akar-processor 0.1.0

Query processor and execution engine for the Akar embedded graph database
Documentation 
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use akar_common::vector::DataChunk;
use akar_parser::ast::Expression;

pub fn resolve_projection_column_index(expr: &Expression, chunk: &DataChunk) -> Option<usize> {
    if let Expression::PropertyAccess(obj, prop) = expr {
        let col_name = if let Expression::Variable(var) = &**obj {
            format!("{}.{}", var, prop)
        } else {
            prop.clone()
        };
        if !chunk.field_names.is_empty() {
            if let Some(idx) = chunk.field_names.iter().position(|n| n == &col_name || n == prop) {
                return Some(idx);
            }
        }
        if let Expression::Variable(var) = &**obj {
            if let Ok(idx) = var.parse::<usize>() {
                return Some(idx);
            }
        }
        return None;
    }
    if let Expression::Variable(name) = expr {
        if let Ok(idx) = name.parse::<usize>() {
            return Some(idx);
        }
        if !chunk.field_names.is_empty() {
            if let Some(idx) = chunk.field_names.iter().position(|n| n == name) {
                return Some(idx);
            }
        }
        return None;
    }
    None
}