constantine/helpers/static_for.nim

59 lines
1.8 KiB
Nim

# Constantine
# Copyright (c) 2018-2019 Status Research & Development GmbH
# Copyright (c) 2020-Present Mamy André-Ratsimbazafy
# Licensed and distributed under either of
# * MIT license (license terms in the root directory or at http://opensource.org/licenses/MIT).
# * Apache v2 license (license terms in the root directory or at http://www.apache.org/licenses/LICENSE-2.0).
# at your option. This file may not be copied, modified, or distributed except according to those terms.
import std/macros
proc replaceNodes(ast: NimNode, what: NimNode, by: NimNode): NimNode =
# Replace "what" ident node by "by"
proc inspect(node: NimNode): NimNode =
case node.kind:
of {nnkIdent, nnkSym}:
if node.eqIdent(what):
return by
return node
of nnkEmpty:
return node
of nnkLiterals:
return node
else:
var rTree = node.kind.newTree()
for child in node:
rTree.add inspect(child)
return rTree
result = inspect(ast)
macro staticFor*(idx: untyped{nkIdent}, start, stopEx: static int, body: untyped): untyped =
result = newStmtList()
for i in start ..< stopEx:
result.add nnkBlockStmt.newTree(
ident("unrolledIter_" & $idx & $i),
body.replaceNodes(idx, newLit i)
)
{.experimental: "dynamicBindSym".}
macro staticFor*(ident: untyped{nkIdent}, choices: typed, body: untyped): untyped =
## matches
## staticFor(curve, TestCurves):
## body
## and unroll the body for each curve in TestCurves
let choices = if choices.kind == nnkSym:
# Unpack symbol
choices.getImpl()
else:
choices.expectKind(nnkBracket)
choices
result = newStmtList()
for choice in choices:
result.add nnkBlockStmt.newTree(
ident($ident & "_" & $choice.intVal),
body.replaceNodes(ident, choice)
)