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#            Nim's Runtime Library
#        (c) Copyright 2015 Andreas Rumpf
#    See the file "copying.txt", included in this
#    distribution, for details about the copyright.
include "system/inclrtl"
## This module contains the interface to the compiler's abstract syntax
## tree (`AST`:idx:). Macros operate on this tree.
## See also:
## * `macros tutorial <https://nim-lang.github.io/Nim/tut3.html>`_
## * `macros section in Nim manual <https://nim-lang.github.io/Nim/manual.html#macros>`_
## .. include:: ../../doc/astspec.txt
# If you look for the implementation of the magic symbol
# ``{.magic: "Foo".}``, search for `mFoo` and `opcFoo`.
  NimNodeKind* = enum
    nnkNone, nnkEmpty, nnkIdent, nnkSym,
    nnkType, nnkCharLit, nnkIntLit, nnkInt8Lit,
    nnkInt16Lit, nnkInt32Lit, nnkInt64Lit, nnkUIntLit, nnkUInt8Lit,
    nnkUInt16Lit, nnkUInt32Lit, nnkUInt64Lit, nnkFloatLit,
    nnkFloat32Lit, nnkFloat64Lit, nnkFloat128Lit, nnkStrLit, nnkRStrLit,
    nnkTripleStrLit, nnkNilLit, nnkComesFrom, nnkDotCall,
    nnkCommand, nnkCall, nnkCallStrLit, nnkInfix,
    nnkPrefix, nnkPostfix, nnkHiddenCallConv,
    nnkExprEqExpr,
    nnkExprColonExpr, nnkIdentDefs, nnkVarTuple,
    nnkPar, nnkObjConstr, nnkCurly, nnkCurlyExpr,
    nnkBracket, nnkBracketExpr, nnkPragmaExpr, nnkRange,
    nnkDotExpr, nnkCheckedFieldExpr, nnkDerefExpr, nnkIfExpr,
    nnkElifExpr, nnkElseExpr, nnkLambda, nnkDo, nnkAccQuoted,
    nnkTableConstr, nnkBind,
    nnkClosedSymChoice,
    nnkOpenSymChoice,
    nnkHiddenStdConv,
    nnkHiddenSubConv, nnkConv, nnkCast, nnkStaticExpr,
    nnkAddr, nnkHiddenAddr, nnkHiddenDeref, nnkObjDownConv,
    nnkObjUpConv, nnkChckRangeF, nnkChckRange64, nnkChckRange,
    nnkStringToCString, nnkCStringToString, nnkAsgn,
    nnkFastAsgn, nnkGenericParams, nnkFormalParams, nnkOfInherit,
    nnkImportAs, nnkProcDef, nnkMethodDef, nnkConverterDef,
    nnkMacroDef, nnkTemplateDef, nnkIteratorDef, nnkOfBranch,
    nnkElifBranch, nnkExceptBranch, nnkElse,
    nnkAsmStmt, nnkPragma, nnkPragmaBlock, nnkIfStmt, nnkWhenStmt,
    nnkForStmt, nnkParForStmt, nnkWhileStmt, nnkCaseStmt,
    nnkTypeSection, nnkVarSection, nnkLetSection, nnkConstSection,
    nnkConstDef, nnkTypeDef,
    nnkYieldStmt, nnkDefer, nnkTryStmt, nnkFinally, nnkRaiseStmt,
    nnkReturnStmt, nnkBreakStmt, nnkContinueStmt, nnkBlockStmt, nnkStaticStmt,
    nnkDiscardStmt, nnkStmtList,
    nnkImportStmt,
    nnkImportExceptStmt,
    nnkExportStmt,
    nnkExportExceptStmt,
    nnkFromStmt,
    nnkIncludeStmt,
    nnkBindStmt, nnkMixinStmt, nnkUsingStmt,
    nnkCommentStmt, nnkStmtListExpr, nnkBlockExpr,
    nnkStmtListType, nnkBlockType,
    nnkWith, nnkWithout,
    nnkTypeOfExpr, nnkObjectTy,
    nnkTupleTy, nnkTupleClassTy, nnkTypeClassTy, nnkStaticTy,
    nnkRecList, nnkRecCase, nnkRecWhen,
    nnkRefTy, nnkPtrTy, nnkVarTy,
    nnkConstTy, nnkMutableTy,
    nnkDistinctTy,
    nnkProcTy,
    nnkIteratorTy,         # iterator type
    nnkSharedTy,           # 'shared T'
    nnkEnumTy,
    nnkEnumFieldDef,
    nnkArglist, nnkPattern
    nnkHiddenTryStmt,
    nnkClosure,
    nnkGotoState,
    nnkState,
    nnkBreakState,
    nnkFuncDef,
    nnkTupleConstr
  NimNodeKinds* = set[NimNodeKind]
  NimTypeKind* = enum  # some types are no longer used, see ast.nim
    ntyNone, ntyBool, ntyChar, ntyEmpty,
    ntyAlias, ntyNil, ntyExpr, ntyStmt,
    ntyTypeDesc, ntyGenericInvocation, ntyGenericBody, ntyGenericInst,
    ntyGenericParam, ntyDistinct, ntyEnum, ntyOrdinal,
    ntyArray, ntyObject, ntyTuple, ntySet,
    ntyRange, ntyPtr, ntyRef, ntyVar,
    ntySequence, ntyProc, ntyPointer, ntyOpenArray,
    ntyString, ntyCString, ntyForward, ntyInt,
    ntyInt8, ntyInt16, ntyInt32, ntyInt64,
    ntyFloat, ntyFloat32, ntyFloat64, ntyFloat128,
    ntyUInt, ntyUInt8, ntyUInt16, ntyUInt32, ntyUInt64,
    ntyUnused0, ntyUnused1, ntyUnused2,
    ntyVarargs,
    ntyUncheckedArray,
    ntyError,
    ntyBuiltinTypeClass, ntyUserTypeClass, ntyUserTypeClassInst,
    ntyCompositeTypeClass, ntyInferred, ntyAnd, ntyOr, ntyNot,
    ntyAnything, ntyStatic, ntyFromExpr, ntyOpt, ntyVoid
  TNimTypeKinds* {.deprecated.} = set[NimTypeKind]
  NimSymKind* = enum
    nskUnknown, nskConditional, nskDynLib, nskParam,
    nskGenericParam, nskTemp, nskModule, nskType, nskVar, nskLet,
    nskConst, nskResult,
    nskProc, nskFunc, nskMethod, nskIterator,
    nskConverter, nskMacro, nskTemplate, nskField,
    nskEnumField, nskForVar, nskLabel,
    nskStub
  TNimSymKinds* {.deprecated.} = set[NimSymKind]
  NimIdent* {.deprecated.} = object of RootObj
    ## represents a Nim identifier in the AST. **Note**: This is only
    ## rarely useful, for identifier construction from a string
 
