version 0.8.5: added Nimrod version of the compiler

rod/filters.nim

@@ -0,0 +1,85 @@
+#
+#
+#           The Nimrod Compiler
+#        (c) Copyright 2009 Andreas Rumpf
+#
+#    See the file "copying.txt", included in this
+#    distribution, for details about the copyright.
+#
+
+# This module implements Nimrod's simple filters and helpers for filters.
+
+import 
+  llstream, os, wordrecg, idents, strutils, ast, astalgo, msgs, options, rnimsyn
+
+proc filterReplace*(stdin: PLLStream, filename: string, call: PNode): PLLStream
+proc filterStrip*(stdin: PLLStream, filename: string, call: PNode): PLLStream
+  # helpers to retrieve arguments:
+proc charArg*(n: PNode, name: string, pos: int, default: Char): Char
+proc strArg*(n: PNode, name: string, pos: int, default: string): string
+proc boolArg*(n: PNode, name: string, pos: int, default: bool): bool
+# implementation
+
+proc invalidPragma(n: PNode) = 
+  liMessage(n.info, errXNotAllowedHere, renderTree(n, {renderNoComments}))
+
+proc getArg(n: PNode, name: string, pos: int): PNode = 
+  result = nil
+  if n.kind in {nkEmpty..nkNilLit}: return 
+  for i in countup(1, sonsLen(n) - 1): 
+    if n.sons[i].kind == nkExprEqExpr: 
+      if n.sons[i].sons[0].kind != nkIdent: invalidPragma(n)
+      if IdentEq(n.sons[i].sons[0].ident, name): 
+        return n.sons[i].sons[1]
+    elif i == pos: 
+      return n.sons[i]
+  
+proc charArg(n: PNode, name: string, pos: int, default: Char): Char = 
+  var x: PNode
+  x = getArg(n, name, pos)
+  if x == nil: result = default
+  elif x.kind == nkCharLit: result = chr(int(x.intVal))
+  else: invalidPragma(n)
+  
+proc strArg(n: PNode, name: string, pos: int, default: string): string = 
+  var x: PNode
+  x = getArg(n, name, pos)
+  if x == nil: result = default
+  elif x.kind in {nkStrLit..nkTripleStrLit}: result = x.strVal
+  else: invalidPragma(n)
+  
+proc boolArg(n: PNode, name: string, pos: int, default: bool): bool = 
+  var x: PNode
+  x = getArg(n, name, pos)
+  if x == nil: result = default
+  elif (x.kind == nkIdent) and IdentEq(x.ident, "true"): result = true
+  elif (x.kind == nkIdent) and IdentEq(x.ident, "false"): result = false
+  else: invalidPragma(n)
+  
+proc filterStrip(stdin: PLLStream, filename: string, call: PNode): PLLStream = 
+  var 
+    line, pattern, stripped: string
+    leading, trailing: bool
+  pattern = strArg(call, "startswith", 1, "")
+  leading = boolArg(call, "leading", 2, true)
+  trailing = boolArg(call, "trailing", 3, true)
+  result = LLStreamOpen("")
+  while not LLStreamAtEnd(stdin): 
+    line = LLStreamReadLine(stdin)
+    stripped = strip(line, leading, trailing)
+    if (len(pattern) == 0) or startsWith(stripped, pattern): 
+      LLStreamWriteln(result, stripped)
+    else: 
+      LLStreamWriteln(result, line)
+  LLStreamClose(stdin)
+
+proc filterReplace(stdin: PLLStream, filename: string, call: PNode): PLLStream = 
+  var line, sub, by: string
+  sub = strArg(call, "sub", 1, "")
+  if len(sub) == 0: invalidPragma(call)
+  by = strArg(call, "by", 2, "")
+  result = LLStreamOpen("")
+  while not LLStreamAtEnd(stdin): 
+    line = LLStreamReadLine(stdin)
+    LLStreamWriteln(result, replace(line, sub, by))
+  LLStreamClose(stdin)