/*
 * f l o a t . c
 * Forth Inspired Command Language
 * ANS Forth FLOAT word-set written in C
 * Author: Guy Carver & John Sadler (john_sadler@alum.mit.edu)
 * Created: Apr 2001
 * $Id: float.c,v 1.10 2010/09/13 18:43:04 asau Exp $
 */
/*
 * Copyright (c) 1997-2001 John Sadler (john_sadler@alum.mit.edu)
 * All rights reserved.
 *
 * Get the latest Ficl release at http://ficl.sourceforge.net
 *
 * I am interested in hearing from anyone who uses Ficl. If you have
 * a problem, a success story, a defect, an enhancement request, or
 * if you would like to contribute to the Ficl release, please
 * contact me by email at the address above.
 *
 * L I C E N S E  and  D I S C L A I M E R
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#include "ficl.h"

#if FICL_WANT_FLOAT
#include <math.h>
#include <values.h>


/*
 * Create a floating point constant.
 * fconstant ( r -"name"- )
 */
static void
ficlPrimitiveFConstant(ficlVm *vm)
{
	ficlDictionary *dictionary = ficlVmGetDictionary(vm);
	ficlString name = ficlVmGetWord(vm);

	FICL_STACK_CHECK(vm->floatStack, 1, 0);

	(void) ficlDictionaryAppendWord(dictionary, name,
	    (ficlPrimitive)ficlInstructionFConstantParen, FICL_WORD_DEFAULT);
	ficlDictionaryAppendCell(dictionary, ficlStackPop(vm->floatStack));
}


ficlWord *
ficlDictionaryAppendFConstant(ficlDictionary *dictionary, char *name,
    ficlFloat value)
{
	ficlString s;
	FICL_STRING_SET_FROM_CSTRING(s, name);
	return (ficlDictionaryAppendConstantInstruction(dictionary, s,
	    ficlInstructionFConstantParen, *(ficlInteger *)(&value)));
}


ficlWord *
ficlDictionarySetFConstant(ficlDictionary *dictionary, char *name,
    ficlFloat value)
{
	ficlString s;
	FICL_STRING_SET_FROM_CSTRING(s, name);
	return (ficlDictionarySetConstantInstruction(dictionary, s,
	    ficlInstructionFConstantParen, *(ficlInteger *)(&value)));
}




static void
ficlPrimitiveF2Constant(ficlVm *vm)
{
	ficlDictionary *dictionary = ficlVmGetDictionary(vm);
	ficlString name = ficlVmGetWord(vm);

	FICL_STACK_CHECK(vm->floatStack, 2, 0);

	(void) ficlDictionaryAppendWord(dictionary, name,
	    (ficlPrimitive)ficlInstructionF2ConstantParen, FICL_WORD_DEFAULT);
	ficlDictionaryAppendCell(dictionary, ficlStackPop(vm->floatStack));
	ficlDictionaryAppendCell(dictionary, ficlStackPop(vm->floatStack));
}

ficlWord *
ficlDictionaryAppendF2Constant(ficlDictionary *dictionary, char *name,
    ficlFloat value)
{
	ficlString s;
	FICL_STRING_SET_FROM_CSTRING(s, name);
	return (ficlDictionaryAppend2ConstantInstruction(dictionary, s,
	    ficlInstructionF2ConstantParen, *(ficl2Integer *)(&value)));
}

ficlWord *
ficlDictionarySetF2Constant(ficlDictionary *dictionary, char *name,
    ficlFloat value)
{
	ficlString s;
	FICL_STRING_SET_FROM_CSTRING(s, name);
	return (ficlDictionarySet2ConstantInstruction(dictionary, s,
	    ficlInstructionF2ConstantParen, *(ficl2Integer *)(&value)));
}

/*
 * Display a float in decimal format.
 * f. ( r -- )
 */
static void
ficlPrimitiveFDot(ficlVm *vm)
{
	ficlFloat f;

	FICL_STACK_CHECK(vm->floatStack, 1, 0);

	f = ficlStackPopFloat(vm->floatStack);
	(void) sprintf(vm->pad, "%#f ", f);
	ficlVmTextOut(vm, vm->pad);
}

/*
 * Display a float in engineering format.
 * fe. ( r -- )
 */
static void
ficlPrimitiveEDot(ficlVm *vm)
{
	ficlFloat f;

	FICL_STACK_CHECK(vm->floatStack, 1, 0);

	f = ficlStackPopFloat(vm->floatStack);
	(void) sprintf(vm->pad, "%#e ", f);
	ficlVmTextOut(vm, vm->pad);
}

