Data writer

Data writer enables serialization of data as string characters written to output stream. Same encoding rules that apply to data reader also apply to data writer.

Additionally, data writer will provide informative representation of data types which can not be parsed by data reader (builtin function, builtin syntax, function and syntax).

Source code

write.h

#ifndef LISP16_WRITE_H
#define LISP16_WRITE_H

#include "mem.h"
#include "stream.h"


lsp_status_t lsp_write(lsp_mem_t *m, lsp_out_stream_t *s, lsp_addr_t addr);

#endif

write.c

#include "write.h"
#include "function.h"
#include "syntax.h"


static lsp_status_t write_number(lsp_mem_t *m, lsp_out_stream_t *s,
                                 lsp_addr_t addr) {
    return lsp_out_stream_write_int(s, lsp_mem_get_number(m, addr));
}


static lsp_status_t write_pair(lsp_mem_t *m, lsp_out_stream_t *s,
                               lsp_addr_t addr) {
    lsp_status_t status = lsp_out_stream_write(s, '(');
    if (status != LSP_SUCCESS)
        return status;

    lsp_bool_t write_space = false;
    while (addr != m->nil) {
        if (write_space) {
            lsp_out_stream_write(s, ' ');
        } else {
            write_space = true;
        }

        lsp_addr_t first = lsp_mem_get_pair_first(m, addr);
        lsp_addr_t second = lsp_mem_get_pair_second(m, addr);

        status = lsp_write(m, s, first);
        if (status != LSP_SUCCESS)
            return status;

        if (!lsp_mem_is_pair(m, second)) {
            status = lsp_out_stream_write_str(s, " . ");
            if (status != LSP_SUCCESS)
                return status;

            status = lsp_write(m, s, second);
            if (status != LSP_SUCCESS)
                return status;

            break;
        }

        addr = second;
    }

    return lsp_out_stream_write(s, ')');
}


static lsp_status_t write_string(lsp_mem_t *m, lsp_out_stream_t *s,
                                 lsp_addr_t addr) {
    lsp_uint16_t len = lsp_mem_get_string_len(m, addr);
    lsp_status_t status = lsp_out_stream_write(s, '"');

    for (lsp_uint16_t i = 0; i < len; ++i) {
        lsp_uint8_t c = lsp_mem_get_string_data(m, addr, i);

        if (c == '"') {
            status = lsp_out_stream_write(s, '\\');
            if (status != LSP_SUCCESS)
                return status;
        }

        status = lsp_out_stream_write(s, c);
        if (status != LSP_SUCCESS)
            return status;
    }

    return lsp_out_stream_write(s, '"');
}


static lsp_status_t write_symbol(lsp_mem_t *m, lsp_out_stream_t *s,
                                 lsp_addr_t addr) {
    lsp_uint16_t len = lsp_mem_get_symbol_len(m, addr);

    for (lsp_uint16_t i = 0; i < len; ++i) {
        lsp_uint8_t c = lsp_mem_get_symbol_name(m, addr, i);
        lsp_status_t status = lsp_out_stream_write(s, c);
        if (status != LSP_SUCCESS)
            return status;
    }

    return LSP_SUCCESS;
}


static lsp_status_t write_builtin_function(lsp_mem_t *m, lsp_out_stream_t *s,
                                           lsp_addr_t addr) {
    lsp_status_t status = lsp_out_stream_write_str(s, "#<builtin-function-");
    if (status != LSP_SUCCESS)
        return status;

    status = lsp_out_stream_write_str(
        s, lsp_functions[lsp_mem_get_builtin_index(m, addr)].name);
    if (status != LSP_SUCCESS)
        return status;

    return lsp_out_stream_write(s, '>');
}


static lsp_status_t write_builtin_syntax(lsp_mem_t *m, lsp_out_stream_t *s,
                                         lsp_addr_t addr) {
    lsp_status_t status = lsp_out_stream_write_str(s, "#<builtin-syntax-");
    if (status != LSP_SUCCESS)
        return status;

    status = lsp_out_stream_write_str(
        s, lsp_syntaxes[lsp_mem_get_builtin_index(m, addr)].name);
    if (status != LSP_SUCCESS)
        return status;

    return lsp_out_stream_write(s, '>');
}


static lsp_status_t write_function(lsp_mem_t *m, lsp_out_stream_t *s,
                                   lsp_addr_t addr) {
    lsp_status_t status = lsp_out_stream_write_str(s, "#<function-");
    if (status != LSP_SUCCESS)
        return status;

    status = lsp_out_stream_write_int(s, addr);
    if (status != LSP_SUCCESS)
        return status;

    return lsp_out_stream_write(s, '>');
}


static lsp_status_t write_syntax(lsp_mem_t *m, lsp_out_stream_t *s,
                                 lsp_addr_t addr) {
    lsp_status_t status = lsp_out_stream_write_str(s, "#<syntax-");
    if (status != LSP_SUCCESS)
        return status;

    status = lsp_out_stream_write_int(s, addr);
    if (status != LSP_SUCCESS)
        return status;

    return lsp_out_stream_write(s, '>');
}


lsp_status_t lsp_write(lsp_mem_t *m, lsp_out_stream_t *s, lsp_addr_t addr) {
    if (lsp_mem_is_number(m, addr))
        return write_number(m, s, addr);

    if (lsp_mem_is_pair(m, addr))
        return write_pair(m, s, addr);

    if (lsp_mem_is_string(m, addr))
        return write_string(m, s, addr);

    if (lsp_mem_is_symbol(m, addr))
        return write_symbol(m, s, addr);

    if (lsp_mem_is_builtin_function(m, addr))
        return write_builtin_function(m, s, addr);

    if (lsp_mem_is_builtin_syntax(m, addr))
        return write_builtin_syntax(m, s, addr);

    if (lsp_mem_is_function(m, addr))
        return write_function(m, s, addr);

    if (lsp_mem_is_syntax(m, addr))
        return write_syntax(m, s, addr);

    return LSP_ERR_WRITE;
}