# # # 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: import pegs var outp = open("doc/grammar.txt", fmWrite) for line in lines("compiler/parser.nim"): if line =~ peg" \s* '#| ' {.*}": outp.write matches[0], "\L" outp.close import llstream, lexer, idents, strutils, ast, astalgo, msgs type TParser*{.final.} = object # A TParser object represents a module that # is being parsed currInd: int # current indentation level firstTok, strongSpaces: bool # Has the first token been read? # Is strongSpaces on? lex*: TLexer # The lexer that is used for parsing tok*: TToken # The current token inPragma: int # Pragma level inSemiStmtList: int proc parseAll*(p: var TParser): PNode proc closeParser*(p: var TParser) proc parseTopLevelStmt*(p: var TParser): PNode # helpers for the other parsers proc isOperator*(tok: TToken): bool proc getTok*(p: var TParser) proc parMessage*(p: TParser, msg: TMsgKind, arg: string = "") proc skipComment*(p: var TParser, node: PNode) proc newNodeP*(kind: TNodeKind, p: TParser): PNode proc newIntNodeP*(kind: TNodeKind, intVal: BiggestInt, p: TParser): PNode proc newFloatNodeP*(kind: TNodeKind, floatVal: BiggestFloat, p: TParser): PNode proc newStrNodeP*(kind: TNodeKind, strVal: string, p: TParser): PNode proc newIdentNodeP*(ident: PIdent, p: TParser): PNode proc expectIdentOrKeyw*(p: TParser) proc expectIdent*(p: TParser) proc parLineInfo*(p: TParser): TLineInfo proc eat*(p: var TParser, tokType: TTokType) proc skipInd*(p: var TParser) proc optPar*(p: var TParser) proc optInd*(p: var TParser, n: PNode) proc indAndComment*(p: var TParser, n: PNode) proc setBaseFlags*(n: PNode, base: TNumericalBase) proc parseSymbol*(p: var TParser, allowNil = false): PNode proc parseTry(p: var TParser; isExpr: bool): PNode proc parseCase(p: var TParser): PNode proc parseStmtPragma(p: var TParser): PNode # implementation proc getTok(p: var TParser) = ## Get the next token from the parser's lexer, and store it in the parser's ## `tok` member. rawGetTok(p.lex, p.tok) proc openParser*(p: var TParser, fileIdx: int32, inputStream: PLLStream, strongSpaces=false) = ## Open a parser, using the given arguments to set up its internal state. ## initToken(p.tok) openLexer(p.lex, fileIdx, inputStream) getTok(p) # read the first token p.firstTok = true p.strongSpaces = strongSpaces proc openParser*(p: var TParser, filename: string, inputStream: PLLStream, strongSpaces=false) = openParser(p, filename.fileInfoIdx, inputStream, strongSpaces) proc closeParser(p: var TParser) = ## Close a parser, freeing up its resources. closeLexer(p.lex) proc parMessage(p: TParser, msg: TMsgKind, arg = "") = ## Produce and emit the parser message `arg` to output. lexMessageTok(p.lex, msg, p.tok, arg) proc parMessage(p: TParser, msg: TMsgKind, tok: TToken) = ## Produce and emit a pars

discard """
  targets: "cpp"
  output: "hello"
  cmd: "nim cpp --clearNimblePath --nimblePath:build/deps/pkgs $file"
"""

# bug #3299

import jester
import asyncdispatch, asyncnet

# bug #5081
#import nre

echo "hello"

#| 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 colcom(p: var TParser, n: PNode) = eat(p, tkColon) skipComment(p, n) proc parseSymbol(p: var TParser, allowNil = false): PNode = #| symbol = '`' (KEYW|IDENT|literal|(operator|'('|')'|'['|']'|'{'|'}'|'=')+)+ '`' #| | IDENT | 'addr' | 'type' case p.tok.tokType of tkSymbol, tkAddr, tkType: result = newIdentNodeP(p.tok.ident, p) getTok(p) of tkAccent: result = newNodeP(nkAccQuoted, p) getTok(p) while true: case p.tok.tokType of tkAccent: if result.len == 0: parMessage(p, errIdentifierExpected, p.tok) break of tkOpr, tkDot, tkDotDot, tkEquals, tkParLe..tkParDotRi: var accm = "" while p.tok.tokType in {tkOpr, tkDot, tkDotDot, tkEquals, tkParLe..tkParDotRi}: accm.add(tokToStr(p.tok)) getTok(p) result.add(newIdentNodeP(getIdent(accm), p)) of tokKeywordLow..tokKeywordHigh, tkSymbol, tkIntLit..tkCharLit: result.add(newIdentNodeP(getIdent(tokToStr(p.tok)), p)) getTok(p) else: parMessage(p, errIdentifierExpected, p.tok) break eat(p, tkAccent) else: if allowNil and p.tok.tokType == tkNil: result = newNodeP(nkNilLit, p) getTok(p) 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 = ast.emptyNode proc indexExpr(p: var TParser): PNode = #| indexExpr = expr result = parseExpr(p) proc indexExprList(p: var TParser, first: PNode, k: TNodeKind, endToken: TTokType): PNode = #| indexExprList = indexExpr ^+ comma result = newNodeP(k, p) addSon(result, first) getTok(p) optInd(p, result) while p.tok.tokType notin {endToken, tkEof}: var a = indexExpr(p) addSon(result, a) if p.tok.tokType != tkComma: break getTok(p) skipComment(p, a) optPar(p) eat(p, endToken) proc colonOrEquals(p: var TParser, a: PNode): PNode = if p.tok.tokType == tkColon: result = newNodeP(nkExprColonExpr, p) getTok(p) #optInd(p, result) addSon(result, a) addSon(result, parseExpr(p)) elif p.tok.tokType == tkEquals: result = newNodeP(nkExprEqExpr, p) getTok(p) #optInd(p, result) addSon(result, a) addSon(result, parseExpr(p)) else: result = a proc exprColonEqExpr(p: var TParser): PNode = #| exprColonEqExpr = expr (':'|'=' expr)? var a = parseExpr(p) result = colonOrEquals(p, a) proc exprList(p: var TParser, endTok: TTokType, result: PNode) = #| exprList = expr ^+ comma getTok(p) optInd(p, result) while (p.tok.tokType != endTok) and (p.tok.tokType != tkEof): var a = parseExpr(p) addSon(result, a) if