/*
 * d i s p l a y FS t a c k
 * Display the parameter stack (code for "f.s")
 * f.s ( -- )
 */
struct stackContext
{
	ficlVm *vm;
	int count;
};

static ficlInteger
ficlFloatStackDisplayCallback(void *c, ficlCell *cell)
{
	struct stackContext *context = (struct stackContext *)c;
	char buffer[80];
#ifdef	_LP64
	(void) snprintf(buffer, sizeof (buffer),
	    "[0x%016lx %3d] %20e (0x%016lx)\n",
	    (unsigned long) cell, context->count++, cell->f, cell->u);
#else
	(void) snprintf(buffer, sizeof (buffer), "[0x%08x %3d] %12e (0x%08x)\n",
	    (unsigned)cell, context->count++, cell->f, cell->u);
#endif
	ficlVmTextOut(context->vm, buffer);
	return (FICL_TRUE);
}

void
ficlVmDisplayFloatStack(ficlVm *vm)
{
	struct stackContext context;
	context.vm = vm;
	context.count = 0;
	ficlStackDisplay(vm->floatStack, ficlFloatStackDisplayCallback,
	    &context);
}

/*
 * Do float stack depth.
 * fdepth ( -- n )
 */
static void
ficlPrimitiveFDepth(ficlVm *vm)
{
	int i;

	FICL_STACK_CHECK(vm->dataStack, 0, 1);

	i = ficlStackDepth(vm->floatStack);
	ficlStackPushInteger(vm->dataStack, i);
}

/*
 * Compile a floating point literal.
 */
static void
ficlPrimitiveFLiteralImmediate(ficlVm *vm)
{
	ficlDictionary *dictionary = ficlVmGetDictionary(vm);
	ficlCell cell;

	FICL_STACK_CHECK(vm->floatStack, 1, 0);

	cell = ficlStackPop(vm->floatStack);
	if (cell.f == 1.0f) {
		ficlDictionaryAppendUnsigned(dictionary, ficlInstructionF1);
	} else if (cell.f == 0.0f) {
		ficlDictionaryAppendUnsigned(dictionary, ficlInstructionF0);
	} else if (cell.f == -1.0f) {
		ficlDictionaryAppendUnsigned(dictionary, ficlInstructionFNeg1);
	} else {
		ficlDictionaryAppendUnsigned(dictionary,
		    ficlInstructionFLiteralParen);
		ficlDictionaryAppendCell(dictionary, cell);
	}
}

/*
 * F l o a t P a r s e S t a t e
 * Enum to determine the current segement of a floating point number
 * being parsed.
 */
#define	NUMISNEG	1
#define	EXPISNEG	2

typedef enum _floatParseState
{
	FPS_START,
	FPS_ININT,
	FPS_INMANT,
	FPS_STARTEXP,
	FPS_INEXP
} FloatParseState;

/*
 * f i c l P a r s e F l o a t N u m b e r
 * vm -- Virtual Machine pointer.
 * s -- String to parse.
 * Returns 1 if successful, 0 if not.
 */
int
ficlVmParseFloatNumber(ficlVm *vm, ficlString s)
{
	unsigned char c;
	unsigned char digit;
	char *trace;
	ficlUnsigned length;
	ficlFloat power;
	ficlFloat accum = 0.0f;
	ficlFloat mant = 0.1f;
	ficlInteger exponent = 0;
	char flag = 0;
	FloatParseState estate = FPS_START;

	FICL_STACK_CHECK(vm->floatStack, 0, 1);

	/*
	 * floating point numbers only allowed in base 10
	 */
	if (vm->base != 10)
		return (0);

	trace = FICL_STRING_GET_POINTER(s);
	length = FICL_STRING_GET_LENGTH(s);

	/* Loop through the string's characters. */
	while ((length--) && ((c = *trace++) != 0)) {
		switch (estate) {
			/* At start of the number so look for a sign. */
		case FPS_START:
			estate = FPS_ININT;
			if (c == '-') {
				flag |= NUMISNEG;
				break;
			}
			if (c == '+') {
				break;
			}
			/* FALLTHROUGH */
		/*
		 * Converting integer part of number.
		 * Only allow digits, decimal and 'E'.
		 */
		case FPS_ININT:
			if (c == '.') {
				estate = FPS_INMANT;
			} else if ((c == 'e') || (c == 'E')) {
				estate = FPS_STARTEXP;
			} else {
				digit = (unsigned char)(c - '0');
				if (digit > 9)
					return (0);

				accum = accum * 10 + digit;
			}
		break;
		/*
		 * Processing the fraction part of number.
		 * Only allow digits and 'E'
		 */
		case FPS_INMANT:
			if ((c == 'e') || (c == 'E')) {
				estate = FPS_STARTEXP;
			} else {
				digit = (unsigned char)(c - '0');
				if (digit > 9)
					return (0);

				accum += digit * mant;
				mant *= 0.1f;
			}
		break;
		/* Start processing the exponent part of number. */
		/* Look for sign. */
		case FPS_STARTEXP:
			estate = FPS_INEXP;

			if (c == '-') {
				flag |= EXPISNEG;
				break;
			} else if (c == '+') {
				break;
			}
			/* FALLTHROUGH */
		/*
		 * Processing the exponent part of number.
		 * Only allow digits.
		 */
		case FPS_INEXP:
			digit = (unsigned char)(c - '0');
			if (digit > 9)
				return (0);

			exponent = exponent * 10 + digit;

		break;
		}
	}

	/* If parser never made it to the exponent this is not a float. */
	if (estate < FPS_STARTEXP)
		return (0);

