880 lines
32 KiB
C++
880 lines
32 KiB
C++
/** @file Tokenizer.cpp
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*
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* @author Roland Conybeare, Jul 2024
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**/
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#include "Tokenizer.hpp"
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namespace xo {
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using xo::mm::MemorySizeInfo;
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using std::byte;
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namespace scm {
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Tokenizer::Tokenizer(const CircularBufferConfig & config,
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bool debug_flag)
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: input_buffer_{DCircularBuffer::map(config)},
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input_state_{debug_flag}
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{}
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void
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Tokenizer::discard_current_line()
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{
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this->input_state_.discard_current_line();
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}
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void
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Tokenizer::visit_pools(const MemorySizeVisitor & visitor) const
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{
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input_buffer_.visit_pools(visitor);
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}
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bool
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Tokenizer::is_1char_punctuation(CharT ch)
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{
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switch(ch) {
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case '\'':
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return true;
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case '(':
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return true;
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case ')':
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return true;
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case '[':
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return true;
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case ']':
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return true;
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case '{':
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return true;
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case '}':
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return true;
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case '<':
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/* can't be 1char punctuation -- can begin lessequal token */
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return false;
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case '>':
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/* can't be 1char punctuation -- can begin greatequal token,
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* and appears in tk_yields token
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*/
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return false;
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case ',':
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return true;
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case ';':
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return true;
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case ':':
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/* can't be 1char punctuation -- can begin assignment token */
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return false;
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case '=':
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/* can't be 1char punctuation -- can begin comparison token '==' */
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return false;
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case '!':
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/* can't be 1char punctuation -- can begin comparison token '!=' */
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return false;
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case '-':
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/* can't be punctuation
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* - can appear inside f64 token: e.g. 1.23e-9.
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* - begins tk_yields token: ->
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*/
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return false;
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case '+':
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/* can't be punctuation -- can appear inside f64 token: e.g. 1.23e+4 */
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return false;
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case '*':
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/* not punctuation -- allowed in symbol */
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return false;
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case '/':
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/* not punctuation -- for symmetry with +,- */
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return false;
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case '.':
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/* can't be punctuation -- can appear inside f64 token: e.g. 1.23 */
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return false;
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}
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return false;
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}
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bool
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Tokenizer::is_2char_punctuation(CharT ch)
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{
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/* can't put '-' here, because of the way it appears in numeric literals
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* characters here may not appear in symbol names
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*/
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switch(ch) {
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case '<':
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/* can begin <= */
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return true;
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case '>':
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/* can begin >= */
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return true;
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case ':':
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/* can begin := */
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return true;
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case '=':
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/* can begin == */
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return true;
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case '!':
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/* can begin != */
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return true;
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}
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return false;
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}
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auto
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Tokenizer::assemble_token(span_type ws_span,
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span_type token_text,
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TkInputState * p_input_state) -> result_type
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{
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/* literal|pretty|streamlined */
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log_config::style = function_style::streamlined;
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scope log(XO_DEBUG(p_input_state->debug_flag()));
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log && log(xtag("token_text", token_text),
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xtag("initial_whitespace", ws_span.size()),
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xtag("input_state", *p_input_state));
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tokentype tk_type = tokentype::tk_invalid;
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std::string tk_text;
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const CharT * tk_start = token_text.lo();
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const CharT * tk_end = token_text.hi();
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const CharT * ix = tk_start;
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/* switch here applies to the first character in a token */
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switch (*ix) {
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case '-':
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case '+':
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if (token_text.size() == 1) {
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/* standalone '+' or '-' */
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if (*ix == '+')
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tk_type = tokentype::tk_plus;
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else if(*ix == '-')
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tk_type = tokentype::tk_minus;
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}
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/** fall through to numeric literal code below **/
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[[fallthrough]];
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case '.':
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case '0':
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case '1':
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case '2':
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case '3':
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case '4':
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case '5':
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case '6':
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case '7':
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case '8':
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case '9':
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{
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/* examples of valid floating-point numbers:
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* .0
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* 1e0
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* 1e
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* 0.
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* +1e0
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* -1e0
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* +1E+2
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* -1E+2
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* -0.123e-10
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* non-examples:
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* .
