diff options
author | treeform <starplant@gmail.com> | 2018-04-12 08:49:24 -0700 |
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committer | Andreas Rumpf <rumpf_a@web.de> | 2018-04-12 17:49:24 +0200 |
commit | f3db632b1d730892e6770a6034acfb8aec077b34 (patch) | |
tree | 6b403b2825c475b34573a82b23f86198eaab4845 /lib | |
parent | 63160855aade7fd64755e4bdc78bf4694513df50 (diff) | |
download | Nim-f3db632b1d730892e6770a6034acfb8aec077b34.tar.gz |
Added count(*) support to sql parser. Fixed warnings in sql parser. (#7490)
Diffstat (limited to 'lib')
-rw-r--r-- | lib/pure/parsesql.nim | 171 |
1 files changed, 99 insertions, 72 deletions
diff --git a/lib/pure/parsesql.nim b/lib/pure/parsesql.nim index ae192ab9a..fcc757bea 100644 --- a/lib/pure/parsesql.nim +++ b/lib/pure/parsesql.nim @@ -11,7 +11,7 @@ ## parser. It parses PostgreSQL syntax and the SQL ANSI standard. import - hashes, strutils, lexbase, streams + hashes, strutils, lexbase # ------------------- scanner ------------------------------------------------- @@ -62,10 +62,6 @@ const "count", ] -proc open(L: var SqlLexer, input: Stream, filename: string) = - lexbase.open(L, input) - L.filename = filename - proc close(L: var SqlLexer) = lexbase.close(L) @@ -496,6 +492,7 @@ type SqlNodeKind* = enum ## kind of SQL abstract syntax tree nkNone, nkIdent, + nkQuotedIdent, nkStringLit, nkBitStringLit, nkHexStringLit, @@ -551,13 +548,18 @@ type nkCreateIndexIfNotExists, nkEnumDef +const + LiteralNodes = { + nkIdent, nkQuotedIdent, nkStringLit, nkBitStringLit, nkHexStringLit, + nkIntegerLit, nkNumericLit + } + type SqlParseError* = object of ValueError ## Invalid SQL encountered SqlNode* = ref SqlNodeObj ## an SQL abstract syntax tree node SqlNodeObj* = object ## an SQL abstract syntax tree node case kind*: SqlNodeKind ## kind of syntax tree - of nkIdent, nkStringLit, nkBitStringLit, nkHexStringLit, - nkIntegerLit, nkNumericLit: + of LiteralNodes: strVal*: string ## AST leaf: the identifier, numeric literal ## string literal, etc. else: @@ -566,21 +568,26 @@ type SqlParser* = object of SqlLexer ## SQL parser object tok: Token + {.deprecated: [EInvalidSql: SqlParseError, PSqlNode: SqlNode, TSqlNode: SqlNodeObj, TSqlParser: SqlParser, TSqlNodeKind: SqlNodeKind].} -proc newNode(k: SqlNodeKind): SqlNode = +proc newNode*(k: SqlNodeKind): SqlNode = new(result) result.kind = k -proc newNode(k: SqlNodeKind, s: string): SqlNode = +proc newNode*(k: SqlNodeKind, s: string): SqlNode = new(result) result.kind = k result.strVal = s +proc newNode*(k: SqlNodeKind, sons: seq[SqlNode]): SqlNode = + new(result) + result.kind = k + result.sons = sons + proc len*(n: SqlNode): int = - if n.kind in {nkIdent, nkStringLit, nkBitStringLit, nkHexStringLit, - nkIntegerLit, nkNumericLit}: + if n.kind in LiteralNodes: result = 0 else: result = n.sons.len @@ -630,7 +637,7 @@ proc eat(p: var SqlParser, keyw: string) = if isKeyw(p, keyw): getTok(p) else: - sqlError(p, keyw.toUpper() & " expected") + sqlError(p, keyw.toUpperAscii() & " expected") proc opt(p: var SqlParser, kind: TokKind) = if p.tok.kind == kind: getTok(p) @@ -689,7 +696,10 @@ proc parseSelect(p: var SqlParser): SqlNode proc identOrLiteral(p: var SqlParser): SqlNode = case p.tok.kind - of tkIdentifier, tkQuotedIdentifier: + of tkQuotedIdentifier: + result = newNode(nkQuotedIdent, p.tok.literal) + getTok(p) + of tkIdentifier: result = newNode(nkIdent, p.tok.literal) getTok(p) of tkStringConstant, tkEscapeConstant, tkDollarQuotedConstant: @@ -713,11 +723,15 @@ proc identOrLiteral(p: var SqlParser): SqlNode = result.add(parseExpr(p)) eat(p, tkParRi) else: - sqlError(p, "expression expected") - getTok(p) # we must consume a token here to prevend endless loops! + if p.tok.literal == "*": + result = newNode(nkIdent, p.tok.literal) + getTok(p) + else: + sqlError(p, "expression expected") + getTok(p) # we must consume a token here to prevend endless loops! proc primary(p: var SqlParser): SqlNode = - if p.tok.kind == tkOperator or isKeyw(p, "not"): + if (p.tok.kind == tkOperator and (p.tok.literal == "+" or p.tok.literal == "-")) or isKeyw(p, "not"): result = newNode(nkPrefix) result.add(newNode(nkIdent, p.tok.literal)) getTok(p) @@ -762,7 +776,7 @@ proc lowestExprAux(p: var SqlParser, v: var SqlNode, limit: int): int = result = opPred while opPred > limit: node = newNode(nkInfix) - opNode = newNode(nkIdent, p.tok.literal.toLower()) + opNode = newNode(nkIdent, p.tok.literal.toLowerAscii()) getTok(p) result = lowestExprAux(p, v2, opPred) node.add(opNode) @@ -1078,11 +1092,23 @@ proc parseSelect(p: var SqlParser): SqlNode = if p.tok.kind != tkComma: break getTok(p) result.add(g) - if isKeyw(p, "limit"): + if isKeyw(p, "order"): getTok(p) - var l = newNode(nkLimit) - l.add(parseExpr(p)) - result.add(l) + eat(p, "by") + var n = newNode(nkOrder) + while true: + var e = parseExpr(p) + if isKeyw(p, "asc"): + getTok(p) # is default + elif isKeyw(p, "desc"): + getTok(p) + var x = newNode(nkDesc) + x.add(e) + e = x + n.add(e) + if p.tok.kind != tkComma: break + getTok(p) + result.add(n) if isKeyw(p, "having"): var h = newNode(nkHaving) while true: @@ -1099,22 +1125,6 @@ proc parseSelect(p: var SqlParser): SqlNode = elif isKeyw(p, "except"): result.add(newNode(nkExcept)) getTok(p) - if isKeyw(p, "order"): - getTok(p) - eat(p, "by") - var n = newNode(nkOrder) - while true: - var e = parseExpr(p) - if isKeyw(p, "asc"): getTok(p) # is default - elif isKeyw(p, "desc"): - getTok(p) - var x = newNode(nkDesc) - x.add(e) - e = x - n.add(e) - if p.tok.kind != tkComma: break - getTok(p) - result.add(n) if isKeyw(p, "join") or isKeyw(p, "inner") or isKeyw(p, "outer") or isKeyw(p, "cross"): var join = newNode(nkJoin) result.add(join) @@ -1122,12 +1132,17 @@ proc parseSelect(p: var SqlParser): SqlNode = join.add(newNode(nkIdent, "")) getTok(p) else: - join.add(newNode(nkIdent, p.tok.literal.toLower())) + join.add(newNode(nkIdent, p.tok.literal.toLowerAscii())) getTok(p) eat(p, "join") join.add(parseFromItem(p)) eat(p, "on") join.add(parseExpr(p)) + if isKeyw(p, "limit"): + getTok(p) + var l = newNode(nkLimit) + l.add(parseExpr(p)) + result.add(l) proc parseStmt(p: var SqlParser; parent: SqlNode) = if isKeyw(p, "create"): @@ -1161,14 +1176,6 @@ proc parseStmt(p: var SqlParser; parent: SqlNode) = else: sqlError(p, "SELECT, CREATE, UPDATE or DELETE expected") -proc open(p: var SqlParser, input: Stream, filename: string) = - ## opens the parser `p` and assigns the input stream `input` to it. - ## `filename` is only used for error messages. - open(SqlLexer(p), input, filename) - p.tok.kind = tkInvalid - p.tok.literal = "" - getTok(p) - proc parse(p: var SqlParser): SqlNode = ## parses the content of `p`'s input stream and returns the SQL AST. ## Syntax errors raise an `SqlParseError` exception. @@ -1183,24 +1190,6 @@ proc close(p: var SqlParser) = ## closes the parser `p`. The associated input stream is closed too. close(SqlLexer(p)) -proc