	/* Set the sign of the number. */
	if (flag & NUMISNEG)
		accum = -accum;

	/* If exponent is not 0 then adjust number by it. */
	if (exponent != 0) {
		/* Determine if exponent is negative. */
		if (flag & EXPISNEG) {
			exponent = -exponent;
		}
		/* power = 10^x */
#if defined(_LP64)
		power = (ficlFloat)pow(10.0, exponent);
#else
		power = (ficlFloat)powf(10.0, exponent);
#endif
		accum *= power;
	}

	ficlStackPushFloat(vm->floatStack, accum);
	if (vm->state == FICL_VM_STATE_COMPILE)
		ficlPrimitiveFLiteralImmediate(vm);

	return (1);
}
#endif  /* FICL_WANT_FLOAT */

#if FICL_WANT_LOCALS
static void
ficlPrimitiveFLocalParen(ficlVm *vm)
{
	ficlLocalParen(vm, 0, 1);
}

static void
ficlPrimitiveF2LocalParen(ficlVm *vm)
{
	ficlLocalParen(vm, 1, 1);
}
#endif /* FICL_WANT_LOCALS */

/*
 * Add float words to a system's dictionary.
 * system -- Pointer to the Ficl system to add float words to.
 */
void
ficlSystemCompileFloat(ficlSystem *system)
{
	ficlDictionary *dictionary = ficlSystemGetDictionary(system);
	ficlDictionary *environment = ficlSystemGetEnvironment(system);
#if FICL_WANT_FLOAT
	ficlCell data;
#endif

	FICL_SYSTEM_ASSERT(system, dictionary);
	FICL_SYSTEM_ASSERT(system, environment);

#if FICL_WANT_LOCALS
	(void) ficlDictionarySetPrimitive(dictionary, "(flocal)",
	    ficlPrimitiveFLocalParen, FICL_WORD_COMPILE_ONLY);
	(void) ficlDictionarySetPrimitive(dictionary, "(f2local)",
	    ficlPrimitiveF2LocalParen, FICL_WORD_COMPILE_ONLY);
#endif /* FICL_WANT_LOCALS */

#if FICL_WANT_FLOAT
	(void) ficlDictionarySetPrimitive(dictionary, "fconstant",
	    ficlPrimitiveFConstant, FICL_WORD_DEFAULT);
	(void) ficlDictionarySetPrimitive(dictionary, "fvalue",
	    ficlPrimitiveFConstant, FICL_WORD_DEFAULT);
	(void) ficlDictionarySetPrimitive(dictionary, "f2constant",
	    ficlPrimitiveF2Constant, FICL_WORD_DEFAULT);
	(void) ficlDictionarySetPrimitive(dictionary, "f2value",
	    ficlPrimitiveF2Constant, FICL_WORD_DEFAULT);
	(void) ficlDictionarySetPrimitive(dictionary, "fdepth",
	    ficlPrimitiveFDepth, FICL_WORD_DEFAULT);
	(void) ficlDictionarySetPrimitive(dictionary, "fliteral",
	    ficlPrimitiveFLiteralImmediate, FICL_WORD_IMMEDIATE);
	(void) ficlDictionarySetPrimitive(dictionary, "f.",
	    ficlPrimitiveFDot, FICL_WORD_DEFAULT);
	(void) ficlDictionarySetPrimitive(dictionary, "f.s",
	    ficlVmDisplayFloatStack, FICL_WORD_DEFAULT);
	(void) ficlDictionarySetPrimitive(dictionary, "fe.",
	    ficlPrimitiveEDot, FICL_WORD_DEFAULT);

	/*
	 * Missing words:
	 *
	 * d>f
	 * f>d
	 * falign
	 * faligned
	 * float+
	 * floats
	 * floor
	 * fmax
	 * fmin
	 */

#if defined(_LP64)
	data.f = MAXDOUBLE;
#else
	data.f = MAXFLOAT;
#endif
	(void) ficlDictionarySetConstant(environment, "max-float", data.i);
	/* not all required words are present */
	(void) ficlDictionarySetConstant(environment, "floating", FICL_FALSE);
	(void) ficlDictionarySetConstant(environment, "floating-ext",
	    FICL_FALSE);
	(void) ficlDictionarySetConstant(environment, "floating-stack",
	    system->stackSize);
#else
	(void) ficlDictionarySetConstant(environment, "floating", FICL_FALSE);
#endif
}