diff options
Diffstat (limited to 'lib/core/macros.nim')
| -rw-r--r-- | lib/core/macros.nim | 1820 |
1 files changed, 1384 insertions, 436 deletions
diff --git a/lib/core/macros.nim b/lib/core/macros.nim index c8cb3d199..7646b165c 100644 --- a/lib/core/macros.nim +++ b/lib/core/macros.nim @@ -8,11 +8,25 @@ # 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 -## .. include:: ../doc/astspec.txt +# If you look for the implementation of the magic symbol +# ``{.magic: "Foo".}``, search for `mFoo` and `opcFoo`. type NimNodeKind* = enum @@ -21,7 +35,7 @@ type nnkInt16Lit, nnkInt32Lit, nnkInt64Lit, nnkUIntLit, nnkUInt8Lit, nnkUInt16Lit, nnkUInt32Lit, nnkUInt64Lit, nnkFloatLit, nnkFloat32Lit, nnkFloat64Lit, nnkFloat128Lit, nnkStrLit, nnkRStrLit, - nnkTripleStrLit, nnkNilLit, nnkMetaNode, nnkDotCall, + nnkTripleStrLit, nnkNilLit, nnkComesFrom, nnkDotCall, nnkCommand, nnkCall, nnkCallStrLit, nnkInfix, nnkPrefix, nnkPostfix, nnkHiddenCallConv, nnkExprEqExpr, @@ -63,19 +77,29 @@ type nnkTupleTy, nnkTupleClassTy, nnkTypeClassTy, nnkStaticTy, nnkRecList, nnkRecCase, nnkRecWhen, nnkRefTy, nnkPtrTy, nnkVarTy, - nnkConstTy, nnkMutableTy, + nnkConstTy, nnkOutTy, nnkDistinctTy, nnkProcTy, nnkIteratorTy, # iterator type - nnkSharedTy, # 'shared T' + nnkSinkAsgn, nnkEnumTy, nnkEnumFieldDef, - nnkArglist, nnkPattern - nnkReturnToken + 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 + NimTypeKind* = enum # some types are no longer used, see ast.nim ntyNone, ntyBool, ntyChar, ntyEmpty, - ntyArrayConstr, ntyNil, ntyExpr, ntyStmt, + ntyAlias, ntyNil, ntyExpr, ntyStmt, ntyTypeDesc, ntyGenericInvocation, ntyGenericBody, ntyGenericInst, ntyGenericParam, ntyDistinct, ntyEnum, ntyOrdinal, ntyArray, ntyObject, ntyTuple, ntySet, @@ -85,97 +109,194 @@ type ntyInt8, ntyInt16, ntyInt32, ntyInt64, ntyFloat, ntyFloat32, ntyFloat64, ntyFloat128, ntyUInt, ntyUInt8, ntyUInt16, ntyUInt32, ntyUInt64, - ntyBigNum, - ntyConst, ntyMutable, ntyVarargs, - ntyIter, + ntyUnused0, ntyUnused1, ntyUnused2, + ntyVarargs, + ntyUncheckedArray, ntyError, - ntyBuiltinTypeClass, ntyConcept, ntyConceptInst, ntyComposite, - ntyAnd, ntyOr, ntyNot + 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, nskMethod, nskIterator, nskClosureIterator, + 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* = object of RootObj - ## represents a Nim identifier in the AST + 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* = ref NimSymObj - ## represents a Nim *symbol* in the compiler; a *symbol* is a looked-up + NimSym* {.deprecated.} = ref NimSymObj + ## Represents a Nim *symbol* in the compiler; a *symbol* is a looked-up ## *ident*. -{.deprecated: [TNimrodNodeKind: NimNodeKind, TNimNodeKinds: NimNodeKinds, - TNimrodTypeKind: NimTypeKind, TNimrodSymKind: NimSymKind, - TNimrodIdent: NimIdent, PNimrodSymbol: NimSym].} const nnkLiterals* = {nnkCharLit..nnkNilLit} + # see matching set CallNodes below nnkCallKinds* = {nnkCall, nnkInfix, nnkPrefix, nnkPostfix, nnkCommand, - nnkCallStrLit} + nnkCallStrLit, nnkHiddenCallConv} + nnkPragmaCallKinds = {nnkExprColonExpr, nnkCall, nnkCallStrLit} -proc `[]`*(n: NimNode, i: int): NimNode {.magic: "NChild", noSideEffect.} - ## get `n`'s `i`'th child. - -proc `[]=`*(n: NimNode, i: int, child: NimNode) {.magic: "NSetChild", - noSideEffect.} - ## set `n`'s `i`'th child to `child`. +{.push warnings: off.} -proc `!`*(s: string): NimIdent {.magic: "StrToIdent", noSideEffect.} - ## constructs an identifier from the string `s` +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 `$`*(i: NimIdent): string {.magic: "IdentToStr", noSideEffect.} - ## converts a Nim identifier to a string +proc `==`*(a, b: NimIdent): bool {.magic: "EqIdent", noSideEffect, deprecated: + "Deprecated since version 0.18.1; Use '==' on 'NimNode' instead.".