diff options
Diffstat (limited to 'nim/pnimsyn.pas')
| -rw-r--r-- | nim/pnimsyn.pas | 355 |
1 files changed, 198 insertions, 157 deletions
diff --git a/nim/pnimsyn.pas b/nim/pnimsyn.pas index 2cb34e708..95d6e64f9 100644 --- a/nim/pnimsyn.pas +++ b/nim/pnimsyn.pas @@ -9,7 +9,7 @@ unit pnimsyn; // This module implements the parser of the standard Nimrod representation. -// The parser is strictly reflects the grammar ("doc/grammar.txt"); however +// 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 build @@ -98,15 +98,21 @@ end; // ---------------- parser helpers -------------------------------------------- +procedure parMessage(const p: TParser; const msg: TMsgKind; + const arg: string = ''); +begin + lexMessage(p.lex^, msg, arg); +end; + procedure skipComment(var p: TParser; node: PNode); begin if p.tok.tokType = tkComment then begin if node <> nil then begin if node.comment = snil then node.comment := ''; - node.comment := node.comment +{&} p.tok.literal; + add(node.comment, p.tok.literal); end else - assert(false); + parMessage(p, errInternal, 'skipComment'); getTok(p); end end; @@ -116,6 +122,11 @@ begin if p.tok.tokType = tkInd then getTok(p) end; +procedure optSad(var p: TParser); +begin + if p.tok.tokType = tkSad then getTok(p) +end; + procedure optInd(var p: TParser; n: PNode); begin skipComment(p, n); @@ -146,12 +157,6 @@ begin else lexMessage(p.lex^, errTokenExpected, TokTypeToStr[tokType]) end; -procedure parMessage(const p: TParser; const msg: TMsgKind; - const arg: string = ''); -begin - lexMessage(p.lex^, msg, arg); -end; - function parLineInfo(const p: TParser): TLineInfo; begin result := getLineInfo(p.lex^) @@ -385,7 +390,7 @@ begin result := newNodeP(nkExprEqExpr, p); addSon(result, a); getTok(p); - optInd(p, result); + //optInd(p, result); case p.tok.tokType of tkVar, tkRef, tkPtr, tkProc: addSon(result, parseTypeDescK(p)); @@ -413,21 +418,16 @@ begin addSon(result, first); getTok(p); optInd(p, result); - while true do begin - if p.tok.tokType = tkBracketRi then begin - getTok(p); break - end; - if p.tok.tokType = tkEof then begin - parMessage(p, errTokenExpected, TokTypeToStr[tkBracketRi]); break - end; + while (p.tok.tokType <> tkBracketRi) and (p.tok.tokType <> tkEof) + and (p.tok.tokType <> tkSad) do begin a := namedTypeOrExpr(p); - optInd(p, a); - if p.tok.tokType = tkComma then begin - getTok(p); - optInd(p, a) - end; addSon(result, a); + if p.tok.tokType <> tkComma then break; + getTok(p); + optInd(p, a) end; + optSad(p); + eat(p, tkBracketRi); end; function exprColonEqExpr(var p: TParser; kind: TNodeKind; @@ -439,7 +439,7 @@ begin if p.tok.tokType = tok then begin result := newNodeP(kind, p); getTok(p); - optInd(p, result); + //optInd(p, result); addSon(result, a); addSon(result, parseExpr(p)); end @@ -454,21 +454,14 @@ var begin getTok(p); optInd(p, result); - while true do begin - if p.tok.tokType = endTok then begin - getTok(p); break - end; - if p.tok.tokType = tkEof then begin - parMessage(p, errTokenExpected, TokTypeToStr[endtok]); break - end; + while (p.tok.tokType <> endTok) and (p.tok.tokType <> tkEof) do begin a := exprColonEqExpr(p, elemKind, sepTok); - optInd(p, a); - if p.tok.tokType = tkComma then begin - getTok(p); - optInd(p, a) - end; addSon(result, a); + if p.tok.tokType <> tkComma then break; + getTok(p); + optInd(p, a) end; + eat(p, endTok); end; function qualifiedIdent(var p: TParser): PNode; @@ -476,7 +469,7 @@ var a: PNode; begin result := parseSymbol(p); - optInd(p, result); + //optInd(p, result); if p.tok.tokType = tkDot then begin getTok(p); optInd(p, result); @@ -494,28 +487,41 @@ var begin getTok(p); optInd(p, result); - while true do begin - if p.tok.tokType = endTok then begin - getTok(p); break - end; - if p.tok.tokType = tkEof then begin - parMessage(p, errTokenExpected, TokTypeToStr[endtok]); break - end; + while (p.tok.tokType <> endTok) and (p.tok.tokType <> tkEof) do begin a := qualifiedIdent(p); - optInd(p, a); - if p.tok.tokType = tkComma then begin - getTok(p); - optInd(p, a) - end; addSon(result, a); + //optInd(p, a); + if p.tok.tokType <> tkComma then break; + getTok(p); + optInd(p, a) + end; + eat(p, endTok); +end; + +procedure exprColonEqExprListAux(var p: TParser; elemKind: TNodeKind; + endTok, sepTok: TTokType; result: PNode); +var + a: PNode; +begin + getTok(p); + optInd(p, result); + while (p.tok.tokType <> endTok) and (p.tok.tokType <> tkEof) + and (p.tok.tokType <> tkSad) do begin + a := exprColonEqExpr(p, elemKind, sepTok); + addSon(result, a); + if p.tok.tokType <> tkComma then break; + getTok(p); + optInd(p, a) end; + optSad(p); + eat(p, endTok); end; function exprColonEqExprList(var p: TParser; kind, elemKind: TNodeKind; endTok, sepTok: TTokType): PNode; begin result := newNodeP(kind, p); - exprListAux(p, elemKind, endTok, sepTok, result); + exprColonEqExprListAux(p, elemKind, endTok, sepTok, result); end; function parseCast(var p: TParser): PNode; @@ -525,12 +531,12 @@ begin eat(p, tkBracketLe); optInd(p, result); addSon(result, parseTypeDesc(p)); - optInd(p, result); + optSad(p); eat(p, tkBracketRi); eat(p, tkParLe); optInd(p, result); addSon(result, parseExpr(p)); - optInd(p, result); + optSad(p); eat(p, tkParRi); end; @@ -541,7 +547,7 @@ begin eat(p, tkParLe); optInd(p, result); addSon(result, parseExpr(p)); - optInd(p, result); + optSad(p); eat(p, tkParRi); end; @@ -667,7 +673,7 @@ begin a := result; result := newNodeP(nkCall, p); addSon(result, a); - exprListAux(p, nkExprEqExpr, tkParRi, tkEquals, result); + exprColonEqExprListAux(p, nkExprEqExpr, tkParRi, tkEquals, result); end; tkDot: begin a := result; @@ -709,8 +715,9 @@ begin opNode := newIdentNodeP(op.ident, p); // skip operator: getTok(p); - skipComment(p, opNode); - skipInd(p); + //skipComment(p, opNode); + //skipInd(p); + optInd(p, opNode); // read sub-expression with higher priority nextop := lowestExprAux(p, v2, opPred); @@ -739,12 +746,12 @@ begin while true do begin getTok(p); // skip `if`, `elif` branch := newNodeP(nkElifExpr, p); - optInd(p, branch); + //optInd(p, branch); addSon(branch, parseExpr(p)); eat(p, tkColon); - optInd(p, branch); + //optInd(p, branch); addSon(branch, parseExpr(p)); - optInd(p, branch); + //optInd(p, branch); addSon(result, branch); if p.tok.tokType <> tkElif then break end; @@ -770,31 +777,33 @@ var begin result := newNodeP(nkPragma, p); getTok(p); - while true do begin - skipComment(p, result); - skipInd(p); - case p.tok.TokType of - tkCurlyDotRi, tkCurlyRi: begin - getTok(p); // skip } or .} - break - end; - tkEof: begin - parMessage(p, errTokenExpected, '.}'); - break - end - else begin - a := exprColonEqExpr(p, nkExprColonExpr, tkColon); - addSon(result, a); - if p.tok.tokType = tkComma then begin - getTok(p); - skipComment(p, a) - end - end + optInd(p, result); + while (p.tok.tokType <> tkCurlyDotRi) and (p.tok.tokType <> tkCurlyRi) + and (p.tok.tokType <> tkEof) and (p.tok.tokType <> tkSad) do begin + a := exprColonEqExpr(p, nkExprColonExpr, tkColon); + addSon(result, a); + if p.tok.tokType = tkComma then begin + getTok(p); + optInd(p, a) end - end + end; + optSad(p); + if (p.tok.tokType = tkCurlyDotRi) or (p.tok.tokType = tkCurlyRi) then + getTok(p) + else + parMessage(p, errTokenExpected, '.