8000
   ## use ``ident"abc"``.
  NimSymObj = object # hidden
  NimSym* {.deprecated.} = ref NimSymObj
    ## represents a Nim *symbol* in the compiler; a *symbol* is a looked-up
    ## *ident*.
  nnkLiterals* = {nnkCharLit..nnkNilLit}
  nnkCallKinds* = {nnkCall, nnkInfix, nnkPrefix, nnkPostfix, nnkCommand,
                   nnkCallStrLit}
  nnkPragmaCallKinds = {nnkExprColonExpr, nnkCall, nnkCallStrLit}
{.push warnings: off.}
proc `!`*(s: string): NimIdent {.magic: "StrToIdent", noSideEffect, deprecated.}
  ## constructs an identifier from the string `s`
  ## **Deprecated since version 0.18.0**: Use ``ident`` or ``newIdentNode`` instead.
proc toNimIdent*(s: string): NimIdent {.magic: "StrToIdent", noSideEffect, deprecated.}
  ## constructs an identifier from the string `s`
  ## **Deprecated since version 0.18.1**; Use ``ident`` or ``newIdentNode`` instead.
proc `==`*(a, b: NimIdent): bool {.magic: "EqIdent", noSideEffect, deprecated.}
  ## compares two Nim identifiers
  ## **Deprecated since version 0.18.1**; Use ``==`` on ``NimNode`` instead.
proc `==`*(a, b: NimNode): bool {.magic: "EqNimrodNode", noSideEffect.}
  ## compares two Nim nodes
proc `==`*(a, b: NimSym): bool {.magic: "EqNimrodNode", noSideEffect, deprecated.}
  ## compares two Nim symbols
  ## **Deprecated since version 0.18.1**; Use ``==(NimNode, NimNode)`` instead.
proc sameType*(a, b: NimNode): bool {.magic: "SameNodeType", noSideEffect.} =
  ## compares two Nim nodes' types. Return true if the types are the same,
  ## eg. true when comparing alias with original type.
proc len*(n: NimNode): int {.magic: "NLen", noSideEffect.}
  ## returns the number of children of `n`.
proc `[]`*(n: NimNode, i: int): NimNode {.magic: "NChild", noSideEffect.}
  ## get `n`'s `i`'th child.
proc `[]`*(n: NimNode, i: BackwardsIndex): NimNode = n[n.len - i.int]
  ## get `n`'s `i`'th child.
template `^^`(n: NimNode, i: untyped): untyped =
  (when i is BackwardsIndex: n.len - int(i) else: int(i))
proc `[]`*[T, U](n: NimNode, x: HSlice[T, U]): seq[NimNode] =
  ## slice operation for NimNode.
  ## returns a seq of child of `n` who inclusive range [n[x.a], n[x.b]].
  let xa = n ^^ x.a
  let L = (n ^^ x.b) - xa + 1
  result = newSeq[NimNode](L)
  for i in 0..<L:
    result[i] = n[i + xa]
proc `[]=`*(n: NimNode, i: int, child: NimNode) {.magic: "NSetChild",
  noSideEffect.}
  ## set `n`'s `i`'th child to `child`.
proc `[]=`*(n: NimNode, i: BackwardsIndex, child: NimNode) =
  ## set `n`'s `i`'th child to `child`.
  n[n.len - i.int] = child
template `or`*(x, y: NimNode): NimNode =
  ## Evaluate ``x`` and when it is not an empty node, return
  ## it. Otherwise evaluate to ``y``. Can be used to chain several
  ## expressions to get the first expression that is not empty.
  ## .. code-block:: nim
  ##   let node = mightBeEmpty() or mightAlsoBeEmpty() or fallbackNode
  let arg = x
  if arg != nil and arg.kind != nnkEmpty:
proc add*(father, child: NimNode): NimNode {.magic: "NAdd", discardable,
  noSideEffect, locks: 0.}
  ## Adds the `child` to the `father` node. Returns the
  ## father node so that calls can be nested.
proc add*(father: NimNode, children: varargs[NimNode]): NimNode {.