} + ## Compares two Nim identifiers. -proc `$`*(s: NimSym): string {.magic: "IdentToStr", noSideEffect.} - ## converts a Nim symbol to a string +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: NimIdent): bool {.magic: "EqIdent", noSideEffect.} - ## compares two Nim identifiers +proc `==`*(a, b: NimSym): bool {.magic: "EqNimrodNode", noSideEffect, deprecated: + "Deprecated since version 0.18.1; Use '==(NimNode, NimNode)' instead.".} + ## Compares two Nim symbols. -proc `==`*(a, b: NimNode): bool {.magic: "EqNimrodNode", noSideEffect.} - ## compares two Nim nodes +{.pop.} 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. + ## 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`. + ## 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, locks: 0.} + 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, locks: 0.} + 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`. + ## Deletes `n` children of `father` starting at index `idx`. proc kind*(n: NimNode): NimNodeKind {.magic: "NKind", noSideEffect.} - ## returns the `kind` of the node `n`. + ## 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.} -proc symbol*(n: NimNode): NimSym {.magic: "NSymbol", noSideEffect.} -proc ident*(n: NimNode): NimIdent {.magic: "NIdent", 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 + ## 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 @@ -183,503 +304,1073 @@ proc getType*(n: NimNode): NimNode {.magic: "NGetType", noSideEffect.} ## 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. + ## 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 strVal*(n: NimNode): string {.magic: "NStrVal", noSideEffect.} +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.} -proc `symbol=`*(n: NimNode, val: NimSym) {.magic: "NSetSymbol", noSideEffect.} -proc `ident=`*(n: NimNode, val: NimIdent) {.magic: "NSetIdent", noSideEffect.} -#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, - n: NimNode=nil): NimNode {.magic: "NNewNimNode", noSideEffect.} -proc copyNimNode*(n: NimNode): NimNode {.magic: "NCopyNimNode", noSideEffect.} -proc copyNimTree*(n: NimNode): NimNode {.magic: "NCopyNimTree", noSideEffect.} +{.push warnings: off.} -proc getImpl*(s: NimSym): NimNode {.magic: "GetImpl", noSideEffect.} = - ## retrieve the implementation of a symbol `s`. `s` can be a routine or a - ## const. - discard +proc `symbol=`*(n: NimNode, val: NimSym) {.magic: "NSetSymbol", noSideEffect, deprecated: + "Deprecated since version 0.18.1; Generate a new 'NimNode' with 'genSym' instead.".} -proc error*(msg: string) {.magic: "NError", benign.} - ## writes an error message at compile time +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 warning*(msg: string) {.magic: "NWarning", benign.} - ## writes a warning message at compile time +{.pop.} -proc hint*(msg: string) {.magic: "NHint", benign.} - ## writes a hint message at compile time +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 newStrLitNode*(s: string): NimNode {.compileTime, noSideEffect.} = - ## creates a string literal node from `s` +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 newIntLitNode*(i: BiggestInt): NimNode {.compileTime.} = - ## creates a int literal node from `i` +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 {.compileTime.} = - ## creates a float literal node from `f` +proc newFloatLitNode*(f: BiggestFloat): NimNode = + ## Creates a float literal node from `f`. result = newNimNode(nnkFloatLit) result.floatVal = f -proc newIdentNode*(i: NimIdent): NimNode {.compileTime.} = - ## creates an identifier node from `i` +{.push warnings: off.} + +proc newIdentNode*(i: NimIdent): NimNode {.deprecated: "use ident(string)".