diff options
Diffstat (limited to 'scalatex/api/src/main/scala/scalatex/stages/Compiler.scala')
| -rw-r--r-- | scalatex/api/src/main/scala/scalatex/stages/Compiler.scala | 103 |
1 files changed, 103 insertions, 0 deletions
diff --git a/scalatex/api/src/main/scala/scalatex/stages/Compiler.scala b/scalatex/api/src/main/scala/scalatex/stages/Compiler.scala new file mode 100644 index 0000000..3df8da7 --- /dev/null +++ b/scalatex/api/src/main/scala/scalatex/stages/Compiler.scala @@ -0,0 +1,103 @@ +package scalatex +package stages + +import acyclic.file + +import scala.reflect.macros.whitebox.Context +import scala.reflect.internal.util.{Position, OffsetPosition} + +/** + * Walks the parsed AST, converting it into a structured Scala c.Tree + */ +object Compiler{ + + def apply(c: Context)(fragPos: c.Position, template: Ast.Block): c.Tree = { + + import c.universe._ + def fragType = tq"scalatags.Text.all.Frag" + + def incPosRec(trees: c.Tree, offset: Int): trees.type = { + + trees.foreach(incPos(_, offset)) + trees + } + def incPos(tree: c.Tree, offset: Int): tree.type = { + + val current = if (tree.pos == NoPosition) 0 else tree.pos.point + c.internal.setPos(tree, + new OffsetPosition( + fragPos.source, + offset + current + fragPos.point + ).asInstanceOf[c.universe.Position] + ) + tree + } + + def compileChain(code: String, parts: Seq[Ast.Chain.Sub], offset: Int): c.Tree = { + + val out = parts.foldLeft(incPosRec(c.parse(code), offset + 1)){ + case (curr, Ast.Chain.Prop(str, offset2)) => + incPos(q"$curr.${TermName(str)}", offset2 + 1) + case (curr, Ast.Chain.Args(str, offset2)) => + val Apply(fun, args) = c.parse(s"omg$str") + incPos(Apply(curr, args.map(incPosRec(_, offset2 - 2))), offset2) + case (curr, Ast.Chain.TypeArgs(str, offset2)) => + val TypeApply(fun, args) = c.parse(s"omg$str") + incPos(TypeApply(curr, args.map(incPosRec(_, offset2 - 2))), offset2) + case (curr, Ast.Block(parts, offset1)) => + incPos(q"$curr(..${compileBlock(parts, offset1)})", offset1) + case (curr, Ast.Header(header, block, offset1)) => + incPos(q"$curr(${compileHeader(header, block, offset1)})", offset1) + } + + out + } + def compileBlock(parts: Seq[Ast.Block.Sub], offset: Int): Seq[c.Tree] = { + val res = parts.map{ + case Ast.Block.Text(str, offset1) => + incPos(q"$str", offset1) + case Ast.Chain(code, parts, offset1) => + compileChain(code, parts, offset1) + case Ast.Header(header, block, offset1) => + compileHeader(header, block, offset1) + case Ast.Block.IfElse(condString, Ast.Block(parts2, offset2), elseBlock, offset1) => + val If(cond, _, _) = c.parse(condString + "{}") + val elseCompiled = elseBlock match{ + case Some(Ast.Block(parts3, offset3)) => compileBlockWrapped(parts3, offset3) + case None => EmptyTree + } + + val res = If(incPosRec(cond, offset1 + 2), compileBlockWrapped(parts2, offset2), elseCompiled) + + incPos(res, offset1) + res + case Ast.Block.For(generators, Ast.Block(parts2, offset2), offset1) => + val fresh = c.fresh() + + val tree = incPosRec(c.parse(s"$generators yield $fresh"), offset1 + 2) + + def rec(t: Tree): Tree = t match { + case a @ Apply(fun, List(f @ Function(vparams, body))) => + val f2 = Function(vparams, rec(body)) + val a2 = Apply(fun, List(f2)) + a2 + case Ident(x: TermName) if x.decoded == fresh => + compileBlockWrapped(parts2, offset2) + } + + rec(tree) + } + res + } + def compileBlockWrapped(parts: Seq[Ast.Block.Sub], offset: Int): c.Tree = { + incPos(q"Seq[$fragType](..${compileBlock(parts, offset)})", offset) + } + def compileHeader(header: String, block: Ast.Block, offset: Int): c.Tree = { + val Block(stmts, expr) = c.parse(s"{$header\n ()}") + Block(stmts, compileBlockWrapped(block.parts, block.offset)) + } + + val res = compileBlockWrapped(template.parts, template.offset) + res + } +}
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