tkInt8Lit: + result = newIntNodeP(nkInt8Lit, p.tok.iNumber, p) + setBaseFlags(result, p.tok.base) + getTok(p) + of tkInt16Lit: + result = newIntNodeP(nkInt16Lit, p.tok.iNumber, p) + setBaseFlags(result, p.tok.base) + getTok(p) + of tkInt32Lit: + result = newIntNodeP(nkInt32Lit, p.tok.iNumber, p) + setBaseFlags(result, p.tok.base) + getTok(p) + of tkInt64Lit: + result = newIntNodeP(nkInt64Lit, p.tok.iNumber, p) + setBaseFlags(result, p.tok.base) + getTok(p) + of tkUIntLit: + result = newIntNodeP(nkUIntLit, p.tok.iNumber, p) + setBaseFlags(result, p.tok.base) + getTok(p) + of tkUInt8Lit: + result = newIntNodeP(nkUInt8Lit, p.tok.iNumber, p) + setBaseFlags(result, p.tok.base) + getTok(p) + of tkUInt16Lit: + result = newIntNodeP(nkUInt16Lit, p.tok.iNumber, p) + setBaseFlags(result, p.tok.base) + getTok(p) + of tkUInt32Lit: + result = newIntNodeP(nkUInt32Lit, p.tok.iNumber, p) + setBaseFlags(result, p.tok.base) + getTok(p) + of tkUInt64Lit: + result = newIntNodeP(nkUInt64Lit, p.tok.iNumber, p) + setBaseFlags(result, p.tok.base) + getTok(p) + of tkFloatLit: + result = newFloatNodeP(nkFloatLit, p.tok.fNumber, p) + setBaseFlags(result, p.tok.base) + getTok(p) + of tkFloat32Lit: + result = newFloatNodeP(nkFloat32Lit, p.tok.fNumber, p) + setBaseFlags(result, p.tok.base) + getTok(p) + of tkFloat64Lit: + result = newFloatNodeP(nkFloat64Lit, p.tok.fNumber, p) + setBaseFlags(result, p.tok.base) + getTok(p) + of tkFloat128Lit: + result = newFloatNodeP(nkFloat128Lit, p.tok.fNumber, p) + setBaseFlags(result, p.tok.base) + getTok(p) + of tkStrLit: + result = newStrNodeP(nkStrLit, p.tok.literal, p) + getTok(p) + of tkRStrLit: + result = newStrNodeP(nkRStrLit, p.tok.literal, p) + getTok(p) + of tkTripleStrLit: + result = newStrNodeP(nkTripleStrLit, p.tok.literal, p) + getTok(p) + of tkCharLit: + result = newIntNodeP(nkCharLit, ord(p.tok.literal[0]), p) + getTok(p) + of tkCustomLit: + let splitPos = p.tok.iNumber.int + let str = newStrNodeP(nkRStrLit, p.tok.literal.substr(0, splitPos-1), p) + let callee = newIdentNodeP(getIdent(p.lex.cache, p.tok.literal.substr(splitPos)), p) + result = newNodeP(nkDotExpr, p) + result.add str + result.add callee + getTok(p) + of tkNil: + result = newNodeP(nkNilLit, p) + getTok(p) + of tkParLe: + # () constructor + if mode in {pmTypeDesc, pmTypeDef}: + result = exprColonEqExprList(p, nkPar, tkParRi) + else: + result = parsePar(p) + of tkCurlyLe: + # {} constructor + result = setOrTableConstr(p) + of tkBracketLe: + # [] constructor + result = exprColonEqExprList(p, nkBracket, tkBracketRi) + of tkCast: + result = parseCast(p) + else: + parMessage(p, errExprExpected, p.tok) + getTok(p) # we must consume a token here to prevent endless loops! + result = p.emptyNode + +proc namedParams(p: var Parser, callee: PNode, + kind: TNodeKind, endTok: TokType): PNode = + let a = callee + result = newNodeP(kind, p) + result.add(a) + # progress guaranteed + exprColonEqExprListAux(p, endTok, result) + +proc commandParam(p: var Parser, isFirstParam: var bool; mode: PrimaryMode): PNode = + if mode == pmTypeDesc: + result = simpleExpr(p, mode) + elif not isFirstParam: + result = exprEqExpr(p) + else: + result = parseExpr(p) + if p.tok.tokType == tkDo: + result = postExprBlocks(p, result) + isFirstParam = false + +proc commandExpr(p: var Parser; r: PNode; mode: PrimaryMode): PNode = + if mode == pmTrySimple: + result = r + else: + result = newNodeP(nkCommand, p) + result.add(r) + var isFirstParam = true + # progress NOT guaranteed + p.hasProgress = false + result.add commandParam(p, isFirstParam, mode) + +proc isDotLike(tok: Token): bool = + result = tok.tokType == tkOpr and tok.ident.s.len > 1 and + tok.ident.s[0] == '.' and tok.ident.s[1] != '.' + +proc primarySuffix(p: var Parser, r: PNode, + baseIndent: int, mode: PrimaryMode): PNode = + #| primarySuffix = '(' (exprColonEqExpr comma?)* ')' + #| | '.' optInd symbolOrKeyword ('[:' exprList ']' ( '(' exprColonEqExpr ')' )?)? generalizedLit? + #| | DOTLIKEOP optInd symbolOrKeyword generalizedLit? + #| | '[' optInd exprColonEqExprList optPar ']' + #| | '{' optInd exprColonEqExprList optPar '}' + # XXX strong spaces need to be reflected above + result = r + + # progress guaranteed + while p.tok.indent < 0 or + (p.tok.tokType == tkDot and p.tok.indent >= baseIndent): + case p.tok.tokType + of tkParLe: + # progress guaranteed + if tsLeading in p.tok.spacing: + result = commandExpr(p, result, mode) + break + result = namedParams(p, result, nkCall, tkParRi) + if result.has2Sons and result.secondSon.kind == nkExprColonExpr: + result.transitionSonsKind(nkObjConstr) + of tkDot: + # progress guaranteed + result = dotExpr(p, result) + result = parseGStrLit(p, result) + of tkBracketLe: + # progress guaranteed + if tsLeading in p.tok.spacing: + result = commandExpr(p, result, mode) + break + result = namedParams(p, result, nkBracketExpr, tkBracketRi) + of tkCurlyLe: + # progress guaranteed + if tsLeading in p.tok.spacing: + result = commandExpr(p, result, mode) + break + result = namedParams(p, result, nkCurlyExpr, tkCurlyRi) + of tkSymbol, tkAccent, tkIntLit..tkCustomLit, tkNil, tkCast, + tkOpr, tkDotDot, tkVar, tkOut, tkStatic, tkType, tkEnum, tkTuple, + tkObject, tkProc: + # XXX: In type sections we allow the free application of the + # command syntax, with the exception of expressions such as + # `foo ref` or `foo ptr`. Unfortunately, these two are also + # used as infix operators for the memory regions feature and + # the current parsing rules don't play well here. + let isDotLike2 = p.tok.isDotLike + if isDotLike2 and p.lex.config.isDefined("nimPreviewDotLikeOps"): + # synchronize with `tkDot` branch + result = dotLikeExpr(p, result) + result = parseGStrLit(p, result) + else: + if isDotLike2: + parMessage(p, warnDotLikeOps, "dot-like operators will be parsed differently with `-d:nimPreviewDotLikeOps`") + if p.inPragma == 0 and (isUnary(p.tok) or p.tok.tokType notin {tkOpr, tkDotDot}): + # actually parsing {.push hints:off.} as {.push(hints:off).} is a sweet + # solution, but pragmas.nim can't handle that + result = commandExpr(p, result, mode) + break + else: + break + +proc parseOperators(p: var Parser, headNode: PNode, + limit: int, mode: PrimaryMode): PNode = + result = headNode + # expand while operators have priorities higher than 'limit' + var opPrec = getPrecedence(p.tok) + let modeB = if mode == pmTypeDef: pmTypeDesc else: mode + # the operator itself must not start on a new line: + # progress guaranteed + while opPrec >= limit and p.tok.indent < 0 and not isUnary(p.tok): + checkBinary(p) + let leftAssoc = ord(not isRightAssociative(p.tok)) + var a = newNodeP(nkInfix, p) + var opNode = newIdentNodeP(p.tok.ident, p) # skip operator: + getTok(p) + flexComment(p, a) + optPar(p) + # read sub-expression with higher priority: + var b = simpleExprAux(p, opPrec + leftAssoc, modeB) + a.add(opNode) + a.add(result) + a.add(b) + result = a + opPrec = getPrecedence(p.tok) + setEndInfo() + +proc simpleExprAux(p: var Parser, limit: int, mode: PrimaryMode): PNode = + var mode = mode + result = primary(p, mode) + if mode == pmTrySimple: + mode = pmNormal + if p.tok.tokType == tkCurlyDotLe and (p.tok.indent < 0 or realInd(p)) and + mode == pmNormal: + var pragmaExp = newNodeP(nkPragmaExpr, p) + pragmaExp.add result + pragmaExp.add p.parsePragma + result = pragmaExp + result = parseOperators(p, result, limit, mode) + +proc simpleExpr(p: var Parser, mode = pmNormal): PNode = + when defined(nimpretty): + inc p.em.doIndentMore + result = simpleExprAux(p, -1, mode) + when defined(nimpretty): + dec p.em.doIndentMore + +proc parsePragma(p: var Parser): PNode = + #| pragma = '{.' optInd (exprColonEqExpr comma?)