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diff --git a/lib/core/macros.nim b/lib/core/macros.nim new file mode 100644 index 000000000..7646b165c --- /dev/null +++ b/lib/core/macros.nim @@ -0,0 +1,1812 @@ +# +# +# 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" +import std/private/since + +when defined(nimPreviewSlimSystem): + import std/[assertions, formatfloat] + + +## This module contains the interface to the compiler's abstract syntax +## tree (`AST`:idx:). Macros operate on this tree. +## +## See also: +## * `macros tutorial <tut3.html>`_ +## * `macros section in Nim manual <manual.html#macros>`_ + +## .. include:: ../../doc/astspec.txt + +## .. importdoc:: system.nim + +# If you look for the implementation of the magic symbol +# ``{.magic: "Foo".}``, search for `mFoo` and `opcFoo`. + +type + 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, nnkOutTy, + nnkDistinctTy, + nnkProcTy, + nnkIteratorTy, # iterator type + nnkSinkAsgn, + nnkEnumTy, + nnkEnumFieldDef, + nnkArgList, nnkPattern + nnkHiddenTryStmt, + nnkClosure, + nnkGotoState, + nnkState, + nnkBreakState, + nnkFuncDef, + nnkTupleConstr, + nnkError, ## erroneous AST node + nnkModuleRef, nnkReplayAction, nnkNilRodNode ## internal IC nodes + nnkOpenSym + + 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, ntyOptDeprecated, 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] + +const + nnkMutableTy* {.deprecated.} = nnkOutTy + nnkSharedTy* {.deprecated.} = nnkSinkAsgn + +type + NimIdent* {.deprecated.} = object of RootObj + ## Represents a Nim identifier in the AST. **Note**: This is only + ## rarely useful, for identifier construction from a string + ## use `ident"abc"`. + + NimSymObj = object # hidden + NimSym* {.deprecated.} = ref NimSymObj + ## Represents a Nim *symbol* in the compiler; a *symbol* is a looked-up + ## *ident*. + + +const + nnkLiterals* = {nnkCharLit..nnkNilLit} + # see matching set CallNodes below + nnkCallKinds* = {nnkCall, nnkInfix, nnkPrefix, nnkPostfix, nnkCommand, + nnkCallStrLit, nnkHiddenCallConv} + nnkPragmaCallKinds = {nnkExprColonExpr, nnkCall, nnkCallStrLit} + +{.push warnings: off.} + +proc toNimIdent*(s: string): NimIdent {.magic: "StrToIdent", noSideEffect, deprecated: + "Deprecated since version 0.18.0: Use 'ident' or 'newIdentNode' instead.".} + ## Constructs an identifier from the string `s`. + +proc `==`*(a, b: NimIdent): bool {.magic: "EqIdent", noSideEffect, deprecated: + "Deprecated since version 0.18.1; Use '==' on 'NimNode' instead.".} + ## Compares two Nim identifiers. + +proc `==`*(a, b: NimNode): bool {.magic: "EqNimrodNode", noSideEffect.} + ## Compare two Nim nodes. Return true if nodes are structurally + ## equivalent. This means two independently created nodes can be equal. + +proc `==`*(a, b: NimSym): bool {.magic: "EqNimrodNode", noSideEffect, deprecated: + "Deprecated since version 0.18.1; Use '==(NimNode, NimNode)' instead.".} + ## Compares two Nim symbols. + +{.pop.} + +proc sameType*(a, b: NimNode): bool {.magic: "SameNodeType", noSideEffect.} = + ## Compares two Nim nodes' types. Return true if the types are the same, + ## e.g. true when comparing alias with original type. + discard + +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: Ordinal](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. + ## ```nim + ## let node = mightBeEmpty() or mightAlsoBeEmpty() or fallbackNode + ## ``` + + let arg = x + if arg != nil and arg.kind != nnkEmpty: + arg + else: + y + +proc add*(father, child: NimNode): NimNode {.magic: "NAdd", discardable, + noSideEffect.} + ## 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.} + ## 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.} + ## Returns an integer value from any integer literal or enum field symbol. + +proc floatVal*(n: NimNode): BiggestFloat {.magic: "NFloatVal", noSideEffect.} + ## Returns a float from any floating point literal. + + +proc symKind*(symbol: NimNode): NimSymKind {.magic: "NSymKind", noSideEffect.} +proc getImpl*(symbol: NimNode): NimNode {.magic: "GetImpl", noSideEffect.} + ## Returns a copy of the declaration of a symbol or `nil`. +proc strVal*(n: NimNode): string {.magic: "NStrVal", noSideEffect.} + ## Returns the string value of an identifier, symbol, comment, or string literal. + ## + ## See also: + ## * `strVal= proc<#strVal=,NimNode,string>`_ for setting the string value. + +{.push warnings: off.} # silence `deprecated` + +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".} + +proc `$`*(i: NimIdent): string {.magic: "NStrVal", noSideEffect, deprecated: + "Deprecated since version 0.18.1; Use 'strVal' instead.".} + ## Converts a Nim identifier to a string. + +proc `$`*(s: NimSym): string {.magic: "NStrVal", noSideEffect, deprecated: + "Deprecated since version 0.18.1; Use 'strVal' instead.".} + ## Converts a Nim symbol to a string. + +{.pop.} + +when (NimMajor, NimMinor, NimPatch) >= (1, 3, 5) or defined(nimSymImplTransform): + proc getImplTransformed*(symbol: NimNode): NimNode {.magic: "GetImplTransf", noSideEffect.} + ## For a typed proc returns the AST after transformation pass; this is useful + ## for debugging how the compiler transforms code (e.g.: `defer`, `for`) but + ## note that code transformations are implementation dependent and subject to change. + ## See an example in `tests/macros/tmacros_various.nim`. + +proc owner*(sym: NimNode): NimNode {.magic: "SymOwner", noSideEffect, deprecated.} + ## Accepts a node of kind `nnkSym` and returns its owner's symbol. + ## The meaning of 'owner' depends on `sym`'s `NimSymKind` and declaration + ## context. For top level declarations this is an `nskModule` symbol, + ## for proc local variables an `nskProc` symbol, for enum/object fields an + ## `nskType` symbol, etc. For symbols without an owner, `nil` is returned. + ## + ## See also: + ## * `symKind proc<#symKind,NimNode>`_ to get the kind of a symbol + ## * `getImpl proc<#getImpl,NimNode>`_ to get the declaration of a symbol + +proc isInstantiationOf*(instanceProcSym, genProcSym: NimNode): bool {.magic: "SymIsInstantiationOf", noSideEffect.