Added updated lapp.nim

Göran Krampe
1 parent 85eedc50
Showing 1 changed file with 98 additions and 43 deletions
lapp.nim
 import strutils
-from os import paramCount, paramStr
+import os
 import tables
 export tables.`[]`
@@ -50,10 +50,10 @@ proc get(L: PLexer; t: var TLexType): string =
       next(L)
     if thisChar(L) == '.':
       t = tfloat
-      result.add(c)
+      result.add(thisChar(L))
       next(L)
       while thisChar(L) in Digits:
-        result.add(c)
+        result.add(thisChar(L))
         next(L)
   of '.': # ".", "..", "..."
     if thisChar(L) == '.':
@@ -89,17 +89,17 @@ type
     vFile,
     vSeq
-  PValue = ref TValue
-  TValue = object
-    case kind: TValueKind
-      of vInt: asInt *: int
-      of vFloat: asFloat *: float
-      of vString: asString *: string
-      of vBool: asBool *: bool
+  PValue* = ref TValue
+  TValue* = object
+    case kind*: TValueKind
+      of vInt: asInt*: int
+      of vFloat: asFloat*: float
+      of vString: asString*: string
+      of vBool: asBool*: bool
       of vFile:
-        asFile *: File
-        fileName *: string
-      of vSeq: asSeq *: seq[PValue]
+        asFile*: File
+        fileName*: string
+      of vSeq: asSeq*: seq[PValue]
 proc boolValue(c: bool): PValue =  PValue(kind: vBool, asBool: c)
@@ -125,7 +125,7 @@ var
   progname, usage: string
   aliases: array[char,string]
   parm_spec =  initTable[string,PSpec]()
-    
+
 proc fail(msg: string)  =
   stderr.writeln(progname & ": " & msg)
   quit(usage)
@@ -205,6 +205,7 @@ proc parseSpec(u: string) =
       defValue = "false"
     if name != nil:
+      # echo("Param: " & name & " type: " & $ftype & " needsvalue: " & $(ftype != "bool") & " default: " & $defValue & " multiple: " & $multiple)
       let spec = PSpec(defVal:defValue, ptype: ftype, needsValue: ftype != "bool",multiple:multiple)
       aliases[alias] = name        
       parm_spec[name] = spec
@@ -212,14 +213,13 @@ proc parseSpec(u: string) =
 proc tail(s: string): string = s[1..(-1)]
 var 
-  files: array[1..MAX_FILES,File]
-  nfiles = 0 
+  files = newSeq[File]()
 proc closeFiles() {.noconv.} =
-  if nfiles == 0: return
-  for i in 1..nfiles: files[i].close()
+  for f in files:
+    f.close()
-proc parseArguments(usage: string, args: seq[string]): Table[string,PValue] =
+proc parseArguments*(usage: string, args: seq[string]): Table[string,PValue] =
   var
     vars = initTable[string,PValue]()
     n = len(args) - 1
@@ -253,6 +253,9 @@ proc parseArguments(usage: string, args: seq[string]): Table[string,PValue] =
   parseSpec(usage)
   addQuitProc(closeFiles)
+  # Collect failures
+  var failures = newSeq[string]()
+  
   # parse the flags and arguments
   while i <= n:
     arg = next()
@@ -275,7 +278,8 @@ proc parseArguments(usage: string, args: seq[string]): Table[string,PValue] =
           for c in arg.tail:
             let f = get_alias(c)
             let i = get_spec(f)
-            if i.needsValue: fail("needs value! " & f)
+            if i.needsValue:
+              failures.add("option " & f & " needs a value")
             flagvalues.add(@[f,"true"])
             i.used = true
     else: # argument (stored as \001, \002, etc
@@ -286,14 +290,28 @@ proc parseArguments(usage: string, args: seq[string]): Table[string,PValue] =
       if not info.multiple:  k += 1
     flagvalues.add(@[flag,value])
     info.used = true
-      
+  
+  # Some options disables checking
+  var enableChecks = true
+  for flag,info in parm_spec:
+    if info.used:
+      if flag == "help" or flag == "version":
+        enableChecks = false
+  
+
   # any flags not mentioned?
   for flag,info in parm_spec:
     if not info.used:
       if info.defVal == "": # no default!
