diff options
Diffstat (limited to 'lib')
| -rw-r--r-- | lib/core/macros.nim | 105 |
1 files changed, 101 insertions, 4 deletions
diff --git a/lib/core/macros.nim b/lib/core/macros.nim index 3473c5d7e..409948629 100644 --- a/lib/core/macros.nim +++ b/lib/core/macros.nim @@ -584,7 +584,8 @@ proc nestList*(theProc: NimIdent, proc treeRepr*(n: NimNode): string {.compileTime, benign.} = ## Convert the AST `n` to a human-readable tree-like string. ## - ## See also `repr` and `lispRepr`. + ## See also `repr`, `lispRepr`, and `astGenRepr`. + proc traverse(res: var string, level: int, n: NimNode) {.benign.} = for i in 0..level-1: res.add " " res.add(($n.kind).substr(3)) @@ -609,7 +610,7 @@ proc treeRepr*(n: NimNode): string {.compileTime, benign.} = proc lispRepr*(n: NimNode): string {.compileTime, benign.} = ## Convert the AST `n` to a human-readable lisp-like string, ## - ## See also `repr` and `treeRepr`. + ## See also `repr`, `treeRepr`, and `astGenRepr`. result = ($n.kind).substr(3) add(result, "(") @@ -632,9 +633,96 @@ proc lispRepr*(n: NimNode): string {.compileTime, benign.} = add(result, ")") +proc astGenRepr*(n: NimNode): string {.compileTime, benign.} = + ## Convert the AST `n` to the code required to generate that AST. So for example + ## + ## .. code-block:: nim + ## astGenRepr: + ## echo "Hello world" + ## + ## Would output: + ## + ## .. code-block:: nim + ## nnkStmtList.newTree( + ## nnkCommand.newTree( + ## newIdentNode(!"echo"), + ## newLit("Hello world") + ## ) + ## ) + ## + ## See also `repr`, `treeRepr`, and `lispRepr`. + + const + NodeKinds = {nnkEmpty, nnkNilLit, nnkIdent, nnkSym, nnkNone} + LitKinds = {nnkCharLit..nnkInt64Lit, nnkFloatLit..nnkFloat64Lit, nnkStrLit..nnkTripleStrLit} + + proc escape(s: string, prefix = "\"", suffix = "\""): string {.noSideEffect.} = + ## Functions copied from strutils + proc toHex(x: BiggestInt, len: Positive): string {.noSideEffect, rtl.} = + const + HexChars = "0123456789ABCDEF" + var + t = x + result = newString(len) + for j in countdown(len-1, 0): + result[j] = HexChars[t and 0xF] + t = t shr 4 + # handle negative overflow + if t == 0 and x < 0: t = -1 + + result = newStringOfCap(s.len + s.len shr 2) + result.add(prefix) + for c in items(s): + case c + of '\0'..'\31', '\128'..'\255': + add(result, "\\x") + add(result, toHex(ord(c), 2)) + of '\\': add(result, "\\\\") + of '\'': add(result, "\\'") + of '\"': add(result, "\\\"") + else: add(result, c) + add(result, suffix) + + 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" & ($n.kind).substr(3) & "Node(") + elif n.kind in LitKinds: + res.add("newLit(") + else: + res.add($n.kind) + + case n.kind + of nnkEmpty: discard + of nnkNilLit: res.add("nil") + of nnkCharLit: res.add("'" & $chr(n.intVal) & "'") + of nnkIntLit..nnkInt64Lit: res.add($n.intVal) + of nnkFloatLit..nnkFloat64Lit: res.add($n.floatVal) + of nnkStrLit..nnkTripleStrLit: res.add($n.strVal.escape()) + of nnkIdent: res.add("!" & ($n.ident).escape()) + of nnkSym: res.add(($n.symbol).escape()) + of nnkNone: assert false + 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 `toTree` function. Printing is done *at compile time*. + ## tree using the `treeRepr` function. 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 @@ -642,7 +730,16 @@ macro dumpTree*(s: untyped): untyped = echo s.treeRepr macro dumpLisp*(s: untyped): untyped = echo s.lispRepr ## 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 `lispRepr` function. Printing is done *at compile time*. + ## + ## See `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` function. 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. ## ## See `dumpTree`. |