Lots of changes to the AST Builder.

Adding IDENTIFIER Token type with optional differentiation between functions, constants and variables for syntax highlighting.
Adding substitute for many AST elements.
Properly starting builder: parsing identifiers, functions, variables, array values, properties, numbers, strings and subexpressions.

LogarithmPlotter/qml/eu/ad5001/LogarithmPlotter/Setting/ExpressionEditor.qml

@@ -504,7 +504,7 @@ Item {
         Generates a list of tokens from the given.
     */
     function tokens(text) {
-        let tokenizer = new Parsing.Tokenizer(new Parsing.Input(text), true, false)
+        let tokenizer = new Parsing.Tokenizer(new Parsing.Input(text), true, true, false)
         let tokenList = []
         let token
         while((token = tokenizer.next()) != null)

LogarithmPlotter/qml/eu/ad5001/LogarithmPlotter/js/parsing/ast.js

@@ -24,10 +24,7 @@
 const DERIVATION_PRECISION = 0.01
 const ZERO_EPISLON = 5e-11 // Number under which a variable is considered 0 when dealing with floating point rounding errors.
 
-const BINARY_OPERATION_PRIORITY = {
-    "+": 10, "-": 10,
-    "*": 20, "/": 20
-}
+const BINARY_OPERATION_PRIORITY = Reference.BINARY_OPERATION_PRIORITY
 
 enum ASEType {
     UNKNOWN,
@@ -417,16 +414,17 @@ class FunctionElement extends AbstractSyntaxElement {
     }
     
     substitute(variable, substitution) {
+        return new FunctionElement(this.functionName, this.args.map(arg => arg.substitute(variable, substitution)))
     }
     
     derivation(variable) {
         //TODO: Use DERIVATIVES elements in reference.
-        return new DerivationElement([this, variable])
+        return new DerivationElement([this, new Variable(variable)])
     }
     
     integral(variable) {
         //TODO: Use INTEGRALS elements in reference.
-        return new IntegralElement([this, variable])
+        return new IntegralElement([this, new Variable(variable)])
     }
     
     toEditableString() {
@@ -487,12 +485,20 @@ class DerivationElement extends FunctionElement {
     }
     
     simplify() {
-        return new DerivationElement([this.args[0].simplify(variables), this.args[1]])
+        return this.args[0].simplify().derivation(this.args[1].variableName).simplify()
+    }
+    
+    substitute(variable, substitution) {
+        if(variable == this.args[1].variableName) {
+            // Simplifu, 
+            return this.simplify().substitute(variable, substitution)
+        } else
+            return new DerivationElement([this.args[0].substitute(variable, substitution), this.args[1]])
     }
     
     integral(variable) {
         // Check if we're integrating and derivating by the same variable
-        return variable.variableName == this.args[1].variableName ? this.args[1] : super(variable)
+        return variable == this.args[1].variableName ? this.args[1] : super(variable)
     }
     
     toLatex() {
@@ -557,26 +563,44 @@ class IntegralElement extends FunctionElement {
     
     simplify() {
         // TODO: When full derivation and integrals are implemented, use dedicated functions for simplification.
-        let func = this.args[this.args.length-2].simplify(variables)
+        let func = this.f.simplify(variables)
         let newElem
         if(func.isConstant() && this.args.length == 4)
             // Simplify integral.
             newElem = new BinaryOperation(
-                new BinaryOperation(this.args[1], '-', this.args[0]).simplify(),
+                new BinaryOperation(this.b, '-', this.a).simplify(),
                 '*',
                 func
-            )
-        else
-            newElem = new IntegralElement(this.args.length == 4 ?
-                [this.a.simplify(), this.b.simplify(), func, this.d] :
-                [func, this.d]
-            )
+            ).simplify()
+        else {
+            let integrated = this.func.integral(this.d.variableName)
+            newElem = new BinaryOperation(
+                integrated.substitute(this.d.variableName, this.b),
+                '-',
+                integrated.substitute(this.d.variableName, this.a)
+            ).simplify()
+            //newElem = new IntegralElement(this.args.length == 4 ?
+            //    [this.a.simplify(), this.b.simplify(), func, this.d] :
+            //    [func, this.d]
+            //)
+        }
         return newElem
     }
     
