Expr

Auto-generated from src/stdlib/expr.mcrs — do not edit manually.

API

• expr_eval

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expr_eval v1.2.0

Evaluate an RPN (Reverse Polish Notation) token stream with a single variable substitution.

Token encoding (all values × 10000):

• Positive integer: literal value pushed onto the stack
• -10000: variable x (replaced by the x argument)
• -1 ADD, -2 SUB, -3 MUL (fixed-point), -4 DIV (fixed-point)
• -5 SIN (degrees × 10000 → result × 10000), -6 COS, -7 SQRT, -8 ABS

Internal stack depth: 16 elements. Behaviour is undefined for malformed token streams.

fn expr_eval(tokens: int[], n: int, x: int): int

Parameters

Parameter	Description
tokens	RPN token array of length n
n	Number of tokens
x	Variable value × 10000 substituted for token -10000

Returns: Top-of-stack value × 10000 after evaluating all tokens

Example

// 2*x + 1  →  RPN: [20000, -10000, -3, 10000, -1]
let prog: int[] = [20000, -10000, -3, 10000, -1];
expr_eval(prog, 5, 15000); // 40000  (2×1.5 + 1 = 4.0)

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