  magic: "NAddMultiple", discardable, noSideEffect, locks: 0.}
  ## Adds each child of `children` to the `father` node.
  ## Returns the `father` node so that calls can be nested.
proc del*(father: NimNode, idx = 0, n = 1) {.magic: "NDel", noSideEffect.}
  ## deletes `n` children of `father` starting at index `idx`.
proc kind*(n: NimNode): NimNodeKind {.magic: "NKind", noSideEffect.}
  ## returns the `kind` of the node `n`.
proc intVal*(n: NimNode): BiggestInt {.magic: "NIntVal", noSideEffect.}
proc floatVal*(n: NimNode): BiggestFloat {.magic: "NFloatVal", noSideEffect.}
{.push warnings: off.}
proc ident*(n: NimNode): NimIdent {.magic: "NIdent", noSideEffect, deprecated.} =
  ## **Deprecated since version 0.18.1**; All functionality is defined on ``NimNode``.
proc symbol*(n: NimNode): NimSym {.magic: "NSymbol", noSideEffect, deprecated.}
  ## **Deprecated since version 0.18.1**; All functionality is defined on ``NimNode``.
proc getImpl*(s: NimSym): NimNode {.magic: "GetImpl", noSideEffect, deprecated: "use `getImpl: NimNode -> NimNode` instead".}
when defined(nimSymKind):
  proc symKind*(symbol: NimNode): NimSymKind {.magic: "NSymKind", noSideEffect.}
  proc getImpl*(symbol: NimNode): NimNode {.magic: "GetImpl", noSideEffect.}
  proc strVal*(n: NimNode): string  {.magic: "NStrVal", noSideEffect.}
    ## retrieve the implementation of `symbol`. `symbol` can be a
    ## routine or a const.
  proc `$`*(i: NimIdent): string {.magic: "NStrVal", noSideEffect, deprecated.}
    ## converts a Nim identifier to a string
    ## **Deprecated since version 0.18.1**; Use ``strVal`` instead.
  proc `$`*(s: NimSym): string {.magic: "NStrVal", noSideEffect, deprecated.}
    ## converts a Nim symbol to a string
    ## **Deprecated since version 0.18.1**; Use ``strVal`` instead.
else: # bootstrapping substitute
  proc getImpl*(symbol: NimNode): NimNode =
    symbol.symbol.getImpl
  proc strValOld(n: NimNode): string {.magic: "NStrVal", noSideEffect.}
  proc `$`*(s: NimSym): string {.magic: "IdentToStr", noSideEffect.}
  proc `$`*(i: NimIdent): string {.magic: "IdentToStr", noSideEffect.}
  proc strVal*(n: NimNode): string =
    if n.kind == nnkIdent:
      $n.ident
    elif n.kind == nnkSym:
      $n.symbol
      n.strValOld
when defined(nimSymImplTransform):
  proc getImplTransformed*(symbol: NimNode): NimNode {.magic: "GetImplTransf", noSideEffect.}
    ## for a typed proc returns the AST after transformation pass
when defined(nimHasSymOwnerInMacro):
  proc owner*(sym: NimNode): NimNode {.magic: "SymOwner", noSideEffect.}
    ## accepts node of kind nnkSym and returns its owner's symbol.
    ## result is also mnde of kind nnkSym if owner exists otherwise
    ## nnkNilLit is returned
when defined(nimHasInstantiationOfInMacro):
  proc isInstantiationOf*(instanceProcSym, genProcSym: NimNode): bool {.magic: "SymIsInstantiationOf", noSideEffect.}
    ## check if proc symbol is instance of the generic proc symbol
    ## useful to check proc symbols against generic symbols
    ## returned by `bindSym`
proc getType*(n: NimNode): NimNode {.magic: "NGetType", noSideEffect.}
  ## with 'getType' you can access the node's `type`:idx:. A Nim type is
  ## mapped to a Nim AST too, so it's slightly confusing but it means the same
  ## API can be used to traverse types. Recursive types are flattened for you
  ## so there is no danger of infinite recursions during traversal. To
  ## resolve recursive types, you have to call 'getType' again. To see what
  ## kind of type it is, call `typeKind` on getType's result.
proc getType*(n: typedesc): NimNode {.magic: "NGetType", noSideEffect.}
  ## Returns the Nim type node for given type. This can be used to turn macro
  ## typedesc parameter into proper NimNode representing type, since typedesc
  ## are an exception in macro calls - they are not mapped implicitly to
  ## NimNode like any other arguments.
proc typeKind*(n: NimNode): NimTypeKind {.magic: "NGetType", noSideEffect.}
  ## Returns the type kind of the node 'n' that should represent a type, that
  ## means the node should have been obtained via ``getType``.
proc getTypeInst*(n: NimNode): NimNode {.magic: "NGetType", noSideEffect.} =
  ## Returns the `type`:idx: of a node in a form matching the way the
  ## type instance was declared in the code.
  runnableExamples:
      Vec[N: static[int], T] = object
        arr: array[N, T]
      Vec4[T] = Vec[4, T]
      Vec4f = Vec4[float32]
    var a: Vec4f
    var b: Vec4[float32]
    var c: Vec[4, float32]
    macro dumpTypeInst(x: typed): untyped =
      newLit(x.getTypeInst.repr)
    doAssert(dumpTypeInst(a) == "Vec4f")
    doAssert(dumpTypeInst(b) == "Vec4[float32]")
    doAssert(dumpTypeInst(c) == "Vec[4, float32]")