} = + ## Creates an identifier node from `i`. result = newNimNode(nnkIdent) result.ident = i -proc newIdentNode*(i: string): NimNode {.compileTime.} = - ## 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 + 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 wrt overloaded symbols, but may be a single + 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) -{.deprecated: [TBindSymRule: BindSymRule].} - -proc bindSym*(ident: string, rule: BindSymRule = brClosed): NimNode {. +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 + ## Creates a node that binds `ident` to a symbol node. The bound symbol ## may be an overloaded symbol. - ## 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 + ## 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 + ## 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.} - ## returns the AST of the invocation expression that invoked this macro. +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 {.compileTime.} = - ## converts the AST `n` to the concrete Nim code and wraps that - ## in a string literal node +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)) -proc lineinfo*(n: NimNode): string {.magic: "NLineInfo", noSideEffect.} - ## returns the position the node appears in the original source file - ## in the form filename(line, col) - -proc internalParseExpr(s: string): NimNode {. +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: string): NimNode {. +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): NimNode {.noSideEffect, compileTime.} = +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. - result = internalParseExpr(s) + ## 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): NimNode {.noSideEffect, compileTime.} = +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. - result = internalParseStmt(s) + ## 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: expr): NimNode {.magic: "ExpandToAst", noSideEffect.} +proc getAst*(macroOrTemplate: untyped): NimNode {.magic: "ExpandToAst", noSideEffect.} ## Obtains the AST nodes returned from a macro or template invocation. + ## See also `genasts.genAst`. ## Example: - ## - ## .. code-block:: nim - ## + ## ```nim ## macro FooMacro() = ## var ast = getAst(BarTemplate()) + ## ``` -proc quote*(bl: stmt, op = "``"): NimNode {.magic: "QuoteAst", noSideEffect.} +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): - ## e.g. `@` is escaped as `@@`, `@@` is escaped as `@@@` and so on. + ## 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. ## - ## Example: + ## A custom operator interpolation needs accent quoted (``) whenever it resolves + ## to a symbol. ## - ## .. code-block:: nim - ## - ## macro check(ex: expr): stmt = - ## # 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, + ## 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) + 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, +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("macro expects a node with " & $min & " children") + if n.len < min: error("Expected a node with at least " & $min & " children, got " & $n.len, n) -proc expectLen*(n: NimNode, len: int) {.compileTime.} = - ## checks that `n` has exactly `len` children. If this is not the case, +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("macro expects a node with " & $len & " children") + 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 {.compileTime.} = - ## produces a new node with children. + children: varargs[NimNode]): NimNode = + ## 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..]``. +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) -proc newCall*(theProc: NimIdent, - args: varargs[NimNode]): NimNode {.compileTime.} = - ## produces a new call node. `theProc` is the proc that is called with - ## the arguments ``args[0..]``. +{.