Create algebraic expression parsing algorithm

[tovaio]

Description

As students, we want Jebra to be able to convert our string input answers into a format it can understand and compare easily, so that we don't have to worry about string formatting issues when typing our answers (e.g. spaces between terms/operators, unnecessary decimal points, etc.).

As developers, we want to develop an algorithm that parses strings containing expressions into a syntax tree, so we can use it to compare students' string answers to our stored correct string answers regardless of differences in format.

Example

Correct answer in database: "25"
Student input: "25.0"

Correct answer in database: "3a + 2b"
Student input: "3a+2b" or "3*a + 2*b" or similar

These answers are correct, but they aren't the same strings. We want an algorithm that parses these strings into some sort of syntax tree and compares these trees.

For example:

• "25" --> num(25)
• "3a + 2b" --> add(mul(num(3), var(a)), mul(num(2), var(b)))

Acceptance Criteria

• Lexing: algorithm reads through input string and splits it into array of tokens
• Parsing: algorithm reads through array of tokens and creates a syntax tree
• Equality: syntax trees can be compared, with commutativity taken into account (e.g. 25 + a == a + 25 or 3a == a*3)

[tovaio]

Note: we can use this package to assist us for this task

[tovaio]

Closed since there are likely publicly available packages that address this need.