proc getTypeInst*(n: typedesc): NimNode {.magic: "NGetType", noSideEffect.}
  ## Version of ``getTypeInst`` which takes a ``typedesc``.
proc getTypeImpl*(n: NimNode): NimNode {.magic: "NGetType", noSideEffect.} =
  ## Returns the `type`:idx: of a node in a form matching the implementation
  ## of the type.  Any intermediate aliases are expanded to arrive at the final
  ## type implementation.  You can instead use ``getImpl`` on a symbol if you
  ## want to find the intermediate aliases.
  runnableExamples:
      Vec[N: static[int], T] = object
        arr: array[N, T]
      Vec4[T] = Vec[4, T]
      Vec4f = Vec4[float32]
    var a: Vec4f
    var b: Vec4[float32]
    var c: Vec[4, float32]
    macro dumpTypeImpl(x: typed): untyped =
      newLit(x.getTypeImpl.repr)
    let t = """
  arr: array[0 .. 3, float32]
    doAssert(dumpTypeImpl(a) == t)
    doAssert(dumpTypeImpl(b) == t)
    doAssert(dumpTypeImpl(c) == t)
when defined(nimHasSignatureHashInMacro):
  proc signatureHash*(n: NimNode): string {.magic: "NSigHash", noSideEffect.}
    ## Returns a stable identifier derived from the signature of a symbol.
    ## The signature combines many factors such as the type of the symbol,
    ## the owning module of the symbol and others. The same identifier is
    ## used in the back-end to produce the mangled symbol name.
proc symBodyHash*(s: NimNode): string {.noSideEffect.} =
  ## Returns a stable digest for symbols derived not only from type signature
  ## and owning module, but also implementation body. All procs/varibles used in
  ## the implementation of this symbol are hashed recursively as well, including
  ## magics from system module.
proc getTypeImpl*(n: typedesc): NimNode {.magic: "NGetType", noSideEffect.}
  ## Version of ``getTypeImpl`` which takes a ``typedesc``.
proc `intVal=`*(n: NimNode, val: BiggestInt) {.magic: "NSetIntVal", noSideEffect.}
proc `floatVal=`*(n: NimNode, val: BiggestFloat) {.magic: "NSetFloatVal", noSideEffect.}
{.push warnings: off.}
proc `symbol=`*(n: NimNode, val: NimSym) {.magic: "NSetSymbol", noSideEffect, deprecated.}
  ## **Deprecated since version 0.18.1**; Generate a new ``NimNode`` with ``genSym`` instead.
proc `ident=`*(n: NimNode, val: NimIdent) {.magic: "NSetIdent", noSideEffect, deprecated.}
  ## **Deprecated since version 0.18.1**; Generate a new ``NimNode`` with ``ident(string)`` instead.
#proc `typ=`*(n: NimNode, typ: typedesc) {.magic: "NSetType".}
# this is not sound! Unfortunately forbidding 'typ=' is not enough, as you
# can easily do:
#   let bracket = semCheck([1, 2])
#   let fake = semCheck(2.0)
#   bracket[0] = fake  # constructs a mixed array with ints and floats!
proc `strVal=`*(n: NimNode, val: string) {.magic: "NSetStrVal", noSideEffect.}
proc newNimNode*(kind: NimNodeKind,
                 lineInfoFrom: NimNode = nil): NimNode
  {.magic: "NNewNimNode", noSideEffect.}
  ## Creates a new AST node of the specified kind.
  ## The ``lineInfoFrom`` parameter is used for line information when the
  ## produced code crashes. You should ensure that it is set to a node that
  ## you are transforming.
proc copyNimNode*(n: NimNode): NimNode {.magic: "NCopyNimNode", noSideEffect.}
proc copyNimTree*(n: NimNode): NimNode {.magic: "NCopyNimTree", noSideEffect.}
proc error*(msg: string, n: NimNode = nil) {.magic: "NError", benign.}
  ## writes an error message at compile time. The optional ``n: NimNode``
  ## parameter is used as the source for file and line number information in
  ## the compilation error message.
proc warning*(msg: string, n: NimNode = nil) {.magic: "NWarning", benign.}
  ## writes a warning message at compile time
proc hint*(msg: string, n: NimNode = nil) {.magic: "NHint", benign.}
  ## writes a hint message at compile time
proc newStrLitNode*(s: string): NimNode {.compileTime, noSideEffect.} =
  ## creates a string literal node from `s`
  result = newNimNode(nnkStrLit)
  result.strVal = s
proc newCommentStmtNode*(s: string): NimNode {.compileTime, noSideEffect.} =
  ## creates a comment statement node
  result = newNimNode(nnkCommentStmt)
  result.strVal = s
proc newIntLitNode*(i: BiggestInt): NimNode {.compileTime.} =
  ## creates a int literal node from `i`
  result = newNimNode(nnkIntLit)
  result.intVal = i
proc newFloatLitNode*(f: BiggestFloat): NimNode {.compileTime.} =
  ## creates a float literal node from `f`
  result = newNimNode(nnkFloatLit)
  result.floatVal = f
{.push warnings: off.}
proc newIdentNode*(i: NimIdent): NimNode {.compileTime, deprecated.} =
  ## creates an identifier node from `i`
  result = newNimNode(nnkIdent)
  result.ident = i
proc newIdentNode*(i: string): NimNode {.magic: "StrToIdent", noSideEffect.}
  ## creates an identifier node from `i`. It is simply an alias for
  ## ``ident(string)``. Use that, it's shorter.
  BindSymRule* = enum    ## specifies how ``bindSym`` behaves
    brClosed,            ## only the symbols in current scope are bound
    brOpen,              ## open wrt overloaded symbols, but may be a single
                         ## symbol if not ambiguous (the rules match that of
                         ## binding in generics)
    brForceOpen          ## same as brOpen, but it will always be open even
                         ## if not ambiguous (this cannot be achieved with
                         ## any other means in the language currently)
proc bindSym*(ident: string | NimNode, rule: BindSymRule = brClosed): NimNode {.
