From a20f522fd61698282d3e01931260c588dd7f40b1 Mon Sep 17 00:00:00 2001 From: Bruce Hill Date: Thu, 2 May 2024 13:48:20 -0400 Subject: Support space indents --- parse.c | 92 +++++++++++++++++++++++++++++++++++++++++------------------------ 1 file changed, 58 insertions(+), 34 deletions(-) (limited to 'parse.c') diff --git a/parse.c b/parse.c index d942148d..cdebf0fb 100644 --- a/parse.c +++ b/parse.c @@ -25,6 +25,8 @@ typedef ast_t* (parser_t)(parse_ctx_t*,const char*); extern void builtin_fail(const char *fmt, ...); +#define SPACES_PER_INDENT 4 + #define PARSER(name) ast_t *name(parse_ctx_t *ctx, const char *pos) #define STUB_PARSER(name) PARSER(name) { (void)ctx; (void)pos; return NULL; } @@ -171,6 +173,29 @@ const char *unescape(const char **out) { } } +static inline int64_t get_indent(parse_ctx_t *ctx, const char *pos) +{ + int64_t line_num = get_line_number(ctx->file, pos); + const char *line = get_line(ctx->file, line_num); + if (*line == ' ') { + int64_t spaces = strspn(line, " "); + if (spaces % SPACES_PER_INDENT != 0) + parser_err(ctx, line + spaces - (spaces % SPACES_PER_INDENT), line + spaces, + "Indentation must be a multiple of 4 spaces, not %ld", spaces); + int64_t indent = spaces / SPACES_PER_INDENT; + if (line[indent] == '\t') + parser_err(ctx, line + indent, line + indent + 1, "This is a tab following spaces, and you can't mix tabs and spaces"); + return indent; + } else if (*line == '\t') { + int64_t indent = strspn(line, "\t"); + if (line[indent] == ' ') + parser_err(ctx, line + indent, line + indent + 1, "This is a space following tabs, and you can't mix tabs and spaces"); + return indent; + } else { + return 0; + } +} + /////////////////////////////////////////////////////////////////////////////////////////////////////////// ///////////////////////////// Text-based parsing primitives /////////////////////////////////////// /////////////////////////////////////////////////////////////////////////////////////////////////////////// @@ -345,16 +370,16 @@ bool comment(const char **pos) { bool indent(parse_ctx_t *ctx, const char **out) { const char *pos = *out; - int64_t starting_indent = get_indent(ctx->file, pos); + int64_t starting_indent = get_indent(ctx, pos); whitespace(&pos); - const char *start_of_line = get_line(ctx->file, get_line_number(ctx->file, pos)); - if (start_of_line <= *out) + const char *next_line = get_line(ctx->file, get_line_number(ctx->file, pos)); + if (next_line <= *out) return false; - if ((int64_t)strspn(start_of_line, "\t") < starting_indent) + if (get_indent(ctx, next_line) != starting_indent + 1) return false; - *out = start_of_line + starting_indent + 1; + *out = next_line + strspn(next_line, " \t"); return true; } @@ -369,7 +394,12 @@ bool newline_with_indentation(const char **out, int64_t target) { return true; } - if ((int64_t)strspn(pos, "\t") >= target) { + if (*pos == ' ') { + if ((int64_t)strspn(pos, " ") >= SPACES_PER_INDENT * target) { + *out = pos + SPACES_PER_INDENT * target; + return true; + } + } else if ((int64_t)strspn(pos, "\t") >= target) { *out = pos + target; return true; } @@ -840,7 +870,7 @@ ast_t *parse_comprehension_suffix(parse_ctx_t *ctx, ast_t *expr) { PARSER(parse_if) { // if [then] [else ] const char *start = pos; - int64_t starting_indent = get_indent(ctx->file, pos); + int64_t starting_indent = get_indent(ctx, pos); if (!match_word(&pos, "if")) return NULL; @@ -857,7 +887,7 @@ PARSER(parse_if) { whitespace(&tmp); ast_t *else_body = NULL; const char *else_start = pos; - if (get_indent(ctx->file, tmp) == starting_indent && match_word(&tmp, "else")) { + if (get_indent(ctx, tmp) == starting_indent && match_word(&tmp, "else")) { pos = tmp; expect_str(ctx, start, &pos, ":", "I expected a ':' here"); else_body = expect(ctx, else_start, &pos, parse_opt_indented_block, "I expected a body for this 'else'"); @@ -868,7 +898,7 @@ PARSER(parse_if) { PARSER(parse_when) { // when (is var : Tag [then] )* [else ] const char *start = pos; - int64_t starting_indent = get_indent(ctx->file, pos); + int64_t starting_indent = get_indent(ctx, pos); if (!match_word(&pos, "when")) return NULL; @@ -880,7 +910,7 @@ PARSER(parse_when) { when_clause_t *clauses = NULL; const char *tmp = pos; whitespace(&tmp); - while (get_indent(ctx->file, tmp) == starting_indent && match_word(&tmp, "is")) { + while (get_indent(ctx, tmp) == starting_indent && match_word(&tmp, "is")) { pos = tmp; spaces(&pos); ast_t *tag_name = expect(ctx, start, &pos, parse_var, "I expected a tag name here"); @@ -911,7 +941,7 @@ PARSER(parse_when) { ast_t *else_body = NULL; const char *else_start = pos; - if (get_indent(ctx->file, tmp) == starting_indent && match_word(&tmp, "else")) { + if (get_indent(ctx, tmp) == starting_indent && match_word(&tmp, "else")) { pos = tmp; expect_str(ctx, start, &pos, ":", "I expected a ':' here"); else_body = expect(ctx, else_start, &pos, parse_opt_indented_block, "I expected a body for this 'else'"); @@ -923,7 +953,7 @@ PARSER(parse_for) { // for [k,] v in iter [] body const char *start = pos; if (!match_word(&pos, "for")) return NULL; - int64_t starting_indent = get_indent(ctx->file, pos); + int64_t starting_indent = get_indent(ctx, pos); ast_t *index = expect(ctx, start, &pos, parse_var, "I expected an iteration variable for this 'for'"); spaces(&pos); ast_t *value = NULL; @@ -939,7 +969,7 @@ PARSER(parse_for) { const char *else_start = pos; whitespace(&else_start); ast_t *empty = NULL; - if (match_word(&else_start, "else") && get_indent(ctx->file, else_start) == starting_indent) { + if (match_word(&else_start, "else") && get_indent(ctx, else_start) == starting_indent) { pos = else_start; expect_str(ctx, start, &pos, ":", "I expected a ':' here"); empty = expect(ctx, pos, &pos, parse_opt_indented_block, "I expected a body for this 'else'"); @@ -1057,7 +1087,7 @@ PARSER(parse_text) { return NULL; } - int64_t starting_indent = get_indent(ctx->file, pos); + int64_t starting_indent = get_indent(ctx, pos); int64_t string_indent = starting_indent + 1; ast_list_t *chunks = NULL; @@ -1088,13 +1118,13 @@ PARSER(parse_text) { chunks = new(ast_list_t, .ast=interp, .next=chunks); chunk_start = pos; } else if (!leading_newline && *pos == open_quote && closing[(int)open_quote]) { // Nested pair begin - if (get_indent(ctx->file, pos) == starting_indent) { + if (get_indent(ctx, pos) == starting_indent) { ++depth; } chunk = CORD_cat_char(chunk, *pos); ++pos; } else if (!leading_newline && *pos == close_quote) { // Nested pair end - if (get_indent(ctx->file, pos) == starting_indent) { + if (get_indent(ctx, pos) == starting_indent) { --depth; if (depth == 0) break; @@ -1517,17 +1547,11 @@ PARSER(parse_extended_expr) { } PARSER(parse_block) { - int64_t block_indent = get_indent(ctx->file, pos); + int64_t block_indent = get_indent(ctx, pos); const char *start = pos; whitespace(&pos); ast_list_t *statements = NULL; while (*pos) { - if (pos > start && pos[-1] == ' ') { - const char *space_start = pos-1; - while (*space_start == ' ') - --space_start; - parser_err(ctx, space_start, pos, "Spaces