+    substitute(variable, substitution) {
+        if(variable == this.args[1].variableName) {
+            // Simplify
+            return this.simplify().substitute(variable, substitution)
+        } else
+            return new IntegralElement(this.args.length == 4 ?
+                [this.a.substitute(variable, substitution), this.b.simplify(variable, substitution), 
+                                       this.f.substitute(variable, substitution), this.d] :
+                [this.f.substitute(variable, substitution), this.d])
+    }
+    
     derivation(variable) {
         // Check if we're integrating and derivating by the same variable
-        return variable.variableName == this.args[1].variableName ? this.args[1] : super(variable)
+        return variable == this.args[1].variableName ? this.args[1] : super(variable)
     }
     
     toLatex() {
@@ -689,6 +713,7 @@ class BinaryOperation extends AbstractSyntaxElement {
                     throw new EvalError("Unknown operator " + ope + ".")
             }
         }
+        // TODO: Check for all nearby operations simplifications
         return result
     }
     

LogarithmPlotter/qml/eu/ad5001/LogarithmPlotter/js/parsing/builder.js

@@ -23,26 +23,217 @@
 
 
 class ExpressionBuilder {
-    constructor(tokenizer) {
+    constructor(tokenizer, rememberTokens = false) {
         this.tokenizer = tokenizer;
+        if(tokenizer.tokenizeWhitespaces) {
+            console.warn('WARNING: The ExpressionTokenizer for ExpressionBuilder was initialized with whitespace support. Disabled.')
+            tokenizer.tokenizeWhitespaces = false
+        }
+        if(tokenizer.differentiateIdentifiers) {
+            console.warn('WARNING: The ExpressionTokenizer for ExpressionBuilder was initialized with identifier differentiation support. Disabled.')
+            tokenizer.differentiateIdentifiers = false
+        }
+        this.tokens = []
+        this.rememberTokens = rememberTokens
         this.stack = []
     }
     
