The following names are correct:
a
image1
arg_5
s2p6d4
The following names are incorrect:
2arg (starting with number)
arg-27 (contains non-literal symbol)
param$ (contains non-literal symbol)
Numbers may start from sign, point or digit and may contain only digits.
The following numbers are correct:
.095
+2334
-.3235
-123.234
2343.454
The following numbers are incorrect:
-.32.34 (two points inside number)
4534a44 ('a' is not a digit)
344.-34 (sign inside argument)
Example 1:
char formula_str[1000]="sqrt(5+min(a,b))";
if(!FormulaParserLib_SetFormula(formula_str))
{
//error handling
}
Example 2:
CString formula_str="sqrt(5+min(a,b))";
if(!FormulaParserLib_SetFormula(formula_str.GetBuffer(1000)))
{
//error handling
}
FormulaParserLib_IsValid
The function checks formula expression validity.
BOOL FormulaParserLib_IsValid(char* formula)
Parameters:formula - [in] formula expression less then 1000 characters to check. If NULL or "" formula expression set with FormulaParserLib_SetFormula is used
Return values:
If the function succeeds and formula is valid, the return value is TRUE. Otherwise the return value is FALSE.
Remarks:
Use the function to check formula expression validity.
Example 1:
char formula_str[1000]="sqrt(5+min(a,b))";
if(!FormulaParserLib_SetFormula(formula_str))
{
//error handling
}
if(!FormulaParserLib_IsValid(NULL)
{
//error handling
}
Example 2:
CString formula_str="sqrt(5+min(a,b))";
if(!FormulaParserLib_IsValid(formula_str.GetBuffer(1000)))
{
//error handling
}
FormulaParserLib_Parse
The function makes parsing of formula.
BOOL FormulaParserLib_Parse()
Parameters:none
Return values:
If the function succeeds and formula parsed without errors, the return value is TRUE.
If any errors during parsing, the return value is FALSE.
Remarks:
Use the function to parse formula expression set with FormulaParserLib_SetFormula.
Example 1:
char formula_str[1000]="sqrt(5+min(a,b))";
if(!FormulaParserLib_SetFormula(formula_str))
{
//error handling
}
if(!FormulaParserLib_IsValid(NULL)
{
//error handling
}
if(!FormulaParserLib_Parse())
{
//error handling
}
Example 2:
CString formula_str="sqrt(5+min(a,b))";
if(!FormulaParserLib_SetFormula(formula_str.GetBuffer(1000)))
{
//error handling
}
if(!FormulaParserLib_IsValid(NULL)
{
//error handling
}
if(!FormulaParserLib_Parse())
{
//error handling
}
FormulaParserLib_GetStatementNumber
The function gets number of statements for the formula.
BOOL FormulaParserLib_GetStatementNumber(long *num)
Parameters:num - [out] number of statement. Memory must be allocated by client
Return values:
If the function succeeds, the return value is TRUE. Otherwise, the return value is FALSE.
Remarks:
Use the function to get number of statements for the formula.
The statements are simple (with only one operation or function) expressions
that allows calculate complex formulas step by step.
Example 1:
char formula_str[1000]="sqrt(5+min(a,b))";
if(!FormulaParserLib_SetFormula(formula_str))
{
//error handling
}
if(!FormulaParserLib_IsValid(NULL)
{
//error handling
}
if(!FormulaParserLib_Parse())
{
//error handling
}
long num;
if(!FormulaParserLib_GetStatementNumber(&num))
{
//error handling
}
Example 2:
CString formula_str="sqrt(5+min(a,b))";
if(!FormulaParserLib_SetFormula(formula_str.GetBuffer(1000)))
{
//error handling
}
if(!FormulaParserLib_IsValid(NULL)
{
//error handling
}
if(!FormulaParserLib_Parse())
{
//error handling
}
long num;
if(!FormulaParserLib_GetStatementNumber(&num))
{
//error handling
}
FormulaParserLib_GetStatement
The function gets formula statements information.
BOOL FormulaParserLib_GetStatement(long num,char* arg1,char* arg2,char* oper,char* funct,char* res)
Parameters:num - [in] number of statement (from 0).
arg1 - [out] left argument (operand) of statement or argument of function.
arg2 - [out] right argument (operand) of statement.
oper - [out] operation.
funct - [out] function.
res - [out] name of result.
Return values:
If the function succeeds, the return value is TRUE. Otherwise, the return value is FALSE.
Remarks:
Memory for arg1,arg2,oper,funct,res parameters must be allocated by client.
This memory must be enough to contain returned strings.
After parsing formula expression is separated on simple calculation steps - statements.
For example for the formula "a+b-c*d/sqrt(e)" such statements may be:
| Result0=a+b | num=0, arg1="a", arg2="b", oper="+", funct="", res="Result0" |
| Result1=c*d | num=1, arg1="c", arg2="d", oper="*", funct="", res="Result1" |
| Result2=sqrt(e) | num=2, arg1="e", arg2="", oper="", funct="sqrt", res="Result2" |
| Result3=Result1/Result2 | num=3, arg1="Result1", arg2="Result2", oper="/", funct="", res="Result3" |
| Result4=Result0-Result3 | num=4, arg1="Result0", arg2="Result3", oper="-", funct="", res="Result4" |
1. Operation:
res = arg1 oper arg2
funct is set to empty string ("")
2. Function:
res = funct(arg1
arg2 and oper are set to empty strings ("")
3. Constant:
res = arg1
arg2,oper,funct are set to empty strings ("")
Example 1:
char formula_str[1000]="sqrt(5+min(a,b))";
if(!FormulaParserLib_SetFormula(formula_str))
{
//error handling
}
if(!FormulaParserLib_IsValid(NULL)
{
//error handling
}
if(!FormulaParserLib_Parse())
{
//error handling
}
long num;
if(!FormulaParserLib_GetStatementNumber(&num))
{
//error handling
}
char arg1[1000],arg2[1000],oper[1000],funct[1000],res[1000];
for(long i=0;i<num;i++)
{
if(!FormulaParserLib_GetStatement(i,arg1,arg2,oper,funct,res))
{
//error handling
}
}
Example 2:
CString formula_str="sqrt(5+min(a,b))";
if(!FormulaParserLib_SetFormula(formula_str.GetBuffer(1000)))
{
//error handling
}
if(!FormulaParserLib_IsValid(NULL)
{
//error handling
}
if(!FormulaParserLib_Parse())
{
//error handling
}
long num;
if(!FormulaParserLib_GetStatementNumber(&num))
{
//error handling
}
CString arg1,arg2,oper,funct,res;
for(long i=0;i<num;i++)
{
if(!FormulaParserLib_GetStatement(i,arg1.GetBuffer(1000),arg2.GetBuffer(1000),oper.GetBuffer(1000),
funct.GetBuffer(1000),res.GetBuffer(1000)))
{
//error handling
}
arg1.ReleaseBuffer();
arg2.ReleaseBuffer();
oper.ReleaseBuffer();
funct.ReleaseBuffer();
res.ReleaseBuffer();
}
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