} + ## Checks if a proc symbol is an 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.} + ## Version of `getType` which takes a `typedesc`. + +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: + type + 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: + type + 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 = """ +object + arr: array[0 .. 3, float32]""" + doAssert(dumpTypeImpl(a) == t) + doAssert(dumpTypeImpl(b) == t) + doAssert(dumpTypeImpl(c) == t) + +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/variables used in + ## the implementation of this symbol are hashed recursively as well, including + ## magics from system module. + discard + +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.".} + +{.pop.} + +proc `strVal=`*(n: NimNode, val: string) {.magic: "NSetStrVal", noSideEffect.} + ## Sets the string value of a string literal or comment. + ## Setting `strVal` is disallowed for `nnkIdent` and `nnkSym` nodes; a new node + ## must be created using `ident` or `bindSym` instead. + ## + ## See also: + ## * `strVal proc<#strVal,NimNode>`_ for getting the string value. + ## * `ident proc<#ident,string>`_ for creating an identifier. + ## * `bindSym proc<#bindSym%2C%2CBindSymRule>`_ for binding a symbol. + +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.} = + ## Creates a new AST node by copying the node `n`. Note that unlike `copyNimTree`, + ## child nodes of `n` are not copied. + runnableExamples: + macro foo(x: typed) = + var s = copyNimNode(x) + doAssert s.len == 0 + doAssert s.kind == nnkStmtList + + foo: + let x = 12 + echo x + +proc copyNimTree*(n: NimNode): NimNode {.magic: "NCopyNimTree", noSideEffect.} = + ## Creates a new AST node by recursively copying the node `n`. Note that + ## unlike `copyNimNode`, this copies `n`, the children of `n`, etc. + runnableExamples: + macro foo(x: typed) = + var s = copyNimTree(x) + doAssert s.len == 2 + doAssert s.kind == nnkStmtList + + foo: + let x = 12 + echo x + +when defined(nimHasNoReturnError): + {.pragma: errorNoReturn, noreturn.} +else: + {.pragma: errorNoReturn.} + +proc error*(msg: string, n: NimNode = nil) {.magic: "NError", benign, errorNoReturn.} + ## 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 {.noSideEffect.} = + ## Creates a string literal node from `s`. + result = newNimNode(nnkStrLit) + result.strVal = s + +proc newCommentStmtNode*(s: string): NimNode {.noSideEffect.} = + ## Creates a comment statement node. + result = newNimNode(nnkCommentStmt) + result.strVal = s + +proc newIntLitNode*(i: BiggestInt): NimNode = + ## Creates an int literal node from `i`. + result = newNimNode(nnkIntLit) + result.intVal = i + +proc newFloatLitNode*(f: BiggestFloat): NimNode = + ## Creates a float literal node from `f`. + result = newNimNode(nnkFloatLit) + result.floatVal = f + +{.push warnings: off.} + +proc newIdentNode*(i: NimIdent): NimNode {.deprecated: "use ident(string)".} = + ## Creates an identifier node from `i`. + result = newNimNode(nnkIdent) + result.ident = i + +{.pop.} + +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. + +proc ident*(name: string): NimNode {.magic: "StrToIdent", noSideEffect.} + ## Create a new ident node from a string. + +type + BindSymRule* = enum ## Specifies how `bindSym` behaves. The difference + ## between open and closed symbols can be found in + ## `<manual.html#symbol-lookup-in-generics-open-and-closed-symbols>`_ + brClosed, ## only the symbols in current scope are bound + brOpen, ## open for 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 `nnkIdent` kind. + ## If `rule == brClosed` either an `nnkClosedSymChoice` tree is + ## returned or `nnkSym` if the symbol is not ambiguous. + ## If `rule == brOpen` either an `nnkOpenSymChoice` tree is + ## returned or `nnkSym` if the symbol is not ambiguous. + ## If `rule == brForceOpen` always an `nnkOpenSymChoice` tree is + ## returned even if the symbol is not ambiguous. + ## + ## See the `manual <manual.html#macros-bindsym>`_ for more details. + +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: + "Deprecated since v0.18.1; use `varargs[untyped]` in the macro prototype instead".} + ## Returns the AST of the invocation expression that invoked this macro. + # see https://github.com/nim-lang/RFCs/issues/387 as candidate replacement. + +proc toStrLit*(n: NimNode): NimNode = + ## Converts the AST `n` to the concrete Nim code and wraps that + ## in a string literal node. + return newStrLitNode(repr(n)) + +type + LineInfo* = object + filename*: string + line*,column*: int + +proc `$`*(arg: LineInfo): string = + ## Return a string representation in the form `filepath(line, column)`. + # 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`. + +proc setLine(arg: NimNode, line: uint16) {.magic: "NLineInfo", noSideEffect.} +proc setColumn(arg: NimNode, column: int16) {.magic: "NLineInfo", noSideEffect.} +proc setFile(arg: NimNode, file: string) {.magic: "NLineInfo", noSideEffect.} + +proc setLineInfo*(arg: NimNode, file: string, line: int, column: int) = + ## Sets the line info on the NimNode. The file needs to exists, but can be a + ## relative path. If you want to attach line info to a block using `quote` + ## you'll need to add the line information after the quote block. + arg.setFile(file) + arg.setLine(line.uint16) + arg.setColumn(column.int16) + +proc setLineInfo*(arg: NimNode, lineInfo: LineInfo) = + ## See `setLineInfo proc<#setLineInfo,NimNode,string,int,int>`_ + setLineInfo(arg, lineInfo.filename, lineInfo.line, lineInfo.column) + +proc lineInfoObj*(n: NimNode): LineInfo = + ## Returns `LineInfo` of `n`, using absolute path for `filename`. + result = LineInfo(filename: n.getFile, line: n.getLine, column: n.getColumn) + +proc lineInfo*(arg: NimNode): string = + ## Return line info in the form `filepath(line, column)`. + $arg.lineInfoObj + +proc internalParseExpr(s, filename: string): NimNode {. + magic: "ParseExprToAst", noSideEffect.