* optPar ('.}' | '}') + result = newNodeP(nkPragma, p) + inc p.inPragma + when defined(nimpretty): + inc p.em.doIndentMore + inc p.em.keepIndents + getTok(p) + optInd(p, result) + while p.tok.tokType notin {tkCurlyDotRi, tkCurlyRi, tkEof}: + p.hasProgress = false + var a = exprColonEqExpr(p) + if not p.hasProgress: break + result.add(a) + if p.tok.tokType == tkComma: + getTok(p) + skipComment(p, a) + optPar(p) + if p.tok.tokType in {tkCurlyDotRi, tkCurlyRi}: + when defined(nimpretty): + if p.tok.tokType == tkCurlyRi: curlyRiWasPragma(p.em) + getTok(p) + else: + parMessage(p, "expected '.}'") + dec p.inPragma + when defined(nimpretty): + dec p.em.doIndentMore + dec p.em.keepIndents + setEndInfo() + +proc identVis(p: var Parser; allowDot=false): PNode = + #| identVis = symbol OPR? # postfix position + #| identVisDot = symbol '.' optInd symbolOrKeyword OPR? + var a = parseSymbol(p) + if p.tok.tokType == tkOpr: + when defined(nimpretty): + starWasExportMarker(p.em) + result = newNodeP(nkPostfix, p) + result.add(newIdentNodeP(p.tok.ident, p)) + result.add(a) + getTok(p) + elif p.tok.tokType == tkDot and allowDot: + result = dotExpr(p, a) + else: + result = a + +proc identWithPragma(p: var Parser; allowDot=false): PNode = + #| identWithPragma = identVis pragma? + #| identWithPragmaDot = identVisDot pragma? + var a = identVis(p, allowDot) + if p.tok.tokType == tkCurlyDotLe: + result = newNodeP(nkPragmaExpr, p) + result.add(a) + result.add(parsePragma(p)) + else: + result = a + +type + DeclaredIdentFlag = enum + withPragma, # identifier may have pragma + withBothOptional # both ':' and '=' parts are optional + withDot # allow 'var ident.ident = value' + DeclaredIdentFlags = set[DeclaredIdentFlag] + +proc parseIdentColonEquals(p: var Parser, flags: DeclaredIdentFlags): PNode = + #| declColonEquals = identWithPragma (comma identWithPragma)* comma? + #| (':' optInd typeDescExpr)? ('=' optInd expr)? + #| identColonEquals = IDENT (comma IDENT)* comma? + #| (':' optInd typeDescExpr)? ('=' optInd expr)?) + var a: PNode + result = newNodeP(nkIdentDefs, p) + # progress guaranteed + while true: + case p.tok.tokType + of tkSymbol, tkAccent: + if withPragma in flags: a = identWithPragma(p, allowDot=withDot in flags) + else: a = parseSymbol(p) + if a.kind == nkEmpty: return + else: break + result.add(a) + if p.tok.tokType != tkComma: break + getTok(p) + optInd(p, a) + if p.tok.tokType == tkColon: + getTok(p) + optInd(p, result) + result.add(parseTypeDesc(p, fullExpr = true)) + else: + result.add(newNodeP(nkEmpty, p)) + if p.tok.tokType != tkEquals and withBothOptional notin flags: + parMessage(p, "':' or '=' expected, but got '$1'", p.tok) + if p.tok.tokType == tkEquals: + getTok(p) + optInd(p, result) + result.add(parseExpr(p)) + else: + result.add(newNodeP(nkEmpty, p)) + setEndInfo() + +proc parseTuple(p: var Parser, indentAllowed = false): PNode = + #| tupleTypeBracket = '[' optInd (identColonEquals (comma/semicolon)?)* optPar ']' + #| tupleType = 'tuple' tupleTypeBracket + #| tupleDecl = 'tuple' (tupleTypeBracket / + #| COMMENT? (IND{>} identColonEquals (IND{=} identColonEquals)*)?) + result = newNodeP(nkTupleTy, p) + getTok(p) + if p.tok.tokType == tkBracketLe: + getTok(p) + optInd(p, result) + # progress guaranteed + while p.tok.tokType in {tkSymbol, tkAccent}: + var a = parseIdentColonEquals(p, {}) + result.add(a) + if p.tok.tokType notin {tkComma, tkSemiColon}: break + when defined(nimpretty): + commaWasSemicolon(p.em) + getTok(p) + skipComment(p, a) + optPar(p) + eat(p, tkBracketRi) + elif indentAllowed: + skipComment(p, result) + if realInd(p): + withInd(p): + rawSkipComment(p, result) + # progress guaranteed + while true: + case p.tok.tokType + of tkSymbol, tkAccent: + var a = parseIdentColonEquals(p, {}) + if p.tok.indent < 0 or p.tok.indent >= p.currInd: + rawSkipComment(p, a) + result.add(a) + of tkEof: break + else: + parMessage(p, errIdentifierExpected, p.tok) + break + if not sameInd(p): break + elif p.tok.tokType == tkParLe: + parMessage(p, errGenerated, "the syntax for tuple types is 'tuple[...]', not 'tuple(...)'") + else: + result = newNodeP(nkTupleClassTy, p) + setEndInfo() + +proc parseParamList(p: var Parser, retColon = true): PNode = + #| paramList = '(' declColonEquals ^* (comma/semicolon) ')' + #| paramListArrow = paramList? ('->' optInd typeDesc)? + #| paramListColon = paramList? (':' optInd typeDesc)? + var a: PNode + result = newNodeP(nkFormalParams, p) + result.add(p.emptyNode) # return type + when defined(nimpretty): + inc p.em.doIndentMore + inc p.em.keepIndents + let hasParLe = p.tok.tokType == tkParLe and p.tok.indent < 0 + if hasParLe: + getTok(p) + optInd(p, result) + # progress guaranteed + while true: + case p.tok.tokType + of tkSymbol, tkAccent: + a = parseIdentColonEquals(p, {withBothOptional, withPragma}) + of tkParRi: + break + of tkVar: + parMessage(p, errGenerated, "the syntax is 'parameter: var T', not 'var parameter: T'") + break + else: + parMessage(p, "expected closing ')'") + break + result.add(a) + if p.tok.tokType notin {tkComma, tkSemiColon}: break + when defined(nimpretty): + commaWasSemicolon(p.em) + getTok(p) + skipComment(p, a) + optPar(p) + eat(p, tkParRi) + let hasRet = if retColon: p.tok.tokType == tkColon + else: p.tok.tokType == tkOpr and p.tok.ident.s == "->" + if hasRet and p.tok.indent < 0: + getTok(p) + optInd(p, result) + result.replaceFirstSon parseTypeDesc(p) + elif not retColon and not hasParLe: + # Mark as "not there" in order to mark for deprecation in the semantic pass: + result = p.emptyNode + when defined(nimpretty): + dec p.em.doIndentMore + dec p.em.keepIndents + setEndInfo() + +proc optPragmas(p: var Parser): PNode = + if p.tok.tokType == tkCurlyDotLe and (p.tok.indent < 0 or realInd(p)): + result = parsePragma(p) + else: + result = p.emptyNode + +proc parseDoBlock(p: var Parser; info: TLineInfo): PNode = + #| doBlock = 'do' paramListArrow pragma? colcom stmt + result = nil + var params = parseParamList(p, retColon=false) + let pragmas = optPragmas(p) + colcom(p, result) + result = parseStmt(p) + if params.kind != nkEmpty or pragmas.kind != nkEmpty: + if params.kind == nkEmpty: + params = newNodeP(nkFormalParams, p) + params.add(p.emptyNode) # return type + result = newProcNode(nkDo, info, + body = result, params = params, name = p.emptyNode, pattern = p.emptyNode, + genericParams = p.emptyNode, pragmas = pragmas, exceptions = p.emptyNode) + setEndInfo() + +proc parseProcExpr(p: var Parser; isExpr: bool; kind: TNodeKind): PNode = + #| routineExpr = ('proc' | 'func' | 'iterator') paramListColon pragma? ('=' COMMENT? stmt)? + #| routineType = ('proc' | 'iterator') paramListColon pragma? + # either a proc type or a anonymous proc + let info = parLineInfo(p) + let hasSignature = p.tok.tokType in {tkParLe, tkColon} and p.tok.indent < 0 + let params = parseParamList(p) + let pragmas = optPragmas(p) + if p.tok.tokType == tkEquals and isExpr: + getTok(p) + result = newProcNode(kind, info, body = p.emptyNode, + params = params, name = p.emptyNode, pattern = p.emptyNode, + genericParams = p.emptyNode, pragmas = pragmas, exceptions = p.emptyNode) + skipComment(p, result) + result.replaceSon bodyPos, parseStmt(p) + else: + result = newNode(if kind == nkIteratorDef: nkIteratorTy else: nkProcTy, info) + if hasSignature or pragmas.kind != nkEmpty: + if hasSignature: + result.add(params) + else: # pragmas but no param list, implies typeclass with pragmas + result.add(p.emptyNode) + if kind == nkFuncDef: + parMessage(p, "func keyword is not allowed in type descriptions, use proc with {.noSideEffect.} pragma instead") + result.add(pragmas) + setEndInfo() + +proc isExprStart(p: Parser): bool = + case p.tok.tokType + of tkSymbol, tkAccent, tkOpr, tkNot, tkNil, tkCast, tkIf, tkFor, + tkProc, tkFunc, tkIterator, tkBind, tkBuiltInMagics, + tkParLe, tkBracketLe, tkCurlyLe, tkIntLit..tkCustomLit, tkVar, tkRef, tkPtr, + tkEnum, tkTuple, tkObject, tkWhen, tkCase, tkOut, tkTry, tkBlock: + result = true + else: result = false + +proc parseSymbolList(p: var Parser, result: PNode) = + # progress guaranteed + while true: + var s = parseSymbol(p, smAllowNil) + if s.kind == nkEmpty: break + result.add(s) + if p.tok.tokType != tkComma: break + getTok(p) + optInd(p, s) + setEndInfo() + +proc parseTypeDescKAux(p: var Parser, kind: TNodeKind, + mode: PrimaryMode): PNode = + result = newNodeP(kind, p) + getTok(p) + if p.tok.indent != -1 and p.tok.indent <= p.currInd: return + optInd(p, result) + let isTypedef = mode == pmTypeDef and p.tok.tokType in {tkObject, tkTuple} + if not isOperator(p.tok) and isExprStart(p): + if isTypedef: + result.add(parseTypeDefValue(p)) + else: + result.add(primary(p, mode)) + if kind == nkDistinctTy and p.tok.tokType == tkSymbol: + # XXX document this feature! + var nodeKind: TNodeKind + if p.tok.ident.s == "with": + nodeKind = nkWith + elif p.tok.ident.s == "without": + nodeKind = nkWithout + else: + return result + getTok(p) + let list = newNodeP(nodeKind, p) + result.add list + parseSymbolList(p, list) + if mode == pmTypeDef and not isTypedef: + result = parseOperators(p, result, -1, mode) + setEndInfo() + +proc parseVarTuple(p: var Parser): PNode + +proc parseFor(p: var Parser): PNode = + #| forStmt = 'for' ((varTuple / identWithPragma) ^+ comma) 'in' expr colcom stmt + #| forExpr = forStmt + getTokNoInd(p) + result = newNodeP(nkForStmt, p) + if p.tok.tokType == tkParLe: + result.add(parseVarTuple(p)) + else: + var a = identWithPragma(p) + result.add(a) + while p.tok.tokType == tkComma: + getTok(p) + optInd(p, a) + if p.tok.tokType == tkParLe: + result.add(parseVarTuple(p)) + break + a = identWithPragma(p) + result.add(a) + eat(p, tkIn) + result.add(parseExpr(p)) + colcom(p, result) + result.add(parseStmt(p)) + setEndInfo() + +template nimprettyDontTouch(body) = + when defined(nimpretty): + inc p.em.keepIndents + body + when defined(nimpretty): + dec p.em.keepIndents + +proc parseExpr(p: var Parser): PNode = + #| expr = (blockExpr + #| | ifExpr + #| | whenExpr + #| | caseStmt + #| | forExpr + #| | tryExpr) + #| / simpleExpr + case p.tok.tokType + of tkBlock: + nimprettyDontTouch: + result = parseBlock(p) + of tkIf: + nimprettyDontTouch: + result = parseIfOrWhenExpr(p, nkIfExpr) + of tkFor: + nimprettyDontTouch: + result = parseFor(p) + of tkWhen: + nimprettyDontTouch: + result = parseIfOrWhenExpr(p, nkWhenStmt) + of tkCase: + # Currently we think nimpretty is good enough with case expressions, + # so it is allowed to touch them: + #nimprettyDontTouch: + result = parseCase(p) + of tkTry: + nimprettyDontTouch: + result = parseTry(p, isExpr=true) + else: result = simpleExpr(p) + setEndInfo() + +proc parseEnum(p: var Parser): PNode +proc parseObject(p: var Parser): PNode +proc parseTypeClass(p: var Parser): PNode + +proc primary(p: var Parser, mode: PrimaryMode): PNode = + #| simplePrimary = SIGILLIKEOP? identOrLiteral primarySuffix* + #| commandStart = &('`'|IDENT|literal|'cast'|'addr'|'type'|'var'|'out'| + #| 'static'|'enum'|'tuple'|'object'|'proc') + #| primary = simplePrimary (commandStart expr (doBlock extraPostExprBlock*)?)? + #| / operatorB primary + #| / routineExpr + #| / rawTypeDesc + #| / prefixOperator primary + # XXX strong spaces need to be reflected in commandStart + # command part is handled in the primarySuffix proc + + # prefix operators: + if isOperator(p.tok): + # Note 'sigil like' operators are currently not reflected in the grammar + # and should be removed for Nim 2.0, I don't think anybody uses them. + let isSigil = isSigilLike(p.tok) + result = newNodeP(nkPrefix, p) + var a = newIdentNodeP(p.tok.ident, p) + result.add(a) + getTok(p) + optInd(p, a) + const identOrLiteralKinds = tkBuiltInMagics + {tkSymbol, tkAccent, tkNil, + tkIntLit..tkCustomLit, tkCast, tkOut, tkParLe, tkBracketLe, tkCurlyLe} + if isSigil and p.tok.tokType in identOrLiteralKinds: + let baseInd = p.lex.currLineIndent + result.add(identOrLiteral(p, mode)) + result = primarySuffix(p, result, baseInd, mode) + else: + result.add(primary(p, pmNormal)) + return + + case p.tok.tokType + of tkProc: + getTok(p) + result = parseProcExpr(p, mode != pmTypeDesc, nkLambda) + of tkFunc: + getTok(p) + result = parseProcExpr(p, mode != pmTypeDesc, nkFuncDef) + of tkIterator: + getTok(p) + result = parseProcExpr(p, mode != pmTypeDesc, nkIteratorDef) + of tkBind: + # legacy syntax, no-op in current nim + result = newNodeP(nkBind, p) + getTok(p) + optInd(p, result) + result.add(primary(p, pmNormal)) + of tkTuple, tkEnum, tkObject, tkConcept, + tkVar, tkOut, tkRef, tkPtr, tkDistinct: + result = parseTypeDesc(p) + else: + let baseInd = p.lex.currLineIndent + result = identOrLiteral(p, mode) + result = primarySuffix(p, result, baseInd, mode) + +proc binaryNot(p: var Parser; a: PNode): PNode = + if p.tok.tokType == tkNot and p.tok.indent < 0: + let notOpr = newIdentNodeP(p.tok.ident, p) + getTok(p) + optInd(p, notOpr) + let b = primary(p, pmTypeDesc) + result = newNodeP(nkInfix, p) + result.add notOpr + result.add a + result.add b + else: + result = a + +proc parseTypeDesc(p: var Parser, fullExpr = false): PNode = + #| rawTypeDesc = (tupleType | routineType | 'enum' | 'object' | + #| ('var' | 'out' | 'ref' | 'ptr' | 'distinct') typeDesc?) + #| ('not' primary)? + #| typeDescExpr = (routineType / simpleExpr) ('not' primary)? + #| typeDesc = rawTypeDesc / typeDescExpr + newlineWasSplitting(p) + if fullExpr: + result = simpleExpr(p, pmTypeDesc) + else: + case p.tok.tokType + of tkTuple: + result = parseTuple(p, false) + of tkProc: + getTok(p) + result = parseProcExpr(p, false, nkLambda) + of tkIterator: + getTok(p) + result = parseProcExpr(p, false, nkIteratorDef) + of tkEnum: + result = newNodeP(nkEnumTy, p) + getTok(p) + of tkObject: + result = newNodeP(nkObjectTy, p) + getTok(p) + of tkConcept: + result = p.emptyNode + parMessage(p, "the 'concept' keyword is only valid in 'type' sections") + of tkVar: result = parseTypeDescKAux(p, nkVarTy, pmTypeDesc) + of tkOut: result = parseTypeDescKAux(p, nkOutTy, pmTypeDesc) + of tkRef: result = parseTypeDescKAux(p, nkRefTy, pmTypeDesc) + of tkPtr: result = parseTypeDescKAux(p, nkPtrTy, pmTypeDesc) + of tkDistinct: result = parseTypeDescKAux(p, nkDistinctTy, pmTypeDesc) + else: + result = simpleExpr(p, pmTypeDesc) + result = binaryNot(p, result) + setEndInfo() + +proc parseTypeDefValue(p: var Parser): PNode = + #| typeDefValue = ((tupleDecl | enumDecl | objectDecl | conceptDecl | + #| ('ref' | 'ptr' | 'distinct') (tupleDecl | objectDecl)) + #| / (simpleExpr (exprEqExpr ^+ comma postExprBlocks?)?)) + #| ('not' primary)? + case p.tok.tokType + of tkTuple: result = parseTuple(p, true) + of tkRef: result = parseTypeDescKAux(p, nkRefTy, pmTypeDef) + of tkPtr: result = parseTypeDescKAux(p, nkPtrTy, pmTypeDef) + of tkDistinct: result = parseTypeDescKAux(p, nkDistinctTy, pmTypeDef) + of tkEnum: + prettySection: + result = parseEnum(p) + of tkObject: + prettySection: + result = parseObject(p) + of tkConcept: + result = parseTypeClass(p) + else: + result = simpleExpr(p, pmTypeDef) + if p.tok.tokType != tkNot: + if result.kind == nkCommand: + var isFirstParam = false + while p.tok.tokType == tkComma: + getTok(p) + optInd(p, result) + result.add(commandParam(p, isFirstParam, pmTypeDef)) + result = postExprBlocks(p, result) + result = binaryNot(p, result) + setEndInfo() + +proc makeCall(n: PNode): PNode = + ## Creates a call if the given node isn't already a call. + if n.kind in nkCallKinds: + result = n + else: + result = newNode(nkCall, n.info) + result.add n + +proc postExprBlocks(p: var Parser, x: PNode): PNode = + #| extraPostExprBlock = ( IND{=} doBlock + #| | IND{=} 'of' exprList ':' stmt + #| | IND{=} 'elif' expr ':' stmt + #| | IND{=} 'except' optionalExprList ':' stmt + #| | IND{=} 'finally' ':' stmt + #| | IND{=} 'else' ':' stmt ) + #| postExprBlocks = (doBlock / ':' (extraPostExprBlock / stmt)) extraPostExprBlock* + result = x + if p.tok.indent >= 0: return + + var + openingParams = p.emptyNode + openingPragmas = p.emptyNode + + if p.tok.tokType == tkDo: + getTok(p) + openingParams = parseParamList(p, retColon=false) + openingPragmas = optPragmas(p) + + if p.tok.tokType == tkColon: + result = makeCall(result) + getTok(p) + skipComment(p, result) + if not (p.tok.tokType in {tkOf, tkElif, tkElse, tkExcept, tkFinally} and sameInd(p)): + var stmtList = newNodeP(nkStmtList, p) + stmtList.add parseStmt(p) + # to keep backwards compatibility (see tests/vm/tstringnil) + if stmtList.firstSon.kind == nkStmtList: stmtList = stmtList.firstSon + + setNodeFlag stmtList, nfBlockArg + if openingParams.kind != nkEmpty or openingPragmas.kind != nkEmpty: + if openingParams.kind == nkEmpty: + openingParams = newNodeP(nkFormalParams, p) + openingParams.add(p.emptyNode) # return type + result.add newProcNode(nkDo, stmtList.info, body = stmtList, + params = openingParams, + name = p.emptyNode, pattern = p.emptyNode, + genericParams = p.emptyNode, + pragmas = openingPragmas, + exceptions = p.emptyNode) + else: + result.add stmtList + + while sameInd(p): + var nextBlock: PNode + let nextToken = p.tok.tokType + if nextToken == tkDo: + let info = parLineInfo(p) + getTok(p) + nextBlock = parseDoBlock(p, info) + else: + case nextToken + of tkOf: + nextBlock = newNodeP(nkOfBranch, p) + exprList(p, tkColon, nextBlock) + of tkElif: + nextBlock = newNodeP(nkElifBranch, p) + getTok(p) + optInd(p, nextBlock) + nextBlock.add parseExpr(p) + of tkExcept: + nextBlock = newNodeP(nkExceptBranch, p) + optionalExprList(p, tkColon, nextBlock) + of tkFinally: + nextBlock = newNodeP(nkFinally, p) + getTok(p) + of tkElse: + nextBlock = newNodeP(nkElse, p) + getTok(p) + else: break + eat(p, tkColon) + nextBlock.add parseStmt(p) + + setNodeFlag nextBlock, nfBlockArg + result.add nextBlock + + if nextBlock.kind in {nkElse, nkFinally}: break + else: + if openingParams.kind != nkEmpty: + parMessage(p, "expected ':'") + +proc parseExprStmt(p: var Parser): PNode = + #| exprStmt = simpleExpr postExprBlocks? + #| / simplePrimary (exprEqExpr ^+ comma) postExprBlocks? + #| / simpleExpr '=' optInd (expr postExprBlocks?) + var a = simpleExpr(p, pmTrySimple) + if p.tok.tokType == tkEquals: + result = newNodeP(nkAsgn, p) + getTok(p) + optInd(p, result) + var b = parseExpr(p) + b = postExprBlocks(p, b) + result.add(a) + result.add(b) + else: + var isFirstParam = false + # if an expression is starting here, a simplePrimary was parsed and + # this is the start of a command + if p.tok.indent < 0 and isExprStart(p): + result = newTree(nkCommand, a.info, a) + let baseIndent = p.currInd + while true: + result.add(commandParam(p, isFirstParam, pmNormal)) + if p.tok.tokType != tkComma or + (p.tok.indent >= 0 and p.tok.indent < baseIndent): + break + getTok(p) + optInd(p, result) + else: + result = a + result = postExprBlocks(p, result) + setEndInfo() + +proc parseModuleName(p: var Parser, kind: TNodeKind): PNode = + result = parseExpr(p) + when false: + # parseExpr already handles 'as' syntax ... + if p.tok.tokType == tkAs and kind == nkImportStmt: + let a = result + result = newNodeP(nkImportAs, p) + getTok(p) + result.add(a) + result.add(parseExpr(p)) + setEndInfo() + +proc parseImport(p: var Parser, kind: TNodeKind): PNode = + #| importStmt = 'import' optInd expr + #| ((comma expr)* + #| / 'except' optInd (expr ^+ comma)) + #| exportStmt = 'export' optInd expr + #| ((comma expr)* + #| / 'except' optInd (expr ^+ comma)) + result = newNodeP(kind, p) + getTok(p) # skip `import` or `export` + optInd(p, result) + var a = parseModuleName(p, kind) + result.add(a) + if p.tok.tokType in {tkComma, tkExcept}: + if p.tok.tokType == tkExcept: + result.transitionSonsKind(succ(kind)) + getTok(p) + optInd(p, result) + while true: + # was: while p.tok.tokType notin {tkEof, tkSad, tkDed}: + p.hasProgress = false + a = parseModuleName(p, kind) + if a.kind == nkEmpty or not p.hasProgress: break + result.add(a) + if p.tok.tokType != tkComma: break + getTok(p) + optInd(p, a) + #expectNl(p) + setEndInfo() + +proc parseIncludeStmt(p: var Parser): PNode = + #| includeStmt = 'include' optInd expr ^+ comma + result = newNodeP(nkIncludeStmt, p) + getTok(p) # skip `import` or `include` + optInd(p, result) + while true: + # was: while