p.tok.tokType != tkComma: break getTok(p) optInd(p, a) proc dotExpr(p: var TParser, a: PNode): PNode = #| dotExpr = expr '.' optInd symbol var info = p.parLineInfo getTok(p) result = newNodeI(nkDotExpr, info) optInd(p, result) addSon(result, a) addSon(result, parseSymbol(p)) proc qualifiedIdent(p: var TParser): PNode = #| qualifiedIdent = symbol ('.' optInd symbol)? result = parseSymbol(p) if p.tok.tokType == tkDot: result = dotExpr(p, result) proc exprColonEqExprListAux(p: var TParser, endTok: TTokType, result: PNode) = assert(endTok in {tkCurlyRi, tkCurlyDotRi, tkBracketRi, tkParRi}) getTok(p) optInd(p, result) while p.tok.tokType != endTok and p.tok.tokType != tkEof: var a = exprColonEqExpr(p) addSon(result, a) if p.tok.tokType != tkComma: break getTok(p) skipComment(p, a) optPar(p) eat(p, endTok) proc exprColonEqExprList(p: var TParser, kind: TNodeKind, endTok: TTokType): PNode = #| exprColonEqExprList = exprColonEqExpr (comma exprColonEqExpr)* (comma)? result = newNodeP(kind, p) exprColonEqExprListAux(p, endTok, result) proc setOrTableConstr(p: var TParser): PNode = #| setOrTableConstr = '{' ((exprColonEqExpr comma)* | ':' ) '}' result = newNodeP(nkCurly, p) getTok(p) # skip '{' optInd(p, result) if p.tok.tokType == tkColon: getTok(p) # skip ':' result.kind = nkTableConstr else: while p.tok.tokType notin {tkCurlyRi, tkEof}: var a = exprColonEqExpr(p) if a.kind == nkExprColonExpr: result.kind = nkTableConstr addSon(result, a) if p.tok.tokType != tkComma: break getTok(p) skipComment(p, a) optPar(p) eat(p, tkCurlyRi) # skip '}' proc parseCast(p: var TParser): PNode = #| castExpr = 'cast' '[' optInd typeDesc optPar ']' '(' optInd expr optPar ')' result = newNodeP(nkCast, p) getTok(p) eat(p, tkBracketLe) optInd(p, result) addSon(result, parseTypeDesc(p)) optPar(p) eat(p, tkBracketRi) eat(p, tkParLe) optInd(p, result) addSon(result, parseExpr(p)) optPar(p) eat(p, tkParRi) proc setBaseFlags(n: PNode, base: TNumericalBase) = case base of base10: discard of base2: incl(n.flags, nfBase2) of base8: incl(n.flags, nfBase8) of base16: incl(n.flags, nfBase16) proc parseGStrLit(p: var TParser, a: PNode): PNode = case p.tok.tokType of tkGStrLit: result = newNodeP(nkCallStrLit, p) addSon(result, a) addSon(result, newStrNodeP(nkRStrLit, p.tok.literal, p)) getTok(p) of tkGTripleStrLit: result = newNodeP(nkCallStrLit, p) addSon(result, a) addSon(result, newStrNodeP(nkTripleStrLit, p.tok.literal, p)) getTok(p) else: result = a type TPrimaryMode = enum pmNormal, pmTypeDesc, pmTypeDef, pmSkipSuffix proc complexOrSimpleStmt(p: var TParser): PNode proc simpleExpr(p: var TParser, mode = pmNormal): PNode proc semiStmtList(p: var TParser, result: PNode) = inc p.inSemiStmtList result.add(complexOrSimpleStmt(p)) while p.tok.tokType == tkSemiColon: getTok(p) optInd(p, result) result.add(complexOrSimpleStmt(p)) dec p.inSemiStmtList result.kind = nkStmtListExpr proc parsePar(p: var TParser): PNode = #| parKeyw = 'discard' | 'include' | 'if' | 'while' | 'case' | 'try' #| | 'finally' | 'except' | 'for' | 'block' | 'const' | 'let' #| | 'when' | 'var' | 'mixin' #| par = '(' optInd #| ( &parKeyw complexOrSimpleStmt ^+ ';' #| | ';' complexOrSimpleStmt ^+ ';' #| | pragmaStmt #| | simpleExpr ( ('=' expr (';' 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) if p.tok.tokType in {tkDiscard, tkInclude, tkIf, tkWhile, tkCase, tkTry, tkDefer, tkFinally, tkExcept, tkFor, tkBlock, tkConst, tkLet, tkWhen, tkVar, 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: var a = simpleExpr(p) if p.tok.tokType == tkEquals: # special case: allow assignments getTok(p) optInd(p, result) let b = parseExpr(p) let asgn = newNodeI(nkAsgn, a.info, 2) asgn.sons[0] = a asgn.sons[1] = 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) result.add(a) if p.tok.tokType == tkComma: getTok(p) skipComment(p, a) while p.tok.tokType != tkParRi and p.tok.tokType != tkEof: var a = exprColonEqExpr(p) addSon(result, a) if p.tok.tokType != tkComma: break getTok(p) skipComment(p, a) optPar(p) eat(p, tkParRi) proc identOrLiteral(p: var TParser, mode: TPrimaryMode): 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 #| | NIL #| generalizedLit = GENERALIZED_STR_LIT | GENERALIZED_TRIPLESTR_LIT #| identOrLiteral = generalizedLit | symbol | literal #| | par | arrayConstr | setOrTableConstr #| | castExpr #| tupleConstr = '(' optInd (exprColonEqExpr comma?)* optPar ')' #| arrayConstr = '[' optInd (exprColonEqExpr comma?)* optPar ']' case p.tok.tokType of tkSymbol, tkType, tkAddr: 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 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 prevend endless loops! result = ast.emptyNode proc namedParams(p: var TParser, callee: PNode, kind: TNodeKind, endTok: TTokType): PNode = let a = callee result = newNodeP(kind, p) addSon(result, a) exprColonEqExprListAux(p, endTok, result) proc parseMacroColon(p: var TParser, x: PNode): PNode proc primarySuffix(p: var TParser, r: PNode, baseIndent: int): PNode = #| primarySuffix = '(' (exprColonEqExpr comma?)