-    parseExpression(delimitors = '') {
-        // Parse a sequence of operations, and orders them based on OPERATION_PRIORITY.
-        let elements = []
-        let operators = []
-        let firstToken = this.tokenizer.peek();
-        if(firstToken.type == TK.TokenType.OPERATOR) // First operations.
-            if(firstToken.value == "-") {
-                // TODO: Set initial argument.
-                this.tokenizer.skip(TK.TokenType.OPERATOR)
+    /**
+     * Parses an expression until the end is reached.
+     * 
+     * @throws {Error} When an unexpected token is encountered.
+     * @returns {AbstractSyntaxElement}
+     */
+    parseFullExpression() {
+        this.parseExpression([])
+        return this.stack.pop()
+    }
+    
+    /**
+     * Parses an expression until the end is reached.
+     * 
+     * @param {string} punctuationDelimitators - List of deliminators that ends the expression
+     * @throws {Error} When an unexpected token is encountered.
+     */
+    parseExpression(punctuationDelimitators = []) {
+        let token
+        while((token = this.tokenizer.peek()) != null) {
+            if(token.type == TK.TokenType.PUNCT && token.value != '(') // Still allow expression creation.
+                if(punctuationDelimitators.includes(token.value))
+                    break
+                else if(punctuationDelimitators.length == 1)
+                    this.tokenizer.raise(`Unexpected ${token.value}. Expected '${punctuationDelimitators[0]}'.`)
+                else
+                    this.tokenizer.raise(`Unexpected ${token.value}. Expected one of: '${punctuationDelimitators[0].join("', '")}'.`)
+            else
+                this.handleSingle()
+        }
+        
+        if(token == null && punctuationDelimitators.length > 0)
+            if(punctuationDelimitators.length == 1)
+                this.tokenizer.raise(`Unexpected end of expression. Expected '${punctuationDelimitators[0]}'.`)
+            else
+                this.tokenizer.raise(`Unexpected end of expression. Expected one of: '${punctuationDelimitators[0].join("', '")}'.`)
+        
+                
+        if(this.stack.length == 0)
+            if(token == null)
+                this.tokenizer.raise(`Unexpected end of expression. Expected at least one element.`)
+            else
+                this.tokenizer.raise(`Unexpected ${token.value}. Expected at least one element.`)
+            
+        if(this.stack.length > 1)
+            this.tokenizer.raise('Invalid expression.')
+    }
+    
+    /**
+     * Handles a single (assumed non-null) token based on its type.
+     * 
+     * @param {AbstractSyntaxElement} token
+     * @throws {Error} When an unexpected token is encountered.
+     */
+    handleSingle(token) {
+        switch(token.type) {
+            case TK.TokenType.IDENTIFIER:
+                this.parseIdentifier()
+                break
+            case TK.TokenType.OPERATOR:
+                if(this.stack.length == 0 && Reference.UNARY_OPERATORS.includes(token.value))
+                    this.parseSingleOperation()
+                else if(this.stack.length > 0 && Reference.BINARY_OPERATORS.includes(token.value))
+                    this.parseBinaryOperations()
+                else if(this.stack.length > 0 && Reference.TERTIARY_OPERATORS.includes(token.value))
+                    this.parseTertiaryOperation()
+                break
+            case TK.TokenType.NUMBER:
+                this.stack.push(new AST.NumberElement(this.tokenizer.next().value))
+                break
+            case TK.TokenType.STRING:
+                this.stack.push(new AST.StringElement(this.tokenizer.next().value))
+                break
+            case TK.TokenType.PUNCT:
+                if(token.value == '(') {
+                    this.tokenizer.skip(TK.TokenType.PUNCT, '(') // Skip the opening parentheses.
+                    this.parseExpression([')'])
                 } else
-                tokenizer.input.raise(`Invalid operator ${firstToken.value} at begining of statement.`)
-        else {
+                    this.tokenizer.raise(`Unexpected ${token.value}. Expected a value.`)
+                break
+            default:
+                this.tokenizer.raise(`Unknown token provided: ${token.value}.`)
+                break
+        }
+        if(this.rememberTokens)
+            this.tokens.push(token)
+    }
     