              magic: "NBindSym", noSideEffect.}
  ## creates a node that binds `ident` to a symbol node. The bound symbol
  ## may be an overloaded symbol.
  ## if `ident` is a NimNode, it must have nkIdent kind.
  ## If ``rule == brClosed`` either an ``nkClosedSymChoice`` tree is
  ## returned or ``nkSym`` if the symbol is not ambiguous.
  ## If ``rule == brOpen`` either an ``nkOpenSymChoice`` tree is
  ## returned or ``nkSym`` if the symbol is not ambiguous.
  ## If ``rule == brForceOpen`` always an ``nkOpenSymChoice`` tree is
  ## returned even if the symbol is not ambiguous.
  ## experimental feature:
  ## use {.experimental: "dynamicBindSym".} to activate it
  ## if called from template / regular code, `ident` and `rule` must be
  ## constant expression / literal value.
  ## if called from macros / compile time procs / static blocks,
  ## `ident` and `rule` can be VM computed value.
proc genSym*(kind: NimSymKind = nskLet; ident = ""): NimNode {.
  magic: "NGenSym", noSideEffect.}
  ## generates a fresh symbol that is guaranteed to be unique. The symbol
  ## needs to occur in a declaration context.
proc callsite*(): NimNode {.magic: "NCallSite", benign,
  deprecated: "use varargs[untyped] in the macro prototype instead".}
  ## returns the AST of the invocation expression that invoked this macro.
  ## **Deprecated since version 0.18.1**.
proc toStrLit*(n: NimNode): NimNode {.compileTime.} =
  ## converts the AST `n` to the concrete Nim code and wraps that
  ## in a string literal node
  return newStrLitNode(repr(n))
  LineInfo* = object
    filename*: string
    line*,column*: int
proc `$`*(arg: Lineinfo): string =
  # BUG: without `result = `, gives compile error
  result = arg.filename & "(" & $arg.line & ", " & $arg.column & ")"
#proc lineinfo*(n: NimNode): LineInfo {.magic: "NLineInfo", noSideEffect.}
  ## returns the position the node appears in the original source file
  ## in the form filename(line, col)
proc getLine(arg: NimNode): int {.magic: "NLineInfo", noSideEffect.}
proc getColumn(arg: NimNode): int {.magic: "NLineInfo", noSideEffect.}
proc getFile(arg: NimNode): string {.magic: "NLineInfo", noSideEffect.}
proc copyLineInfo*(arg: NimNode, info: NimNode) {.magic: "NLineInfo", noSideEffect.}
  ## copy lineinfo from info node
proc lineInfoObj*(n: NimNode): LineInfo {.compileTime.} =
  ## returns ``LineInfo`` of ``n``, using absolute path for ``filename``
  result.filename = n.getFile
  result.line = n.getLine
  result.column = n.getColumn
proc lineInfo*(arg: NimNode): string {.compileTime.} =
  $arg.lineInfoObj
proc internalParseExpr(s: string): NimNode {.
  magic: "ParseExprToAst", noSideEffect.}
proc internalParseStmt(s: string): NimNode {.
  magic: "ParseStmtToAst", noSideEffect.}
proc internalErrorFlag*(): string {.magic: "NError", noSideEffect.}
  ## Some builtins set an error flag. This is then turned into a proper
  ## exception. **Note**: Ordinary application code should not call this.
proc parseExpr*(s: string): NimNode {.noSideEffect, compileTime.} =
  ## Compiles the passed string to its AST representation.
  ## Expects a single expression. Raises ``ValueError`` for parsing errors.
  result = internalParseExpr(s)
  let x = internalErrorFlag()
  if x.len > 0: raise newException(ValueError, x)
proc parseStmt*(s: string): NimNode {.noSideEffect, compileTime.} =
  ## Compiles the passed string to its AST representation.
  ## Expects one or more statements. Raises ``ValueError`` for parsing errors.
  result = internalParseStmt(s)
  let x = internalErrorFlag()
  if x.len > 0: raise newException(ValueError, x)
proc getAst*(macroOrTemplate: untyped): NimNode {.magic: "ExpandToAst", noSideEffect.}