}'); end; // ---------------------- statement parser ------------------------------------ +function isExprStart(const p: TParser): bool; +begin + case p.tok.tokType of + tkSymbol, tkAccent, tkOpr, tkNot, tkNil, tkCast, tkIf, tkLambda, + tkParLe, tkBracketLe, tkCurlyLe, tkIntLit..tkCharLit: result := true; + else result := false; + end; +end; + function parseExprStmt(var p: TParser): PNode; var a, b, e: PNode; @@ -813,16 +822,16 @@ begin result.info := a.info; addSon(result, a); while true do begin - case p.tok.tokType of + (*case p.tok.tokType of tkColon, tkInd, tkSad, tkDed, tkEof, tkComment: break; else begin end - end; + end;*) + if not isExprStart(p) then break; e := parseExpr(p); - if p.tok.tokType = tkComma then begin - getTok(p); - skipComment(p, e) - end; addSon(result, e); + if p.tok.tokType <> tkComma then break; + getTok(p); + optInd(p, a); end; if sonsLen(result) <= 1 then result := a else a := result; @@ -897,7 +906,7 @@ begin break end; end; - optInd(p, a); + //optInd(p, a); if p.tok.tokType = tkAs then begin getTok(p); optInd(p, a); @@ -906,11 +915,10 @@ begin addSon(a, b); addSon(a, parseSymbol(p)); end; - if p.tok.tokType = tkComma then begin - getTok(p); - optInd(p, a) - end; addSon(result, a); + if p.tok.tokType <> tkComma then break; + getTok(p); + optInd(p, a) end; end; @@ -942,12 +950,11 @@ begin break end; end; - optInd(p, a); - if p.tok.tokType = tkComma then begin - getTok(p); - optInd(p, a) - end; addSon(result, a); + //optInd(p, a); + if p.tok.tokType <> tkComma then break; + getTok(p); + optInd(p, a) end; end; @@ -977,7 +984,7 @@ begin end end; addSon(result, a); - optInd(p, a); + //optInd(p, a); eat(p, tkImport); optInd(p, result); while true do begin @@ -989,12 +996,11 @@ begin break end; end; - optInd(p, a); - if p.tok.tokType = tkComma then begin - getTok(p); - optInd(p, a) - end; + //optInd(p, a); addSon(result, a); + if p.tok.tokType <> tkComma then break; + getTok(p); + optInd(p, a) end; end; @@ -1074,6 +1080,7 @@ begin result := newNodeP(nkCaseStmt, p); getTok(p); addSon(result, parseExpr(p)); + if p.tok.tokType = tkColon then getTok(p); skipComment(p, result); inElif := false; while true do begin @@ -1145,22 +1152,15 @@ begin result := newNodeP(nkForStmt, p); getTok(p); optInd(p, result); - while true do begin - if p.tok.tokType = tkIn then begin - getTok(p); break - end; - if p.tok.tokType = tkEof then begin - parMessage(p, errTokenExpected, TokTypeToStr[tkIn]); break - end; - - a := parseSymbol(p); - if a = nil then break; + a := parseSymbol(p); + addSon(result, a); + while p.tok.tokType = tkComma do begin + getTok(p); optInd(p, a); - if p.tok.tokType = tkComma then begin - getTok(p); optInd(p, a) - end; - addSon(result, a); + a := parseSymbol(p); + addSon(result, a); end; + eat(p, tkIn); addSon(result, exprColonEqExpr(p, nkRange, tkDotDot)); eat(p, tkColon); skipComment(p, result); @@ -1246,12 +1246,11 @@ begin if a = nil then exit; end end; - optInd(p, a); - if p.tok.tokType = tkComma then begin - getTok(p); - optInd(p, a) - end; addSon(result, a); + //optInd(p, a); + if p.tok.tokType <> tkComma then break; + getTok(p); + optInd(p, a) end; if p.tok.tokType = tkColon then begin getTok(p); optInd(p, result); @@ -1282,15 +1281,17 @@ begin while true do begin case p.tok.tokType of tkSymbol, tkAccent: a := parseIdentColonEquals(p, false); - tkParRi: begin getTok(p); break end; + tkParRi: break; else begin parMessage(p, errTokenExpected, ')'+''); break; end; end; - optInd(p, a); - if p.tok.tokType = tkComma then begin - getTok(p); optInd(p, a) - end; + //optInd(p, a); addSon(result, a); + if p.tok.tokType <> tkComma then break; + getTok(p); + optInd(p, a) end; + optSad(p); + eat(p, tkParRi); end; if p.tok.tokType = tkColon then begin getTok(p); @@ -1336,18 +1337,15 @@ begin getTok(p); eat(p, tkBracketLe); optInd(p, result); - while true do begin - case p.tok.tokType of - tkSymbol, tkAccent: a := parseIdentColonEquals(p, false); - tkBracketRi: begin getTok(p); break end; - else begin parMessage(p, errTokenExpected, ']'+''); break; end; - end; - optInd(p, a); - if p.tok.tokType = tkComma then begin - getTok(p); optInd(p, a) - end; - addSon(result, a); + while (p.tok.tokType = tkSymbol) or (p.tok.tokType = tkAccent) do begin + a := parseIdentColonEquals(p, false); + addSon(result, a); + if p.tok.tokType <> tkComma then