bshell/bshell/parse/lex/arithmetic.c

#include "lex-internal.h"

static enum bshell_status arithmetic_hyphen(struct lex_ctx *ctx)
{
	fx_wchar c = peek_char(ctx);
	if (!fx_wchar_is_alnum(c)) {
		push_symbol(ctx, SYM_HYPHEN);
		handle_lex_state_transition(ctx, SYM_HYPHEN);
		return BSHELL_SUCCESS;
	}

	struct lex_token *tok = NULL;
	enum bshell_status status = read_word(
		ctx,
		READ_NO_SET_TOKEN_START | READ_APPEND_HYPHEN,
		&tok);
	if (status != BSHELL_SUCCESS) {
		return status;
	}

	unsigned int token_type = TOK_WORD;
	if (convert_word_to_int(tok)) {
		token_type = TOK_INT;

		/* because of APPEND_HYPHEN (which is needed to ensure operator
		 * tokens are detected properly), the resulting number will be
		 * negative.
		 * this token will be preceded by a HYPHEN token, so the number
		 * must be positive */
		tok->tok_int *= -1;
		push_symbol(ctx, SYM_HYPHEN);
	} else if (convert_word_to_operator(ctx, tok)) {
		token_type = TOK_OPERATOR;
	}

	enqueue_token(ctx, tok);
	return BSHELL_SUCCESS;
}

static enum bshell_status arithmetic_symbol(struct lex_ctx *ctx)
{
	const struct lex_token_def *sym = NULL;
	enum bshell_status status = read_symbol(ctx, &sym);

	if (status != BSHELL_SUCCESS) {
		return status;
	}

	handle_lex_state_transition(ctx, sym->id);

	struct lex_token *tok = NULL;
	switch (sym->id) {
	case SYM_SQUOTE:
		status = read_literal_string(ctx, &tok);
		if (status != BSHELL_SUCCESS) {
			return status;
		}
		enqueue_token(ctx, tok);
		return BSHELL_SUCCESS;
	case SYM_HYPHEN:
		return arithmetic_hyphen(ctx);
	case SYM_HASH:
		return read_line_comment(ctx);
	case SYM_DOLLAR:
		status = read_var(ctx, TOK_VAR, &tok);
		if (status != BSHELL_SUCCESS) {
			return status;
		}

		enqueue_token(ctx, tok);
		return status;
	case SYM_AT:
		status = read_var(ctx, TOK_VAR_SPLAT, &tok);
		if (status != BSHELL_SUCCESS) {
			return status;
		}

		enqueue_token(ctx, tok);
		return status;
	case SYM_DOLLAR_LEFT_BRACE:
		status = read_braced_var(ctx, TOK_VAR, &tok);
		if (status != BSHELL_SUCCESS) {
			return status;
		}

		enqueue_token(ctx, tok);
		return status;
	default:
		break;
	}

	push_symbol(ctx, sym->id);

	return BSHELL_SUCCESS;
}

static enum bshell_status arithmetic_word(struct lex_ctx *ctx)
{
	struct lex_token *word = NULL;
	enum bshell_status status = read_word(ctx, 0, &word);
	if (status != BSHELL_SUCCESS) {
		return status;
	}

	unsigned int token_type = TOK_WORD;
	bool kw = false, number = false;
	if (convert_word_to_keyword(word)) {
		token_type = word->tok_keyword;
	} else if (convert_word_to_int(word)) {
		token_type = TOK_INT;
	}

	handle_lex_state_transition(ctx, token_type);

	enqueue_token(ctx, word);
	return BSHELL_SUCCESS;
}

static enum bshell_status arithmetic_pump_token(struct lex_ctx *ctx)
{
	fx_wchar c = peek_char(ctx);
	bool newline = false;

	set_token_start(ctx);
	while (fx_wchar_is_space(c)) {
		if (c == '\n') {
			newline = true;
		}

		set_token_end(ctx);
		advance_char_noread(ctx);
		c = peek_char_noread(ctx);
	}

	if (newline) {
		struct lex_token *tok = lex_token_create(TOK_LINEFEED);
		enqueue_token(ctx, tok);
		lex_state_change(ctx, LEX_STATE_STATEMENT);
		return BSHELL_SUCCESS;
	}

	if (char_can_begin_symbol(ctx, c)) {
		return arithmetic_symbol(ctx);
	}

	return arithmetic_word(ctx);
}

static const struct lex_state_link links[] = {
	LINK_CHANGE(TOK_WORD, LEX_STATE_COMMAND),
	LINK_PUSH(SYM_DQUOTE, LEX_STATE_STRING, 0),
	LINK_PUSH(SYM_DOLLAR_LEFT_PAREN, LEX_STATE_STATEMENT, 0),
	LINK_POP(SYM_RIGHT_PAREN),
	LINK_CHANGE(SYM_SEMICOLON, LEX_STATE_STATEMENT),
	LINK_PUSH(SYM_AT_LEFT_BRACE, LEX_STATE_HASHTABLE, 0),
	LINK_PUSH(
		SYM_LEFT_PAREN,
		LEX_STATE_STATEMENT,
		STATEMENT_F_DISABLE_KEYWORDS),
	LINK_END,
};

const struct lex_state_type lex_arithmetic_state = {
	.s_id = LEX_STATE_ARITHMETIC,
	.s_pump_token = arithmetic_pump_token,
	.s_links = links,
};