  ## Obtains the AST nodes returned from a macro or template invocation.
  ## Example:
  ## .. code-block:: nim
  ##   macro FooMacro() =
  ##     var ast = getAst(BarTemplate())
proc quote*(bl: typed, op = "``"): NimNode {.magic: "QuoteAst", noSideEffect.}
  ## Quasi-quoting operator.
  ## Accepts an expression or a block and returns the AST that represents it.
  ## Within the quoted AST, you are able to interpolate NimNode expressions
  ## from the surrounding scope. If no operator is given, quoting is done using
  ## backticks. Otherwise, the given operator must be used as a prefix operator
  ## for any interpolated expression.
  ## Example:
  ## .. code-block:: nim
  ##   macro check(ex: untyped): typed =
  ##     # this is a simplified version of the check macro from the
  ##     # unittest module.
  ##     # If there is a failed check, we want to make it easy for
  ##     # the user to jump to the faulty line in the code, so we
  ##     # get the line info here:
  ##     var info = ex.lineinfo
  ##     # We will also display the code string of the failed check:
  ##     var expString = ex.toStrLit
  ##     # Finally we compose the code to implement the check:
  ##     result = quote do:
  ##       if not `ex`:
  ##         echo `info` & ": Check failed: " & `expString`
proc expectKind*(n: NimNode, k: NimNodeKind) {.compileTime.} =
  ## checks that `n` is of kind `k`. If this is not the case,
  ## compilation aborts with an error message. This is useful for writing
  ## macros that check the AST that is passed to them.
  if n.kind != k: error("Expected a node of kind " & $k & ", got " & $n.kind, n)
proc expectMinLen*(n: NimNode, min: int) {.compileTime.} =
  ## checks that `n` has at least `min` children. If this is not the case,
  ## compilation aborts with an error message. This is useful for writing
  ## macros that check its number of arguments.
  if n.len < min: error("macro expects a node with " & $min & " children", n)
proc expectLen*(n: NimNode, len: int) {.compileTime.} =
  ## checks that `n` has exactly `len` children. If this is not the case,
  ## compilation aborts with an error message. This is useful for writing
  ## macros that check its number of arguments.
  if n.len != len: error("macro expects a node with " & $len & " children", n)
proc expectLen*(n: NimNode, min, max: int) {.compileTime.} =
  ## checks that `n` has a number of children in the range ``min..max``.
  ## If this is not the case, compilation aborts with an error message.
  ## This is useful for writing macros that check its number of arguments.
  if n.len < min or n.len > max:
    error("macro expects a node with " & $min & ".." & $max " children", n)
proc newTree*(kind: NimNodeKind,
              children: varargs[NimNode]): NimNode {.compileTime.} =
  ## produces a new node with children.
  result = newNimNode(kind)
  result.add(children)
proc newCall*(theProc: NimNode,
              args: varargs[NimNode]): NimNode {.compileTime.} =
  ## produces a new call node. `theProc` is the proc that is called with
  ## the arguments ``args[0..]``.
  result = newNimNode(nnkCall)
  result.add(theProc)
  result.add(args)
{.push warnings: off.}
proc newCall*(theProc: NimIdent,
              args: varargs[NimNode]): NimNode {.compileTime, deprecated.} =
  ## produces a new call node. `theProc` is the proc that is called with
  ## the arguments ``args[0..]``.
  ## **Deprecated since version 0.18.1**; Use ``newCall(string, ...)``,
  ## or ``newCall(NimNode, ...)`` instead.
  result = newNimNode(nnkCall)
  result.add(newIdentNode(theProc))
  result.add(args)
proc newCall*(theProc: string,
              args: varargs[NimNode]): NimNode {.compileTime.} =
  ## produces a new call node. `theProc` is the proc that is called with
  ## the arguments ``args[0..]``.
  result = newNimNode(nnkCall)
  result.add(newIdentNode(theProc))
  result.add(args)
proc newLit*(c: char): NimNode {.compileTime.} =
  ## produces a new character literal node.
  result = newNimNode(nnkCharLit)
  result.intVal = ord(c)
proc newLit*(i: int): NimNode {.compileTime.} =
  ## produces a new integer literal node.
  result = newNimNode(nnkIntLit)
  result.intVal = i
proc newLit*(i: int8): NimNode {.compileTime.} =
  ## produces a new integer literal node.
  result = newNimNode(nnkInt8Lit)
  result.intVal = i
proc newLit*(i: int16): NimNode {.compileTime.} =
  ## produces a new integer literal node.
  result = newNimNode(nnkInt16Lit)
  result.intVal = i
proc newLit*(i: int32): NimNode {.compileTime.} =
  ## produces a new integer literal node.
  result = newNimNode(nnkInt32Lit)
  result.intVal = i
proc newLit*(i: int64): NimNode {.compileTime.} =
  ## produces a new integer literal node.
  result = newNimNode(nnkInt64Lit)
  result.intVal = i
proc newLit*(i: uint): NimNode {.compileTime.} =
  ## produces a new unsigned integer literal node.
  result = newNimNode(nnkUIntLit)
  result.intVal = BiggestInt(i)
proc newLit*(i: uint8): NimNode {.compileTime.} =
  ## produces a new unsigned integer literal node.
  result = newNimNode(nnkUInt8Lit)
  result.intVal = BiggestInt(i)
proc newLit*(i: uint16): NimNode {.compileTime.} =
  ## produces a new unsigned integer literal node.
  result = newNimNode(nnkUInt16Lit)
  result.intVal = BiggestInt(i)
proc newLit*(i: uint32): NimNode {.compileTime.} =
  ## produces a new unsigned integer literal node.
  result = newNimNode(nnkUInt32Lit)
  result.intVal = BiggestInt(i)
proc newLit*(i: uint64): NimNode {.compileTime.} =
  ## produces a new unsigned integer literal node.
  result = newNimNode(nnkUInt64Lit)
  result.intVal = BiggestInt(i)