are not allowed for indentation, only tabs!"); - } ast_t *stmt = optional(ctx, &pos, parse_statement); if (!stmt) { const char *line_start = pos; @@ -1547,7 +1571,7 @@ PARSER(parse_block) { } statements = new(ast_list_t, .ast=stmt, .next=statements); whitespace(&pos); // TODO: check for newline - if (get_indent(ctx->file, pos) != block_indent) { + if (get_indent(ctx, pos) != block_indent) { pos = stmt->end; // backtrack break; } @@ -1563,12 +1587,12 @@ PARSER(parse_opt_indented_block) { PARSER(parse_namespace) { const char *start = pos; whitespace(&pos); - int64_t indent = get_indent(ctx->file, pos); + int64_t indent = get_indent(ctx, pos); ast_list_t *statements = NULL; for (;;) { const char *next = pos; whitespace(&next); - if (get_indent(ctx->file, next) != indent) break; + if (get_indent(ctx, next) != indent) break; ast_t *stmt; if ((stmt=optional(ctx, &pos, parse_struct_def)) ||(stmt=optional(ctx, &pos, parse_enum_def)) @@ -1587,7 +1611,7 @@ PARSER(parse_namespace) { // break; // } } else { - if (get_indent(ctx->file, next) > indent && next < strchrnul(next, '\n')) + if (get_indent(ctx, next) > indent && next < strchrnul(next, '\n')) parser_err(ctx, next, strchrnul(next, '\n'), "I couldn't parse this namespace declaration"); break; } @@ -1603,7 +1627,7 @@ PARSER(parse_file_body) { for (;;) { const char *next = pos; whitespace(&next); - if (get_indent(ctx->file, next) != 0) break; + if (get_indent(ctx, next) != 0) break; ast_t *stmt; if ((stmt=optional(ctx, &pos, parse_struct_def)) ||(stmt=optional(ctx, &pos, parse_enum_def)) @@ -1634,7 +1658,7 @@ PARSER(parse_struct_def) { const char *start = pos; if (!match_word(&pos, "struct")) return NULL; - int64_t starting_indent = get_indent(ctx->file, pos); + int64_t starting_indent = get_indent(ctx, pos); spaces(&pos); const char *name = get_id(&pos); @@ -1667,7 +1691,7 @@ PARSER(parse_struct_def) { if (match(&pos, ":")) { const char *ns_pos = pos; whitespace(&ns_pos); - int64_t ns_indent = get_indent(ctx->file, ns_pos); + int64_t ns_indent = get_indent(ctx, ns_pos); if (ns_indent > starting_indent) { pos = ns_pos; namespace = optional(ctx, &pos, parse_namespace); @@ -1682,7 +1706,7 @@ ast_t *parse_enum_def(parse_ctx_t *ctx, const char *pos) { // tagged union: enum Foo(a, b(x:Int,y:Int)=5, ...) [: \n namespace] const char *start = pos; if (!match_word(&pos, "enum")) return NULL; - int64_t starting_indent = get_indent(ctx->file, pos); + int64_t starting_indent = get_indent(ctx, pos); spaces(&pos); const char *name = get_id(&pos); if (!name) @@ -1746,7 +1770,7 @@ ast_t *parse_enum_def(parse_ctx_t *ctx, const char *pos) { if (match(&pos, ":")) { const char *ns_pos = pos; whitespace(&ns_pos); - int64_t ns_indent = get_indent(ctx->file, ns_pos); + int64_t ns_indent = get_indent(ctx, ns_pos); if (ns_indent > starting_indent) { pos = ns_pos; namespace = optional(ctx, &pos, parse_namespace); @@ -1762,7 +1786,7 @@ PARSER(parse_lang_def) { const char *start = pos; // lang Name: [namespace...] if (!match_word(&pos, "lang")) return NULL; - int64_t starting_indent = get_indent(ctx->file, pos); + int64_t starting_indent = get_indent(ctx, pos); spaces(&pos); const char *name = get_id(&pos); if (!name) @@ -1773,7 +1797,7 @@ PARSER(parse_lang_def) { if (match(&pos, ":")) { const char *ns_pos = pos; whitespace(&ns_pos); - int64_t ns_indent = get_indent(ctx->file, ns_pos); + int64_t ns_indent = get_indent(ctx, ns_pos); if (ns_indent > starting_indent) { pos = ns_pos; namespace = optional(ctx, &pos, parse_namespace); -- cgit v1.2.3