initial import of the C runtime

src/runtime/c/utils/pgf-translate.c

@@ -0,0 +1,179 @@
+#include <gu/variant.h>
+#include <gu/map.h>
+#include <gu/dump.h>
+#include <gu/log.h>
+#include <gu/enum.h>
+#include <gu/file.h>
+#include <pgf/pgf.h>
+#include <pgf/data.h>
+#include <pgf/parser.h>
+#include <pgf/linearize.h>
+#include <pgf/expr.h>
+#include <pgf/edsl.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <locale.h>
+
+int main(int argc, char* argv[]) {
+	// Set the character locale, so we can produce proper output.
+	setlocale(LC_CTYPE, "");
+
+	// Create the pool that is used to allocate everything
+	GuPool* pool = gu_new_pool();
+	int status = EXIT_SUCCESS;
+	if (argc != 5) {
+		fprintf(stderr, "usage: %s pgf cat from_lang to_lang\n", argv[0]);
+		status = EXIT_FAILURE;
+		goto fail;
+	}
+	char* filename = argv[1];
+
+	// Transform C strings to libgu strings
+	GuString cat = gu_str_string(argv[2], pool);
+	GuString from_lang = gu_str_string(argv[3], pool);
+	GuString to_lang = gu_str_string(argv[4], pool);
+	
+	FILE* infile = fopen(filename, "r");
+	if (infile == NULL) {
+		fprintf(stderr, "couldn't open %s\n", filename);
+		status = EXIT_FAILURE;
+		goto fail;
+	}
+
+	// Create an input stream from the input file
+	GuIn* in = gu_file_in(infile, pool);
+
+	// Create an exception frame that catches all errors.
+	GuExn* err = gu_new_exn(NULL, gu_kind(type), pool);
+
+	// Read the PGF grammar.
+	PgfPGF* pgf = pgf_read(in, pool, err);
+
+	// If an error occured, it shows in the exception frame
+	if (!gu_ok(err)) {
+		fprintf(stderr, "Reading PGF failed\n");
+		status = EXIT_FAILURE;
+		goto fail_read;
+	}
+
+	// Look up the source and destination concrete categories
+	PgfConcr* from_concr =
+		gu_map_get(pgf->concretes, &from_lang, PgfConcr*);
+	PgfConcr* to_concr =
+		gu_map_get(pgf->concretes, &to_lang, PgfConcr*);
+	if (!from_concr || !to_concr) {
+		fprintf(stderr, "Unknown language");
+		status = EXIT_FAILURE;
+		goto fail_concr;
+	}
+
+	// Create the parser for the source category
+	PgfParser* parser = pgf_new_parser(from_concr, pool);
+
+	// Create a linearizer for the destination category
+	PgfLzr* lzr = pgf_new_lzr(to_concr, pool);
+
+	// Arbitrarily choose linearization index 0. Usually the initial
+	// categories we are interested in only have one field.
+	int lin_idx = 0;
+
+	// Create an output stream for stdout
+	GuOut* out = gu_file_out(stdout, pool);
+
+	// Locale-encoding writers are currently unsupported
+	// GuWriter* wtr = gu_locale_writer(out, pool);
+	// Use a writer with hard-coded utf-8 encoding for now.
+	GuWriter* wtr = gu_new_utf8_writer(out, pool);
+
+	// The interactive translation loop.
+	// XXX: This currently reads stdin directly, so it doesn't support
+	// encodings properly. TODO: use a locale reader for input
+	while (true) {
+		fprintf(stdout, "> ");
+		fflush(stdout);
+		char buf[4096];
+		char* line = fgets(buf, sizeof(buf), stdin);
+		if (line == NULL) {
+			if (ferror(stdin)) {
+				fprintf(stderr, "Input error\n");
+				status = EXIT_FAILURE;
+			}
+			break;
+		} else if (line[0] == '\0') {
+			// End nicely on empty input
+			break;
+		}
+		// We create a temporary pool for translating a single
+		// sentence, so our memory usage doesn't increase over time.
+		GuPool* ppool = gu_new_pool();
+
+		// Begin parsing a sentence of the specified category
+		PgfParse* parse =
+			pgf_parser_parse(parser, cat, lin_idx, pool);
+		if (parse == NULL) {
+			fprintf(stderr, "Couldn't begin parsing");
+			status = EXIT_FAILURE;
+			break;
+		}
+
+		// naive tokenization
+		char* tok = strtok(line, " \n");
+		while (tok) {
+			GuString tok_s = gu_str_string(tok, pool);
+			gu_debug("parsing token \"%s\"", tok);
+			// feed the token to get a new parse state
+			parse = pgf_parse_token(parse, tok_s, ppool);
+			if (!parse) {
+				fprintf(stderr,
+					"Unexpected token: \"%s\"\n", tok);
+				goto fail_parse;
+			}
+			tok = strtok(NULL, " \n");
+		}
+
+		// Now begin enumerating the resulting syntax trees
+		GuEnum* result = pgf_parse_result(parse, ppool);
+
+		while (true) {
+			PgfExpr expr = gu_next(result, PgfExpr, ppool);
+			// The enumerator will return a null variant at the
+			// end of the results.
+			if (gu_variant_is_null(expr)) {
+				break;
+			}
+			gu_putc(' ', wtr, err);
+			// Write out the abstract syntax tree
+			pgf_expr_print(expr, wtr, err);
+			gu_putc('\n', wtr, err);
+
+			// Enumerate the concrete syntax trees corresponding
+			// to the abstract tree.
+			GuEnum* cts = pgf_lzr_concretize(lzr, expr, ppool);
+			while (true) {
+				PgfCncTree ctree =
+					gu_next(cts, PgfCncTree, ppool);
+				if (gu_variant_is_null(ctree)) {
+					break;
+				}
+				gu_puts("  ", wtr, err);
+				// Linearize the concrete tree as a simple
+				// sequence of strings.
+				pgf_lzr_linearize_simple(lzr, ctree, lin_idx,
+							 wtr, err);
+				gu_putc('\n', wtr, err);
+				gu_writer_flush(wtr, err);
+			}
+		}
+	fail_parse:
+		// Free all resources allocated during parsing and linearization
+		gu_pool_free(ppool);
+	}
+fail_concr:
+fail_read:
+	fclose(infile);
+fail:
+	gu_pool_free(pool);
+	return status;
+}
+