proc newLit*(b: bool): NimNode {.compileTime.} =
  ## produces a new boolean literal node.
  result = if b: bindSym"true" else: bindSym"false"
when false:
  # the float type is not really a distinct type as described in https://github.com/nim-lang/Nim/issues/5875
  proc newLit*(f: float): NimNode {.compileTime.} =
    ## produces a new float literal node.
    result = newNimNode(nnkFloatLit)
    result.floatVal = f
proc newLit*(f: float32): NimNode {.compileTime.} =
  ## produces a new float literal node.
  result = newNimNode(nnkFloat32Lit)
  result.floatVal = f
proc newLit*(f: float64): NimNode {.compileTime.} =
  ## produces a new float literal node.
  result = newNimNode(nnkFloat64Lit)
  result.floatVal = f
when declared(float128):
  proc newLit*(f: float128): NimNode {.compileTime.} =
    ## produces a new float literal node.
    result = newNimNode(nnkFloat128Lit)
    result.floatVal = f
proc newLit*(arg: enum): NimNode {.compileTime.} =
  result = newCall(
    arg.type.getTypeInst[1],
    newLit(int(arg))
proc newLit*[N,T](arg: array[N,T]): NimNode {.compileTime.}
proc newLit*[T](arg: seq[T]): NimNode {.compileTime.}
proc newLit*[T](s: set[T]): NimNode {.compileTime.}
proc newLit*(arg: tuple): NimNode {.compileTime.}
proc newLit*(arg: object): NimNode {.compileTime.} =
  result = nnkObjConstr.newTree(arg.type.getTypeInst[1])
  for a, b in arg.fieldPairs:
    result.add nnkExprColonExpr.newTree( newIdentNode(a), newLit(b) )
proc newLit*[N,T](arg: array[N,T]): NimNode {.compileTime.} =
  result = nnkBracket.newTree
  for x in arg:
    result.add newLit(x)
proc newLit*[T](arg: seq[T]): NimNode {.compileTime.} =
  var bracket = nnkBracket.newTree
  for x in arg:
    bracket.add newLit(x)
  result = nnkCall.newTree(
    nnkBracketExpr.newTree(
      nnkAccQuoted.newTree( bindSym"@" ),
      getTypeInst( bindSym"T" )
    bracket
proc newLit*[T](s: set[T]): NimNode {.compileTime.} =
  result = nnkCurly.newTree
  for x in s:
    result.add newLit(x)
proc newLit*(arg: tuple): NimNode {.compileTime.} =
  result = nnkPar.newTree
  for a,b in arg.fieldPairs:
    result.add nnkExprColonExpr.newTree(newIdentNode(a), newLit(b))
proc newLit*(s: string): NimNode {.compileTime.} =
  ## produces a new string literal node.
  result = newNimNode(nnkStrLit)
  result.strVal = s
proc nestList*(op: NimNode; pack: NimNode): NimNode {.compileTime.} =
  ## nests the list `pack` into a tree of call expressions:
  ## ``[a, b, c]`` is transformed into ``op(a, op(c, d))``.
  ## This is also known as fold expression.
  if pack.len < 1:
    error("`nestList` expects a node with at least 1 child")
  result = pack[^1]
  for i in countdown(pack.len - 2, 0):
    result = newCall(op, pack[i], result)
proc nestList*(op: NimNode; pack: NimNode; init: NimNode): NimNode {.compileTime.} =
  ## nests the list `pack` into a tree of call expressions:
  ## ``[a, b, c]`` is transformed into ``op(a, op(c, d))``.
  ## This is also known as fold expression.
  result = init
  for i in countdown(pack.len - 1, 0):
    result = newCall(op, pack[i], result)
{.push warnings: off.}
proc nestList*(theProc: NimIdent, x: NimNode): NimNode {.compileTime, deprecated.} =
  ## **Deprecated since version 0.18.1**; Use one of ``nestList(NimNode, ...)`` instead.
  nestList(newIdentNode(theProc), x)
proc treeTraverse(n: NimNode; res: var string; level = 0; isLisp = false, indented = false) {.benign.} =
  if level > 0:
    if indented:
      res.add("\n")
      for i in 0 .. level-1:
        if isLisp:
          res.add(" ")          # dumpLisp indentation
        else:
          res.add("  ")         # dumpTree indentation
      res.add(" ")
  if isLisp:
    res.add("(")
  res.add(($n.kind).substr(3))
  case n.kind
  of nnkEmpty, nnkNilLit:
    discard # same as nil node in this representation
  of nnkCharLit .. nnkInt64Lit:
    res.add(" " & $n.intVal)
  of nnkFloatLit .. nnkFloat64Lit:
    res.add(" " & $n.floatVal)
  of nnkStrLit .. nnkTripleStrLit, nnkCommentStmt, nnkIdent, nnkSym:
    res.add(" " & $n.strVal.newLit.repr)
  of nnkNone:
    assert false
    for j in 0 .. n.len-1:
      n[j].treeTraverse(res, level+1, isLisp, indented)
  if isLisp:
    res.add(")")
proc treeRepr*(n: NimNode): string {.compileTime, benign.} =
  ## Convert the AST `n` to a human-readable tree-like string.
  ## See also `repr`, `lispRepr`, and `astGenRepr`.
  n.treeTraverse(result, isLisp = false, indented = true)
proc lispRepr*(n: NimNode; indented = false): string {.compileTime, benign.} =
  ## Convert the AST ``n`` to a human-readable lisp-like string.
  ## See also ``repr``, ``treeRepr``, and ``astGenRepr``.
  n.treeTraverse(result, isLisp = true, indented = indented)
