1 files changed, 154 insertions, 0 deletions
diff --git a/src/pcheck.cc b/src/pcheck.cc
new file mode 100644
index 0000000..d5401f7
--- /dev/null
+++ b/src/pcheck.cc
@@ -0,0 +1,154 @@
+/*
+ *  Copyright 2006-2012 Adrian Thurston <thurston@complang.org>
+ */
+
+/*  This file is part of Colm.
+ *
+ *  Colm is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 2 of the License, or
+ *  (at your option) any later version.
+ * 
+ *  Colm is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ * 
+ *  You should have received a copy of the GNU General Public License
+ *  along with Colm; if not, write to the Free Software
+ *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA 
+ */
+
+#include "pcheck.h"
+#include <assert.h>
+
+/* Construct a new parameter checker with for paramSpec. */
+ParamCheck::ParamCheck( const char *paramSpec, int argc,  const char **argv )
+:
+	state(noparam),
+	argOffset(0),
+	curArg(0),
+	iCurArg(1),
+	paramSpec(paramSpec), 
+	argc(argc), 
+	argv(argv)
+{
+}
+
+/* Check a single option. Returns the index of the next parameter.  Sets p to
+ * the arg character if valid, 0 otherwise.  Sets parg to the parameter arg if
+ * there is one, NULL otherwise. */
+bool ParamCheck::check()
+{
+	bool requiresParam;
+
+	if ( iCurArg >= argc ) {            /* Off the end of the arg list. */
+		state = noparam;
+		return false;
+	}
+
+	if ( argOffset != 0 && *argOffset == 0 ) {
+		/* We are at the end of an arg string. */
+		iCurArg += 1;
+		if ( iCurArg >= argc ) {
+			state = noparam;
+			return false;
+		}
+		argOffset = 0;
+	}
+
+	if ( argOffset == 0 ) {
+		/* Set the current arg. */
+		curArg = argv[iCurArg];
+
+		/* We are at the beginning of an arg string. */
+		if ( argv[iCurArg] == 0 ||        /* Argv[iCurArg] is null. */
+			 argv[iCurArg][0] != '-' ||   /* Not a param. */
+			 argv[iCurArg][1] == 0 ) {    /* Only a dash. */
+			parameter = 0;
+			parameterArg = 0;
+
+			iCurArg += 1;
+			state = noparam;
+			return true;
+		}
+		argOffset = argv[iCurArg] + 1;
+	}
+
+	/* Get the arg char. */
+	char argChar = *argOffset;
+	
+	/* Loop over all the parms and look for a match. */
+	const char *pSpec = paramSpec;
+	while ( *pSpec != 0 ) {
+		char pSpecChar = *pSpec;
+
+		/* If there is a ':' following the char then
+		 * it requires a parm.  If a parm is required
+		 * then move ahead two in the parmspec. Otherwise
+		 * move ahead one in the parm spec. */
+		if ( pSpec[1] == ':' ) {
+			requiresParam = true;
+			pSpec += 2;
+		}
+		else {
+			requiresParam = false;
+			pSpec += 1;
+		}
+
+		/* Do we have a match. */
+		if ( argChar == pSpecChar ) {
+			if ( requiresParam ) {
+				if ( argOffset[1] == 0 ) {
+					/* The param must follow. */
+					if ( iCurArg + 1 == argc ) {
+						/* We are the last arg so there
+						 * cannot be a parameter to it. */
+						parameter = argChar;
+						parameterArg = 0;
+						iCurArg += 1;
+						argOffset = 0;
+						state = invalid;
+						return true;
+					}
+					else {
+						/* the parameter to the arg is the next arg. */
+						parameter = pSpecChar;
+						parameterArg = argv[iCurArg + 1];
+						iCurArg += 2;
+						argOffset = 0;
+						state = match;
+						return true;
+					}
+				}
+				else {
+					/* The param for the arg is built in. */
+					parameter = pSpecChar;
+					parameterArg = argOffset + 1;
+					iCurArg += 1;
+					argOffset = 0;
+					state = match;
+					return true;
+				}
+			}
+			else {
+				/* Good, we matched the parm and no
+				 * arg is required. */
+				parameter = pSpecChar;
+				parameterArg = 0;
+				argOffset += 1;
+				state = match;
+				return true;
+			}
+		}
+	}
+
+	/* We did not find a match. Bad Argument. */
+	parameter = argChar;
+	parameterArg = 0;
+	argOffset += 1;
+	state = invalid;
+	return true;
+}
+
+