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 {.compileTime.} = - ## produces a new call node. `theProc` is the proc that is called with - ## the arguments ``args[0..]``. + 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 {.compileTime.} = - ## produces a new character literal node. +proc newLit*(c: char): NimNode = + ## Produces a new character literal node. result = newNimNode(nnkCharLit) result.intVal = ord(c) -proc newLit*(i: BiggestInt): NimNode {.compileTime.} = - ## produces a new integer literal node. +proc newLit*(i: int): NimNode = + ## Produces a new integer literal node. result = newNimNode(nnkIntLit) result.intVal = i -proc newLit*(b: bool): NimNode {.compileTime.} = - ## produces a new boolean literal node. - result = if b: bindSym"true" else: bindSym"false" +proc newLit*(i: int8): NimNode = + ## Produces a new integer literal node. + result = newNimNode(nnkInt8Lit) + result.intVal = i -proc newLit*(f: BiggestFloat): NimNode {.compileTime.} = - ## produces a new float literal node. - result = newNimNode(nnkFloatLit) - result.floatVal = f +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*(s: string): NimNode {.compileTime.} = - ## produces a new string literal node. +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 -proc nestList*(theProc: NimIdent, - x: NimNode): NimNode {.compileTime.} = - ## nests the list `x` into a tree of call expressions: - ## ``[a, b, c]`` is transformed into ``theProc(a, theProc(c, d))``. - var L = x.len - result = newCall(theProc, x[L-2], x[L-1]) - for i in countdown(L-3, 0): - # XXX the 'copyNimTree' here is necessary due to a bug in the evaluation - # engine that would otherwise create an endless loop here. :-( - # This could easily user code and so should be fixed in evals.nim somehow. - result = newCall(theProc, x[i], copyNimTree(result)) - -proc treeRepr*(n: NimNode): string {.compileTime, benign.} = +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(" " & $n[0].strVal.newLit.repr) + else: + for j in 0 ..< n.len: + n[j].treeTraverse(res, level+1, isLisp, indented) + else: + for j in 0 ..< n.len: + n[j].treeTraverse(res, level+1, isLisp, indented) + + if isLisp: + res.add(")") + +proc treeRepr*(n: NimNode): string {.benign.} = ## Convert the AST `n` to a human-readable tree-like string. ## - ## See also `repr` and `lispRepr`. + ## See also `repr`, `lispRepr`_, and `astGenRepr`_. + result = "" + n.treeTraverse(result, isLisp = false, indented = true) + +proc lispRepr*(n: NimNode; indented = false): string {.benign.} = + ## Convert the AST `n` to a human-readable lisp-like string. + ## + ## See also `repr`, `treeRepr`_, and `astGenRepr`_. + result = "" + n.treeTraverse(result, isLisp = true, indented = indented) + +proc astGenRepr*(n: NimNode): string {.benign.} = + ## Convert the AST `n` to the code required to generate that AST. + ## + ## See also `repr`_, `treeRepr`_, and `lispRepr`_. + + const + NodeKinds = {nnkEmpty, nnkIdent, nnkSym, nnkNone, nnkCommentStmt} + LitKinds = {nnkCharLit..nnkInt64Lit, nnkFloatLit..nnkFloat64Lit, nnkStrLit..nnkTripleStrLit} + proc traverse(res: var string, level: int, n: NimNode) {.benign.} = for i in 0..level-1: res.add " " - res.add(($n.kind).substr(3)) + 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: discard # same as nil node in this representation - of nnkNilLit: res.add(" nil") - of nnkCharLit..nnkInt64Lit: res.add(" " & $n.intVal) - of nnkFloatLit..nnkFloat64Lit: res.add(" " & $n.floatVal) - of nnkStrLit..nnkTripleStrLit: res.add(" " & $n.strVal) - of nnkIdent: res.add(" !\"" & $n.ident & '"') - of nnkSym: res.add(" \"" & $n.symbol & '"') + 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: " & $n.len) + if n.len > 0: + res.add(" " & n[0].strVal.newLit.repr) else: - for j in 0..n.len-1: + res.add(".newTree(") + for j in 0..