* ')' doBlocks? #| | doBlocks #| | '.' optInd symbol generalizedLit? #| | '[' optInd indexExprList optPar ']' #| | '{' optInd indexExprList optPar '}' #| | &( '`'|IDENT|literal|'cast'|'addr'|'type') expr # command syntax result = r while p.tok.indent < 0 or (p.tok.tokType == tkDot and p.tok.indent >= baseIndent): case p.tok.tokType of tkParLe: if p.strongSpaces and p.tok.strongSpaceA > 0: break result = namedParams(p, result, nkCall, tkParRi) if result.len > 1 and result.sons[1].kind == nkExprColonExpr: result.kind = nkObjConstr else: parseDoBlocks(p, result) of tkDo: var a = result result = newNodeP(nkCall, p) addSon(result, a) parseDoBlocks(p, result) of tkDot: result = dotExpr(p, result) result = parseGStrLit(p, result) of tkBracketLe: if p.strongSpaces and p.tok.strongSpaceA > 0: break result = namedParams(p, result, nkBracketExpr, tkBracketRi) of tkCurlyLe: if p.strongSpaces and p.tok.strongSpaceA > 0: break result = namedParams(p, result, nkCurlyExpr, tkCurlyRi) of tkSymbol, tkAccent, tkIntLit..tkCharLit, tkNil, tkCast, tkAddr, tkType: if p.inPragma == 0: # actually parsing {.push hints:off.} as {.push(hints:off).} is a sweet # solution, but pragmas.nim can't handle that let a = result result = newNodeP(nkCommand, p) addSon(result, a) when true: addSon result, parseExpr(p) else: while p.tok.tokType != tkEof: let x = parseExpr(p) addSon(result, x) if p.tok.tokType != tkComma: break getTok(p) optInd(p, x) if p.tok.tokType == tkDo: parseDoBlocks(p, result) else: result = parseMacroColon(p, result) break else: break proc primary(p: var TParser, mode: TPrimaryMode): PNode proc simpleExprAux(p: var TParser, limit: int, mode: TPrimaryMode): PNode proc parseOperators(p: var TParser, headNode: PNode, limit: int, mode: TPrimaryMode): PNode = result = headNode # expand while operators have priorities higher than 'limit' var opPrec = getPrecedence(p.tok, p.strongSpaces) let modeB = if mode == pmTypeDef: pmTypeDesc else: mode # the operator itself must not start on a new line: while opPrec >= limit and p.tok.indent < 0 and not isUnary(p): checkBinary(p) var leftAssoc = 1-ord(isRightAssociative(p.tok)) var a = newNodeP(nkInfix, p) var opNode = newIdentNodeP(p.tok.ident, p) # skip operator: getTok(p) optInd(p, a) # read sub-expression with higher priority: var b = simpleExprAux(p, opPrec + leftAssoc, modeB) addSon(a, opNode) addSon(a, result) addSon(a, b) result = a opPrec = getPrecedence(p.tok, p.strongSpaces) proc simpleExprAux(p: var TParser, limit: int, mode: TPrimaryMode): PNode = result = primary(p, mode) result = parseOperators(p, result, limit, mode) proc simpleExpr(p: var TParser, mode = pmNormal): PNode = result = simpleExprAux(p, -1, mode) proc parseIfExpr(p: var TParser, kind: TNodeKind): PNode = #| condExpr = expr colcom expr optInd #| ('elif' expr colcom expr optInd)* #| 'else' colcom expr #| ifExpr = 'if' condExpr #| whenExpr = 'when' condExpr result = newNodeP(kind, p) while true: getTok(p) # skip `if`, `elif` var branch = newNodeP(nkElifExpr, p) addSon(branch, parseExpr(p)) colcom(p, branch) addSon(branch, parseExpr(p)) optInd(p, branch) addSon(result, branch) if p.tok.tokType != tkElif: break var branch = newNodeP(nkElseExpr, p) eat(p, tkElse) colcom(p, branch) addSon(branch, parseExpr(p)) addSon(result, branch) proc parsePragma(p: var TParser): PNode = #| pragma = '{.' optInd (exprColonExpr comma?)* optPar ('.}' | '}') result = newNodeP(nkPragma, p) inc p.inPragma getTok(p) optInd(p, result) while p.tok.tokType notin {tkCurlyDotRi, tkCurlyRi, tkEof}: var a = exprColonEqExpr(p) addSon(result, a) if p.tok.tokType == tkComma: getTok(p) skipComment(p, a) optPar(p) if p.tok.tokType in {tkCurlyDotRi, tkCurlyRi}: getTok(p) else: parMessage(p, errTokenExpected, ".}") dec p.inPragma proc identVis(p: var TParser; allowDot=false): PNode = #| identVis = symbol opr? # postfix position #| identVisDot = symbol '.' optInd symbol opr? var a = parseSymbol(p) if p.tok.tokType == tkOpr: result = newNodeP(nkPostfix, p) addSon(result, newIdentNodeP(p.tok.ident, p)) addSon(result, a) getTok(p) elif p.tok.tokType == tkDot and allowDot: result = dotExpr(p, a) else: result = a proc identWithPragma(p: var TParser; allowDot=false): PNode = #| identWithPragma = identVis pragma? #| identWithPragmaDot = identVisDot pragma? var a = identVis(p, allowDot) if p.tok.tokType == tkCurlyDotLe: result = newNodeP(nkPragmaExpr, p) addSon(result, a) addSon(result, parsePragma(p)) else: result = a type TDeclaredIdentFlag = enum withPragma, # identifier may have pragma withBothOptional # both ':' and '=' parts are optional TDeclaredIdentFlags = set[TDeclaredIdentFlag] proc parseIdentColonEquals(p: var TParser, flags: TDeclaredIdentFlags): PNode = #| declColonEquals = identWithPragma (comma identWithPragma)* comma? #| (':' optInd typeDesc)? ('=' optInd expr)? #| identColonEquals = ident (comma ident)* comma? #| (':' optInd typeDesc)? ('=' optInd expr)?) var a: PNode result = newNodeP(nkIdentDefs, p) while true: case p.tok.tokType of tkSymbol, tkAccent: if withPragma in flags: a = identWithPragma(p) else: a = parseSymbol(p) if a.kind == nkEmpty: return else: break addSon(result, a) if p.tok.tokType != tkComma: break getTok(p) optInd(p, a) if p.tok.tokType == tkColon: getTok(p) optInd(p, result) addSon(result, parseTypeDesc(p)) else: addSon(result, ast.emptyNode) if p.tok.tokType != tkEquals and withBothOptional notin flags: parMessage(p, errColonOrEqualsExpected, p.tok) if p.tok.tokType == tkEquals: getTok(p) optInd(p, result) addSon(result, parseExpr(p)) else: addSon(result, ast.emptyNode) proc parseTuple(p: var TParser, indentAllowed = false): PNode = #| inlTupleDecl = 'tuple' #| [' optInd (identColonEquals (comma/semicolon)?)