Red Juice v1.4.6

Introduction

Red Juice is a home-made language with the purpose of procedurally generate mathematical problems.

You can output lines and equations while executing formal expressions and storing them in variables.

Since v1.4, it is now a Turing Complete language.

Installation

First, you need to build giac (see this page for more info) :

Warning : Giac needs a node version before 12

# build with max capacity (might be long anyway)
JOBS=4 npm install giac@latest

Then you can install with the following :

npm install red-juice --production

Usage

With node

then

const interpreter = require('red-juice');

...

const errors = interpreter.verify(code);
if(errors.length){
   //print/handle errors
} else {
   const output = interpreter.eval(code);
   // see example for output format
}

Commande line

node red-juice.js inputFile [-v][-h][-q][-d][-o outputFile][-j][-f][-s seed][-l]

-v / --verbose : more info
-h / --help : show this message
-q / --quiet : do not log output
-d / --debug : show debug log
-o / --output : indicate output file (activate json format)
-j / --json : json format
-f / --final : show as final exercise
-s / --seed : indicate numeric seed
-l / --latex : enable latex output of vars

Example

The code :

VAR A = 2;
VAR B = (A + 1)/2;
$\frac{{A}}{{B}}$ #LaTeX expression
START ex1;
    TIME 60;
    IF A < 5;
        ${A}\times {B}$
        this is a test
        START partA;
            this is partA
        END partA;
    ELSE;
        START partA;
            this is partA
        END partA;
    ENDIF;
END ex1;

Will output (

{
    "content" : {
        "" : "$\frac{2}{\frac{3}{2}}$\n",
        "#ex1" : "$2\times \frac{3}{2}$\nthis is a test\n",
        "#ex1#partA" : "this is partA\n"
    },
    "timers" : {
        "#ex1" : 60
    }
}

Writing rules

• A line without a semicolon (;) is an output line.
• Everything after an hashtag (#) is considered commented. (even outside code lines)
• Indentation doesn't matter.
• Variables in output surrounded by braces ({var}) will be replaced by its value in LaTeX.
• Variables can be tested in output with {var:something}, it will be replaced with 'something' only if 'var' is not null.
• Same thing, {!var:something}, it will be replaced with something only if 'var' is null.
• Tests in output can be more complex like {var > 0 || var2 != 5:something}
• In output you can use {simplify:something} and what's inside will be simplified and output in LaTeX
• If the simplify output is red, it means it failed somehow (there is maybe some * missing between values)
• Code line must start with a keyword (see below).
• Expression will be computed and stored as formal. (1/3 will keep its formal value and be simplified if needed)
• Keywords should be uppercase, but will work as any capitalization.
• You can use predefined constants like PI.
• Variable names must start with a letter.
• Expression are written with basic mathematical symbols (-+*/^%) and functions. (see below)
• Functions can be used with any capitalization.

Keywords

VAR - Assignation

Example :

VAR A = RAND(1, 10);
VAR A = e^SIN(A);

IF, ELIF, ELSE, ENDIF - Condition

Example :

IF A < 5;
    do something
ELIF A > 6 && A <= 10 || A >= 15;
    do something else
ELSE;
    do something else
ENDIF;

WHILE, ENDWHILE - Loops

Example :

WHILE A != B;
   do something
ENDWHILE;

START, END - Partition

Example :

will be outputed in part with blank name
START part1;
    will be outputed in part with name #part1
    START partA;
        will be outputed in part with name #part1#partA
    END partA;
    START partB;
        will be outputed in part with name #part1#partB
    END partB;
END part1;

TIME - Indication

Example :

START part1;
    TIME 60; #indicate for #part1
    START partA;
        TIME 65; #indicate for #part1#partA
    END partA;
    TIME 30; #overwrite for #part1
END part1;

Functions and operators list

Basic functions

Name	Alias	Arguments	More info
rand		2	random value between argument 1 and argument 2 included
randnn		2	random value not null between argument 1 and argument 2 included
abs		1	absolute value or module of complex
sign		1	sign (-1,0,+1)
max		2	maximum
min		2	minimum
round		1
floor		1
frac		1
ceil		1
factorial		1
sqrt		1	square root
exp	e^var	1	exponential
log	ln	1	natural logarithm
log10		1	base 10 logarithm