<n.len: res.add "\n" traverse(res, level + 1, n[j]) + if j != n.len-1: + res.add(",") + + res.add("\n") + for i in 0..level-1: res.add " " + res.add(")") + + if n.kind in NodeKinds+LitKinds: + res.add(")") result = "" traverse(result, 0, n) -proc lispRepr*(n: NimNode): string {.compileTime, benign.} = - ## Convert the AST `n` to a human-readable lisp-like string, +macro dumpTree*(s: untyped): untyped = echo s.treeRepr + ## Accepts a block of nim code and prints the parsed abstract syntax + ## tree using the `treeRepr` proc. Printing is done *at compile time*. ## - ## See also `repr` and `treeRepr`. - - result = ($n.kind).substr(3) - add(result, "(") - - case n.kind - of nnkEmpty: discard # same as nil node in this representation - of nnkNilLit: add(result, "nil") - of nnkCharLit..nnkInt64Lit: add(result, $n.intVal) - of nnkFloatLit..nnkFloat64Lit: add(result, $n.floatVal) - of nnkStrLit..nnkTripleStrLit: add(result, $n.strVal) - of nnkIdent: add(result, "!\"" & $n.ident & '"') - of nnkSym: add(result, $n.symbol) - of nnkNone: assert false - else: - if n.len > 0: - add(result, lispRepr(n[0])) - for j in 1..n.len-1: - add(result, ", ") - add(result, lispRepr(n[j])) - - add(result, ")") + ## 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 dumpTree*(s: stmt): stmt {.immediate.} = echo s.treeRepr +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 `toTree` function. Printing is done *at compile time*. + ## 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 dumpLisp*(s: stmt): stmt {.immediate.} = echo s.lispRepr +macro dumpAstGen*(s: untyped): untyped = echo s.astGenRepr ## Accepts a block of nim code and prints the parsed abstract syntax - ## tree using the `toLisp` function. Printing is done *at compile time*. + ## tree using the `astGenRepr` proc. Printing is done *at compile time*. ## - ## See `dumpTree`. - -macro dumpTreeImm*(s: stmt): stmt {.immediate, deprecated.} = echo s.treeRepr - ## The ``immediate`` version of `dumpTree`. - -macro dumpLispImm*(s: stmt): stmt {.immediate, deprecated.} = echo s.lispRepr - ## The ``immediate`` version of `dumpLisp`. - + ## 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 {.compileTime, noSideEffect.} = - ## Create a new empty node +proc newEmptyNode*(): NimNode {.noSideEffect.} = + ## Create a new empty node. result = newNimNode(nnkEmpty) -proc newStmtList*(stmts: varargs[NimNode]): NimNode {.compileTime.}= - ## Create a new statement list +proc newStmtList*(stmts: varargs[NimNode]): NimNode = + ## Create a new statement list. result = newNimNode(nnkStmtList).add(stmts) -proc newPar*(exprs: varargs[NimNode]): NimNode {.compileTime.}= - ## Create a new parentheses-enclosed expression +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 {.compileTime.} = - ## Create a new block statement with label +proc newBlockStmt*(label, body: NimNode): NimNode = + ## Create a new block statement with label. return newNimNode(nnkBlockStmt).add(label, body) -proc newBlockStmt*(body: NimNode): NimNode {.compiletime.} = - ## Create a new block: stmt +proc newBlockStmt*(body: NimNode): NimNode = + ## Create a new block: stmt. return newNimNode(nnkBlockStmt).add(newEmptyNode(), body) -proc newVarStmt*(name, value: NimNode): NimNode {.compiletime.} = - ## Create a new var stmt +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 {.compiletime.} = - ## Create a new let stmt +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 {.compileTime.} = - ## Create a new const stmt +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 {.compileTime.} = +proc newAssignment*(lhs, rhs: NimNode): NimNode = return newNimNode(nnkAsgn).add(lhs, rhs) -proc newDotExpr*(a, b: NimNode): NimNode {.compileTime.