parseSQL*(input: Stream, filename: string): SqlNode = - ## parses the SQL from `input` into an AST and returns the AST. - ## `filename` is only used for error messages. - ## Syntax errors raise an `SqlParseError` exception. - var p: SqlParser - open(p, input, filename) - try: - result = parse(p) - finally: - close(p) - -proc parseSQL*(input: string, filename=""): SqlNode = - ## parses the SQL from `input` into an AST and returns the AST. - ## `filename` is only used for error messages. - ## Syntax errors raise an `SqlParseError` exception. - parseSQL(newStringStream(input), "") - - type SqlWriter = object indent: int @@ -1218,12 +1207,12 @@ proc add(s: var SqlWriter, thing: string) = proc addKeyw(s: var SqlWriter, thing: string) = var keyw = thing if s.upperCase: - keyw = keyw.toUpper() + keyw = keyw.toUpperAscii() s.add(keyw) proc addIden(s: var SqlWriter, thing: string) = var iden = thing - if iden.toLower() in reservedKeywords: + if iden.toLowerAscii() in reservedKeywords: iden = '"' & iden & '"' s.add(iden) @@ -1251,15 +1240,20 @@ proc addMulti(s: var SqlWriter, n: SqlNode, sep = ',', prefix, suffix: char) = ra(n.sons[i], s) s.add(suffix) +proc quoted(s: string): string = + "\"" & replace(s, "\"", "\"\"") & "\"" + proc ra(n: SqlNode, s: var SqlWriter) = if n == nil: return case n.kind of nkNone: discard of nkIdent: - if allCharsInSet(n.strVal, {'\33'..'\127'}) and n.strVal.toLower() notin reservedKeywords: + if allCharsInSet(n.strVal, {'\33'..'\127'}): s.add(n.strVal) else: - s.add("\"" & replace(n.strVal, "\"", "\"\"") & "\"") + s.add(quoted(n.strVal)) + of nkQuotedIdent: + s.add(quoted(n.strVal)) of nkStringLit: s.add(escape(n.strVal, "'", "'")) of nkBitStringLit: @@ -1361,18 +1355,19 @@ proc ra(n: SqlNode, s: var SqlWriter) = s.addKeyw("select") if n.kind == nkSelectDistinct: s.addKeyw("distinct") - s.addMulti(n.sons[0]) - for i in 1 .. n.len-1: + for i in 0 ..< n.len: ra(n.sons[i], s) of nkSelectColumns: - assert(false) + for i, column in n.sons: + if i > 0: s.add(',') + ra(column, s) of nkSelectPair: ra(n.sons[0], s) if n.sons.len == 2: s.addKeyw("as") ra(n.sons[1], s) of nkFromItemPair: - if n.sons[0].kind == nkIdent: + if n.sons[0].kind in {nkIdent, nkQuotedIdent}: ra(n.sons[0], s) else: assert n.sons[0].kind == nkSelect @@ -1472,3 +1467,35 @@ proc renderSQL*(n: SqlNode, upperCase=false): string = proc `$`*(n: SqlNode): string = ## an alias for `renderSQL`. renderSQL(n) + +when not defined(js): + import streams + + proc open(L: var SqlLexer, input: Stream, filename: string) = + lexbase.open(L, input) + L.filename = filename + + proc open(p: var SqlParser, input: Stream, filename: string) = + ## opens the parser `p` and assigns the input stream `input` to it. + ## `filename` is only used for error messages. + open(SqlLexer(p), input, filename) + p.tok.kind = tkInvalid + p.tok.literal = "" + getTok(p) + + proc parseSQL*(input: Stream, filename: string): SqlNode = + ## parses the SQL from `input` into an AST and returns the AST. + ## `filename` is only used for error messages. + ## Syntax errors raise an `SqlParseError` exception. + var p: SqlParser + open(p, input, filename) + try: + result = parse(p) + finally: + close(p) + + proc parseSQL*(input: string, filename=""): SqlNode = + ## parses the SQL from `input` into an AST and returns the AST. + ## `filename` is only used for error messages. + ## Syntax errors raise an `SqlParseError` exception. + parseSQL(newStringStream(input), "") |