Complexes

Name	Alias	Arguments	More info
re		1	real part of complex
im		1	imaginary part of complex
arg		1	argument
conj		1	conjugate

Trigonometry

Name	Alias	Arguments	More info
sin		1	sine
cos		1	cosine
tan		1	tangent
cot		1	cotangent
asin		1	arc sine
acos		1	arc cosine
atan		1	arc tangent
sinh		1	hyperbolic sine
cosh		1	hyperbolic cosine
tanh		1	hyperbolic tangent
asinh		1	argument of hyperbolic sine
acosh		1	argument of hyperbolic cosine
atanh		1	argument of hyperbolic tangent
asinh		1	argument of hyperbolic sine
acosh		1	argument of hyperbolic cosine
atanh		1	argument of hyperbolic tangent

Operators

Name	Alias	Arguments	More info
neg	-var	1	negative value
not	!var	1	inverse value
plus	var1 + var2	2	addition
minus	var1 - var2	2	substraction
div	var1 / var2	2	division
mod	var1 % var2	2	modulo
pow	var1 ^ var2	2	power
times	var1 * var2	2	multiplication
eq	var1 == var2	2	equal
neq	var1 != var2	2	not equal
gte	var1 >= var2	2	greater than or equal
lte	var1 <= var2	2	less than or equal
gt	var1 > var2	2	greater than
lt	var1 < var2	2	less than
and	var1 && var2	2
or	`var1		var2`

Vectors and Matrices

Name	Alias	Arguments	More info
length	len	1	size of var
randvec		3	random vector of size arg 1 and values between arg 2 and arg 3
randmat		4	random matrix of size arg 1 x arg 2 and values between arg 3 and arg 4
get	var1[var2]	2	get value of cell in var
cross		2	cross product between 2 vectors
vec{n}		n	creates a vector with n given values (ex: vec3(1,2,3))
tran	~mat1	1	transpose of matrix
mtimes	mat1.*mat2	2	cell by cell multiplication
rank		1	rank of matrix
det		1	determinant of matrix
ker		1	kernel of matrix
image		1	image of matrix
idn		1	identity matrix of given size
zeros		2	create a matrix of size arg 1 x arg 2 filled with 0
ones		2	create a matrix of size arg 1 x arg 2 filled with 1

Constants

Name	Alias	Explanation
e		exponential
pi	PI	π
infinity	inf	∞
i		complex i
euler_gamma		Euler constant γ
true	True	boolean value
false	False	boolean value

Changelog

• 1.4.6: fixed auto install of giac.node
• 1.4.5: added max node version + more info to install
• 1.4.4: multiple subscriptions in formula (ex : [1][2])
• 1.4.3: zeros and ones matrix functions
• 1.4.2:
  • VAR A[B] = ...; var subscription by other var
  • no LaTeX in output by default in CLI (need --latex)
  • loop bug fix
• 1.4.1: command line interface
• 1.4.0: loops with WHILE, ENDWHILE
• 1.3.5: Predefined capitalization for constants
• 1.3.4: len function for vectors and matrices
• 1.3.3: better looking vectors in LaTeX
• 1.3.2: variable cell attribution VAR A[0] = 2;
• 1.3.1 :
  • More constants : e, i, infinity, inf, euler_gamma, true, false
  • vec{n} creates vectors size n
  • subscriptable vars in expressions A[0] * A[1]
• 1.3.0 :
  • Matrices and vectors functions
  • Safe giac call (avoid ERROR: something in output)
• 1.2.9 : TIME keyword and output format change
• 1.2.8 : RANDNN function
• 1.2.7 : Remove blank outputed lines
• 1.2.6 : Word blacklist for output
• 1.2.5 : {simplify:2x+2x} -> 4\\cdot x
• 1.2.4 : Version number to be shown in editor
• 1.2.3 : Added error 'Restricted variable name'
• 1.2.2 : Fix when output had a lot of -- or +-
• 1.2.1 : +- and -- handling (not replacing already there)
• 1.2 : A lot of functions ported from giac (see above)
• 1.1.1 :
  • Fixed mis-implementation of Shunting Yard
  • Operators into functions (! -> not)
• 1.1 :
  • LaTeX conditions {v:{v > 1:new version}{v == 0:same version}}
  • Bug fix
• 1.0 :
  • Versioning
  • Not operators (!, !=`)
  • Negative things (-func, -var)
  • Debug switch
  • Bug fix