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* -
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* +
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* e0
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* .e0
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* -.e-0
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* +.e+0
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*
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* in particular: to be recognized as a number,
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* must contain at least one digit
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*/
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log && log("possible number-token");
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/* true if initial sign -/+ encountered */
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bool sign_flag = false;
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/* true if '.' encountered */
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bool period_flag = false;
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/* true if 'e' | 'E' encountered.
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*/
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bool exponent_flag = false;
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/* true when sign '-' | '+' precedes exponenct digits */
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bool exponent_sign_flag = false;
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/* true when at least one digit follows exponent marker */
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bool exponent_digit_flag = false;
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/* true if at least one digit encountered */
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bool number_flag = false;
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log && log(xtag("*ix", *ix),
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xtag("tk.length", token_text.size()));
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if (log && (ix + 1 < tk_end))
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log(xtag("*(ix+1)", *(ix + 1)));
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if ((*ix == '-') && (ix + 2 == token_text.hi()) && (*(ix + 1) == '>')) {
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/* composing exactly '->' */
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tk_type = tokentype::tk_yields;
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} else {
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/* token (if valid) will be one of: {tk_i64, tk_f64, tk_dot}: */
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for (; ix != token_text.hi(); ++ix) {
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if ((*ix == '-') || (*ix == '+')) {
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/* sign allowed:
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* 1. before period and before first digit
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* 2. after exponent
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*/
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if (!period_flag && !number_flag && !sign_flag) {
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sign_flag = true;
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} else if (exponent_flag && !exponent_digit_flag) {
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exponent_sign_flag = true;
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} else {
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return result_type::make_error_consume_current_line
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(__FUNCTION__ /*src_function*/,
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"improperly placed sign indicator",
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(ix - tk_start),
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*p_input_state);
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}
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} else if (*ix == '.') {
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if (period_flag) {
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return result_type::make_error_consume_current_line
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(__FUNCTION__ /*src_function*/,
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"duplicate decimal point in numeric literal",
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(ix - tk_start),
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*p_input_state);
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}
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period_flag = true;
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} else if ((*ix == 'e') || (*ix == 'E')) {
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if (exponent_flag) {
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return result_type::make_error_consume_current_line
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(__FUNCTION__ /*src_function*/,
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"duplicate exponent marker in numeric literal",
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(ix - tk_start),
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*p_input_state);
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}
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exponent_flag = true;
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} else if (isdigit(*ix)) {
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if (exponent_flag) {
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/* need digit before exponent to recognize as number */
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exponent_digit_flag = true;
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} else {
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number_flag = true;
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}
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} else {
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return result_type::make_error_consume_current_line
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(__FUNCTION__ /*src_function*/,
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"unexpected character in numeric constant" /*error_description*/,
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(ix - tk_start),
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*p_input_state);
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}
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}
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if (number_flag) {
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if (period_flag || exponent_flag) {
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tk_type = tokentype::tk_f64;
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} else {
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tk_type = tokentype::tk_i64;
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}
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} else if (period_flag && !exponent_flag) {
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tk_type = tokentype::tk_dot;
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} else {
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/* not a valid token */
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}
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log && log(xtag("sign_flag", sign_flag));
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log && log(xtag("period_flag", period_flag),
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xtag("exponent_flag", exponent_flag),
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xtag("exponent_sign_flag", exponent_sign_flag),
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xtag("number_flag", number_flag));
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log && log(xtag("tk_type", tk_type));
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}
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break;
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}
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case '*':
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if (token_text.size() == 1) {
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/* standalone '*' */
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tk_type = tokentype::tk_star;
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++ix;
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} else {
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/* '*' isn't punctuation -- but may allow appearance in a longer token
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*
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* thinking that x*y is a symbol with an embedded '*' character;
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* in particular want to support kebab-case symbols like 'foo-config'
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*/
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}
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break;
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case '/':
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if (token_text.size() == 1) {
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/* standalone '/' */
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tk_type = tokentype::tk_slash;
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++ix;
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}
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break;
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case '=':
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log && log("singleassign or cmpeq token");
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if (*(ix + 1) == '=') {
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tk_type = tokentype::tk_cmpeq;
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++ix;