} + +proc internalParseStmt(s, filename: 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; filename: string = ""): NimNode {.noSideEffect.} = + ## Compiles the passed string to its AST representation. + ## Expects a single expression. Raises `ValueError` for parsing errors. + ## A filename can be given for more informative errors. + result = internalParseExpr(s, filename) + let x = internalErrorFlag() + if x.len > 0: raise newException(ValueError, x) + +proc parseStmt*(s: string; filename: string = ""): NimNode {.noSideEffect.} = + ## Compiles the passed string to its AST representation. + ## Expects one or more statements. Raises `ValueError` for parsing errors. + ## A filename can be given for more informative errors. + result = internalParseStmt(s, filename) + 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. + ## See also `genasts.genAst`. + ## Example: + ## ```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. The original meaning of the interpolation + ## operator may be obtained by escaping it (by prefixing it with itself) when used + ## as a unary operator: + ## e.g. `@` is escaped as `@@`, `&%` is escaped as `&%&%` and so on; see examples. + ## + ## A custom operator interpolation needs accent quoted (``) whenever it resolves + ## to a symbol. + ## + ## See also `genasts <genasts.html>`_ which avoids some issues with `quote`. + runnableExamples: + macro check(ex: untyped) = + # 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` + check 1 + 1 == 2 + + runnableExamples: + # example showing how to define a symbol that requires backtick without + # quoting it. + var destroyCalled = false + macro bar() = + let s = newTree(nnkAccQuoted, ident"=destroy") + # let s = ident"`=destroy`" # this would not work + result = quote do: + type Foo = object + # proc `=destroy`(a: var Foo) = destroyCalled = true # this would not work + proc `s`(a: var Foo) = destroyCalled = true + block: + let a = Foo() + bar() + doAssert destroyCalled + + runnableExamples: + # custom `op` + var destroyCalled = false + macro bar(ident) = + var x = 1.5 + result = quote("@") do: + type Foo = object + let `@ident` = 0 # custom op interpolated symbols need quoted (``) + proc `=destroy`(a: var Foo) = + doAssert @x == 1.5 + doAssert compiles(@x == 1.5) + let b1 = @[1,2] + let b2 = @@[1,2] + doAssert $b1 == "[1, 2]" + doAssert $b2 == "@[1, 2]" + destroyCalled = true + block: + let a = Foo() + bar(someident) + doAssert destroyCalled + + proc `&%`(x: int): int = 1 + proc `&%`(x, y: int): int = 2 + + macro bar2() = + var x = 3 + result = quote("&%") do: + var y = &%x # quoting operator + doAssert &%&%y == 1 # unary operator => need to escape + doAssert y &% y == 2 # binary operator => no need to escape + doAssert y == 3 + bar2() + +proc expectKind*(n: NimNode, k: NimNodeKind) = + ## 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) = + ## 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("Expected a node with at least " & $min & " children, got " & $n.len, n) + +proc expectLen*(n: NimNode, len: int) = + ## 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("Expected a node with " & $len & " children, got " & $n.len, n) + +proc expectLen*(n: NimNode, min, max: int) = + ## 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("Expected a node with " & $min & ".." & $max & " children, got " & $n.len, n) + +proc newTree*(kind: NimNodeKind, + children: varargs[NimNode]): NimNode = + ## Produces a new node with children. + result = newNimNode(kind) + result.add(children) + +proc newCall*(theProc: NimNode, args: varargs[NimNode]): NimNode = + ## 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 {.deprecated: + "Deprecated since v0.18.1; use 'newCall(string, ...)' or 'newCall(NimNode, ...)' instead".} = + ## 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) + +{.pop.} + +proc newCall*(theProc: string, + args: varargs[NimNode]): NimNode = + ## 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 = + ## Produces a new character literal node. + result = newNimNode(nnkCharLit) + result.intVal = ord(c) + +proc newLit*(i: int): NimNode = + ## Produces a new integer literal node. + result = newNimNode(nnkIntLit) + result.intVal = i + +proc newLit*(i: int8): NimNode = + ## Produces a new integer literal node. + result = newNimNode(nnkInt8Lit) + result.intVal = i + +proc newLit*(i: int16): NimNode = + ## Produces a new integer literal node. + result = newNimNode(nnkInt16Lit) + result.intVal = i + +proc newLit*(i: int32): NimNode = + ## Produces a new integer literal node. + result = newNimNode(nnkInt32Lit) + result.intVal = i + +proc newLit*(i: int64): NimNode = + ## Produces a new integer literal node. + result = newNimNode(nnkInt64Lit) + result.intVal = i + +proc newLit*(i: uint): NimNode = + ## Produces a new unsigned integer literal node. + result = newNimNode(nnkUIntLit) + result.intVal = BiggestInt(i) + +proc newLit*(i: uint8): NimNode = + ## Produces a new unsigned integer literal node. + result = newNimNode(nnkUInt8Lit) + result.intVal = BiggestInt(i) + +proc newLit*(i: uint16): NimNode = + ## Produces a new unsigned integer literal node. + result = newNimNode(nnkUInt16Lit) + result.intVal = BiggestInt(i) + +proc newLit*(i: uint32): NimNode = + ## Produces a new unsigned integer literal node. + result = newNimNode(nnkUInt32Lit) + result.intVal = BiggestInt(i) + +proc newLit*(i: uint64): NimNode = + ## Produces a new unsigned integer literal node. + result = newNimNode(nnkUInt64Lit) + result.intVal = BiggestInt(i) + +proc newLit*(b: bool): NimNode = + ## Produces a new boolean literal node. + result = if b: bindSym"true" else: bindSym"false" + +proc newLit*(s: string): NimNode = + ## Produces a new string literal node. + result = newNimNode(nnkStrLit) + result.strVal = s + +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 = + ## Produces a new float literal node. + result = newNimNode(nnkFloatLit) + result.floatVal = f + +proc newLit*(f: float32): NimNode = + ## Produces a new float literal node. + result = newNimNode(nnkFloat32Lit) + result.floatVal = f + +proc newLit*(f: float64): NimNode = + ## Produces a new float literal node. + result = newNimNode(nnkFloat64Lit) + result.floatVal = f + +when declared(float128): + proc newLit*(f: float128): NimNode = + ## Produces a new float literal node. + result = newNimNode(nnkFloat128Lit) + result.floatVal = f + +proc newLit*(arg: enum): NimNode = + result = newCall( + arg.typeof.getTypeInst[1], + newLit(int(arg)) + ) + +proc newLit*[N,T](arg: array[N,T]): NimNode +proc newLit*[T](arg: seq[T]): NimNode +proc newLit*[T](s: set[T]): NimNode +proc newLit*[T: tuple](arg: T): NimNode + +proc newLit*(arg: object): NimNode = + result = nnkObjConstr.newTree(arg.typeof.getTypeInst[1]) + for a, b in arg.fieldPairs: + result.add nnkExprColonExpr.newTree( newIdentNode(a), newLit(b) ) + +proc newLit*(arg: ref object): NimNode = + ## produces a new ref type literal node. + result = nnkObjConstr.newTree(arg.typeof.getTypeInst[1]) + for a, b in fieldPairs(arg[]): + result.add nnkExprColonExpr.newTree(newIdentNode(a), newLit(b)) + +proc newLit*[N,T](arg: array[N,T]): NimNode = + result = nnkBracket.newTree + for x in arg: + result.add newLit(x) + +proc newLit*[T](arg: seq[T]): NimNode = + let bracket = nnkBracket.newTree + for x in arg: + bracket.add newLit(x) + result = nnkPrefix.newTree( + bindSym"@", + bracket + ) + if arg.len == 0: + # add type cast for empty seq + var typ = getTypeInst(typeof(arg))[1] + result = newCall(typ,result) + +proc newLit*[T](s: set[T]): NimNode = + result = nnkCurly.newTree + for x in s: + result.add newLit(x) + if result.len == 0: + # add type cast for empty set + var typ = getTypeInst(typeof(s))[1] + result = newCall(typ,result) + +proc isNamedTuple(T: typedesc): bool {.magic: "TypeTrait".} + ## See `typetraits.isNamedTuple` + +proc newLit*[T: tuple](arg: T): NimNode = + ## use -d:nimHasWorkaround14720 to restore behavior prior to PR, forcing + ## a named tuple even when `arg` is unnamed. + result = nnkTupleConstr.newTree + when defined(nimHasWorkaround14720) or isNamedTuple(T): + for a, b in arg.fieldPairs: + result.add nnkExprColonExpr.newTree(newIdentNode(a), newLit(b)) + else: + for b in arg.fields: + result.add newLit(b) + +proc nestList*(op: NimNode; pack: NimNode): NimNode = + ## 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 = + ## 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) + +proc eqIdent*(a: string; b: string): bool {.magic: "EqIdent", noSideEffect.} + ## Style insensitive comparison. + +proc eqIdent*(a: NimNode; b: string): bool {.magic: "EqIdent", noSideEffect.} + ## Style insensitive comparison. `a` can be an identifier or a + ## symbol. `a` may be wrapped in an export marker + ## (`nnkPostfix`) or quoted with backticks (`nnkAccQuoted`), + ## these nodes will be unwrapped. + +proc eqIdent*(a: string; b: NimNode): bool {.magic: "EqIdent", noSideEffect.} + ## Style insensitive comparison. `b` can be an identifier or a + ## symbol. `b` may be wrapped in an export marker + ## (`nnkPostfix`) or quoted with backticks (`nnkAccQuoted`), + ## these nodes will be unwrapped. + +proc eqIdent*(a: NimNode; b: NimNode): bool {.magic: "EqIdent", noSideEffect.} + ## Style insensitive comparison. `a` and `b` can be an + ## identifier or a symbol. Both may be wrapped in an export marker + ## (`nnkPostfix`) or quoted with backticks (`nnkAccQuoted`), + ## these nodes will be unwrapped. + +const collapseSymChoice = not defined(nimLegacyMacrosCollapseSymChoice) + +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 + else: + 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 nnkUIntLit .. nnkUInt64Lit: + res.add(" " & $cast[uint64](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 + elif n.kind in {nnkOpenSymChoice, nnkClosedSymChoice} and collapseSymChoice: + res.add(" " & $n.len) + if n.len > 0: + var allSameSymName = true + for i in 0..<n.len: + if n[i].kind != nnkSym or not eqIdent(n[i], n[0]): + allSameSymName = false + break + if allSameSymName: + res.add(" " & $n[0].strVal.newLit.repr) + else: + for j in 0 ..< n.len: + n[j].treeTraverse(res, level+1, isLisp, indented) + else: + for j in 0 ..< n.len: + n[j].treeTraverse(res, level+1, isLisp, indented) + + if isLisp: + res.add(")") + +proc treeRepr*(n: NimNode): string {.benign.} = + ## Convert the AST `n` to a human-readable tree-like string. + ## + ## See also `repr`, `lispRepr`_, and `astGenRepr`_. + result = "" + n.treeTraverse(result, isLisp = false, indented = true) + +proc lispRepr*(n: NimNode; indented = false): string {.benign.} = + ## Convert the AST `n` to a human-readable lisp-like string. + ## + ## See also `repr`, `treeRepr`_, and `astGenRepr`_. + result = "" + n.treeTraverse(result, isLisp = true, indented = indented) + +proc astGenRepr*(n: NimNode): string {.benign.} = + ## Convert the AST `n` to the code required to generate that AST. + ## + ## See also `repr`_, `treeRepr`_, and `lispRepr`_. + + const + NodeKinds = {nnkEmpty, nnkIdent, nnkSym, nnkNone, nnkCommentStmt} + LitKinds = {nnkCharLit..nnkInt64Lit, nnkFloatLit..nnkFloat64Lit, nnkStrLit..nnkTripleStrLit} + + proc traverse(res: var string, level: int, n: NimNode) {.benign.