} = - ## Create new dot expression - ## a.dot(b) -> `a.b` +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 {.compileTime.} = - ## Create new colon expression - ## newColonExpr(a, b) -> `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 {.compileTime.} = - ## Creates a new ``nnkIdentDefs`` node of a specific kind and value. + 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 + ## `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 + ## 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: ## - ## .. code-block:: nim - ## + ## ```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``: - ## - ## .. code-block:: nim - ## + ## `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 {.compileTime.} = - ## New nil literal shortcut +proc newNilLit*(): NimNode = + ## New nil literal shortcut. result = newNimNode(nnkNilLit) -proc last*(node: NimNode): NimNode {.compileTime.} = node[<node.len] - ## Return the last item in nodes children. Same as `node[^1]` +proc last*(node: NimNode): NimNode = node[node.len-1] + ## Return the last item in nodes children. Same as `node[^1]`. const - RoutineNodes* = {nnkProcDef, nnkMethodDef, nnkDo, nnkLambda, nnkIteratorDef} + RoutineNodes* = {nnkProcDef, nnkFuncDef, nnkMethodDef, nnkDo, nnkLambda, + nnkIteratorDef, nnkTemplateDef, nnkConverterDef, nnkMacroDef} AtomicNodes* = {nnkNone..nnkNilLit} - CallNodes* = {nnkCall, nnkInfix, nnkPrefix, nnkPostfix, nnkCommand, - nnkCallStrLit, nnkHiddenCallConv} + # see matching set nnkCallKinds above + CallNodes* = nnkCallKinds -proc expectKind*(n: NimNode; k: set[NimNodeKind]) {.compileTime.} = - assert n.kind in k, "Expected one of " & $k & ", got " & $n.kind - -proc newProc*(name = newEmptyNode(); params: openArray[NimNode] = [newEmptyNode()]; - body: NimNode = newStmtList(), procType = nnkProcDef): NimNode {.compileTime.} = - ## shortcut for creating a new proc +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, + ## The `params` array must start with the return type of the proc, ## followed by a list of IdentDefs which specify the params. - assert procType in RoutineNodes + 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), ##params - newEmptyNode(), ## pragmas + newNimNode(nnkFormalParams).add(params), + pragmas, newEmptyNode(), body) -proc newIfStmt*(branches: varargs[tuple[cond, body: NimNode]]): - NimNode {.compiletime.} = - ## Constructor for ``if`` statements. - ## - ## .. code-block:: nim - ## - ## newIfStmt( - ## (Ident, StmtList), - ## ... - ## ) - ## +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(newNimNode(nnkElifBranch).add(i.cond, i.body)) + 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]) -proc copyChildrenTo*(src, dest: NimNode) {.compileTime.}= - ## Copy all children from `src` to `dest` - for i in 0 .. < src.len: + 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): stmt = +template expectRoutine(node: NimNode) = expectKind(node, RoutineNodes) -proc name*(someProc: NimNode): NimNode {.compileTime.} = +proc name*(someProc: NimNode): NimNode = someProc.expectRoutine result = someProc[0] -proc `name=`*(someProc: NimNode; val: NimNode) {.compileTime.} = - someProc.expectRoutine - someProc[0] = val + 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 params*(someProc: NimNode): NimNode {.compileTime.} = - someProc.expectRoutine - result = someProc[3] -proc `params=`* (someProc: NimNode; params: NimNode) {.compileTime.}= +proc `name=`*(someProc: NimNode; val: NimNode) = someProc.expectRoutine - assert params.kind == nnkFormalParams - someProc[3] = params + if someProc[0].kind == nnkPostfix: + someProc[0][1] = val + else: someProc[0] = val -proc pragma*(someProc: NimNode): NimNode {.compileTime.