* optPar ']' #| extTupleDecl = 'tuple' #| COMMENT? (IND{>} identColonEquals (IND{=} identColonEquals)*)? #| tupleClass = 'tuple' result = newNodeP(nkTupleTy, p) getTok(p) if p.tok.tokType == tkBracketLe: getTok(p) optInd(p, result) while p.tok.tokType in {tkSymbol, tkAccent}: var a = parseIdentColonEquals(p, {}) addSon(result, a) if p.tok.tokType notin {tkComma, tkSemiColon}: break getTok(p) skipComment(p, a) optPar(p) eat(p, tkBracketRi) elif indentAllowed: skipComment(p, result) if realInd(p): withInd(p): rawSkipComment(p, result) 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) addSon(result, a) of tkEof: break else: parMessage(p, errIdentifierExpected, p.tok) break if not sameInd(p): break else: result = newNodeP(nkTupleClassTy, p) proc parseParamList(p: var TParser, retColon = true): PNode = #| paramList = '(' declColonEquals ^* (comma/semicolon) ')' #| paramListArrow = paramList? ('->' optInd typeDesc)? #| paramListColon = paramList? (':' optInd typeDesc)? var a: PNode result = newNodeP(nkFormalParams, p) addSon(result, ast.emptyNode) # return type let hasParLe = p.tok.tokType == tkParLe and p.tok.indent < 0 if hasParLe: getTok(p) optInd(p, result) while true: case p.tok.tokType of tkSymbol, tkAccent: a = parseIdentColonEquals(p, {withBothOptional, withPragma}) of tkParRi: break else: parMessage(p, errTokenExpected, ")") break addSon(result, a) if p.tok.tokType notin {tkComma, tkSemiColon}: break getTok(p) skipComment(p, a) optPar(p) eat(p, tkParRi) let hasRet = if retColon: p.tok.tokType == tkColon else: p.tok.tokType == tkOpr and identEq(p.tok.ident, "->") if hasRet and p.tok.indent < 0: getTok(p) optInd(p, result) result.sons[0] = parseTypeDesc(p) elif not retColon and not hasParle: # Mark as "not there" in order to mark for deprecation in the semantic pass: result = ast.emptyNode proc optPragmas(p: var TParser): PNode = if p.tok.tokType == tkCurlyDotLe and (p.tok.indent < 0 or realInd(p)): result = parsePragma(p) else: result = ast.emptyNode proc parseDoBlock(p: var TParser): PNode = #| doBlock = 'do' paramListArrow pragmas? colcom stmt let info = parLineInfo(p) getTok(p) let params = parseParamList(p, retColon=false) let pragmas = optPragmas(p) colcom(p, result) result = newProcNode(nkDo, info, parseStmt(p), params = params, pragmas = pragmas) proc parseDoBlocks(p: var TParser, call: PNode) = #| doBlocks = doBlock ^* IND{=} if p.tok.tokType == tkDo: addSon(call, parseDoBlock(p)) while sameInd(p) and p.tok.tokType == tkDo: addSon(call, parseDoBlock(p)) proc parseProcExpr(p: var TParser, isExpr: bool): PNode = #| procExpr = 'proc' paramListColon pragmas? ('=' COMMENT? stmt)? # either a proc type or a anonymous proc let info = parLineInfo(p) getTok(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) skipComment(p, result) result = newProcNode(nkLambda, info, parseStmt(p), params = params, pragmas = pragmas) else: result = newNodeI(nkProcTy, info) if hasSignature: addSon(result, params) addSon(result, pragmas) proc isExprStart(p: TParser): bool = case p.tok.tokType of tkSymbol, tkAccent, tkOpr, tkNot, tkNil, tkCast, tkIf, tkProc, tkIterator, tkBind, tkAddr, tkParLe, tkBracketLe, tkCurlyLe, tkIntLit..tkCharLit, tkVar, tkRef, tkPtr, tkTuple, tkObject, tkType, tkWhen, tkCase, tkOut: result = true else: result = false proc parseSymbolList(p: var TParser, result: PNode, allowNil = false) = while true: var s = parseSymbol(p, allowNil) if s.kind == nkEmpty: break addSon(result, s) if p.tok.tokType != tkComma: break getTok(p) optInd(p, s) proc parseTypeDescKAux(p: var TParser, kind: TNodeKind, mode: TPrimaryMode): PNode = #| distinct = 'distinct' optInd typeDesc result = newNodeP(kind, p) getTok(p) optInd(p, result) if not isOperator(p.tok) and isExprStart(p): addSon(result, primary(p, mode)) if kind == nkDistinctTy and p.tok.tokType in {tkWith, tkWithout}: let nodeKind = if p.tok.tokType == tkWith: nkWith else: nkWithout getTok(p) let list = newNodeP(nodeKind, p) result.addSon list parseSymbolList(p, list, allowNil = true) proc parseExpr(p: var TParser): PNode = #| expr = (ifExpr #| | whenExpr #| | caseExpr #| | tryExpr) #| / simpleExpr case p.tok.tokType: of tkIf: result = parseIfExpr(p, nkIfExpr) of tkWhen: result = parseIfExpr(p, nkWhenExpr) of tkCase: result = parseCase(p) of tkTry: result = parseTry(p, isExpr=true) else: result = simpleExpr(p) proc parseEnum(p: var TParser): PNode proc parseObject(p: var TParser): PNode proc parseTypeClass(p: var TParser): PNode proc primary(p: var TParser, mode: TPrimaryMode): PNode = #| typeKeyw = 'var' | 'out' | 'ref' | 'ptr' | 'shared' | 'tuple' #| | 'proc' | 'iterator' | 'distinct' | 'object' | 'enum' #| primary = typeKeyw typeDescK #| / prefixOperator* identOrLiteral primarySuffix* #| / 'static' primary #| / 'bind' primary if isOperator(p.tok): let isSigil = isSigilLike(p.tok) result = newNodeP(nkPrefix, p) var a = newIdentNodeP(p.tok.ident, p) addSon(result, a) getTok(p) optInd(p, a) if isSigil: #XXX prefix operators let baseInd = p.lex.currLineIndent addSon(result, primary(p, pmSkipSuffix)) result = primarySuffix(p, result, baseInd) else: addSon(result, primary(p, pmNormal)) return case p.tok.tokType: of tkTuple: result = parseTuple(p, mode == pmTypeDef) of tkProc: result = parseProcExpr(p, mode notin {pmTypeDesc, pmTypeDef}) of tkIterator: when false: if mode in {pmTypeDesc, pmTypeDef}: result = parseProcExpr(p, false) result.kind = nkIteratorTy else: # no anon iterators for now: parMessage(p, errExprExpected, p.tok) getTok(p) # we must consume a token here to prevend endless loops! result = ast.emptyNode else: result = parseProcExpr(p, mode notin {pmTypeDesc, pmTypeDef}) if result.kind == nkLambda: result.kind = nkIteratorDef else: result.kind = nkIteratorTy of tkEnum: if mode == pmTypeDef: result = parseEnum(p) else: result = newNodeP(nkEnumTy, p) getTok(p) of tkObject: if mode == pmTypeDef: result = parseObject(p) else: result = newNodeP(nkObjectTy, p) getTok(p) of tkGeneric, tkConcept: if mode == pmTypeDef: let wasGeneric = p.tok.tokType == tkGeneric result = parseTypeClass(p) # hack so that it's remembered and can be marked as deprecated in # sem'check: if wasGeneric: result.flags.incl nfBase2 else: parMessage(p, errInvalidToken, p.tok) of tkStatic: let info = parLineInfo(p) getTokNoInd(p) let next = primary(p, pmNormal) if next.kind == nkBracket and next.sonsLen == 1: result = newNode(nkStaticTy, info, @[next.sons[0]]) else: result = newNode(nkStaticExpr, info, @[next]) of tkBind: result = newNodeP(nkBind, p) getTok(p) optInd(p, result) addSon(result, primary(p, pmNormal)) of tkVar: result = parseTypeDescKAux(p, nkVarTy, mode) of tkOut: result = parseTypeDescKAux(p, nkVarTy, mode) of tkRef: result = parseTypeDescKAux(p, nkRefTy, mode) of tkPtr: result = parseTypeDescKAux(p, nkPtrTy, mode) of tkDistinct: result = parseTypeDescKAux(p, nkDistinctTy, mode) else: let baseInd = p.lex.currLineIndent result = identOrLiteral(p, mode) if mode != pmSkipSuffix: result = primarySuffix(p, result, baseInd) proc parseTypeDesc(p: var TParser): PNode = #| typeDesc = simpleExpr result = simpleExpr(p, pmTypeDesc) proc parseTypeDefAux(p: var TParser): PNode = #| typeDefAux = simpleExpr #| | 'concept' typeClass result = simpleExpr(p, pmTypeDef) 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 = newNodeI(nkCall, n.info) result.add n proc parseMacroColon(p: var TParser, x: PNode): PNode = #| macroColon = ':' stmt? ( IND{=} 'of' exprList ':' stmt #| | IND{=} 'elif' expr ':' stmt #| | IND{=} 'except' exprList ':' stmt #| | IND{=} 'else' ':' stmt )* result = x if p.tok.tokType == tkColon and p.tok.indent < 0: result = makeCall(result) getTok(p) skipComment(p, result) let stmtList = newNodeP(nkStmtList, p) if p.tok.tokType notin {tkOf, tkElif, tkElse, tkExcept}: let body = parseStmt(p) stmtList.add body #addSon(result, makeStmtList(body)) while sameInd(p): var b: PNode case p.tok.tokType of tkOf: b = newNodeP(nkOfBranch, p) exprList(p, tkColon, b) of tkElif: b = newNodeP(nkElifBranch, p) getTok(p) optInd(p, b) addSon(b, parseExpr(p)) of tkExcept: b = newNodeP(nkExceptBranch, p) exprList(p, tkColon, b) of tkElse: b = newNodeP(nkElse, p) getTok(p) else: break eat(p, tkColon) addSon(b, parseStmt(p)) addSon(stmtList, b) if b.kind == nkElse: break if stmtList.len == 1 and stmtList[0].kind == nkStmtList: # to keep backwards compatibility (see tests/vm/tstringnil) result.add stmtList[0] else: result.add stmtList proc parseExprStmt(p: var TParser): PNode = #| exprStmt = simpleExpr #| (( '=' optInd expr ) #| / ( expr ^+ comma #| doBlocks #| / macroColon #| ))? var a = simpleExpr(p) if p.tok.tokType == tkEquals: getTok(p) optInd(p, result) var b = parseExpr(p) result = newNodeI(nkAsgn, a.info) addSon(result, a) addSon(result, b) else: # simpleExpr parsed 'p a' from 'p a, b'? if p.tok.indent < 0 and p.tok.tokType == tkComma and a.kind == nkCommand: result = a while true: getTok(p) optInd(p, result) var e = parseExpr(p) addSon(result, e) if p.tok.tokType != tkComma: break elif p.tok.indent < 0 and isExprStart(p): if a.kind == nkCommand: result = a else: result = newNode(nkCommand, a.info, @[a]) while true: var e = parseExpr(p) addSon(result, e) if p.tok.tokType != tkComma: break getTok(p) optInd(p, result) else: result = a if p.tok.tokType == tkDo and p.tok.indent < 0: result = makeCall(result) parseDoBlocks(p, result) return result result = parseMacroColon(p, result) proc parseModuleName(p: var TParser, 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)) proc parseImport(p: var TParser, kind: TNodeKind): PNode = #| importStmt = 'import' 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) addSon(result, a) if p.tok.tokType in {tkComma, tkExcept}: if p.tok.tokType == tkExcept: result.kind = succ(kind) getTok(p) optInd(p, result) while true: # was: while p.tok.tokType notin {tkEof, tkSad, tkDed}: a = parseModuleName(p, kind) if a.kind == nkEmpty: break addSon(result, a) if p.tok.tokType != tkComma: break getTok(p) optInd(p, a) #expectNl(p) proc parseIncludeStmt(p: var TParser): 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}: var a = parseExpr(p) if a.kind == nkEmpty: break addSon(result, a) if p.tok.tokType != tkComma: break getTok(p) optInd(p, a) #expectNl(p) proc parseFromStmt(p: var TParser): PNode = #| fromStmt = 'from' moduleName 'import' optInd expr (comma expr)* result = newNodeP(nkFromStmt, p) getTok(p) # skip `from` optInd(p, result) var a = parseModuleName(p, nkImportStmt) addSon(result, a) #optInd(p, a); eat(p, tkImport) optInd(p, result) while true: # p.tok.tokType notin {tkEof, tkSad, tkDed}: a = parseExpr(p) if a.kind == nkEmpty: break addSon(result, a) if p.tok.tokType != tkComma: break getTok(p) optInd(p, a) #expectNl(p) proc parseReturnOrRaise(p: var TParser, kind: TNodeKind): PNode = #| returnStmt = 'return' optInd expr? #| raiseStmt = 'raise' optInd expr? #| yieldStmt = 'yield' optInd expr? #| discardStmt = 'discard' optInd expr? #| breakStmt = 'break' optInd expr? #| continueStmt = 'break' optInd expr? result = newNodeP(kind, p) getTok(p) if p.tok.tokType == tkComment: skipComment(p, result) addSon(result, ast.emptyNode) elif p.tok.indent >= 0 and p.tok.indent <= p.currInd or not isExprStart(p): # NL terminates: addSon(result, ast.emptyNode) else: addSon(result, parseExpr(p)) proc parseIfOrWhen(p: var TParser, 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) addSon(branch, parseExpr(p)) colcom(p, branch) addSon(branch, parseStmt(p)) skipComment(p, branch) addSon(result, 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) addSon(branch, parseStmt(p)) addSon(result, branch) proc parseWhile(p: var TParser): PNode = #| whileStmt = 'while' expr colcom stmt result = newNodeP(nkWhileStmt, p) getTok(p) optInd(p, result) addSon(result, parseExpr(p)) colcom(p, result) addSon(result, parseStmt(p)) proc parseCase(p: var TParser): 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) addSon(result, 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) addSon(b, parseExpr(p)) of tkElse: b = newNodeP(nkElse, p) getTok(p) else: break colcom(p, b) addSon(b, parseStmt(p)) addSon(result, b) if b.kind == nkElse: break if wasIndented: p.currInd = oldInd proc parseTry(p: var TParser; isExpr: bool): PNode = #| tryStmt = 'try' colcom stmt &(IND{=}? 'except'|'finally') #| (IND{=}? 'except' exprList colcom stmt)* #| (IND{=}? 'finally' colcom stmt)? #| tryExpr = 'try' colcom stmt &(optInd 'except'|'finally') #| (optInd 'except' exprList colcom stmt)* #| (optInd 'finally' colcom stmt)? result = newNodeP(nkTryStmt, p) getTok(p) colcom(p, result) addSon(result, parseStmt(p)) var b: PNode = nil while sameOrNoInd(p) or isExpr: case p.tok.tokType of tkExcept: b = newNodeP(nkExceptBranch, p) exprList(p, tkColon, b) of tkFinally: b = newNodeP(nkFinally, p) getTok(p) else: break colcom(p, b) addSon(b, parseStmt(p)) addSon(result, b) if b.kind == nkFinally: break if b == nil: parMessage(p, errTokenExpected, "except") proc parseExceptBlock(p: var TParser, kind: TNodeKind): PNode = #| exceptBlock = 'except' colcom stmt result = newNodeP(kind, p) getTok(p) colcom(p, result) addSon(result, parseStmt(p)) proc parseFor(p: var TParser): PNode = #| forStmt = 'for' (identWithPragma ^+ comma) 'in' expr colcom stmt result = newNodeP(nkForStmt, p) getTokNoInd(p) var a = identWithPragma(p) addSon(result, a) while p.tok.tokType == tkComma: getTok(p) optInd(p, a) a = identWithPragma(p) addSon(result, a) eat(p, tkIn) addSon(result, parseExpr(p)) colcom(p, result) addSon(result, parseStmt(p)) proc parseBlock(p: var TParser): PNode = #| blockStmt = 'block' symbol? colcom stmt result = newNodeP(nkBlockStmt, p) getTokNoInd(p) if p.tok.tokType == tkColon: addSon(result, ast.emptyNode) else: addSon(result, parseSymbol(p)) colcom(p, result) addSon(result, parseStmt(p)) proc parseStaticOrDefer(p: var TParser; k: TNodeKind): PNode = #| staticStmt = 'static' colcom stmt #| deferStmt = 'defer' colcom stmt result = newNodeP(k, p) getTok(p) colcom(p, result) addSon(result, parseStmt(p)) proc parseAsm(p: var TParser): PNode = #| asmStmt = 'asm' pragma? (STR_LIT | RSTR_LIT | TRIPLE_STR_LIT) result = newNodeP(nkAsmStmt, p) getTokNoInd(p) if p.tok.tokType == tkCurlyDotLe: addSon(result, parsePragma(p)) else: addSon(result, ast.emptyNode) case p.tok.tokType of tkStrLit: addSon(result, newStrNodeP(nkStrLit, p.tok.literal, p)) of tkRStrLit: addSon(result, newStrNodeP(nkRStrLit, p.tok.literal, p)) of tkTripleStrLit: addSon(result, newStrNodeP(nkTripleStrLit, p.tok.literal, p)) else: parMessage(p, errStringLiteralExpected) addSon(result, ast.emptyNode) return getTok(p) proc parseGenericParam(p: var TParser): PNode = #| genericParam = symbol (comma symbol)* (colon expr)? ('=' optInd expr)? var a: PNode result = newNodeP(nkIdentDefs, p) while true: case p.tok.tokType of tkSymbol, tkAccent: a = parseSymbol(p) if a.kind == nkEmpty: return else: break addSon(result, a) if p.tok.tokType != tkComma: break getTok(p) optInd(p, a) if p.tok.tokType == tkColon: getTok(p) optInd(p, result) addSon(result, parseExpr(p)) else: addSon(result, ast.emptyNode) if p.tok.tokType == tkEquals: getTok(p) optInd(p, result) addSon(result, parseExpr(p)) else: addSon(result, ast.emptyNode) proc parseGenericParamList(p: var TParser): PNode = #| genericParamList = '[' optInd #| genericParam ^* (comma/semicolon) optPar ']' result = newNodeP(nkGenericParams, p) getTok(p) optInd(p, result) while p.tok.tokType in {tkSymbol, tkAccent}: var a = parseGenericParam(p) addSon(result, a) if p.tok.tokType notin {tkComma, tkSemiColon}: break getTok(p) skipComment(p, a) optPar(p) eat(p, tkBracketRi) proc parsePattern(p: var TParser): PNode = #| pattern = '{' stmt '}' eat(p, tkCurlyLe) result = parseStmt(p) eat(p, tkCurlyRi) proc validInd(p: var TParser): bool = result = p.tok.indent < 0 or p.tok.indent > p.currInd proc parseRoutine(p: var TParser, 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) addSon(result, identVis(p)) if p.tok.tokType == tkCurlyLe and p.validInd: addSon(result, p.parsePattern) else: addSon(result, ast.emptyNode) if p.tok.tokType == tkBracketLe and p.validInd: result.add(p.parseGenericParamList) else: addSon(result, ast.emptyNode) addSon(result, p.parseParamList) if p.tok.tokType == tkCurlyDotLe and p.validInd: addSon(result, p.parsePragma) else: addSon(result, ast.emptyNode) # empty exception tracking: addSon(result, ast.emptyNode) if p.tok.tokType == tkEquals and p.validInd: getTok(p) skipComment(p, result) addSon(result, parseStmt(p)) else: addSon(result, ast.emptyNode) indAndComment(p, result) proc newCommentStmt(p: var TParser): PNode = #| commentStmt = COMMENT result = newNodeP(nkCommentStmt, p) result.comment = p.tok.literal getTok(p) type TDefParser = proc (p: var TParser): PNode {.nimcall.