} = + for i in 0..level-1: res.add " " + if n.kind in NodeKinds: + res.add("new" & ($n.kind).substr(3) & "Node(") + elif n.kind in LitKinds: + res.add("newLit(") + elif n.kind == nnkNilLit: + res.add("newNilLit()") + else: + 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 + elif n.kind in {nnkOpenSymChoice, nnkClosedSymChoice} and collapseSymChoice: + res.add(", # unrepresentable symbols: " & $n.len) + if n.len > 0: + res.add(" " & n[0].strVal.newLit.repr) + else: + 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: + ## ```nim + ## dumpTree: + ## echo "Hello, World!" + ## ``` + ## + ## Outputs: + ## ``` + ## 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: + ## ```nim + ## dumpLisp: + ## echo "Hello, World!" + ## ``` + ## + ## Outputs: + ## ``` + ## (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: + ## ```nim + ## dumpAstGen: + ## echo "Hello, World!" + ## ``` + ## + ## Outputs: + ## ``` + ## nnkStmtList.newTree( + ## nnkCommand.newTree( + ## newIdentNode("echo"), + ## newLit("Hello, World!") + ## ) + ## ) + ## ``` + ## + ## Also see `dumpTree` and `dumpLisp`. + +proc newEmptyNode*(): NimNode {.noSideEffect.} = + ## Create a new empty node. + result = newNimNode(nnkEmpty) + +proc newStmtList*(stmts: varargs[NimNode]): NimNode = + ## Create a new statement list. + result = newNimNode(nnkStmtList).add(stmts) + +proc newPar*(exprs: NimNode): NimNode = + ## Create a new parentheses-enclosed expression. + newNimNode(nnkPar).add(exprs) + +proc newPar*(exprs: varargs[NimNode]): NimNode {.deprecated: + "don't use newPar/nnkPar to construct tuple expressions; use nnkTupleConstr instead".} = + ## Create a new parentheses-enclosed expression. + newNimNode(nnkPar).add(exprs) + +proc newBlockStmt*(label, body: NimNode): NimNode = + ## Create a new block statement with label. + return newNimNode(nnkBlockStmt).add(label, body) + +proc newBlockStmt*(body: NimNode): NimNode = + ## Create a new block: stmt. + return newNimNode(nnkBlockStmt).add(newEmptyNode(), body) + +proc newVarStmt*(name, value: NimNode): NimNode = + ## Create a new var stmt. + return newNimNode(nnkVarSection).add( + newNimNode(nnkIdentDefs).add(name, newNimNode(nnkEmpty), value)) + +proc newLetStmt*(name, value: NimNode): NimNode = + ## Create a new let stmt. + return newNimNode(nnkLetSection).add( + newNimNode(nnkIdentDefs).add(name, newNimNode(nnkEmpty), value)) + +proc newConstStmt*(name, value: NimNode): NimNode = + ## Create a new const stmt. + newNimNode(nnkConstSection).add( + newNimNode(nnkConstDef).add(name, newNimNode(nnkEmpty), value)) + +proc newAssignment*(lhs, rhs: NimNode): NimNode = + return newNimNode(nnkAsgn).add(lhs, rhs) + +proc newDotExpr*(a, b: NimNode): NimNode = + ## Create new dot expression. + ## a.dot(b) -> `a.b` + return newNimNode(nnkDotExpr).add(a, b) + +proc newColonExpr*(a, b: NimNode): NimNode = + ## Create new colon expression. + ## newColonExpr(a, b) -> `a: b` + newNimNode(nnkExprColonExpr).add(a, b) + +proc newIdentDefs*(name, kind: NimNode; + default = newEmptyNode()): NimNode = + ## Creates a new `nnkIdentDefs` node of a specific kind and value. + ## + ## `nnkIdentDefs` need to have at least three children, but they can have + ## more: first comes a list of identifiers followed by a type and value + ## nodes. This helper proc creates a three node subtree, the first subnode + ## being a single identifier name. Both the `kind` node and `default` + ## (value) nodes may be empty depending on where the `nnkIdentDefs` + ## appears: tuple or object definitions will have an empty `default` node, + ## `let` or `var` blocks may have an empty `kind` node if the + ## identifier is being assigned a value. Example: + ## + ## ```nim + ## var varSection = newNimNode(nnkVarSection).add( + ## newIdentDefs(ident("a"), ident("string")), + ## newIdentDefs(ident("b"), newEmptyNode(), newLit(3))) + ## # --> var + ## # a: string + ## # b = 3 + ## ``` + ## + ## If you need to create multiple identifiers you need to use the lower level + ## `newNimNode`: + ## ```nim + ## result = newNimNode(nnkIdentDefs).add( + ## ident("a"), ident("b"), ident("c"), ident("string"), + ## newStrLitNode("Hello")) + ## ``` + newNimNode(nnkIdentDefs).add(name, kind, default) + +proc newNilLit*(): NimNode = + ## New nil literal shortcut. + result = newNimNode(nnkNilLit) + +proc last*(node: NimNode): NimNode = node[node.len-1] + ## Return the last item in nodes children. Same as `node[^1]`. + + +const + RoutineNodes* = {nnkProcDef, nnkFuncDef, nnkMethodDef, nnkDo, nnkLambda, + nnkIteratorDef, nnkTemplateDef, nnkConverterDef, nnkMacroDef} + AtomicNodes* = {nnkNone..nnkNilLit} + # see matching set nnkCallKinds above + CallNodes* = nnkCallKinds + +proc expectKind*(n: NimNode; k: set[NimNodeKind]) = + ## 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 notin k: error("Expected one of " & $k & ", got " & $n.kind, n) + +proc newProc*(name = newEmptyNode(); + params: openArray[NimNode] = [newEmptyNode()]; + body: NimNode = newStmtList(); + procType = nnkProcDef; + pragmas: NimNode = newEmptyNode()): NimNode = + ## Shortcut for creating a new proc. + ## + ## The `params` array must start with the return type of the proc, + ## followed by a list of IdentDefs which specify the params. + if procType notin RoutineNodes: + error("Expected one of " & $RoutineNodes & ", got " & $procType) + pragmas.expectKind({nnkEmpty, nnkPragma}) + result = newNimNode(procType).add( + name, + newEmptyNode(), + newEmptyNode(), + newNimNode(nnkFormalParams).add(params), + pragmas, + newEmptyNode(), + body) + +proc newIfStmt*(branches: varargs[tuple[cond, body: NimNode]]): NimNode = + ## Constructor for `if` statements. + ## ```nim + ## newIfStmt( + ## (Ident, StmtList), + ## ... + ## ) + ## ``` + result = newNimNode(nnkIfStmt) + if len(branches) < 1: + error("If statement must have at least one branch") + for i in branches: + result.add(newTree(nnkElifBranch, i.cond, i.body)) + +proc newEnum*(name: NimNode, fields: openArray[NimNode], + public, pure: bool): NimNode = + + ## Creates a