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Diffstat (limited to 'nimsuggest/tests/fixtures/mclass_macro.nim')
| -rw-r--r-- | nimsuggest/tests/fixtures/mclass_macro.nim | 164 |
1 files changed, 164 insertions, 0 deletions
diff --git a/nimsuggest/tests/fixtures/mclass_macro.nim b/nimsuggest/tests/fixtures/mclass_macro.nim new file mode 100644 index 000000000..cfca0bf3f --- /dev/null +++ b/nimsuggest/tests/fixtures/mclass_macro.nim @@ -0,0 +1,164 @@ + +import macros + +macro class*(head, body: untyped): untyped = + # The macro is immediate, since all its parameters are untyped. + # This means, it doesn't resolve identifiers passed to it. + + var typeName, baseName: NimNode + + # flag if object should be exported + var exported: bool + + if head.kind == nnkInfix and head[0].kind == nnkIdent and $head[0] == "of": + # `head` is expression `typeName of baseClass` + # echo head.treeRepr + # -------------------- + # Infix + # Ident !"of" + # Ident !"Animal" + # Ident !"RootObj" + typeName = head[1] + baseName = head[2] + + elif head.kind == nnkInfix and head[0].kind == nnkIdent and + $head[0] == "*" and head[2].kind == nnkPrefix and + head[2][0].kind == nnkIdent and $head[2][0] == "of": + # `head` is expression `typeName* of baseClass` + # echo head.treeRepr + # -------------------- + # Infix + # Ident !"*" + # Ident !"Animal" + # Prefix + # Ident !"of" + # Ident !"RootObj" + typeName = head[1] + baseName = head[2][1] + exported = true + + else: + quit "Invalid node: " & head.lispRepr + + # The following prints out the AST structure: + # + # import macros + # dumptree: + # type X = ref object of Y + # z: int + # -------------------- + # StmtList + # TypeSection + # TypeDef + # Ident !"X" + # Empty + # RefTy + # ObjectTy + # Empty + # OfInherit + # Ident !"Y" + # RecList + # IdentDefs + # Ident !"z" + # Ident !"int" + # Empty + + # create a type section in the result + result = newNimNode(nnkStmtList) + result.add( + if exported: + # mark `typeName` with an asterisk + quote do: + type `typeName`* = ref object of `baseName` + else: + quote do: + type `typeName` = ref object of `baseName` + ) + + # echo treeRepr(body) + # -------------------- + # StmtList + # VarSection + # IdentDefs + # Ident !"name" + # Ident !"string" + # Empty + # IdentDefs + # Ident !"age" + # Ident !"int" + # Empty + # MethodDef + # Ident !"vocalize" + # Empty + # Empty + # FormalParams + # Ident !"string" + # Empty + # Empty + # StmtList + # StrLit ... + # MethodDef + # Ident !"age_human_yrs" + # Empty + # Empty + # FormalParams + # Ident !"int" + # Empty + # Empty + # StmtList + # DotExpr + # Ident !"this" + # Ident !"age" + + # var declarations will be turned into object fields + var recList = newNimNode(nnkRecList) + + # expected name of constructor + let ctorName = newIdentNode("new" & $typeName) + + # Iterate over the statements, adding `this: T` + # to the parameters of functions, unless the + # function is a constructor + for node in body.children: + case node.kind: + + of nnkMethodDef, nnkProcDef: + # check if it is the ctor proc + if node.name.kind != nnkAccQuoted and node.name.basename == ctorName: + # specify the return type of the ctor proc + node.params[0] = typeName + else: + # inject `self: T` into the arguments + node.params.insert(1, newIdentDefs(ident("self"), typeName)) + result.add(node) + + of nnkVarSection: + # variables get turned into fields of the type. + for n in node.children: + recList.add(n) + + else: + result.add(node) + + # Inspect the tree structure: + # + # echo result.treeRepr + # -------------------- + # StmtList + # TypeSection + # TypeDef + # Ident !"Animal" + # Empty + # RefTy + # ObjectTy + # Empty + # OfInherit + # Ident !"RootObj" + # Empty <= We want to replace this + # MethodDef + # ... + + result[0][0][2][0][2] = recList + + # Lets inspect the human-readable version of the output + #echo repr(result) |