break; + getTok(p); + optInd(p, a) end; + optSad(p); + eat(p, tkBracketRi); end; else begin InternalError(parLineInfo(p), 'pnimsyn.parseTypeDescK'); @@ -1389,18 +1387,15 @@ begin result := newNodeP(nkGenericParams, p); getTok(p); optInd(p, result); - while true do begin - case p.tok.tokType of - tkSymbol, tkAccent: a := parseGenericParam(p); - tkBracketRi: begin getTok(p); break end; - else begin parMessage(p, errTokenExpected, ']'+''); break; end; - end; - optInd(p, a); - if p.tok.tokType = tkComma then begin - getTok(p); optInd(p, a) - end; + while (p.tok.tokType = tkSymbol) or (p.tok.tokType = tkAccent) do begin + a := parseGenericParam(p); addSon(result, a); + if p.tok.tokType <> tkComma then break; + getTok(p); + optInd(p, a) end; + optSad(p); + eat(p, tkBracketRi); end; function parseRoutine(var p: TParser; kind: TNodeKind): PNode; @@ -1484,7 +1479,8 @@ begin break end end - end + end; + popInd(p.lex^); end; tkSymbol, tkAccent: addSon(result, defparser(p)); else parMessage(p, errIdentifierExpected, tokToStr(p.tok)); @@ -1628,7 +1624,8 @@ begin break end end - end + end; + popInd(p.lex^); end; tkWhen: result := parseRecordWhen(p); tkCase: result := parseRecordCase(p); @@ -1688,9 +1685,34 @@ begin indAndComment(p, result); // special extension! end; +function parseVarTuple(var p: TParser): PNode; +var + a: PNode; +begin + result := newNodeP(nkVarTuple, p); + getTok(p); // skip '(' + optInd(p, result); + while (p.tok.tokType = tkSymbol) or (p.tok.tokType = tkAccent) do begin + a := identWithPragma(p); + addSon(result, a); + if p.tok.tokType <> tkComma then break; + getTok(p); + optInd(p, a) + end; + addSon(result, nil); // no type desc + optSad(p); + eat(p, tkParRi); + eat(p, tkEquals); + optInd(p, result); + addSon(result, parseExpr(p)); +end; + function parseVariable(var p: TParser): PNode; begin - result := parseIdentColonEquals(p, true); + if p.tok.tokType = tkParLe then + result := parseVarTuple(p) + else + result := parseIdentColonEquals(p, true); indAndComment(p, result); // special extension! end; @@ -1708,10 +1730,15 @@ begin tkFrom: result := parseFromStmt(p); tkInclude: result := parseIncludeStmt(p); tkComment: result := newCommentStmt(p); - //tkSad, tkInd, tkDed: assert(false); - else result := parseExprStmt(p) + else begin + if isExprStart(p) then + result := parseExprStmt(p) + else + result := nil; + end end; - skipComment(p, result); + if result <> nil then + skipComment(p, result); end; function complexOrSimpleStmt(var p: TParser): PNode; @@ -1738,6 +1765,8 @@ begin end; function parseStmt(var p: TParser): PNode; +var + a: PNode; begin if p.tok.tokType = tkInd then begin result := newNodeP(nkStmtList, p); @@ -1748,9 +1777,14 @@ begin tkSad: getTok(p); tkEof: break; tkDed: begin getTok(p); break end; - else addSon(result, complexOrSimpleStmt(p)); - end; - end + else begin + a := complexOrSimpleStmt(p); + if a = nil then break; + addSon(result, a); + end + end + end; + popInd(p.lex^); end else begin // the case statement is only needed for better error messages: @@ -1762,7 +1796,7 @@ begin end else begin result := simpleStmt(p); - skipComment(p, result); + if result = nil then parMessage(p, errExprExpected, tokToStr(p.tok)); if p.tok.tokType = tkSad then getTok(p); end end @@ -1770,6 +1804,8 @@ begin end; function parseModule(var p: TParser): PNode; +var + a: PNode; begin result := newNodeP(nkStmtList, p); while true do begin @@ -1777,7 +1813,11 @@ begin tkSad: getTok(p); tkDed, tkInd: parMessage(p, errInvalidIndentation); tkEof: break; - else addSon(result, complexOrSimpleStmt(p)); + else begin + a := complexOrSimpleStmt(p); + if a = nil then parMessage(p, errExprExpected, tokToStr(p.tok)); + addSon(result, a); + end end end end; @@ -1795,6 +1835,7 @@ begin tkEof: break; else begin result := complexOrSimpleStmt(p); + if result = nil then parMessage(p, errExprExpected, tokToStr(p.tok)); break end end |