diff options
Diffstat (limited to 'src/parse/expressions.c')
| -rw-r--r-- | src/parse/expressions.c | 248 |
1 files changed, 248 insertions, 0 deletions
diff --git a/src/parse/expressions.c b/src/parse/expressions.c new file mode 100644 index 00000000..d643d4e7 --- /dev/null +++ b/src/parse/expressions.c @@ -0,0 +1,248 @@ +// Recursive descent parser for parsing code + +#include <stdbool.h> +#include <string.h> + +#include "../ast.h" +#include "../stdlib/util.h" +#include "binops.h" +#include "containers.h" +#include "context.h" +#include "controlflow.h" +#include "errors.h" +#include "files.h" +#include "functions.h" +#include "numbers.h" +#include "expressions.h" +#include "suffixes.h" +#include "text.h" +#include "types.h" +#include "utils.h" + +ast_t *parse_parens(parse_ctx_t *ctx, const char *pos) { + const char *start = pos; + spaces(&pos); + if (!match(&pos, "(")) return NULL; + whitespace(&pos); + ast_t *expr = optional(ctx, &pos, parse_extended_expr); + if (!expr) return NULL; + + ast_t *comprehension = parse_comprehension_suffix(ctx, expr); + while (comprehension) { + expr = comprehension; + pos = comprehension->end; + comprehension = parse_comprehension_suffix(ctx, expr); + } + + whitespace(&pos); + expect_closing(ctx, &pos, ")", "I wasn't able to parse the rest of this expression"); + + // Update the span to include the parens: + return new (ast_t, .file = (ctx)->file, .start = start, .end = pos, .tag = expr->tag, .__data = expr->__data); +} + +ast_t *parse_reduction(parse_ctx_t *ctx, const char *pos) { + const char *start = pos; + if (!match(&pos, "(")) return NULL; + + whitespace(&pos); + ast_e op = match_binary_operator(&pos); + if (op == Unknown) return NULL; + + ast_t *key = NewAST(ctx->file, pos, pos, Var, .name = "$"); + for (bool progress = true; progress;) { + ast_t *new_term; + progress = + (false || (new_term = parse_index_suffix(ctx, key)) || (new_term = parse_method_call_suffix(ctx, key)) + || (new_term = parse_field_suffix(ctx, key)) || (new_term = parse_fncall_suffix(ctx, key)) + || (new_term = parse_optional_suffix(ctx, key)) || (new_term = parse_non_optional_suffix(ctx, key))); + if (progress) key = new_term; + } + if (key && key->tag == Var) key = NULL; + else if (key) pos = key->end; + + whitespace(&pos); + if (!match(&pos, ":")) return NULL; + + ast_t *iter = optional(ctx, &pos, parse_extended_expr); + if (!iter) return NULL; + ast_t *suffixed = parse_comprehension_suffix(ctx, iter); + while (suffixed) { + iter = suffixed; + pos = suffixed->end; + suffixed = parse_comprehension_suffix(ctx, iter); + } + + whitespace(&pos); + expect_closing(ctx, &pos, ")", "I wasn't able to parse the rest of this reduction"); + + return NewAST(ctx->file, start, pos, Reduction, .iter = iter, .op = op, .key = key); +} + +ast_t *parse_heap_alloc(parse_ctx_t *ctx, const char *pos) { + const char *start = pos; + if (!match(&pos, "@")) return NULL; + spaces(&pos); + ast_t *val = expect(ctx, start, &pos, parse_term_no_suffix, "I expected an expression for this '@'"); + + for (;;) { + ast_t *new_term; + if ((new_term = parse_index_suffix(ctx, val)) || (new_term = parse_fncall_suffix(ctx, val)) + || (new_term = parse_method_call_suffix(ctx, val)) || (new_term = parse_field_suffix(ctx, val))) { + val = new_term; + } else break; + } + pos = val->end; + + ast_t *ast = NewAST(ctx->file, start, pos, HeapAllocate, .value = val); + for (;;) { + ast_t *next = parse_optional_suffix(ctx, ast); + if (!next) next = parse_non_optional_suffix(ctx, ast); + if (!next) break; + ast = next; + } + return ast; +} + +ast_t *parse_stack_reference(parse_ctx_t *ctx, const char *pos) { + const char *start = pos; + if (!match(&pos, "&")) return NULL; + spaces(&pos); + ast_t *val = expect(ctx, start, &pos, parse_term_no_suffix, "I expected an expression for this '&'"); + + for (;;) { + ast_t *new_term; + if ((new_term = parse_index_suffix(ctx, val)) || (new_term = parse_fncall_suffix(ctx, val)) + || (new_term = parse_method_call_suffix(ctx, val)) || (new_term = parse_field_suffix(ctx, val))) { + val = new_term; + } else break; + } + pos = val->end; + + ast_t *ast = NewAST(ctx->file, start, pos, StackReference, .value = val); + for (;;) { + ast_t *next = parse_optional_suffix(ctx, ast); + if (!next) next = parse_non_optional_suffix(ctx, ast); + if (!next) break; + ast = next; + } + return ast; +} + +ast_t *parse_not(parse_ctx_t *ctx, const char *pos) { + const char *start = pos; + if (!match_word(&pos, "not")) return NULL; + spaces(&pos); + ast_t *val = expect(ctx, start, &pos, parse_term, "I expected an expression for this 'not'"); + return