} proc parseSection(p: var TParser, kind: TNodeKind, defparser: TDefParser): PNode = #| section(p) = COMMENT? p / (IND{>} (p / COMMENT)^+IND{=} DED) result = newNodeP(kind, p) if kind != nkTypeSection: getTok(p) skipComment(p, result) if realInd(p): withInd(p): skipComment(p, result) while sameInd(p): case p.tok.tokType of tkSymbol, tkAccent, tkParLe: var a = defparser(p) skipComment(p, a) addSon(result, a) of tkComment: var a = newCommentStmt(p) addSon(result, a) else: parMessage(p, errIdentifierExpected, p.tok) break if result.len == 0: 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 addSon(result, defparser(p)) else: parMessage(p, errIdentifierExpected, p.tok) proc parseConstant(p: var TParser): PNode = #| constant = identWithPragma (colon typedesc)? '=' optInd expr indAndComment result = newNodeP(nkConstDef, p) addSon(result, identWithPragma(p)) if p.tok.tokType == tkColon: getTok(p) optInd(p, result) addSon(result, parseTypeDesc(p)) else: addSon(result, ast.emptyNode) eat(p, tkEquals) optInd(p, result) addSon(result, parseExpr(p)) indAndComment(p, result) proc parseEnum(p: var TParser): PNode = #| enum = 'enum' optInd (symbol optInd ('=' optInd expr COMMENT?)? comma?)+ result = newNodeP(nkEnumTy, p) getTok(p) addSon(result, ast.emptyNode) optInd(p, result) flexComment(p, result) while true: var a = parseSymbol(p) if a.kind == nkEmpty: return if p.tok.indent >= 0 and p.tok.indent <= p.currInd: add(result, a) break if p.tok.tokType == tkEquals and p.tok.indent < 0: getTok(p) optInd(p, a) var b = a a = newNodeP(nkEnumFieldDef, p) addSon(a, b) addSon(a, parseExpr(p)) if p.tok.indent < 0 or p.tok.indent >= p.currInd: rawSkipComment(p, a) if p.tok.tokType == tkComma and p.tok.indent < 0: getTok(p) rawSkipComment(p, a) else: if p.tok.indent < 0 or p.tok.indent >= p.currInd: rawSkipComment(p, a) addSon(result, a) if p.tok.indent >= 0 and p.tok.indent <= p.currInd or p.tok.tokType == tkEof: break if result.len <= 1: lexMessageTok(p.lex, errIdentifierExpected, p.tok, prettyTok(p.tok)) proc parseObjectPart(p: var TParser): PNode proc parseObjectWhen(p: var TParser): PNode = #| objectWhen = 'when' expr colcom objectPart COMMENT? #| ('elif' expr colcom objectPart COMMENT?)* #| ('else' colcom objectPart COMMENT?)? result = newNodeP(nkRecWhen, p) while sameInd(p): getTok(p) # skip `when`, `elif` var branch = newNodeP(nkElifBranch, p) optInd(p, branch) addSon(branch, parseExpr(p)) colcom(p, branch) addSon(branch, parseObjectPart(p)) flexComment(p, branch) addSon(result, 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) addSon(branch, parseObjectPart(p)) flexComment(p, branch) addSon(result, branch) proc parseObjectCase(p: var TParser): PNode = #| objectBranch = 'of' exprList colcom objectPart #| objectBranches = objectBranch (IND{=} objectBranch)* #| (IND{=} 'elif' expr colcom objectPart)* #| (IND{=} 'else' colcom objectPart)? #| objectCase = 'case' identWithPragma ':' typeDesc ':'? COMMENT? #| (IND{>} objectBranches DED #| | IND{=} objectBranches) result = newNodeP(nkRecCase, p) getTokNoInd(p) var a = newNodeP(nkIdentDefs, p) addSon(a, identWithPragma(p)) eat(p, tkColon) addSon(a, parseTypeDesc(p)) addSon(a, ast.emptyNode) addSon(result, 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 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 addSon(b, fields) addSon(result, b) if b.kind == nkElse: break if wasIndented: p.currInd = oldInd proc parseObjectPart(p: var TParser): 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: addSon(result, parseObjectPart(p)) else: parMessage(p, errIdentifierExpected, p.tok) break else: 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 = ast.emptyNode proc parseObject(p: var TParser): PNode = #| object = 'object' pragma? ('of' typeDesc)? COMMENT? objectPart result = newNodeP(nkObjectTy, p) getTok(p) if p.tok.tokType == tkCurlyDotLe and p.validInd: addSon(result, parsePragma(p)) else: addSon(result, ast.emptyNode) if p.tok.tokType == tkOf and p.tok.indent < 0: var a = newNodeP(nkOfInherit, p) getTok(p) addSon(a, parseTypeDesc(p)) addSon(result, a) else: addSon(result, ast.emptyNode) if p.tok.tokType == tkComment: skipComment(p, result) # an initial IND{>} HAS to follow: if not realInd(p): addSon(result, emptyNode) return addSon(result, parseObjectPart(p)) proc parseTypeClassParam(p: var TParser): PNode = if p.tok.tokType in {tkOut, tkVar}: result = newNodeP(nkVarTy, p) getTok(p) result.addSon(p.parseSymbol) else: result = p.parseSymbol proc parseTypeClass(p: var TParser): PNode = #| typeClassParam = ('var' | 'out')? symbol #| typeClass = typeClassParam ^* ',' (pragma)? ('of' typeDesc ^* ',')? #| &IND{>} stmt result = newNodeP(nkTypeClassTy, p) getTok(p) var args = newNodeP(nkArgList, p) addSon(result, args) addSon(args, p.parseTypeClassParam) while