new enum. `name` must be an ident. Fields are allowed to be + ## either idents or EnumFieldDef: + ## ```nim + ## newEnum( + ## name = ident("Colors"), + ## fields = [ident("Blue"), ident("Red")], + ## public = true, pure = false) + ## + ## # type Colors* = Blue Red + ## ``` + + expectKind name, nnkIdent + if len(fields) < 1: + error("Enum must contain at least one field") + for field in fields: + expectKind field, {nnkIdent, nnkEnumFieldDef} + + let enumBody = newNimNode(nnkEnumTy).add(newEmptyNode()).add(fields) + var typeDefArgs = [name, newEmptyNode(), enumBody] + + if public: + let postNode = newNimNode(nnkPostfix).add( + newIdentNode("*"), typeDefArgs[0]) + + typeDefArgs[0] = postNode + + if pure: + let pragmaNode = newNimNode(nnkPragmaExpr).add( + typeDefArgs[0], + add(newNimNode(nnkPragma), newIdentNode("pure"))) + + typeDefArgs[0] = pragmaNode + + let + typeDef = add(newNimNode(nnkTypeDef), typeDefArgs) + typeSect = add(newNimNode(nnkTypeSection), typeDef) + + return typeSect + +proc copyChildrenTo*(src, dest: NimNode) = + ## Copy all children from `src` to `dest`. + for i in 0 ..< src.len: + dest.add src[i].copyNimTree + +template expectRoutine(node: NimNode) = + expectKind(node, RoutineNodes) + +proc name*(someProc: NimNode): NimNode = + someProc.expectRoutine + result = someProc[0] + if result.kind == nnkPostfix: + if result[1].kind == nnkAccQuoted: + result = result[1][0] + else: + result = result[1] + elif result.kind == nnkAccQuoted: + result = result[0] + +proc `name=`*(someProc: NimNode; val: NimNode) = + someProc.expectRoutine + if someProc[0].kind == nnkPostfix: + someProc[0][1] = val + else: someProc[0] = val + +proc params*(someProc: NimNode): NimNode = + if someProc.kind == nnkProcTy: + someProc[0] + else: + someProc.expectRoutine + someProc[3] + +proc `params=`* (someProc: NimNode; params: NimNode) = + expectKind(params, nnkFormalParams) + if someProc.kind == nnkProcTy: + someProc[0] = params + else: + someProc.expectRoutine + someProc[3] = params + +proc pragma*(someProc: NimNode): NimNode = + ## Get the pragma of a proc type. + ## These will be expanded. + if someProc.kind == nnkProcTy: + result = someProc[1] + else: + someProc.expectRoutine + result = someProc[4] +proc `pragma=`*(someProc: NimNode; val: NimNode) = + ## Set the pragma of a proc type. + expectKind(val, {nnkEmpty, nnkPragma}) + if someProc.kind == nnkProcTy: + someProc[1] = val + else: + someProc.expectRoutine + someProc[4] = val + +proc addPragma*(someProc, pragma: NimNode) = + ## Adds pragma to routine definition. + someProc.expectKind(RoutineNodes + {nnkProcTy}) + var pragmaNode = someProc.pragma + if pragmaNode.isNil or pragmaNode.kind == nnkEmpty: + pragmaNode = newNimNode(nnkPragma) + someProc.pragma = pragmaNode + pragmaNode.add(pragma) + +template badNodeKind(n, f) = + error("Invalid node kind " & $n.kind & " for macros.`" & $f & "`", n) + +proc body*(someProc: NimNode): NimNode = + case someProc.kind: + of RoutineNodes: + return someProc[6] + of nnkBlockStmt, nnkWhileStmt: + return someProc[1] + of nnkForStmt: + return someProc.last + else: + badNodeKind someProc, "body" + +proc `body=`*(someProc: NimNode, val: NimNode) = + case someProc.kind + of RoutineNodes: + someProc[6] = val + of nnkBlockStmt, nnkWhileStmt: + someProc[1] = val + of nnkForStmt: + someProc[len(someProc)-1] = val + else: + badNodeKind someProc, "body=" + +proc basename*(a: NimNode): NimNode = + ## Pull an identifier from prefix/postfix expressions. + case a.kind + of nnkIdent: result = a + of nnkPostfix, nnkPrefix: result = a[1] + of nnkPragmaExpr: result = basename(a[0]) + else: + error("Do not know how to get basename of (" & treeRepr(a) & ")\n" & + repr(a), a) + +proc `$`*(node: NimNode): string = + ## Get the string of an identifier node. + case node.kind + of nnkPostfix: + result = node.basename.strVal & "*" + of nnkStrLit..nnkTripleStrLit, nnkCommentStmt, nnkSym, nnkIdent: + result = node.strVal + of nnkOpenSymChoice, nnkClosedSymChoice, nnkOpenSym: + result = $node[0] + of nnkAccQuoted: + result = "" + for i in 0 ..< node.len: + result.add(repr(node[i])) + else: + badNodeKind node, "$" + +iterator items*(n: NimNode): NimNode {.inline.} = + ## Iterates over the children of the NimNode `n`. + for i in 0 ..< n.len: + yield n[i] + +iterator pairs*(n: NimNode): (int, NimNode) {.inline.} = + ## Iterates over the children of the NimNode `n` and its indices. + for i in 0 ..< n.len: + yield (i, n[i]) + +iterator children*(n: NimNode): NimNode {.inline.} = + ## Iterates over the children of the NimNode `n`. + for i in 0 ..< n.len: + yield n[i] + +template findChild*(n: NimNode; cond: untyped): NimNode {.dirty.} = + ## Find the first child node matching condition (or nil). + ## ```nim + ## var res = findChild(n, it.kind == nnkPostfix and + ## it.basename.ident == ident"foo") + ## ``` + block: + var res: NimNode + for it in n.children: + if cond: + res = it + break + res + +proc insert*(a: NimNode; pos: int; b: NimNode) = + ## Insert node `b` into node `a` at `pos`. + if len(a)-1 < pos: + # add some empty nodes first + for i in len(a)-1..pos-2: + a.add newEmptyNode() + a.add b + else: + # push the last item onto the list again + # and shift each item down to pos up one + a.add(a[a.len-1]) + for i in countdown(len(a) - 3, pos): + a[i + 1] = a[i] + a[pos] = b + +proc `basename=`*(a: NimNode; val: string) = + case a.kind + of nnkIdent: + a.strVal = val + of nnkPostfix, nnkPrefix: + a[1] = ident(val) + of nnkPragmaExpr: `basename=`(a[0], val) + else: + error("Do not know how to get basename of (" & treeRepr(a) & ")\n" & + repr(a), a) + +proc postfix*(node: NimNode; op: string): NimNode = + newNimNode(nnkPostfix).add(ident(op), node) + +proc prefix*(node: NimNode; op: string): NimNode = + newNimNode(nnkPrefix).add(ident(op), node) + +proc infix*(a: NimNode; op: string; + b: NimNode): NimNode = + newNimNode(nnkInfix).add(ident(op), a, b) + +proc unpackPostfix*(node: NimNode): tuple[node: NimNode; op: string] = + node.expectKind nnkPostfix + result = (node[1], $node[0]) + +proc unpackPrefix*(node: NimNode): tuple[node: NimNode; op: string] = + node.expectKind nnkPrefix + result = (node[1], $node[0]) + +proc unpackInfix*(node: NimNode): tuple[left: NimNode; op: string; right: NimNode] = + expectKind(node, nnkInfix) + result = (node[1], $node[0], node[2]) + +proc copy*(node: NimNode): NimNode = + ## An alias for `copyNimTree<#copyNimTree,NimNode>`_. + return node.copyNimTree() + +proc expectIdent*(n: NimNode, name: string) {.since: (1,1).