Manual: Difference between revisions

Latest revision as of 07:23, 1 April 2025

Complete list of var, dim and exoprog functions

ICONV/OCONV PATTERNS

Decimal (MD/MC)

input	conversion (string)	output
1234	MD2	12.34
1234	MD20	1234.00
1234	MD20,	1,234.00
1234.5678	MD2	12.35
1234.5678	MD20	1234.57
1234.5678	MD20,	1,234.57
1234	MC2	12,34
1234	MC20	1234,00
1234	MC20,	1.234,00
1234	MD20-	1234.00

Date (D)

input	conversion (string)	output
12345	D	18 OCT 2001
12345	D/	10/18/2001
12345	D-	10-18-2001
12345	D2	18 OCT 01
12345	D/E	18/10/2001
12345	DS	2001 OCT 18
12345	DS/	2001/10/18
12345	DM	10
12345	DMA	OCTOBER
12345	DY	2001
12345	DY2	01
12345	DD	18
12345	DW	4
12345	DWA	THURSDAY
12345	DQ	4
12345	DJ	291
12345	DL	31

Time (MT)

input	conversion (string)	output
234800	MT	17:13
234800	MTH	05:13PM
234800	MTS	17:13:20
234800	MTHS	05:13:20PM
0	MT	00:00
0	MTH	12:00AM
0	MTS	00:00:00
0	MTHS	12:00:00AM

Hex (HEX/MX)

input	conversion (string)	output
ab	HEX	(same as HEX8 or HEX4 depending on platform)
ab	HEX8	0000006100000062
ab	HEX4	00610062
ab	HEX2	6162
15	MX	F
254	MX	FE
255	MX	FF
256	MX	100
27354234	MX	1A1647A

Text (L/R/T)

input	conversion	(string)output
abcd	L#3	abc
ab	L#3	ab␣
abcd	R#3	bcd
ab	R#3	␣ab
ab	T#3	ab␣
abcd	T#3	abc™d␣␣
42	L(0)#5	42000
42	R(0)#5	00042
42	T(0)#5	42000

Dictionaries

Exodus dictionaries enable classic multivalue database data definition. Dictionaries are just normal Exodus multivalue files that contain one record for each data column definition. You can use Exodus's edir program to manually edit dictionaries.

Dictionary file names must start with the word "dict_". For example, if you have a "books" file, then you will probably have a "dict_books" file.

You can list the contents of a dictionary by typing "list dict_filename".

Exodus Dictionary Format

0	DICTID	Field/Column Code
1	DICTTYPE	"F" or "S" : "F" means use Field No (i.e. raw data) and "S" means use Source Code (i.e. a function).
2	FIELDNO	Field number (0=key, 1=field 1 etc for "Fields"
3	TITLE	Title on reports
4	SM	S or M or Mnn : "Single Value" or "Multivalue" or "Multivalue Group nn"
5	KEYPARTNO	Multipart keys are separated by * characters.
6
7	CONVERSION	Conversion (MD/MT/D etc.)
8	SOURCE	Source Code of a subroutine to calculate the field. Multivalues are lines and the result must be placed in a variable "ANS".
9	JUST	"L" or "R" or "T" requesting left, right or text justification
10	WIDTH	Column Width on fixed width reports

Sort/Select Command

Exodus provides the classic multivalue sort/select command within any Exodus program followed by readnext().

Classic multivalue select/readnext functions only provide the keys of the selected records. Exodus provides the classic select/readnext and also selectrecords/readnextrecord which provides complete records instead of just keys.

The format of the select/sselect command is as follows:

 SELECT|SSELECT

 {max_number_of_records}

 {using filename}

 filename

 {datakeyvalue} ...

 {BY|BY-DSND fieldname} ...
 
 {

  WITH

  {NO|ALL|ANY}

  dict_field_id

  {
   CONTAINING|STARTING|ENDING|LIKE|EQ|NE|NOT|GT|LT|GE|LE=|<>|>|<|>=|<= value(s)
   |
   BETWEEN value AND value
  }

  {AND|OR}

 } ...

Functions and Commands

String Commands

Most string functions like trim() that return a new modified string have a corresponding modify in place command like function like trimmer() that is is usually much faster. So we have convert and converter, replace and replacer, insert and inserter and so on.

Therefore by preference use

trimmer(v1);
// or
v1.trimmer()

instead of

v1 = trim(v1);
// or
v1 = v1.trim();

Function Types

TYPE	FUNCTION TYPE
var=	traditional functions that return values and can be used in expressions and be on the right hand side of assignments
if	traditional conditional statements that started with "if" or ended with "then/else" (or could have)
cmd	traditional commands with no outputs
expr	traditional commands that now have outputs and can be used in expressions

Parameters/Argument Types

in	Parameters that provide data to the function. Can be variables or raw data like 1 or "X"
unspecified	Same as "in". Omission of the most common type de-clutters the documentation. NB When defining your own subroutines and functions "in" cannot be omitted from the source code.
io	Parameters that may provide and/or return data. Must be variables. Cannot be raw data like 1 or "X"
out	Parameters that return data. Must be variables. Cannot be raw data like 1 or "X"

Optional Parameters

Key	Default
= ""	""
= " "	" "
= "."	"."
= 1	1
= 0	0
= true	true
= false	false

Field mark characters

Exodus implements a PICK OS data structure called a "dynamic array". This is simply any string which uses six specific unprintable ASCII delimiter characters (\x1A to \x1F) to separate its various parts. The parts are referred to as records, fields, values, subvalues, text, and subtext and fall within each other.

Dynamic arrays therefore implement sparse six dimensional arrays.

Typical CPU caching architecture favours similar values being adjacent in memory therefore implementing them as strings of values separated by delimiter characters can have performance advantages over more complex structures.

In practice the vast majority of dynamic arrays consist of "fields" separated by the FM character (\x1E) but it is very common for fields to have values separated by the VM character (\x1D) and values to have subvalues using SM (\x1D).

Since the six delimiter characters fall in the unprintable character range certain other characters have been designated as usable for coding and printing. For example the FM character is represented as ^ and can be entered in source code appended with _var to indicate that the string must be converted to internal format.

var v1 = "f1^f2^f3"_var; // Three fields

var v2 = "f1^v1]v2]v3^f3"_var; // Three fields, 2nd field has 3 values. It is "multivalued".

Anything which contains a collection of fields can be considered as a "record" and records can be stored in files with a unique primary key. The fields might represent different columns of a traditional database table. So anonymous field number 1 might be a contact name, field 2 the contact address, field 3 a multivalued list of contact points. etc.

Delimiter name	var	Hex	Display	cstr " "	char ' '
Record Mark	RM	\x1F	`	_RM	RM_
Field Mark	FM	\x1E	^	_FM	FM_
Value Mark	VM	\x1D	]	_VM	VM_
Subvalue Mark	SM	\x1C	}	_SM	SM_
Text Mark	TM	\x1B	\|	_TM	TM_
Subtext Mark	STM	\x1A	~	_STM	STM_

Delimiter Name :	Record Mark	Field Mark	Value Mark	Subvalue Mark	Text Mark	Subtext Mark
var :	RM	FM	VM	SM	TM	STM
Display :	`	^	]	}	\|	~
Hex :	\x1F	\x1E	\x1D	\x1C	\x1B	\x1A
cstr " " :	_RM	_FM	_VM	_SM	_TM	_STM
char ' ' :	RM_	FM_	VM_	SM_	TM_	STM_