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++ix;
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} else {
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/* standalone '=' */
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tk_type = tokentype::tk_singleassign;
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++ix;
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}
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break;
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case '!':
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if (*(ix + 1) == '=') {
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tk_type = tokentype::tk_cmpne;
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++ix;
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++ix;
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} else {
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/* standlone '!' */
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// TODO
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}
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break;
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case '"':
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{
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log && log("recognize string-token");
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tk_type = tokentype::tk_string;
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tk_text.reserve(token_text.hi() - token_text.lo());
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++ix; /*skip initial " char*/
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/* true on final " */
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bool endofstring = false;
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for (; ix != token_text.hi(); ++ix) {
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log && log(xtag("*ix", *ix));
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switch(*ix) {
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case '"':
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endofstring = true;
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/* skip final " char, don't capture */
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++ix;
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break;
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case '\\':
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/* skip escape char, don't capture */
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++ix;
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if (ix == token_text.hi()) {
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return result_type::make_error_consume_current_line
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(__FUNCTION__ /*src_function*/,
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"expecting key following escape character \\",
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(ix - tk_start),
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*p_input_state);
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}
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switch(*ix) {
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case '\\':
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log && log(xtag("*ix", *ix), xtag("escaped", "t"));
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tk_text.push_back(*ix);
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break;
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case 'n':
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log && log(xtag("*ix", *ix), xtag("newline", "t"));
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tk_text.push_back('\n');
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break;
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case 't':
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log && log(xtag("*ix", *ix), xtag("tab", "t"));
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tk_text.push_back('\t');
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break;
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case 'r':
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log && log(xtag("*ix", *ix), xtag("cr", "t"));
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tk_text.push_back('\r');
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break;
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case '"':
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log && log(xtag("*ix", *ix), xtag("quote", "t"));
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tk_text.push_back('"');
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break;
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default:
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return result_type::make_error_consume_current_line
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(__FUNCTION__ /*src_function*/,
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"expecting one of n|r|\"|\\ following escape \\",
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(ix - tk_start),
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*p_input_state);
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}
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break;
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default:
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tk_text.push_back(*ix);
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break;
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}
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if (endofstring)
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break;
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}
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if (!endofstring) {
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return result_type::make_error_consume_current_line
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(__FUNCTION__ /*src_function*/,
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"missing terminating '\"' to complete literal string",
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(ix - tk_start),
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*p_input_state);
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}
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log && log(tostr("tokenizer::assemble_token",
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xtag("tk_text", tk_text)));
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break;
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}
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case '\'':
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{
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log && log("quote token");
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tk_type = tokentype::tk_quote;
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++ix;
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break;
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}
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case '#':
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case 'a': case 'A':
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case 'b': case 'B':
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case 'c': case 'C':
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case 'd': case 'D':
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case 'e': case 'E':
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case 'f': case 'F':
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case 'g': case 'G':
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case 'h': case 'H':
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case 'i': case 'I':
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case 'j': case 'J':
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case 'k': case 'K':
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case 'l': case 'L':
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case 'm': case 'M':
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case 'n': case 'N':
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case 'o': case 'O':
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case 'p': case 'P':
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case 'q': case 'Q':
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case 'r': case 'R':
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case 's': case 'S':
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case 't': case 'T':
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case 'u': case 'U':
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case 'v': case 'V':
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case 'w': case 'W':
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case 'x': case 'X':
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case 'y': case 'Y':
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case 'z': case 'Z':
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{
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/* symbol/identifier must begin with a letter?
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* we want to accept some other chars too.
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* specifically want to allow identifiers:
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* this-is-the-way
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* this+is+also+the+way
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* how/much/is/that/doggy
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* put*an*asterisk*in*that
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* something%special%
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*
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* like pure lisp, we don't allow:
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* - identifier beginning with digit
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* - period .