} = - ## Get the pragma of a proc type - ## These will be expanded - someProc.expectRoutine - result = someProc[4] -proc `pragma=`*(someProc: NimNode; val: NimNode){.compileTime.}= - ## Set the pragma of a proc type - someProc.expectRoutine - assert val.kind in {nnkEmpty, nnkPragma} - someProc[4] = val - - -template badNodeKind(k; f): stmt{.immediate.} = - assert false, "Invalid node kind " & $k & " for macros.`" & $f & "`" +proc params*(someProc: NimNode): NimNode = + if someProc.kind == nnkProcTy: + someProc[0] + else: + someProc.expectRoutine + someProc[3] -proc body*(someProc: NimNode): NimNode {.compileTime.} = +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.`" & $f & "`", n) + +proc body*(someProc: NimNode): NimNode = case someProc.kind: of RoutineNodes: return someProc[6] @@ -688,9 +1379,9 @@ proc body*(someProc: NimNode): NimNode {.compileTime.} = of nnkForStmt: return someProc.last else: - badNodeKind someProc.kind, "body" + badNodeKind someProc, "body" -proc `body=`*(someProc: NimNode, val: NimNode) {.compileTime.} = +proc `body=`*(someProc: NimNode, val: NimNode) = case someProc.kind of RoutineNodes: someProc[6] = val @@ -699,143 +1390,132 @@ proc `body=`*(someProc: NimNode, val: NimNode) {.compileTime.} = of nnkForStmt: someProc[len(someProc)-1] = val else: - badNodeKind someProc.kind, "body=" - -proc basename*(a: NimNode): NimNode {.compiletime, benign.} + badNodeKind someProc, "body=" +proc basename*(a: NimNode): NimNode = + ## Pull an identifier from prefix/postfix expressions. + case a.kind + of nnkIdent: result = a + of nnkPostfix, nnkPrefix: result = a[1] + of nnkPragmaExpr: result = basename(a[0]) + else: + error("Do not know how to get basename of (" & treeRepr(a) & ")\n" & + repr(a), a) -proc `$`*(node: NimNode): string {.compileTime.} = - ## Get the string of an identifier node +proc `$`*(node: NimNode): string = + ## Get the string of an identifier node. case node.kind - of nnkIdent: - result = $node.ident of nnkPostfix: - result = $node.basename.ident & "*" - of nnkStrLit..nnkTripleStrLit: + result = node.basename.strVal & "*" + of nnkStrLit..nnkTripleStrLit, nnkCommentStmt, nnkSym, nnkIdent: result = node.strVal - of nnkSym: - result = $node.symbol - of nnkOpenSymChoice, nnkClosedSymChoice: + of nnkOpenSymChoice, nnkClosedSymChoice, nnkOpenSym: result = $node[0] + of nnkAccQuoted: + result = "" + for i in 0 ..< node.len: + result.add(repr(node[i])) else: - badNodeKind node.kind, "$" - -proc ident*(name: string): NimNode {.compileTime,inline.} = newIdentNode(name) - ## Create a new ident node from a string + badNodeKind node, "$" iterator items*(n: NimNode): NimNode {.inline.} = - ## Iterates over the children of the NimNode ``n``. + ## 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``. + ## Iterates over the children of the NimNode `n`. for i in 0 ..< n.len: yield n[i] -template findChild*(n: NimNode; cond: expr): NimNode {. - immediate, dirty.} = +template findChild*(n: NimNode; cond: untyped): NimNode {.dirty.} = ## Find the first child node matching condition (or nil). - ## - ## .. code-block:: nim + ## ```nim ## var res = findChild(n, it.kind == nnkPostfix and - ## it.basename.ident == !"foo") + ## it.basename.ident == ident"foo") + ## ``` block: - var result: NimNode + var res: NimNode for it in n.children: if cond: - result = it + res = it break - result + res -proc insert*(a: NimNode; pos: int; b: NimNode) {.compileTime.} = - ## Insert node B into A at pos +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 + # 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 + # 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): NimNode = - ## Pull an identifier from prefix/postfix expressions - case a.kind - of nnkIdent: return a - of nnkPostfix, nnkPrefix: return a[1] - else: - quit "Do not know how to get basename of (" & treeRepr(a) & ")\n" & repr(a) - -proc `basename=`*(a: NimNode; val: string) {.compileTime.