Fixed float parsing, exported PValue, added example.nim.

Göran Krampe
1 parent 19ec8d35
Showing 4 changed files with 82 additions and 15 deletions
.gitignore
README.md
example.nim
lapp.nim
 nimcache
 lapp
+example
+Lapp is a command line parser that uses the regular help text for the synopsis as the specification
+for the options and arguments, it was originally written by Steve Donovan in Lua:
+
+http://lua-users.org/wiki/LappFramework
+
+...and ported to Nim by Steve. Then I made it work with current Nim.
+
+See example.nim for how to use it.
+import lapp, tables
+
+# This is a trivial example trying to cover all features of lapp.
+
+let help = """
+  example [options] command filenames
+    
+    -r  Just an optional single character flag. Show the args using repr.
+    -a,--alpha  Or with additional long variant, no whitespace there.
+    -n: A colon can be added, but has no meaning, instead () specifies further.
+    -N (default 10) And it can take a value, and have a default value.
+    -f (default 0.04) And be a float
+    -s (default banana) Or a string
+    -x (int) And it can be typed with int, string, float, stdin, stdout - without a
+            default value. This implies that the option is mandatory!
+    -X (int...) And allow multiples.
+    -v,--verbose: (bool...) Verbosity level, "..." means can be multiple.
+    -o,--out (default stdout) A file to direct to.
+    <command> Arguments are string by default.
+    <file>: (default stdin...) One or more files or stdin by default
+
+    
+    The first line in this help text is arbitrary, or rather
+    its only the lines (trimmed) beginning with '-' or '<' that constitute
+    the speciciation, so this text is also ignored.
+    
+    Things we know are not working:
+      ranges. The lexer in lapp does it, but there is no more support.
+  """
+
+# We call `parse` in lapp with our help text as argument.
+# This will both parse the help text above and then, parse the
+# arguments passed to this program. A table is returned
+# with all command line elements in it, keyed by their name
+# and with a PValue as value.
+var args = parse(help)
+
+# Let's examine what we got using repr
+for k,v in args:
+  echo "Parameter: " & k & " PValue: " & repr(v)
+
+# Or print out a bit cleaner
+echo "Parameters and their values:"
+echo "r == " & $args["r"].asBool
+echo "alpha == " & $args["alpha"].asBool  # Long name is used as key, if its specified
+echo "n == " & $args["n"].asBool
+echo "N == " & $args["N"].asInt
+echo "f == " & $args["f"].asFloat
+echo "s == " & $args["s"].asString
+echo "x == " & $args["x"].asInt
+echo "X == " & $args["X"].asSeq.map(proc(x:PValue):int = x.asInt)
+echo "verbose == " & $args["verbose"].asSeq.len
+echo "out == " & $args["out"].filename
+echo "command == " & $args["command"].asString
+echo "file == " & $args["file"].asSeq.map(proc(x:PValue):string = x.filename)
+
+
@@ -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)
  
@@ -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
@@ -314,7 +315,7 @@ proc parseArguments(usage: string, args: seq[string]): Table[string,PValue] =
       try:
         v = value.parseFloat
       except:
-        fail("bad integer")
+        fail("bad float")
       pval = floatValue(v)
     of "bool":
       pval = boolValue(value.parseBool)
@@ -359,12 +360,12 @@ proc parse*(usage: string): Table[string,PValue] =
  
 when isMainModule:
   var args = parse"""
-  head [flags] filename
+  head [flags] [file1, file2 ...] [outfile]
     -n: (default 10) number of lines
     -v,--verbose: (bool...) verbosity level 
     -a,--alpha  useless parm
     <file>: (default stdin...)
-    |<out>: (default stdout)
+    <out>: (default stdout)
   """
  
   echo args["n"].asInt