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*
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* unlike pure lisp, we don't allow anywhere in a symbol:
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* - colon :
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* - semicolon ;
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* - comma ,
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*
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* also we don't allow symbols to begin with special chars
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*/
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tk_type = tokentype::tk_symbol;
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break;
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}
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case '<':
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{
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log && log("leftangle or lessequal token");
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if (*(ix + 1) == '=') {
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tk_type = tokentype::tk_cmple;
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++ix;
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++ix;
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} else {
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tk_type = tokentype::tk_leftangle;
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++ix;
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}
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break;
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}
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case '>':
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{
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log && log("rightangle or greatequal token");
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if (*(ix + 1) == '=') {
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tk_type = tokentype::tk_cmpge;
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++ix;
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++ix;
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} else {
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tk_type = tokentype::tk_rightangle;
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++ix;
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}
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break;
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}
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case '(':
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tk_type = tokentype::tk_leftparen;
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++ix;
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break;
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case ')':
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tk_type = tokentype::tk_rightparen;
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++ix;
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break;
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case '[':
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tk_type = tokentype::tk_leftbracket;
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++ix;
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break;
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case ']':
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tk_type = tokentype::tk_rightbracket;
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++ix;
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break;
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case '{':
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tk_type = tokentype::tk_leftbrace;
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++ix;
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break;
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case '}':
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tk_type = tokentype::tk_rightbrace;
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++ix;
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break;
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case ',':
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tk_type = tokentype::tk_comma;
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++ix;
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break;
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case ';':
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tk_type = tokentype::tk_semicolon;
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++ix;
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break;
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case ':':
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{
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log && log("colon or assignment token");
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if (*(ix + 1) == '=') {
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tk_type = tokentype::tk_assign;
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++ix;
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++ix;
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} else {
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tk_type = tokentype::tk_colon;
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++ix;
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}
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break;
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}
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default:
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break;
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}
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if (tk_type == tokentype::tk_invalid) {
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return result_type::make_error_consume_current_line