}= +proc `basename=`*(a: NimNode; val: string) = case a.kind - of nnkIdent: macros.`ident=`(a, !val) - of nnkPostfix, nnkPrefix: a[1] = ident(val) + of nnkIdent: + a.strVal = val + of nnkPostfix, nnkPrefix: + a[1] = ident(val) + of nnkPragmaExpr: `basename=`(a[0], val) else: - quit "Do not know how to get basename of (" & treeRepr(a) & ")\n" & repr(a) + error("Do not know how to get basename of (" & treeRepr(a) & ")\n" & + repr(a), a) -proc postfix*(node: NimNode; op: string): NimNode {.compileTime.} = +proc postfix*(node: NimNode; op: string): NimNode = newNimNode(nnkPostfix).add(ident(op), node) -proc prefix*(node: NimNode; op: string): NimNode {.compileTime.} = +proc prefix*(node: NimNode; op: string): NimNode = newNimNode(nnkPrefix).add(ident(op), node) proc infix*(a: NimNode; op: string; - b: NimNode): NimNode {.compileTime.} = + b: NimNode): NimNode = newNimNode(nnkInfix).add(ident(op), a, b) -proc unpackPostfix*(node: NimNode): tuple[node: NimNode; op: string] {. - compileTime.} = +proc unpackPostfix*(node: NimNode): tuple[node: NimNode; op: string] = node.expectKind nnkPostfix - result = (node[0], $node[1]) + result = (node[1], $node[0]) -proc unpackPrefix*(node: NimNode): tuple[node: NimNode; op: string] {. - compileTime.} = +proc unpackPrefix*(node: NimNode): tuple[node: NimNode; op: string] = node.expectKind nnkPrefix - result = (node[0], $node[1]) + result = (node[1], $node[0]) -proc unpackInfix*(node: NimNode): tuple[left: NimNode; op: string; - right: NimNode] {.compileTime.} = - assert node.kind == nnkInfix - result = (node[0], $node[1], node[2]) +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 {.compileTime.} = - ## An alias for copyNimTree(). +proc copy*(node: NimNode): NimNode = + ## An alias for `copyNimTree<#copyNimTree,NimNode>`_. return node.copyNimTree() -proc cmpIgnoreStyle(a, b: cstring): int {.noSideEffect.} = - proc toLower(c: char): char {.inline.} = - if c in {'A'..'Z'}: result = chr(ord(c) + (ord('a') - ord('A'))) - else: result = c - var i = 0 - var j = 0 - while true: - while a[i] == '_': inc(i) - while b[j] == '_': inc(j) # BUGFIX: typo - var aa = toLower(a[i]) - var bb = toLower(b[j]) - result = ord(aa) - ord(bb) - if result != 0 or aa == '\0': break - inc(i) - inc(j) - -proc eqIdent* (a, b: string): bool = cmpIgnoreStyle(a, b) == 0 - ## Check if two idents are identical. - -proc hasArgOfName* (params: NimNode; name: string): bool {.compiletime.}= - ## Search nnkFormalParams for an argument. - assert params.kind == nnkFormalParams - for i in 1 .. <params.len: - template node: expr = params[i] - if name.eqIdent( $ node[0]): - return true - -proc addIdentIfAbsent*(dest: NimNode, ident: string) {.compiletime.} = - ## Add ident to dest if it is not present. This is intended for use +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 @@ -846,19 +1526,287 @@ proc addIdentIfAbsent*(dest: NimNode, ident: string) {.compiletime.} = else: discard dest.add(ident(ident)) -proc boolVal*(n: NimNode): bool {.compileTime, noSideEffect.} = +proc boolVal*(n: NimNode): bool {.noSideEffect.} = if n.kind == nnkIntLit: n.intVal != 0 else: n == bindSym"true" # hacky solution for now -when not defined(booting): - template emit*(e: static[string]): stmt = - ## accepts a single string argument and treats it as nim code - ## that should be inserted verbatim in the program - ## Example: - ## - ## .. code-block:: nim - ## emit("echo " & '"' & "hello world".toUpper & '"') - ## - macro payload: stmt {.gensym.} = - result = parseStmt(e) - payload() +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 |