-        fail("required option or argument missing: " & flag)
-      flagvalues.add(@[flag,info.defVal])
-          
+        failures.add("required option or argument missing: " & flag)
+      else:
+        flagvalues.add(@[flag,info.defVal])
+
+  if enableChecks:
+    # any failures up until now - then we fail
+    if failures.len > 0:
+      fail(failures.join("\n") & "\n")
+
   # cool, we have the info, can convert known flags
   for item in flagvalues:
     var pval: PValue;
@@ -307,14 +325,14 @@ proc parseArguments(usage: string, args: seq[string]): Table[string,PValue] =
       try:
         v = value.parseInt
       except:
-        fail("bad integer")
+        fail("bad integer for " & flag)
       pval = intValue(v)
     of "float":
       var v: float
       try:
         v = value.parseFloat
       except:
-        fail("bad integer")
+        fail("bad float for " & flag)
       pval = floatValue(v)
     of "bool":
       pval = boolValue(value.parseBool)
@@ -324,12 +342,17 @@ proc parseArguments(usage: string, args: seq[string]): Table[string,PValue] =
       var f: File
       try:
         if info.ptype == "infile":
-          f = if value=="stdin": stdin else: open(value,fmRead)
+          if value == "stdin":
+            f = stdin
+          else:
+            f = open(value, fmRead)
         else:
-          f = if value=="stdout": stdout else: open(value,fmWrite)
+          if value == "stdout":
+            f = stdout
+          else:
+            f = open(value, fmWrite)
         # they will be closed automatically on program exit
-        nfiles += 1
-        if nfiles <= MAX_FILES:  files[nfiles] = f
+        files.add(f)
       except:
         fail("cannot open " & value)
       pval = fileValue(f,value)
@@ -357,23 +380,55 @@ proc parse*(usage: string): Table[string,PValue] =
     args[i] = paramStr(i)
   return parseArguments(usage,args)    
+# Helper proc for verbosity level.
+proc verbosityLevel*(args: Table[string,PValue]): int =
+  if args.hasKey("verbose"):
+    let verbosity = args["verbose"].asSeq
+    result = verbosity.len
+    if not verbosity[0].asBool:
+      result = 0
+  else:
+    result = 0
+
+# Helper to check if we should show version
+proc showVersion*(args: Table[string,PValue]): bool =
+  args["version"].asBool
+
+# Helper to check if we should show help
+proc showHelp*(args: Table[string,PValue]): bool =
+  args["help"].asBool
+
+
+# Typical usage
 when isMainModule:
-  var args = parse"""
-  head [flags] filename
-    -n: (default 10) number of lines
-    -v,--verbose: (bool...) verbosity level 
-    -a,--alpha  useless parm
-    <file>: (default stdin...)
-    |<out>: (default stdout)
+  let help = """
+  head [flags] files... [out]
+    -h,--help                     Show this help
+    --version                     Show version
+    -n: (default 10)              Number of lines to show
+    -v,--verbose: (bool...)       Verbosity level, ignored
+    -o,--out: (default stdout)    Optional outfile, defaults to stdout
+    <files>: (default stdin...)   Files to take head of
   """
+  # On parsing failure this will show usage automatically
+  var args = parse(help)
-  echo args["n"].asInt
-  echo args["alpha"].asBool
+  # These two are special, they short out
+  if args.showHelp: quit(help)
+  if args.showVersion: quit("Version: 1.99")
+  
+  # Ok, so what did we get...
+  let n = args["n"].asInt
+  
+  # This one is a helper
+  let v = verbosityLevel(args)
-  for v in args["verbose"].asSeq:
-    echo "got ",v.asBool
+  echo "Lines to show: " & $n
+  echo "Verbosity level: " & $verbosityLevel(args)
   let myfiles = args["files"].asSeq
+  var outFile = args["out"].asFile
+  
   for f in myfiles:
-    echo f.asFile.readLine()
-        
+    for i in 1..n:
+      writeln(outFile, string(f.asFile.readLine()))