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(__FUNCTION__ /*src_function*/,
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"illegal input character",
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(ix - tk_start),
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*p_input_state);
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}
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if ((tk_type == tokentype::tk_i64)
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|| (tk_type == tokentype::tk_f64)
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|| (tk_type == tokentype::tk_symbol))
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{
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/* note: capturing token text here;
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* for numeric literals will re-parse in token::i64_value() / token::f64_value()
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*/
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tk_text = std::string(tk_start, tk_end);
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} else if (tk_type == tokentype::tk_string) {
|
|
; /* nothing to do here -- desired tk_text already constructed */
|
|
}
|
|
|
|
if (tk_type == tokentype::tk_symbol) {
|
|
/* check for keywords */
|
|
|
|
bool keep_text = false;
|
|
|
|
if ((tk_text == "true") || (tk_text == "false")) {
|
|
tk_type = tokentype::tk_bool;
|
|
keep_text = true;
|
|
} else if (tk_text == "nil") {
|
|
tk_type = tokentype::tk_nil;
|
|
} else if (tk_text == "type") {
|
|
tk_type = tokentype::tk_type;
|
|
} else if (tk_text == "def") {
|
|
tk_type = tokentype::tk_def;
|
|
} else if (tk_text == "deftype") {
|
|
tk_type = tokentype::tk_deftype;
|
|
} else if (tk_text == "lambda") {
|
|
tk_type = tokentype::tk_lambda;
|
|
} else if (tk_text == "if") {
|
|
tk_type = tokentype::tk_if;
|
|
} else if (tk_text == "then") {
|
|
tk_type = tokentype::tk_then;
|
|
} else if (tk_text == "else") {
|
|
tk_type = tokentype::tk_else;
|
|
} else if (tk_text == "let") {
|
|
tk_type = tokentype::tk_let;
|
|
} else if (tk_text == "in") {
|
|
tk_type = tokentype::tk_in;
|
|
} else if (tk_text == "end") {
|
|
tk_type = tokentype::tk_end;
|
|
} else if (tk_text == "#q") {
|
|
tk_type = tokentype::tk_quote;
|
|
} else {
|
|
/* keep as symbol */
|
|
keep_text = true;
|
|
}
|
|
|
|
if (!keep_text)
|
|
tk_text.clear();
|
|
}
|
|
|
|
// TOOD: report tk_text as span,
|
|
// but must pin / unpin
|
|
|
|
return result_type(Token(tk_type, std::move(tk_text)),
|
|
span_type::concat(ws_span,
|
|
span_type(tk_start, tk_end)));
|
|
} /*assemble_token*/
|
|
|
|
auto
|
|
Tokenizer::assemble_final_token(span_type token_text,
|
|
TkInputState * p_input_state) -> result_type
|
|
{
|
|
return assemble_token(token_text.prefix(0) /*ws_span*/,
|
|
token_text,
|
|
p_input_state);
|
|
}
|
|
|
|
auto
|
|
Tokenizer::buffer_input_line(span_type input_ext,
|
|
bool eof_flag) -> std::pair<input_error, span_type>
|
|
{
|
|
scope log(XO_DEBUG(input_state_.debug_flag()));
|
|
|
|
log && log(xtag("input_ext", input_ext));
|
|
|
|
auto buf_input_0 = input_buffer_.input_range().hi();
|
|
|
|
auto remainder = input_buffer_.append(input_ext);
|
|
auto remainder2 = input_buffer_.append(span_type::from_cstr("\n"));
|
|
//(DCircularBuffer::const_span_type::from_cstr("\n"));
|
|
|
|
if (!remainder.empty() || !remainder2.empty()) {
|
|
throw std::runtime_error(tostr("Tokenizer::buffer_line: line too long!",
|
|
xtag("remainder.size", remainder.size())));
|
|
}
|
|
|
|
auto buf_input_1 = input_buffer_.input_range().hi();
|
|
|
|
span_type input_ours = span_type(buf_input_0,
|
|
buf_input_1);
|
|
|
|
return this->input_state_.capture_current_line(input_ours, eof_flag);
|
|
}
|
|
|
|
auto
|
|
Tokenizer::scan(const span_type & input) -> result_type
|
|
{
|
|
scope log(XO_DEBUG(input_state_.debug_flag()));
|
|
log && log(xtag("input", input));
|
|
|
|
/* - Always at beginning of token when scan() invoked
|
|
* - scan will not report any portion of line as consumed until it has
|
|
* emitted all tokens in that line.
|
|
* rationale: caller is allowed to discard storage that
|
|
* scan() reports as consumed. But will be holding that line
|
|
* until all tokens have been read.
|
|
* - this means caller will typically call scan()
|
|
* with the same input span multiple times
|
|
*/
|
|
|
|
const CharT * ix = this->input_state_.skip_leading_whitespace();
|
|
|
|
if(ix == input.hi()) {
|
|
log && log("end buffered input -> consume current line");
|
|
|
|
/* entirety of current line has been tokenized
|
|
* -> caller may consume it
|
|
*/
|
|
this->input_state_.consume_current_line();
|
|
|
|
return result_type::make_whitespace(input);
|
|
}
|
|
|
|
/* ix: if ix < input.hi: first non-whitespace character after input_state_.current_pos_ */
|
|
|
|
// TODO:
|
|
// 1. hoist complete_flag up here
|
|
// 2. use in each branch
|
|
// 3. common check for prefix-capturing after if-cascade below done
|
|
|
|
/* here: *ix is not whitespace */
|
|
|
|
auto whitespace_z = input_state_.whitespace();
|
|
|
|
log && log(xtag("whitespace_z", whitespace_z));
|
|
|
|
/* tk_start points to known beginning of token
|
|
* (after any whitespace)
|
|
*
|
|
* goal is to leave ix pointing to 1 char past the end of the token
|
|
*/
|
|
const CharT * tk_start = ix;
|
|
|
|
if (is_1char_punctuation(*ix)) {
|
|
/* 1-character token */
|
|
++ix;
|
|
} else if (is_2char_punctuation(*ix)) {
|
|
CharT ch1 = *ix;
|
|
|
|
(void)ch1;
|
|
|
|
++ix;
|
|
|
|
CharT ch2 = *ix;
|
|
|
|
if (((ch2 >= '0') && (ch2 <= '9'))
|
|
|| ((ch2 >= 'A') && (ch2 <= 'Z'))
|
|
|| ((ch2 >= 'a') && (ch2 <= 'z')))
|
|
{
|
|
/* treat as 1 char punctuation */
|
|
;
|
|
} else {
|
|
/* include next char */
|
|
++ix;
|
|
}
|
|
} else if (*ix == '"') {
|
|
bool complete_flag = false;
|
|
|
|
/* 1. embedded space/tab allowed in string literal.
|
|
* 2. embedded newline/cr not allowed.