+    /**
+     * Parses a single token element.
+     * 
+     * @throws {Error} When an unexpected token is encountered.
+     */
+    parseSingle() {
+        let token = this.tokenizer.peek()
+        if(token != null)
+            this.handleSingle(token)
+    }
+    
+    parseIdentifier() {
+        // Assuming the right type.
+        let token = this.tokenizer.read(TK.TokenType.IDENTIFIER)
+        if(Reference.CONSTANTS_LIST.includes(token.value))
+            this.stack.push(new AST.Constant(token.value))
+        else
+            this.stack.push(new AST.Variable(token.value))
+        this.checkIdentifierFollowupTokens()
+    }
+    
+    /**
+     * Parses a function based on a previously called identifier.
+     * NOTE: Expects to have at least one stack element for function name.
+     */
+    parseFunction() {
+        // TODO: Implement dynamic functions values instead of being based on names.
+        let functionValue = this.stack.pop()
+        if(!(functionValue instanceof AST.Variable))
+            this.tokenizer.raise("Executing functions from dynamic variables is not implemented".)
+        let functionName = functionValue.variableName
+        let args = []
+        let token
+        while((token = this.tokenizer.peek()) != null && token.value != ')') {
+            this.tokenizer.skip(TK.TokenType.PUNCT) // Skip the opening parenthesis and the commas.
+            parseExpression([',',')'])
+            args.push(this.stack.pop())
+        }
+            
+        if(token == null)
+            this.tokenizer.raise(`Unexpected end of expression. Expected ')'.`)
+        
+        if(this.functionName == 'derivation')
+            this.stack.push(new AST.DerivationElement(args))
+        else if(this.functionName == 'integral')
+            this.stack.push(new AST.IntegralElement(args))
+        else
+            this.stack.push(new AST.FunctionElement(functionName, args))
+    }
+    
+    
+    /**
+     * Parses an object property based on a previously called identifier.
+     * NOTE: Expects to have at least one stack element for property object name.
+     */
+    parseProperty() {
+        this.tokenizer.skip(TK.TokenType.PUNCT, '.') // Skipping the dot.
+        let token = this.tokenizer.read(TK.TokenType.IDENTIFIER)
+        this.stack.push(new AST.PropertyElement(this.stack.pop(), token.value))
+        this.checkIdentifierFollowupTokens()
+    }
+    
+    /**
+     * Parses the value of the element of an array at a given index based on a previously called identifier.
+     * NOTE: Expects to have at least one stack element for property object name.
+     */
+    parseArrayValue() {
+        this.tokenizer.skip(TK.TokenType.PUNCT, '[') // Skipping the array opener.
+        let obj = this.stack.pop()
+        parseExpression([']'])
+        this.stack.push(new AST.ArrayElement(obj, this.stack.pop()))
+        this.checkIdentifierFollowupTokens()
+    }
+    
+    /**
+     * Checks for followup tokens following a value getting.
+     * E.g: getting the property of an object, an array member, or calling a function.
+     * NOTE: Expects to have at least one stack element for previous calling object.
+     */
+    checkIdentifierFollowupTokens() {
+        let peeked = this.tokenizer.peek()
+        if(peeked != null && peeked.type == TK.TokenType.PUNCT)
+            switch(peeked.value) {
+                case '(':
+                    // Function call
+                    this.parseFunction()
+                    break
+                case '.':
+                    // Member property
+                    this.parseProperty()
+                    break
+                case '[':
+                    // Array value
+                    this.parseArrayValue()
+                    break
             }
     }
     
-    parseOperation()`
+    parseBinaryOperations() {
+        if((this.tokenizer.peek().value in AST.BINARY_OPERATION_PRIORITY))
+            throw new Error("Current token is not a binary operator.")
+        if(this.stack.length == 0)
+            throw new Error(`The operator ${this.tokenizer.peek().value} can only be used after a value.`)
+        // Parse a sequence of operations, and orders them based on OPERATION_PRIORITY.
+        let elements = [this.stack.pop()]
+        let operators = [this.tokenizer.next()]
+        let token
+        while((token = this.tokenizer.peek()) != null) {
+        }
+    }
 }

LogarithmPlotter/qml/eu/ad5001/LogarithmPlotter/js/parsing/reference.js

@@ -28,6 +28,21 @@ const CONSTANTS = {
 };
 const CONSTANTS_LIST = Object.keys(CONSTANTS);
 
+const UNARY_OPERATORS = []
+
+const BINARY_OPERATION_PRIORITY = {
+    'and': 0, 'or': 0, 'in': 0,
+    '==': 10, '!=' : 10,
+    '>': 10, '<': 10, '>=': 10, '<=': 10,
+    '%': 20, '||': 20,
+    '+': 30, '-': 30,
+    '*': 40, '/': 40,
+    '^': 50
+}
+const BINARY_OPERATORS = Object.keys(BINARY_OPERATION_PRIORITY)
+
+const TERTIARY_OPERATORS = ['?']
+
 const FUNCTIONS = {
     "abs": Math.abs,
     "acos": Math.acos,

LogarithmPlotter/qml/eu/ad5001/LogarithmPlotter/js/parsing/tokenizer.js

@@ -23,13 +23,14 @@
 const WHITESPACES = " \t\n\r"
 const STRING_LIMITORS = '"\'`';
 const OPERATORS = "+-*/^%?:=!><";
-const PUNCTUTATION = "()[]{},.";
+const PUNCTUTATION = "()[],.";
 const NUMBER_CHARS = "0123456789"
 const IDENTIFIER_CHARS = "abcdefghijklmnopqrstuvwxyz0123456789_₀₁₂₃₄₅₆₇₈₉αβγδεζηθκλμξρςστφχψωₐₑₒₓₔₕₖₗₘₙₚₛₜ"
 