NewAST(ctx->file, start, pos, Not, .value = val); +} + +ast_t *parse_negative(parse_ctx_t *ctx, const char *pos) { + const char *start = pos; + if (!match(&pos, "-")) return NULL; + spaces(&pos); + ast_t *val = expect(ctx, start, &pos, parse_term, "I expected an expression for this '-'"); + return NewAST(ctx->file, start, pos, Negative, .value = val); +} + +ast_t *parse_bool(parse_ctx_t *ctx, const char *pos) { + const char *start = pos; + if (match_word(&pos, "yes")) return NewAST(ctx->file, start, pos, Bool, .b = true); + else if (match_word(&pos, "no")) return NewAST(ctx->file, start, pos, Bool, .b = false); + else return NULL; +} + +ast_t *parse_none(parse_ctx_t *ctx, const char *pos) { + const char *start = pos; + if (!match_word(&pos, "none")) return NULL; + return NewAST(ctx->file, start, pos, None); +} + +ast_t *parse_deserialize(parse_ctx_t *ctx, const char *pos) { + const char *start = pos; + if (!match_word(&pos, "deserialize")) return NULL; + + spaces(&pos); + expect_str(ctx, start, &pos, "(", "I expected arguments for this `deserialize` call"); + whitespace(&pos); + ast_t *value = expect(ctx, start, &pos, parse_extended_expr, "I expected an expression here"); + whitespace(&pos); + expect_str(ctx, start, &pos, "->", + "I expected a `-> Type` for this `deserialize` call so I know what it deserializes to"); + whitespace(&pos); + type_ast_t *type = expect(ctx, start, &pos, parse_type, "I couldn't parse the type for this deserialization"); + whitespace(&pos); + expect_closing(ctx, &pos, ")", "I expected a closing ')' for this `deserialize` call"); + return NewAST(ctx->file, start, pos, Deserialize, .value = value, .type = type); +} + +ast_t *parse_var(parse_ctx_t *ctx, const char *pos) { + const char *start = pos; + const char *name = get_id(&pos); + if (!name) return NULL; + return NewAST(ctx->file, start, pos, Var, .name = name); +} + +ast_t *parse_term_no_suffix(parse_ctx_t *ctx, const char *pos) { + spaces(&pos); + ast_t *term = NULL; + (void)(false || (term = parse_none(ctx, pos)) || (term = parse_num(ctx, pos)) // Must come before int + || (term = parse_int(ctx, pos)) || (term = parse_negative(ctx, pos)) // Must come after num/int + || (term = parse_heap_alloc(ctx, pos)) || (term = parse_stack_reference(ctx, pos)) + || (term = parse_bool(ctx, pos)) || (term = parse_text(ctx, pos)) || (term = parse_path(ctx, pos)) + || (term = parse_lambda(ctx, pos)) || (term = parse_parens(ctx, pos)) || (term = parse_table(ctx, pos)) + || (term = parse_set(ctx, pos)) || (term = parse_deserialize(ctx, pos)) || (term = parse_var(ctx, pos)) + || (term = parse_list(ctx, pos)) || (term = parse_reduction(ctx, pos)) || (term = parse_pass(ctx, pos)) + || (term = parse_defer(ctx, pos)) || (term = parse_skip(ctx, pos)) || (term = parse_stop(ctx, pos)) + || (term = parse_return(ctx, pos)) || (term = parse_not(ctx, pos)) || (term = parse_extern(ctx, pos)) + || (term = parse_inline_c(ctx, pos))); + return term; +} + +ast_t *parse_term(parse_ctx_t *ctx, const char *pos) { + const char *start = pos; + if (match(&pos, "???")) parser_err(ctx, start, pos, "This value needs to be filled in!"); + + ast_t *term = parse_term_no_suffix(ctx, pos); + if (!term) return NULL; + + for (bool progress = true; progress;) { + ast_t *new_term; + progress = + (false || (new_term = parse_index_suffix(ctx, term)) || (new_term = parse_method_call_suffix(ctx, term)) + || (new_term = parse_field_suffix(ctx, term)) || (new_term = parse_fncall_suffix(ctx, term)) + || (new_term = parse_optional_suffix(ctx, term)) || (new_term = parse_non_optional_suffix(ctx, term))); + if (progress) term = new_term; + } + return term; +} + +ast_t *parse_expr(parse_ctx_t *ctx, const char *pos) { return parse_infix_expr(ctx, pos, 0); } + +ast_t *parse_extended_expr(parse_ctx_t *ctx, const char *pos) { + ast_t *expr = NULL; + + if (false || (expr = optional(ctx, &pos, parse_for)) || (expr = optional(ctx, &pos, parse_while)) + || (expr = optional(ctx, &pos, parse_if)) || (expr = optional(ctx, &pos, parse_when)) + || (expr = optional(ctx, &pos, parse_repeat)) || (expr = optional(ctx, &pos, parse_do))) + return expr; + + return parse_expr(ctx, pos); +} + +ast_t *parse_expr_str(const char *str) { + file_t *file = spoof_file("<string>", str); + parse_ctx_t ctx = { + .file = file, + .on_err = NULL, + }; + + const char *pos = file->text; + whitespace(&pos); + ast_t *ast = parse_extended_expr(&ctx, pos); + pos = ast->end; + whitespace(&pos); + if (pos < file->text + file->len && *pos != '\0') + parser_err(&ctx, pos, pos + strlen(pos), "I couldn't parse this part of the string"); + return ast; +} |