p.tok.tokType == tkComma: getTok(p) addSon(args, p.parseTypeClassParam) if p.tok.tokType == tkCurlyDotLe and p.validInd: addSon(result, parsePragma(p)) else: addSon(result, ast.emptyNode) if p.tok.tokType == tkOf and p.tok.indent < 0: var a = newNodeP(nkOfInherit, p) getTok(p) while true: addSon(a, parseTypeDesc(p)) if p.tok.tokType != tkComma: break getTok(p) addSon(result, a) else: addSon(result, ast.emptyNode) if p.tok.tokType == tkComment: skipComment(p, result) # an initial IND{>} HAS to follow: if not realInd(p): addSon(result, emptyNode) else: addSon(result, parseStmt(p)) proc parseTypeDef(p: var TParser): PNode = #| #| typeDef = identWithPragmaDot genericParamList? '=' optInd typeDefAux #| indAndComment? result = newNodeP(nkTypeDef, p) addSon(result, identWithPragma(p, allowDot=true)) if p.tok.tokType == tkBracketLe and p.validInd: addSon(result, parseGenericParamList(p)) else: addSon(result, ast.emptyNode) if p.tok.tokType == tkEquals: getTok(p) optInd(p, result) addSon(result, parseTypeDefAux(p)) else: addSon(result, ast.emptyNode) indAndComment(p, result) # special extension! proc parseVarTuple(p: var TParser): PNode = #| varTuple = '(' optInd identWithPragma ^+ comma optPar ')' '=' optInd expr result = newNodeP(nkVarTuple, p) getTok(p) # skip '(' optInd(p, result) while p.tok.tokType in {tkSymbol, tkAccent}: var a = identWithPragma(p) addSon(result, a) if p.tok.tokType != tkComma: break getTok(p) skipComment(p, a) addSon(result, ast.emptyNode) # no type desc optPar(p) eat(p, tkParRi) eat(p, tkEquals) optInd(p, result) addSon(result, parseExpr(p)) proc parseVariable(p: var TParser): PNode = #| variable = (varTuple / identColonEquals) indAndComment if p.tok.tokType == tkParLe: result = parseVarTuple(p) else: result = parseIdentColonEquals(p, {withPragma}) indAndComment(p, result) proc parseBind(p: var TParser, k: TNodeKind): PNode = #| bindStmt = 'bind' optInd qualifiedIdent ^+ comma #| mixinStmt = 'mixin' optInd qualifiedIdent ^+ comma result = newNodeP(k, p) getTok(p) optInd(p, result) while true: var a = qualifiedIdent(p) addSon(result, a) if p.tok.tokType != tkComma: break getTok(p) optInd(p, a) #expectNl(p) proc parseStmtPragma(p: var TParser): PNode = #| pragmaStmt = pragma (':' COMMENT? stmt)? result = parsePragma(p) if p.tok.tokType == tkColon and p.tok.indent < 0: let a = result result = newNodeI(nkPragmaBlock, a.info) getTok(p) skipComment(p, result) result.add a result.add parseStmt(p) proc simpleStmt(p: var TParser): 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 = ast.emptyNode if result.kind notin {nkEmpty, nkCommentStmt}: skipComment(p, result) proc complexOrSimpleStmt(p: var TParser): PNode = #| complexOrSimpleStmt = (ifStmt | whenStmt | whileStmt #| | tryStmt | forStmt #| | blockStmt | staticStmt | deferStmt | asmStmt #| | 'proc' routine #| | 'method' 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 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.addSon(primary(p, pmTypeDesc)) eat(p, tkParRi) result = parseOperators(p, result, -1, pmNormal) else: result = parseSection(p, nkTypeSection, parseTypeDef) of tkConst: result = parseSection(p, nkConstSection, parseConstant) of tkLet: result = parseSection(p, nkLetSection, parseVariable) of tkWhen: result = parseIfOrWhen(p, nkWhenStmt) of tkVar: result = parseSection(p, nkVarSection, parseVariable) 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 TParser): PNode = #| stmt = (IND{>} complexOrSimpleStmt^+(IND{=} / ';') DED) #| / simpleStmt ^+ ';' if p.tok.indent > p.currInd: 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 var a = complexOrSimpleStmt(p) if a.kind != nkEmpty: addSon(result, a) else: parMessage(p, errExprExpected, p.tok) getTok(p) else: # the case statement is only needed for better error messages: case p.tok.tokType of tkIf, tkWhile, tkCase, tkTry, tkFor, tkBlock, tkAsm, tkProc, tkIterator, tkMacro, tkType, tkConst, tkWhen, tkVar: parMessage(p, errComplexStmtRequiresInd) result = ast.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) let a = simpleStmt(p) if a.kind == nkEmpty: parMessage(p, errExprExpected, p.tok) result.add(a) if p.tok.tokType != tkSemiColon: break getTok(p) proc parseAll(p: var TParser): PNode = ## Parses the rest of the input stream held by the parser into a PNode. result = newNodeP(nkStmtList, p) while p.tok.tokType != tkEof: var a = complexOrSimpleStmt(p) if a.kind != nkEmpty: addSon(result, a) else: parMessage(p, errExprExpected, p.tok) # bugfix: consume a token here to prevent an endless loop: getTok(p) if p.tok.indent != 0: parMessage(p, errInvalidIndentation) proc parseTopLevelStmt(p: var TParser): PNode = ## Implements an iterator which, when called repeatedly, returns the next ## top-level statement or emptyNode if end of stream. result = ast.emptyNode while true: if p.tok.indent != 0: if p.firstTok and p.tok.indent < 0: discard elif p.tok.tokType != tkSemiColon: 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 proc parseString*(s: string; filename: string = ""; line: int = 0; errorHandler: TErrorHandler = 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 parser: TParser # XXX for now the builtin 'parseStmt/Expr' functions do not know about strong # spaces... parser.lex.errorHandler = errorHandler openParser(parser, filename, stream, false) result = parser.parseAll closeParser(parser)