} = + ## Check that `eqIdent(n,name)` holds true. If this is not the + ## case, compilation aborts with an error message. This is useful + ## for writing macros that check the AST that is passed to them. + if not eqIdent(n, name): + error("Expected identifier to be `" & name & "` here", n) + +proc hasArgOfName*(params: NimNode; name: string): bool = + ## Search `nnkFormalParams` for an argument. + expectKind(params, nnkFormalParams) + for i in 1..<params.len: + for j in 0..<params[i].len-2: + if name.eqIdent($params[i][j]): + return true + +proc addIdentIfAbsent*(dest: NimNode, ident: string) = + ## Add `ident` to `dest` if it is not present. This is intended for use + ## with pragmas. + for node in dest.children: + case node.kind + of nnkIdent: + if ident.eqIdent($node): return + of nnkExprColonExpr: + if ident.eqIdent($node[0]): return + else: discard + dest.add(ident(ident)) + +proc boolVal*(n: NimNode): bool {.noSideEffect.} = + if n.kind == nnkIntLit: n.intVal != 0 + else: n == bindSym"true" # hacky solution for now + +proc nodeID*(n: NimNode): int {.magic: "NodeId".} + ## Returns the id of `n`, when the compiler has been compiled + ## with the flag `-d:useNodeids`, otherwise returns `-1`. This + ## proc is for the purpose to debug the compiler only. + +macro expandMacros*(body: typed): untyped = + ## Expands one level of macro - useful for debugging. + ## Can be used to inspect what happens when a macro call is expanded, + ## without altering its result. + ## + ## For instance, + ## + ## ```nim + ## import std/[sugar, macros] + ## + ## let + ## x = 10 + ## y = 20 + ## expandMacros: + ## dump(x + y) + ## ``` + ## + ## will actually dump `x + y`, but at the same time will print at + ## compile time the expansion of the `dump` macro, which in this + ## case is `debugEcho ["x + y", " = ", x + y]`. + echo body.toStrLit + result = body + +proc extractTypeImpl(n: NimNode): NimNode = + ## attempts to extract the type definition of the given symbol + case n.kind + of nnkSym: # can extract an impl + result = n.getImpl.extractTypeImpl() + of nnkObjectTy, nnkRefTy, nnkPtrTy: result = n + of nnkBracketExpr: + if n.typeKind == ntyTypeDesc: + result = n[1].extractTypeImpl() + else: + doAssert n.typeKind == ntyGenericInst + result = n[0].getImpl() + of nnkTypeDef: + result = n[2] + else: error("Invalid node to retrieve type implementation of: " & $n.kind) + +proc customPragmaNode(n: NimNode): NimNode = + expectKind(n, {nnkSym, nnkDotExpr, nnkBracketExpr, nnkTypeOfExpr, nnkType, nnkCheckedFieldExpr}) + let + typ = n.getTypeInst() + + if typ.kind == nnkBracketExpr and typ.len > 1 and typ[1].kind == nnkProcTy: + return typ[1][1] + elif typ.typeKind == ntyTypeDesc: + let impl = getImpl( + if kind(typ[1]) == nnkBracketExpr: typ[1][0] + else: typ[1] + ) + if impl.kind == nnkNilLit: + return impl + elif impl[0].kind == nnkPragmaExpr: + return impl[0][1] + else: + return impl[0] # handle types which don't have macro at all + + if n.kind == nnkSym: # either an variable or a proc + let impl = n.getImpl() + if impl.kind in RoutineNodes: + return impl.pragma + elif impl.kind in {nnkIdentDefs, nnkConstDef} and impl[0].kind == nnkPragmaExpr: + return impl[0][1] + else: + let timpl = getImpl(if typ.kind == nnkBracketExpr: typ[0] else: typ) + if timpl.len>0 and timpl[0].len>1: + return timpl[0][1] + else: + return timpl + + if n.kind in {nnkDotExpr, nnkCheckedFieldExpr}: + let name = $(if n.kind == nnkCheckedFieldExpr: n[0][1] else: n[1]) + var typInst = getTypeInst(if n.kind == nnkCheckedFieldExpr or n[0].kind == nnkHiddenDeref: n[0][0] else: n[0]) + while typInst.kind in {nnkVarTy, nnkBracketExpr}: typInst = typInst[0] + var typDef = getImpl(typInst) + while typDef != nil: + typDef.expectKind(nnkTypeDef) + let typ = typDef[2].extractTypeImpl() + if typ.kind notin {nnkRefTy, nnkPtrTy, nnkObjectTy}: break + let isRef = typ.kind in {nnkRefTy, nnkPtrTy} + if isRef and typ[0].kind in {nnkSym, nnkBracketExpr}: # defines ref type for another object(e.g. X = ref X) + typDef = getImpl(typ[0]) + else: # object definition, maybe an object directly defined as a ref type + let + obj = (if isRef: typ[0] else: typ) + var identDefsStack = newSeq[NimNode](obj[2].len) + for i in 0..<identDefsStack.len: identDefsStack[i] = obj[2][i] + while identDefsStack.len > 0: + var identDefs = identDefsStack.pop() + + case identDefs.kind + of nnkRecList: + for child in identDefs.children: + identDefsStack.add(child) + of nnkRecCase: + # Add condition definition + identDefsStack.add(identDefs[0]) + # Add branches + for i in 1 ..< identDefs.len: + identDefsStack.add(identDefs[i].last) + else: + for i in 0 .. identDefs.len - 3: + let varNode = identDefs[i] + if varNode.kind == nnkPragmaExpr: + var varName = varNode[0] + if varName.kind == nnkPostfix: + # This is a public field. We are skipping the postfix * + varName = varName[1] + if eqIdent($varName, name): + return varNode[1] + + if obj[1].kind == nnkOfInherit: # explore the parent object + typDef = getImpl(obj[1][0]) + else: + typDef = nil + +macro hasCustomPragma*(n: typed, cp: typed{nkSym}): untyped = + ## Expands to `true` if expression `n` which is expected to be `nnkDotExpr` + ## (if checking a field), a proc or a type has custom pragma `cp`. + ## + ## See also `getCustomPragmaVal`_. + ## + ## ```nim + ## template myAttr() {.pragma.