Module parsesql

The parsesql module implements a high performance SQL file parser. It parses PostgreSQL syntax and the SQL ANSI standard.

Imports

hashes, strutils, lexbase, streams

Types

SqlLexer = object of BaseLexer
  filename: string

the parser object.

SqlNodeKind = enum
  nkNone, nkIdent, nkStringLit, nkBitStringLit, nkHexStringLit, nkIntegerLit,
  nkNumericLit, nkPrimaryKey, nkForeignKey, nkNotNull, nkNull, nkStmtList, nkDot,
  nkDotDot, nkPrefix, nkInfix, nkCall, nkColumnReference, nkReferences, nkDefault,
  nkCheck, nkConstraint, nkUnique, nkIdentity, nkColumnDef, ## name, datatype, constraints
  nkInsert, nkUpdate, nkDelete, nkSelect, nkSelectDistinct, nkSelectColumns, nkAsgn,
  nkFrom, nkGroup, nkHaving, nkOrder, nkDesc, nkUnion, nkIntersect, nkExcept,
  nkColumnList, nkValueList, nkWhere, nkCreateTable, nkCreateTableIfNotExists,
  nkCreateType, nkCreateTypeIfNotExists, nkCreateIndex, nkCreateIndexIfNotExists,
  nkEnumDef

kind of SQL abstract syntax tree

SqlParseError = object of ValueError

Invalid SQL encountered

SqlNode = ref SqlNodeObj

an SQL abstract syntax tree node

SqlNodeObj = object
  case kind*: SqlNodeKind       ## kind of syntax tree
  of nkIdent, nkStringLit, nkBitStringLit, nkHexStringLit, nkIntegerLit, nkNumericLit:
      strVal*: string          ## AST leaf: the identifier, numeric literal
                    ## string literal, etc.
    
  else:
      sons*: seq[SqlNode]      ## the node's children

an SQL abstract syntax tree node

SqlParser = object of SqlLexer
  tok: Token

SQL parser object

Procs

proc len(n: SqlNode): int {.raises: [], tags: [].}

proc `[]`(n: SqlNode; i: int): SqlNode {.raises: [], tags: [].}

proc add(father, n: SqlNode) {.raises: [], tags: [].}

proc parseSQL(input: Stream; filename: string): SqlNode {.
    raises: [Exception, Exception, ValueError, SqlParseError],
    tags: [ReadIOEffect, RootEffect].}

parses the SQL from input into an AST and returns the AST. filename is only used for error messages. Syntax errors raise an EInvalidSql exception.

proc renderSQL(n: SqlNode): string {.raises: [Exception], tags: [RootEffect].}

Converts an SQL abstract syntax tree to its string representation.

proc `$`(n: SqlNode): string {.raises: [Exception], tags: [RootEffect].}

an alias for renderSQL.