p.tok.tokType notin {tkEof, tkSad, tkDed}: + p.hasProgress = false + var a = parseExpr(p) + if a.kind == nkEmpty or not p.hasProgress: break + result.add(a) + if p.tok.tokType != tkComma: break + getTok(p) + optInd(p, a) + #expectNl(p) + setEndInfo() + +proc parseFromStmt(p: var Parser): PNode = + #| fromStmt = 'from' expr 'import' optInd expr (comma expr)* + result = newNodeP(nkFromStmt, p) + getTok(p) # skip `from` + optInd(p, result) + var a = parseModuleName(p, nkImportStmt) + result.add(a) #optInd(p, a); + eat(p, tkImport) + optInd(p, result) + while true: + # p.tok.tokType notin {tkEof, tkSad, tkDed}: + p.hasProgress = false + a = parseExpr(p) + if a.kind == nkEmpty or not p.hasProgress: break + result.add(a) + if p.tok.tokType != tkComma: break + getTok(p) + optInd(p, a) + #expectNl(p) + setEndInfo() + +proc parseReturnOrRaise(p: var Parser, kind: TNodeKind): PNode = + #| returnStmt = 'return' optInd expr? + #| raiseStmt = 'raise' optInd expr? + #| yieldStmt = 'yield' optInd expr? + #| discardStmt = 'discard' optInd expr? + #| breakStmt = 'break' optInd expr? + #| continueStmt = 'continue' optInd expr? + result = newNodeP(kind, p) + getTok(p) + if p.tok.tokType == tkComment: + skipComment(p, result) + result.add(p.emptyNode) + elif p.tok.indent >= 0 and p.tok.indent <= p.currInd or not isExprStart(p): + # NL terminates: + result.add(p.emptyNode) + # nimpretty here! + else: + var e = parseExpr(p) + e = postExprBlocks(p, e) + result.add(e) + setEndInfo() + +proc parseIfOrWhen(p: var Parser, kind: TNodeKind): PNode = + #| condStmt = expr colcom stmt COMMENT? + #| (IND{=} 'elif' expr colcom stmt)* + #| (IND{=} 'else' colcom stmt)? + #| ifStmt = 'if' condStmt + #| whenStmt = 'when' condStmt + result = newNodeP(kind, p) + while true: + getTok(p) # skip `if`, `when`, `elif` + var branch = newNodeP(nkElifBranch, p) + optInd(p, branch) + branch.add(parseExpr(p)) + colcom(p, branch) + branch.add(parseStmt(p)) + skipComment(p, branch) + result.add(branch) + if p.tok.tokType != tkElif or not sameOrNoInd(p): break + if p.tok.tokType == tkElse and sameOrNoInd(p): + var branch = newNodeP(nkElse, p) + eat(p, tkElse) + colcom(p, branch) + branch.add(parseStmt(p)) + result.add(branch) + setEndInfo() + +proc parseIfOrWhenExpr(p: var Parser, kind: TNodeKind): PNode = + #| condExpr = expr colcom stmt optInd + #| ('elif' expr colcom stmt optInd)* + #| 'else' colcom stmt + #| ifExpr = 'if' condExpr + #| whenExpr = 'when' condExpr + result = newNodeP(kind, p) + while true: + getTok(p) # skip `if`, `when`, `elif` + var branch = newNodeP(nkElifExpr, p) + optInd(p, branch) + branch.add(parseExpr(p)) + colcom(p, branch) + branch.add(parseStmt(p)) + skipComment(p, branch) + result.add(branch) + if p.tok.tokType != tkElif: break + if p.tok.tokType == tkElse: + var branch = newNodeP(nkElseExpr, p) + eat(p, tkElse) + colcom(p, branch) + branch.add(parseStmt(p)) + result.add(branch) + setEndInfo() + +proc parseWhile(p: var Parser): PNode = + #| whileStmt = 'while' expr colcom stmt + result = newNodeP(nkWhileStmt, p) + getTok(p) + optInd(p, result) + result.add(parseExpr(p)) + colcom(p, result) + result.add(parseStmt(p)) + setEndInfo() + +proc parseCase(p: var Parser): PNode = + #| ofBranch = 'of' exprList colcom stmt + #| ofBranches = ofBranch (IND{=} ofBranch)* + #| (IND{=} 'elif' expr colcom stmt)* + #| (IND{=} 'else' colcom stmt)? + #| caseStmt = 'case' expr ':'? COMMENT? + #| (IND{>} ofBranches DED + #| | IND{=} ofBranches) + var + b: PNode + inElif = false + wasIndented = false + result = newNodeP(nkCaseStmt, p) + getTok(p) + result.add(parseExpr(p)) + if p.tok.tokType == tkColon: getTok(p) + skipComment(p, result) + + let oldInd = p.currInd + if realInd(p): + p.currInd = p.tok.indent + wasIndented = true + + while sameInd(p): + case p.tok.tokType + of tkOf: + if inElif: break + b = newNodeP(nkOfBranch, p) + exprList(p, tkColon, b) + of tkElif: + inElif = true + b = newNodeP(nkElifBranch, p) + getTok(p) + optInd(p, b) + b.add(parseExpr(p)) + of tkElse: + b = newNodeP(nkElse, p) + getTok(p) + else: break + colcom(p, b) + b.add(parseStmt(p)) + result.add(b) + if b.kind == nkElse: break + + if wasIndented: + p.currInd = oldInd + setEndInfo() + +proc parseTry(p: var Parser; isExpr: bool): PNode = + #| tryStmt = 'try' colcom stmt &(IND{=}? 'except'|'finally') + #| (IND{=}? 'except' optionalExprList colcom stmt)* + #| (IND{=}? 'finally' colcom stmt)? + #| tryExpr = 'try' colcom stmt &(optInd 'except'|'finally') + #| (optInd 'except' optionalExprList colcom stmt)* + #| (optInd 'finally' colcom stmt)? + result = newNodeP(nkTryStmt, p) + let parentIndent = p.currInd # isExpr + getTok(p) + colcom(p, result) + result.add(parseStmt(p)) + var b: PNode = nil + + while sameOrNoInd(p) or (isExpr and parentIndent <= p.tok.indent): + case p.tok.tokType + of tkExcept: + b = newNodeP(nkExceptBranch, p) + optionalExprList(p, tkColon, b) + of tkFinally: + b = newNodeP(nkFinally, p) + getTok(p) + else: break + colcom(p, b) + b.add(parseStmt(p)) + result.add(b) + if b == nil: parMessage(p, "expected 'except'") + setEndInfo() + +proc parseExceptBlock(p: var Parser, kind: TNodeKind): PNode = + result = newNodeP(kind, p) + getTok(p) + colcom(p, result) + result.add(parseStmt(p)) + setEndInfo() + +proc parseBlock(p: var Parser): PNode = + #| blockStmt = 'block' symbol? colcom stmt + #| blockExpr = 'block' symbol? colcom stmt + result = newNodeP(nkBlockStmt, p) + getTokNoInd(p) + if p.tok.tokType == tkColon: result.add(p.emptyNode) + else: result.add(parseSymbol(p)) + colcom(p, result) + result.add(parseStmt(p)) + setEndInfo() + +proc parseStaticOrDefer(p: var Parser; k: TNodeKind): PNode = + #| staticStmt = 'static' colcom stmt + #| deferStmt = 'defer' colcom stmt + result = newNodeP(k, p) + getTok(p) + colcom(p, result) + result.add(parseStmt(p)) + setEndInfo() + +proc parseAsm(p: var Parser): PNode = + #| asmStmt = 'asm' pragma? (STR_LIT | RSTR_LIT | TRIPLESTR_LIT) + result = newNodeP(nkAsmStmt, p) + getTokNoInd(p) + if p.tok.tokType == tkCurlyDotLe: result.add(parsePragma(p)) + else: result.add(p.emptyNode) + case p.tok.tokType + of tkStrLit: result.add(newStrNodeP(nkStrLit, p.tok.literal, p)) + of tkRStrLit: result.add(newStrNodeP(nkRStrLit, p.tok.literal, p)) + of tkTripleStrLit: result.add(newStrNodeP(nkTripleStrLit, p.tok.literal, p)) + else: + parMessage(p, "the 'asm' statement takes a string literal") + result.add(p.emptyNode) + return + getTok(p) + setEndInfo() + +proc parseGenericParam(p: var Parser): PNode = + #| genericParam = symbol (comma symbol)* (colon expr)? ('=' optInd expr)? + var a: PNode + result = newNodeP(nkIdentDefs, p) + # progress guaranteed + while true: + case p.tok.tokType + of tkIn, tkOut: + let x = p.lex.cache.getIdent(if p.tok.tokType == tkIn: "in" else: "out") + a = newNodeP(nkPrefix, p) + a.add newIdentNodeP(x, p) + getTok(p) + expectIdent(p) + a.add(parseSymbol(p)) + of tkSymbol, tkAccent: + a = parseSymbol(p) + if a.kind == nkEmpty: return + else: break + result.add(a) + if p.tok.tokType != tkComma: break + getTok(p) + optInd(p, a) + if p.tok.tokType == tkColon: + getTok(p) + optInd(p, result) + result.add(parseExpr(p)) + else: + result.add(p.emptyNode) + if p.tok.tokType == tkEquals: + getTok(p) + optInd(p, result) + result.add(parseExpr(p)) + else: + result.add(p.emptyNode) + setEndInfo() + +proc parseGenericParamList(p: var Parser): PNode = + #| genericParamList = '[' optInd + #| genericParam ^* (comma/semicolon) optPar ']' + result = newNodeP(nkGenericParams, p) + getTok(p) + optInd(p, result) + # progress guaranteed + while p.tok.tokType in {tkSymbol, tkAccent, tkIn, tkOut}: + var a = parseGenericParam(p) + result.add(a) + if p.tok.tokType notin {tkComma, tkSemiColon}: break + when defined(nimpretty): + commaWasSemicolon(p.em) + getTok(p) + skipComment(p, a) + optPar(p) + eat(p, tkBracketRi) + setEndInfo() + +proc parsePattern(p: var Parser): PNode = + #| pattern = '{' stmt '}' + eat(p, tkCurlyLe) + result = parseStmt(p) + eat(p, tkCurlyRi) + setEndInfo() + +proc parseRoutine(p: var Parser, kind: TNodeKind): PNode = + #| indAndComment = (IND{>} COMMENT)? | COMMENT? + #| routine = optInd identVis pattern? genericParamList? + #| paramListColon pragma? ('=' COMMENT? stmt)? indAndComment + result = newNodeP(kind, p) + getTok(p) + optInd(p, result) + if kind in {nkProcDef, nkLambda, nkIteratorDef, nkFuncDef} and + p.tok.tokType notin {tkSymbol, tokKeywordLow..tokKeywordHigh, tkAccent}: + # no name; lambda or proc type + # in every context that we can parse a routine, we can also parse these + result = parseProcExpr(p, true, if kind == nkProcDef: nkLambda else: kind) + return + result.add(identVis(p)) + if p.tok.tokType == tkCurlyLe and p.validInd: result.add(p.parsePattern) + else: result.add(p.emptyNode) + if p.tok.tokType == tkBracketLe and p.validInd: + result.add(p.parseGenericParamList) + else: + result.add(p.emptyNode) + result.add(p.parseParamList) + if p.tok.tokType == tkCurlyDotLe and p.validInd: result.add(p.parsePragma) + else: result.add(p.emptyNode) + # empty exception tracking: + result.add(p.emptyNode) + let maybeMissEquals = p.tok.tokType != tkEquals + if (not maybeMissEquals) and p.validInd: + getTok(p) + skipComment(p, result) + result.add(parseStmt(p)) + else: + result.add(p.emptyNode) + indAndComment(p, result, maybeMissEquals) + let body = result.lastSon + if body.kind == nkStmtList and body.hasSon and body.firstSon.comment.len > 0 and body.firstSon.kind != nkCommentStmt: + if result.comment.len == 0: + # proc fn*(a: int): int = a ## foo + # => moves comment `foo` to `fn` + result.comment = body.firstSon.comment + body.firstSon.comment = "" + #else: + # assert false, p.lex.config$body.info # avoids hard to track bugs, fail early. + # Yeah, that worked so well. There IS a bug in this logic, now what? + setEndInfo() + +proc newCommentStmt(p: var Parser): PNode = + #| commentStmt = COMMENT + result = newNodeP(nkCommentStmt, p) + result.comment = p.tok.literal + getTok(p) + +proc parseSection(p: var Parser, kind: TNodeKind, + defparser: proc (p: var Parser): PNode {.nimcall.}): PNode = + #| section(RULE) = COMMENT? RULE / (IND{>} (RULE / COMMENT)^+IND{=} DED) + result = newNodeP(kind, p) + if kind != nkTypeSection: getTok(p) + skipComment(p, result) + if realInd(p): + withInd(p): + skipComment(p, result) + # progress guaranteed + while sameInd(p): + case p.tok.tokType + of tkSymbol, tkAccent, tkParLe: + var a = defparser(p) + skipComment(p, a) + result.add(a) + of tkComment: + var a = newCommentStmt(p) + result.add(a) + else: + parMessage(p, errIdentifierExpected, p.tok) + break + if not result.hasSon: parMessage(p, errIdentifierExpected, p.tok) + elif p.tok.tokType in {tkSymbol, tkAccent, tkParLe} and p.tok.indent < 0: + # tkParLe is allowed for ``var (x, y) = ...`` tuple parsing + result.add(defparser(p)) + else: + parMessage(p, errIdentifierExpected, p.tok) + setEndInfo() + +proc parseEnum(p: var Parser): PNode = + #| enumDecl = 'enum' optInd (symbol pragma? optInd ('=' optInd expr COMMENT?)? comma?)+ + result = newNodeP(nkEnumTy, p) + getTok(p) + result.add(p.emptyNode) + optInd(p, result) + flexComment(p, result) + # progress guaranteed + while true: + var a = parseSymbol(p) + if a.kind == nkEmpty: return + + var symPragma = a + var pragma: PNode + if (p.tok.indent < 0 or p.tok.indent >= p.currInd) and p.tok.tokType == tkCurlyDotLe: + pragma = optPragmas(p) + symPragma = newNodeP(nkPragmaExpr, p) + symPragma.add(a) + symPragma.add(pragma) + # nimpretty support here + if p.tok.indent >= 0 and p.tok.indent <= p.currInd: + result.add(symPragma) + break + + if p.tok.tokType == tkEquals and p.tok.indent < 0: + getTok(p) + optInd(p, symPragma) + var b = symPragma + symPragma = newNodeP(nkEnumFieldDef, p) + symPragma.add(b) + symPragma.add(parseExpr(p)) + if p.tok.indent < 0 or p.tok.indent >= p.currInd: + rawSkipComment(p, symPragma) + if p.tok.tokType == tkComma and p.tok.indent < 0: + getTok(p) + rawSkipComment(p, symPragma) + else: + if p.tok.indent < 0 or p.tok.indent >= p.currInd: + rawSkipComment(p, symPragma) + result.add(symPragma) + if p.tok.indent >= 0 and p.tok.indent <= p.currInd or + p.tok.tokType == tkEof: + break + if not result.has2Sons: + parMessage(p, errIdentifierExpected, p.tok) + setEndInfo() + +proc parseObjectPart(p: var Parser): PNode +proc parseObjectWhen(p: var Parser): PNode = + #| objectWhen = 'when' expr colcom objectPart COMMENT? + #| ('elif' expr colcom objectPart COMMENT?)* + #| ('else' colcom objectPart COMMENT?)? + result = newNodeP(nkRecWhen, p) + # progress guaranteed + while sameInd(p): + getTok(p) # skip `when`, `elif` + var branch = newNodeP(nkElifBranch, p) + optInd(p, branch) + branch.add(parseExpr(p)) + colcom(p, branch) + branch.add(parseObjectPart(p)) + flexComment(p, branch) + result.add(branch) + if p.tok.tokType != tkElif: break + if p.tok.tokType == tkElse and sameInd(p): + var branch = newNodeP(nkElse, p) + eat(p, tkElse) + colcom(p, branch) + branch.add(parseObjectPart(p)) + flexComment(p, branch) + result.add(branch) + setEndInfo() + +proc parseObjectCase(p: var Parser): PNode = + #| objectBranch = 'of' exprList colcom objectPart + #| objectBranches = objectBranch (IND{=} objectBranch)* + #| (IND{=} 'elif' expr colcom objectPart)* + #| (IND{=} 'else' colcom objectPart)? + #| objectCase = 'case' declColonEquals ':'? COMMENT? + #| (IND{>} objectBranches DED + #| | IND{=} objectBranches) + result = newNodeP(nkRecCase, p) + getTokNoInd(p) + var a = parseIdentColonEquals(p, {withPragma}) + result.add(a) + if p.tok.tokType == tkColon: getTok(p) + flexComment(p, result) + var wasIndented = false + let oldInd = p.currInd + if realInd(p): + p.currInd = p.tok.indent + wasIndented = true + # progress guaranteed + while sameInd(p): + var b: PNode + case p.tok.tokType + of tkOf: + b = newNodeP(nkOfBranch, p) + exprList(p, tkColon, b) + of tkElse: + b = newNodeP(nkElse, p) + getTok(p) + else: break + colcom(p, b) + var fields = parseObjectPart(p) + if fields.kind == nkEmpty: + parMessage(p, errIdentifierExpected, p.tok) + fields = newNodeP(nkNilLit, p) # don't break further semantic checking + b.add(fields) + result.add(b) + if b.kind == nkElse: break + if wasIndented: + p.currInd = oldInd + setEndInfo() + +proc parseObjectPart(p: var Parser): PNode = + #| objectPart = IND{>} objectPart^+IND{=} DED + #| / objectWhen / objectCase / 'nil' / 'discard' / declColonEquals + if realInd(p): + result = newNodeP(nkRecList, p) + withInd(p): + rawSkipComment(p, result) + while sameInd(p): + case p.tok.tokType + of tkCase, tkWhen, tkSymbol, tkAccent, tkNil, tkDiscard: + result.add(parseObjectPart(p)) + else: + parMessage(p, errIdentifierExpected, p.tok) + break + elif sameOrNoInd(p): + case p.tok.tokType + of tkWhen: + result = parseObjectWhen(p) + of tkCase: + result = parseObjectCase(p) + of tkSymbol, tkAccent: + result = parseIdentColonEquals(p, {withPragma}) + if p.tok.indent < 0 or p.tok.indent >= p.currInd: + rawSkipComment(p, result) + of tkNil, tkDiscard: + result = newNodeP(nkNilLit, p) + getTok(p) + else: + result = p.emptyNode + else: + result = p.emptyNode + setEndInfo() + +proc parseObject(p: var Parser): PNode = + #| objectDecl = 'object' ('of' typeDesc)? COMMENT? objectPart + result = newNodeP(nkObjectTy, p) + getTok(p) + result.add(p.emptyNode) # compatibility with old pragma node + if p.tok.tokType == tkOf and p.tok.indent < 0: + var a = newNodeP(nkOfInherit, p) + getTok(p) + a.add(parseTypeDesc(p)) + result.add(a) + else: + result.add(p.emptyNode) + if p.tok.tokType == tkComment: + skipComment(p, result) + # an initial IND{>} HAS to follow: + if not realInd(p): + result.add(p.emptyNode) + else: + result.add(parseObjectPart(p)) + setEndInfo() + +proc parseTypeClassParam(p: var Parser): PNode = + let modifier = + case p.tok.tokType + of tkVar: nkVarTy + of tkOut: nkOutTy + of tkPtr: nkPtrTy + of tkRef: nkRefTy + of tkStatic: nkStaticTy + of tkType: nkTypeOfExpr + else: nkEmpty + + if modifier != nkEmpty: + result = newNodeP(modifier, p) + getTok(p) + result.add(p.parseSymbol) + else: + result = p.parseSymbol + setEndInfo() + +proc parseTypeClass(p: var Parser): PNode = + #| conceptParam = ('var' | 'out' | 'ptr' | 'ref' | 'static' | 'type')? symbol + #| conceptDecl = 'concept' conceptParam ^* ',' (pragma)? ('of' typeDesc ^* ',')? + #| &IND{>} stmt + result = newNodeP(nkTypeClassTy, p) + getTok(p) + if p.tok.tokType == tkComment: + skipComment(p, result) + + if p.tok.indent < 0: + var args = newNodeP(nkArgList, p) + result.add(args) + args.add(p.parseTypeClassParam) + while p.tok.tokType == tkComma: + getTok(p) + args.add(p.parseTypeClassParam) + else: + result.add(p.emptyNode) # see ast.isNewStyleConcept + if p.tok.tokType == tkCurlyDotLe and p.validInd: + result.add(parsePragma(p)) + else: + result.add(p.emptyNode) + if p.tok.tokType == tkOf and p.tok.indent < 0: + var a = newNodeP(nkOfInherit, p) + getTok(p) + # progress guaranteed + while true: + a.add(parseTypeDesc(p)) + if p.tok.tokType != tkComma: break + getTok(p) + result.add(a) + else: + result.add(p.emptyNode) + if p.tok.tokType == tkComment: + skipComment(p, result) + # an initial IND{>} HAS to follow: + if not realInd(p): + if result.isNewStyleConcept: + parMessage(p, "routine expected, but found '$1' (empty new-styled concepts are not allowed)", p.tok) + result.add(p.emptyNode) + else: + result.add(parseStmt(p)) + setEndInfo() + +proc parseTypeDef(p: var Parser): PNode = + #| + #| typeDef = identVisDot genericParamList? pragma '=' optInd typeDefValue + #| indAndComment? + result = newNodeP(nkTypeDef, p) + var identifier = identVis(p, allowDot=true) + var identPragma = identifier + var pragma: PNode + var genericParam: PNode + + if p.tok.tokType == tkBracketLe and p.validInd: + genericParam = parseGenericParamList(p) + else: + genericParam = p.emptyNode + + pragma = optPragmas(p) + if pragma.kind != nkEmpty: + identPragma = newNodeP(nkPragmaExpr, p) + identPragma.add(identifier) + identPragma.add(pragma) + + result.add(identPragma) + result.add(genericParam) + + if p.tok.tokType == tkEquals: + result.info = parLineInfo(p) + getTok(p) + optInd(p, result) + result.add(parseTypeDefValue(p)) + else: + result.add(p.emptyNode) + indAndComment(p, result) # special extension! + setEndInfo() + +proc parseVarTuple(p: var Parser): PNode = + #| varTupleLhs = '(' optInd (identWithPragma / varTupleLhs) ^+ comma optPar ')' (':' optInd typeDescExpr)? + #| varTuple = varTupleLhs '=' optInd expr + result = newNodeP(nkVarTuple, p) + getTok(p) # skip '(' + optInd(p, result) + # progress guaranteed + while p.tok.tokType in {tkSymbol, tkAccent, tkParLe}: + var a: PNode + if p.tok.tokType == tkParLe: + a = parseVarTuple(p) + a.add(p.emptyNode) + else: + a = identWithPragma(p, allowDot=true) + result.add(a) + if p.tok.tokType != tkComma: break + getTok(p) + skipComment(p, a) + optPar(p) + eat(p, tkParRi) + if p.tok.tokType == tkColon: + getTok(p) + optInd(p, result) + result.add(parseTypeDesc(p, fullExpr = true)) + else: + result.add(p.emptyNode) # no type desc + setEndInfo() + +proc parseVariable(p: var Parser): PNode = + #| colonBody = colcom stmt postExprBlocks? + #| variable = (varTuple / identColonEquals) colonBody? indAndComment + if p.tok.tokType == tkParLe: + result = parseVarTuple(p) + eat(p, tkEquals) + optInd(p, result) + result.add(parseExpr(p)) + else: result = parseIdentColonEquals(p, {withPragma, withDot}) + result.setLastSon postExprBlocks(p, result.lastSon) + indAndComment(p, result) + setEndInfo() + +proc parseConstant(p: var Parser): PNode = + #| constant = (varTuple / identWithPragma) (colon typeDesc)? '=' optInd expr indAndComment + if p.tok.tokType == tkParLe: result = parseVarTuple(p) + else: + result = newNodeP(nkConstDef, p) + result.add(identWithPragma(p)) + if p.tok.tokType == tkColon: + getTok(p) + optInd(p, result) + result.add(parseTypeDesc(p)) + else: + result.add(p.emptyNode) + eat(p, tkEquals) + optInd(p, result) + #add(result, parseStmtListExpr(p)) + let a = parseExpr(p) + result.add postExprBlocks(p, a) + indAndComment(p, result) + setEndInfo() + +proc parseBind(p: var Parser, k: TNodeKind): PNode = + #| bindStmt = 'bind' optInd qualifiedIdent ^+ comma + #| mixinStmt = 'mixin' optInd qualifiedIdent ^+ comma + result = newNodeP(k, p) + getTok(p) + optInd(p, result) + # progress guaranteed + while true: + var a = qualifiedIdent(p) + result.add(a) + if p.tok.tokType != tkComma: break + getTok(p) + optInd(p, a) + #expectNl(p) + setEndInfo() + +proc parseStmtPragma(p: var Parser): PNode = + #| pragmaStmt = pragma (':' COMMENT? stmt)? + result = parsePragma(p) + if p.tok.tokType == tkColon and p.tok.indent < 0: + let a = result + result = newNode(nkPragmaBlock, a.info) + getTok(p) + skipComment(p, result) + result.add a + result.add parseStmt(p) + setEndInfo() + +proc simpleStmt(p: var Parser): PNode = + #| simpleStmt = ((returnStmt | raiseStmt | yieldStmt | discardStmt | breakStmt + #| | continueStmt | pragmaStmt | importStmt | exportStmt | fromStmt + #| | includeStmt | commentStmt) / exprStmt) COMMENT? + #| + case p.tok.tokType + of tkReturn: result = parseReturnOrRaise(p, nkReturnStmt) + of tkRaise: result = parseReturnOrRaise(p, nkRaiseStmt) + of tkYield: result = parseReturnOrRaise(p, nkYieldStmt) + of tkDiscard: result = parseReturnOrRaise(p, nkDiscardStmt) + of tkBreak: result = parseReturnOrRaise(p, nkBreakStmt) + of tkContinue: result = parseReturnOrRaise(p, nkContinueStmt) + of tkCurlyDotLe: result = parseStmtPragma(p) + of tkImport: result = parseImport(p, nkImportStmt) + of tkExport: result = parseImport(p, nkExportStmt) + of tkFrom: result = parseFromStmt(p) + of tkInclude: result = parseIncludeStmt(p) + of tkComment: result = newCommentStmt(p) + else: + if isExprStart(p): result = parseExprStmt(p) + else: result = p.emptyNode + if result.kind notin {nkEmpty, nkCommentStmt}: skipComment(p, result) + +proc complexOrSimpleStmt(p: var Parser): PNode = + #| complexOrSimpleStmt = (ifStmt | whenStmt | whileStmt + #| | tryStmt | forStmt + #| | blockStmt | staticStmt | deferStmt | asmStmt + #| | 'proc' routine + #| | 'method' routine + #| | 'func' routine + #| | 'iterator' routine + #| | 'macro' routine + #| | 'template' routine + #| | 'converter' routine + #| | 'type' section(typeDef) + #| | 'const' section(constant) + #| | ('let' | 'var' | 'using') section(variable) + #| | bindStmt | mixinStmt) + #| / simpleStmt + case p.tok.tokType + of tkIf: result = parseIfOrWhen(p, nkIfStmt) + of tkWhile: result = parseWhile(p) + of tkCase: result = parseCase(p) + of tkTry: result = parseTry(p, isExpr=false) + of tkFinally: result = parseExceptBlock(p, nkFinally) + of tkExcept: result = parseExceptBlock(p, nkExceptBranch) + of tkFor: result = parseFor(p) + of tkBlock: result = parseBlock(p) + of tkStatic: result = parseStaticOrDefer(p, nkStaticStmt) + of tkDefer: result = parseStaticOrDefer(p, nkDefer) + of tkAsm: result = parseAsm(p) + of tkProc: result = parseRoutine(p, nkProcDef) + of tkFunc: result = parseRoutine(p, nkFuncDef) + of tkMethod: result = parseRoutine(p, nkMethodDef) + of tkIterator: result = parseRoutine(p, nkIteratorDef) + of tkMacro: result = parseRoutine(p, nkMacroDef) + of tkTemplate: result = parseRoutine(p, nkTemplateDef) + of tkConverter: result = parseRoutine(p, nkConverterDef) + of tkType: + getTok(p) + if p.tok.tokType == tkParLe: + getTok(p) + result = newNodeP(nkTypeOfExpr, p) + result.add(primary(p, pmTypeDesc)) + eat(p, tkParRi) + result = parseOperators(p, result, -1, pmNormal) + else: + result = parseSection(p, nkTypeSection, parseTypeDef) + of tkConst: + prettySection: + result = parseSection(p, nkConstSection, parseConstant) + of tkLet: + prettySection: + result = parseSection(p, nkLetSection, parseVariable) + of tkVar: + prettySection: + result = parseSection(p, nkVarSection, parseVariable) + of tkWhen: result = parseIfOrWhen(p, nkWhenStmt) + of tkBind: result = parseBind(p, nkBindStmt) + of tkMixin: result = parseBind(p, nkMixinStmt) + of tkUsing: result = parseSection(p, nkUsingStmt, parseVariable) + else: result = simpleStmt(p) + +proc parseStmt(p: var Parser): PNode = + #| stmt = (IND{>} complexOrSimpleStmt^+(IND{=} / ';') DED) + #| / simpleStmt ^+ ';' + if p.tok.indent > p.currInd: + # nimpretty support here + result = newNodeP(nkStmtList, p) + withInd(p): + while true: + if p.tok.indent == p.currInd: + discard + elif p.tok.tokType == tkSemiColon: + getTok(p) + if p.tok.indent < 0 or p.tok.indent == p.currInd: discard + else: break + else: + if p.tok.indent > p.currInd and p.tok.tokType != tkDot: + parMessage(p, errInvalidIndentation) + break + if p.tok.tokType in {tkCurlyRi, tkParRi, tkCurlyDotRi, tkBracketRi}: + # XXX this ensures tnamedparamanonproc still compiles; + # deprecate this syntax later + break + p.hasProgress = false + if p.tok.tokType in {tkElse, tkElif}: + break # Allow this too, see tests/parser/tifexprs + + let a = complexOrSimpleStmt(p) + if a.kind == nkEmpty and not p.hasProgress: + parMessage(p, errExprExpected, p.tok) + break + else: + result.add a + + if not p.hasProgress and p.tok.tokType == tkEof: break + else: + # the case statement is only needed for better error messages: + case p.tok.tokType + of tkIf, tkWhile, tkCase, tkTry, tkFor, tkBlock, tkAsm, tkProc, tkFunc, + tkIterator, tkMacro, tkType, tkConst, tkWhen, tkVar: + parMessage(p, "nestable statement requires indentation") + result = p.emptyNode + else: + if p.inSemiStmtList > 0: + result = simpleStmt(p) + if result.kind == nkEmpty: parMessage(p, errExprExpected, p.tok) + else: + result = newNodeP(nkStmtList, p) + while true: + if p.tok.indent >= 0: + parMessage(p, errInvalidIndentation) + p.hasProgress = false + let a = simpleStmt(p) + let err = not p.hasProgress + if a.kind == nkEmpty: parMessage(p, errExprExpected, p.tok) + result.add(a) + if p.tok.tokType != tkSemiColon: break + getTok(p) + if err and p.tok.tokType == tkEof: break + setEndInfo() + +proc checkFirstLineIndentation*(p: var Parser) = + if p.tok.indent != 0 and tsLeading in p.tok.spacing: + parMessage(p, errInvalidIndentation) + +proc parseTopLevelStmt*(p: var Parser): PNode = + ## Implements an iterator which, when called repeatedly, returns the next + ## top-level statement or emptyNode if end of stream. + result = p.emptyNode + # progress guaranteed + while true: + # nimpretty support here + if p.tok.indent != 0: + if p.firstTok and p.tok.indent < 0: discard + elif p.tok.tokType != tkSemiColon: + # special casing for better error messages: + if p.tok.tokType == tkOpr and p.tok.ident.s == "*": + parMessage(p, errGenerated, + "invalid indentation; an export marker '*' follows the declared identifier") + else: + parMessage(p, errInvalidIndentation) + p.firstTok = false + case p.tok.tokType + of tkSemiColon: + getTok(p) + if p.tok.indent <= 0: discard + else: parMessage(p, errInvalidIndentation) + p.firstTok = true + of tkEof: break + else: + result = complexOrSimpleStmt(p) + if result.kind == nkEmpty: parMessage(p, errExprExpected, p.tok) + break + setEndInfo() + +proc parseAll*(p: var Parser): PNode = + ## Parses the rest of the input stream held by the parser into a PNode. + result = newNodeP(nkStmtList, p) + while true: + let nextStmt = p.parseTopLevelStmt() + if nextStmt.kind == nkEmpty: + break + result &= nextStmt + setEndInfo() + +proc parseString*(s: string; cache: IdentCache; config: ConfigRef; + filename: string = ""; line: int = 0; + errorHandler: ErrorHandler = nil): PNode = + ## Parses a string into an AST, returning the top node. + ## `filename` and `line`, although optional, provide info so that the + ## compiler can generate correct error messages referring to the original + ## source. + var stream = llStreamOpen(s) + stream.lineOffset = line + + var p = Parser() + p.lex.errorHandler = errorHandler + openParser(p, AbsoluteFile filename, stream, cache, config) + + result = p.parseAll + closeParser(p) + setEndInfo() |