} + ## type + ## MyObj = object + ## myField {.myAttr.}: int + ## + ## proc myProc() {.myAttr.} = discard + ## + ## var o: MyObj + ## assert(o.myField.hasCustomPragma(myAttr)) + ## assert(myProc.hasCustomPragma(myAttr)) + ## ``` + let pragmaNode = customPragmaNode(n) + for p in pragmaNode: + if (p.kind == nnkSym and p == cp) or + (p.kind in nnkPragmaCallKinds and p.len > 0 and p[0].kind == nnkSym and p[0] == cp): + return newLit(true) + return newLit(false) + +macro getCustomPragmaVal*(n: typed, cp: typed{nkSym}): untyped = + ## Expands to value of custom pragma `cp` of expression `n` which is expected + ## to be `nnkDotExpr`, a proc or a type. + ## + ## See also `hasCustomPragma`_. + ## + ## ```nim + ## template serializationKey(key: string) {.pragma.} + ## type + ## MyObj {.serializationKey: "mo".} = object + ## myField {.serializationKey: "mf".}: int + ## var o: MyObj + ## assert(o.myField.getCustomPragmaVal(serializationKey) == "mf") + ## assert(o.getCustomPragmaVal(serializationKey) == "mo") + ## assert(MyObj.getCustomPragmaVal(serializationKey) == "mo") + ## ``` + result = nil + let pragmaNode = customPragmaNode(n) + for p in pragmaNode: + if p.kind in nnkPragmaCallKinds and p.len > 0 and p[0].kind == nnkSym and p[0] == cp: + if p.len == 2 or (p.len == 3 and p[1].kind == nnkSym and p[1].symKind == nskType): + result = p[1] + else: + let def = p[0].getImpl[3] + result = newTree(nnkPar) + for i in 1 ..< def.len: + let key = def[i][0] + let val = p[i] + result.add newTree(nnkExprColonExpr, key, val) + break + if result.kind == nnkEmpty: + error(n.repr & " doesn't have a pragma named " & cp.repr()) # returning an empty node results in most cases in a cryptic error, + +macro unpackVarargs*(callee: untyped; args: varargs[untyped]): untyped = + ## Calls `callee` with `args` unpacked as individual arguments. + ## This is useful in 2 cases: + ## * when forwarding `varargs[T]` for some typed `T` + ## * when forwarding `varargs[untyped]` when `args` can potentially be empty, + ## due to a compiler limitation + runnableExamples: + template call1(fun: typed; args: varargs[untyped]): untyped = + unpackVarargs(fun, args) + # when varargsLen(args) > 0: fun(args) else: fun() # this would also work + template call2(fun: typed; args: varargs[typed]): untyped = + unpackVarargs(fun, args) + proc fn1(a = 0, b = 1) = discard (a, b) + call1(fn1, 10, 11) + call1(fn1) # `args` is empty in this case + if false: call2(echo, 10, 11) # would print 1011 + result = newCall(callee) + for i in 0 ..< args.len: + result.add args[i] + +proc getProjectPath*(): string = discard + ## Returns the path to the currently compiling project. + ## + ## This is not to be confused with `system.currentSourcePath <system.html#currentSourcePath.t>`_ + ## which returns the path of the source file containing that template + ## call. + ## + ## For example, assume a `dir1/foo.nim` that imports a `dir2/bar.nim`, + ## have the `bar.nim` print out both `getProjectPath` and + ## `currentSourcePath` outputs. + ## + ## Now when `foo.nim` is compiled, the `getProjectPath` from + ## `bar.nim` will return the `dir1/` path, while the `currentSourcePath` + ## will return the path to the `bar.nim` source file. + ## + ## Now when `bar.nim` is compiled directly, the `getProjectPath` + ## will now return the `dir2/` path, and the `currentSourcePath` + ## will still return the same path, the path to the `bar.nim` source + ## file. + ## + ## The path returned by this proc is set at compile time. + ## + ## See also: + ## * `getCurrentDir proc <os.html#getCurrentDir>`_ + +proc getSize*(arg: NimNode): int {.magic: "NSizeOf", noSideEffect.} = + ## Returns the same result as `system.sizeof` if the size is + ## known by the Nim compiler. Returns a negative value if the Nim + ## compiler does not know the size. +proc getAlign*(arg: NimNode): int {.magic: "NSizeOf", noSideEffect.} = + ## Returns the same result as `system.alignof` if the alignment + ## is known by the Nim compiler. It works on `NimNode` for use + ## in macro context. Returns a negative value if the Nim compiler + ## does not know the alignment. +proc getOffset*(arg: NimNode): int {.magic: "NSizeOf", noSideEffect.} = + ## Returns the same result as `system.offsetof` if the offset is + ## known by the Nim compiler. It expects a resolved symbol node + ## from a field of a type. Therefore it only requires one argument + ## instead of two. Returns a negative value if the Nim compiler + ## does not know the offset. + +proc isExported*(n: NimNode): bool {.noSideEffect.} = + ## Returns whether the symbol is exported or not. + +proc extractDocCommentsAndRunnables*(n: NimNode): NimNode = + ## returns a `nnkStmtList` containing the top-level doc comments and + ## runnableExamples in `a`, stopping at the first child that is neither. + ## Example: + ## + ## ```nim + ## import std/macros + ## macro transf(a): untyped = + ## result = quote do: + ## proc fun2*() = discard + ## let header = extractDocCommentsAndRunnables(a.body) + ## # correct usage: rest is appended + ## result.body = header + ## result.body.add quote do: discard # just an example + ## # incorrect usage: nesting inside a nnkStmtList: + ## # result.body = quote do: (`header`; discard) + ## + ## proc fun*() {.transf.} = + ## ## first comment + ## runnableExamples: discard + ## runnableExamples: discard + ## ## last comment + ## discard # first statement after doc comments + runnableExamples + ## ## not docgen'd + ## ``` + + result = newStmtList() + for ni in n: + case ni.kind + of nnkCommentStmt: + result.add ni + of nnkCall, nnkCommand: + if ni[0].kind == nnkIdent and ni[0].eqIdent "runnableExamples": + result.add ni + else: break + else: break |