|
|
*/
|
|
CharT prev_ch = '"';
|
|
|
|
++ix;
|
|
|
|
for (; ix != input.hi(); ++ix) {
|
|
/* looking for unescaped " char to end literal */
|
|
if (*ix == '"') {
|
|
if (prev_ch != '\\') {
|
|
++ix; /* include terminating " for assemble_token */
|
|
complete_flag = true;
|
|
break;
|
|
}
|
|
} else if ((*ix == '\n') || (*ix == '\r')) {
|
|
log && log ("string literal with naked newline or CR");
|
|
|
|
return result_type::make_error_consume_current_line
|
|
(__FUNCTION__ /*src_function*/,
|
|
"must use \\n or \\r to encode newline/cr in string literal",
|
|
(ix - tk_start),
|
|
this->input_state_);
|
|
}
|
|
|
|
prev_ch = *ix;
|
|
}
|
|
|
|
if (!complete_flag) {
|
|
log && log("unterminated string literal");
|
|
|
|
return result_type::make_error_consume_current_line
|
|
(__FUNCTION__ /*src_function*/,
|
|
"unterminated string literal",
|
|
(ix - tk_start),
|
|
this->input_state_);
|
|
}
|
|
} else {
|
|
/* ix is start of some token */
|
|
|
|
if (*ix == '-') {
|
|
/* this section load-bearing for input '->' scanning from beginning of token */
|
|
++ix;
|
|
|
|
if (ix == input.hi()) {
|
|
/* need more input to know if/when token complete -- see captured-prefix5 below */
|
|
} else {
|
|
CharT ch2 = *ix;
|
|
|
|
if (ch2 == '>') {
|
|
/* include next char and complete token */
|
|
++ix;
|
|
|
|
log && log("complete '->' token");
|
|
|
|
this->input_state_.advance_until(ix);
|
|
|
|
return assemble_token(span_type(input.lo(), tk_start),
|
|
span_type(tk_start, ix) /*token*/,
|
|
&(this->input_state_));
|
|
}
|
|
|
|
/* here: -123, -.5e-21 for example */
|
|
}
|
|
} else if (*ix == '>') {
|
|
/* this section load-bearing for input '>=' scanning from beginning of token.
|
|
* Need this because '>' necessarily excluded from is_1char_punctuation()
|
|
*/
|
|
++ix;
|
|
|
|
if (ix == input.hi()) {
|
|
/* need more input to know if/when token complete -- see captured-prefix5 below */
|
|
} else {
|
|
CharT ch2 = *ix;
|
|
|
|
if (ch2 != '=') {
|
|
log && log("complete '>=' token");
|
|
|
|
this->input_state_.advance_until(ix);
|
|
|
|
/* ignore next char and complete token */
|
|
return assemble_token(span_type(input.lo(), tk_start),
|
|
span_type(tk_start, ix) /*token*/,
|
|
&(this->input_state_));
|
|
}
|
|
|
|
/* here: >= for example */
|
|
}
|
|
}
|
|
|
|
/* scan until:
|
|
* - whitespace
|
|
* - punctuation
|
|
*/
|
|
for (; ix != input.hi(); ++ix) {
|
|
if (TkInputState::is_whitespace(*ix)
|
|
|| is_1char_punctuation(*ix)
|
|
|| is_2char_punctuation(*ix))
|
|
{
|
|
break;
|
|
}
|
|
|
|
/* this section load-bearing for input '>' after beginning of a token, e.g. p> */
|
|
if ((ix > tk_start) && (*ix == '>'))
|
|
break;
|
|
|
|
/* this section load-bearing for input '->' at the end of another token, e.g. p->q */
|
|
if (*ix == '-') {
|
|
if (ix + 1 == input.hi()) {
|
|
/* need more input to know if/when token complete
|
|
*
|
|
* apple-banana parses as: {tk_symbol: apple-banana}
|
|
* apple-> parses as: {tk_symbol: apple} {tk_yields}
|
|
* apple- illegal (may not end symbol with '-')
|
|
*/
|
|
break;
|
|
}
|
|
|
|
if (*(ix + 1) == '>') {
|
|
/* treat '->' as punctuation; complete preceding token */
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
log && log("assemble token z", xtag("token_z", ix - tk_start));
|
|
|
|
assert(tk_start < ix);
|
|
|
|
this->input_state_.advance_until(ix);
|
|
|
|
return assemble_token(span_type(input.lo(), tk_start),
|
|
span_type(tk_start, ix) /*token*/,
|
|
&(this->input_state_));
|
|
} /*_scan_aux*/
|
|
} /*namespace scm*/
|
|
} /*namespace xo*/
|
|
|
|
/* end Tokenizer.cpp */
|