proc astGenRepr*(n: NimNode): string {.compileTime, benign.} =
  ## Convert the AST ``n`` to the code required to generate that AST.
  ## See also ``repr``, ``treeRepr``, and ``lispRepr``.
    NodeKinds = {nnkEmpty, nnkIdent, nnkSym, nnkNone, nnkCommentStmt}
    LitKinds = {nnkCharLit..nnkInt64Lit, nnkFloatLit..nnkFloat64Lit, nnkStrLit..nnkTripleStrLit}
  proc traverse(res: var string, level: int, n: NimNode) {.benign.} =
    for i in 0..level-1: res.add "  "
    if n.kind in NodeKinds:
      res.add("new" & ($n.kind).substr(3) & "Node(")
    elif n.kind in LitKinds:
      res.add("newLit(")
    elif n.kind == nnkNilLit:
      res.add("newNilLit()")
      res.add($n.kind)
    case n.kind
    of nnkEmpty, nnkNilLit: discard
    of nnkCharLit: res.add("'" & $chr(n.intVal) & "'")
    of nnkIntLit..nnkInt64Lit: res.add($n.intVal)
    of nnkFloatLit..nnkFloat64Lit: res.add($n.floatVal)
    of nnkStrLit..nnkTripleStrLit, nnkCommentStmt, nnkIdent, nnkSym:
      res.add(n.strVal.newLit.repr)
    of nnkNone: assert false
      res.add(".newTree(")
      for j in 0..<n.len:
        res.add "\n"
        traverse(res, level + 1, n[j])
        if j != n.len-1:
          res.add(",")
      res.add("\n")
      for i in 0..level-1: res.add "  "
      res.add(")")
    if n.kind in NodeKinds+LitKinds:
      res.add(")")
  result = ""
  traverse(result, 0, n)
macro dumpTree*(s: untyped): untyped = echo s.treeRepr
  ## Accepts a block of nim code and prints the parsed abstract syntax
  ## tree using the ``treeRepr`` proc. Printing is done *at compile time*.
  ## You can use this as a tool to explore the Nim's abstract syntax
  ## tree and to discover what kind of nodes must be created to represent
  ## a certain expression/statement.
  ## For example:
  ## .. code-block:: nim
  ##    dumpTree:
  ##      echo "Hello, World!"
  ## Outputs:
  ## .. code-block::
  ##    StmtList
  ##      Command
  ##        Ident "echo"
  ##        StrLit "Hello, World!"
  ## Also see ``dumpAstGen`` and ``dumpLisp``.
macro dumpLisp*(s: untyped): untyped = echo s.lispRepr(indented = true)
  ## Accepts a block of nim code and prints the parsed abstract syntax
  ## tree using the ``lispRepr`` proc. Printing is done *at compile time*.
  ## You can use this as a tool to explore the Nim's abstract syntax
  ## tree and to discover what kind of nodes must be created to represent
  ## a certain expression/statement.
  ## For example:
  ## .. code-block:: nim
  ##    dumpLisp:
  ##      echo "Hello, World!"
  ## Outputs:
  ## .. code-block::
  ##    (StmtList
  ##     (Command
  ##      (Ident "echo")
  ##      (StrLit "Hello, World!")))
  ## Also see ``dumpAstGen`` and ``dumpTree``.
macro dumpAstGen*(s: untyped): untyped = echo s.astGenRepr
  ## Accepts a block of nim code and prints the parsed abstract syntax
  ## tree using the ``astGenRepr`` proc. Printing is done *at compile time*.
  ## You can use this as a tool to write macros quicker by writing example
  ## outputs and then copying the snippets into the macro for modification.
  ## For example:
  ## .. code-block:: nim
  ##    dumpAstGen:
  ##      echo "Hello, World!"
  ## Outputs:
  ## .. code-block:: nim
  ##    nnkStmtList.newTree(
  ##      nnkCommand.newTree(
  ##        newIdentNode("echo"),
  ##        newLit("Hello, World!")
  ##      )
  ## Also see ``dumpTree`` and ``dumpLisp``.
macro dumpTreeImm*(s: untyped): untyped {.deprecated.} = echo s.treeRepr
  ## Deprecated. Use `dumpTree` instead.
macro dumpLispImm*(s: untyped): untyped {.deprecated.} = echo s.lispRepr
  ## Deprecated. Use `dumpLisp` instead.
proc newEmptyNode*(): NimNode {.compileTime, noSideEffect.} =
  ## Create a new empty node
  result = newNimNode(nnkEmpty)
proc newStmtList*(stmts: varargs[NimNode]): NimNode {.compileTime.}=
  ## Create a new statement list
  result = newNimNode(nnkStmtList).add(stmts)
proc newPar*(exprs: varargs[NimNode]): NimNode {.compileTime.}=
  ## Create a new parentheses-enclosed expression
  newNimNode(nnkPar).add(exprs)
proc newBlockStmt*(label, body: NimNode): NimNode {.compileTime.} =
  ## Create a new block statement with label
  return newNimNode(nnkBlockStmt).add(label, body)
proc newBlockStmt*(body: NimNode): NimNode {.compiletime.} =
  ## Create a new block: stmt
  return newNimNode(nnkBlockStmt).add(newEmptyNode(), body)
proc newVarStmt*(name, value: NimNode): NimNode {.compiletime.} =
  ## Create a new var stmt
  return newNimNode(nnkVarSection).add(
    newNimNode(nnkIdentDefs).add(name, newNimNode(nnkEmpty), value))
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