 var TokenType = {
     // Expression type
     "WHITESPACE": "WHITESPACE",
+    "IDENTIFIER": "IDENTIFIER",
     "VARIABLE": "VARIABLE",
     "CONSTANT": "CONSTANT",
     "FUNCTION": "FUNCTION",
@@ -49,10 +50,11 @@ class Token {
 }
 
 class ExpressionTokenizer {
-    constructor(input, tokenizeWhitespaces = false, errorOnUnknown = true) {
-        this.input = input;
-        this.currentToken = null;
+    constructor(input, tokenizeWhitespaces = false, differentiateIdentifiers = false, errorOnUnknown = true) {
+        this.input = input
+        this.currentToken = null
         this.tokenizeWhitespaces = tokenizeWhitespaces
+        this.differentiateIdentifiers = differentiateIdentifiers
         this.errorOnUnknown = errorOnUnknown
     }
     
@@ -115,10 +117,16 @@ class ExpressionTokenizer {
         while(!this.input.atEnd() && IDENTIFIER_CHARS.includes(this.input.peek().toLowerCase())) {
             identifier += this.input.next();
         }
-        if(Reference.CONSTANTS_LIST.includes(identifier.toLowerCase())) {
-            return new Token(TokenType.CONSTANT, identifier.toLowerCase(), this.input.position-identifier.length)
-        } else if(Reference.FUNCTIONS_LIST.includes(identifier.toLowerCase())) {
-            return new Token(TokenType.FUNCTION, identifier.toLowerCase(), this.input.position-identifier.length)
+        let identifierLC = identifier.toLowerCase()
+        if(Reference.CONSTANTS_LIST.includes(identifierLC)) {
+            return new Token(TokenType.CONSTANT, identifierLC, this.input.position-identifier.length)
+        } else if(Reference.FUNCTIONS_LIST.includes(identifierLC)) {
+            return new Token(TokenType.FUNCTION, identifierLC, this.input.position-identifier.length)
+        } else if(Reference.UNARY_OPERATORS.includes(identifierLC) || 
+            Reference.BINARY_OPERATORS.includes(identifierLC) ||
+            Reference.TERTIARY_OPERATORS.includes(identifierLC)
+        ) {
+            return new Token(TokenType.OPERATOR, identifierLC, this.input.position-identifier.length)
         } else {
             return new Token(TokenType.VARIABLE, identifier, this.input.position-identifier.length)
         }
@@ -137,7 +145,7 @@ class ExpressionTokenizer {
         if(Reference.CONSTANTS_LIST.includes(c)) return new Token(TokenType.CONSTANT, this.input.next(), this.input.position-1);
         if(PUNCTUTATION.includes(c)) return new Token(TokenType.PUNCT, this.input.next(), this.input.position-1);
         if(this.errorOnUnknown)
-            this.input.throw("Unknown token character " + c)
+            this.raise("Unknown token character " + c)
         else
             return new Token(TokenType.UNKNOWN, this.input.next(), this.input.position-1);
     }
@@ -157,13 +165,24 @@ class ExpressionTokenizer {
         return tmp;
     }
 
+    read(type, value) {
+        let next = this.next()
+        if(type != null && next.type != type)
+            this.raise(`Unexpected ${next.type.toLowerCase()} ${next.value}. Expected type was ${type.toLowerCase()}.`);
+        if(value != null && next.value == value)
+            this.raise(`Unexpected ${next.type.toLowerCase()} ${next.value}. Expected value was ${value}.`);
+        return next
+    }
+    
     atEnd() {
         return this.peek() == null;
     }
     
-    skip(type) {
-        let next = this.next();
-        if(next.type != type)
-            input.raise("Unexpected token " + next.type.toLowerCase() + ' "' + next.value + '". Expected ' + type.toLowerCase());
+    skip(type, value) {
+        this.read(type, value)
+    }
+    
+    raise(message) {
+        this.input.raise(message)
     }
 }