From 0ae4a423354a75200ba476e245e4068400165797 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?P=C5=99emysl=20Janouch?= Date: Thu, 1 Jun 2017 10:39:29 +0200 Subject: [PATCH] Make the printer generic Now you can concatenate lists like strings. --- ell.c | 113 ++++++++++++++++++++++++++++++++++++--------------------- repl.c | 2 +- 2 files changed, 73 insertions(+), 42 deletions(-) diff --git a/ell.c b/ell.c index e5f7c57..e3951c4 100644 --- a/ell.c +++ b/ell.c @@ -356,7 +356,12 @@ ell_lexer_errorf (struct ell_lexer *self, const char *fmt, ...) { // --- Printing ---------------------------------------------------------------- -static void ell_print_seq (struct ell_v *v); +// This can be wrapped inside a larger structure, and errors simply accumulated +struct ell_printer { + void (*putchar) (struct ell_printer *self, unsigned char c); +}; + +static void ell_print_seq (struct ell_printer *printer, struct ell_v *v); static bool ell_print_string_needs_quoting (struct ell_v *s) { @@ -370,30 +375,35 @@ ell_print_string_needs_quoting (struct ell_v *s) { } static bool -ell_print_string (struct ell_v *s) { +ell_print_string (struct ell_printer *printer, struct ell_v *s) { if (s->type != ELL_STRING) return false; if (!ell_print_string_needs_quoting (s)) { - printf ("%s", s->string); + for (size_t i = 0; i < s->len; i++) + printer->putchar (printer, s->string[i]); return true; } - putchar (ELL_LEXER_STRING_QUOTE); + printer->putchar (printer, ELL_LEXER_STRING_QUOTE); for (size_t i = 0; i < s->len; i++) { unsigned char c = s->string[i]; - if (c < 32) - printf ("\\x%02x", c); - else if (c == ELL_LEXER_ESCAPE || c == ELL_LEXER_STRING_QUOTE) - printf ("\\%c", c); - else - putchar (c); + if (c < 32) { + printer->putchar (printer, '\\'); + printer->putchar (printer, 'x'); + printer->putchar (printer, "0123456789abcdef"[c >> 4]); + printer->putchar (printer, "0123456789abcdef"[c & 15]); + } else if (c == ELL_LEXER_ESCAPE || c == ELL_LEXER_STRING_QUOTE) { + printer->putchar (printer, '\\'); + printer->putchar (printer, c); + } else + printer->putchar (printer, c); } - putchar (ELL_LEXER_STRING_QUOTE); + printer->putchar (printer, ELL_LEXER_STRING_QUOTE); return true; } static bool -ell_print_block (struct ell_v *list) { +ell_print_block (struct ell_printer *printer, struct ell_v *list) { if (!list->head || strcmp (list->head->string, "block")) return false; @@ -402,57 +412,57 @@ ell_print_block (struct ell_v *list) { if (line->type != ELL_LIST) return false; - putchar ('{'); + printer->putchar (printer, '{'); for (struct ell_v *line = list; line; line = line->next) { - putchar (' '); - ell_print_seq (line->head); - putchar (line->next ? ';' : ' '); + printer->putchar (printer, ' '); + ell_print_seq (printer, line->head); + printer->putchar (printer, line->next ? ';' : ' '); } - putchar ('}'); + printer->putchar (printer, '}'); return true; } static bool -ell_print_set (struct ell_v *list) { +ell_print_set (struct ell_printer *printer, struct ell_v *list) { if (!list->head || strcmp (list->head->string, "set") || !list->head->next || list->head->next->next) return false; - putchar ('@'); - ell_print_seq (list->head->next); + printer->putchar (printer, '@'); + ell_print_seq (printer, list->head->next); return true; } static bool -ell_print_list (struct ell_v *list) { +ell_print_list (struct ell_printer *printer, struct ell_v *list) { if (!list->head || strcmp (list->head->string, "list")) return false; - putchar ('['); - ell_print_seq (list->head->next); - putchar (']'); + printer->putchar (printer, '['); + ell_print_seq (printer, list->head->next); + printer->putchar (printer, ']'); return true; } static void -ell_print_v (struct ell_v *v) { - if (ell_print_string (v) - || ell_print_block (v) - || ell_print_set (v) - || ell_print_list (v)) +ell_print_v (struct ell_printer *printer, struct ell_v *v) { + if (ell_print_string (printer, v) + || ell_print_block (printer, v) + || ell_print_set (printer, v) + || ell_print_list (printer, v)) return; - putchar ('('); - ell_print_seq (v->head); - putchar (')'); + printer->putchar (printer, '('); + ell_print_seq (printer, v->head); + printer->putchar (printer, ')'); } static void -ell_print_seq (struct ell_v *v) { +ell_print_seq (struct ell_printer *printer, struct ell_v *v) { for (; v; v = v->next) { - ell_print_v (v); + ell_print_v (printer, v); if (v->next) - putchar (' '); + printer->putchar (printer, ' '); } } @@ -984,6 +994,27 @@ static struct ell_v * ell_boolean (bool b) { return ell_string ("1", b); } // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - +static void +ell_stdout_printer_putchar (struct ell_printer *self, unsigned char c) { + (void) self; + (void) putchar (c); +} + +static struct ell_printer ell_stdout_printer = { ell_stdout_printer_putchar }; + +struct ell_buffer_printer { + struct ell_printer super; ///< Superclass + struct ell_buffer *output; ///< Where to append the result to +}; + +static void +ell_buffer_printer_putchar (struct ell_printer *printer, unsigned char c) { + struct ell_buffer_printer *self = (struct ell_buffer_printer *) printer; + ell_buffer_append_c (self->output, c); +} + +// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - + ell_defn (ell_fn_local) { struct ell_v *names = args; if (!names || names->type != ELL_LIST) @@ -1088,7 +1119,7 @@ ell_defn (ell_fn_print) { (void) result; for (; args; args = args->next) { if (args->type != ELL_STRING) - ell_print_v (args); + ell_print_v (&ell_stdout_printer, args); else if (fwrite (args->string, 1, args->len, stdout) != args->len) return ell_error (ell, "write failed: %s", strerror (errno)); } @@ -1097,12 +1128,12 @@ ell_defn (ell_fn_print) { ell_defn (ell_fn_cat) { struct ell_buffer buf = ELL_BUFFER_INITIALIZER; + struct ell_buffer_printer bp = { { ell_buffer_printer_putchar }, &buf }; for (; args; args = args->next) { - if (args->type != ELL_STRING) { - free (buf.s); - return ell_error (ell, "cannot concatenate lists"); - } - ell_buffer_append (&buf, args->string, args->len); + if (args->type != ELL_STRING) + ell_print_v (&bp.super, args); + else + ell_buffer_append (&buf, args->string, args->len); } bool ok = !(ell->memory_failure |= buf.memory_failure) && ell_check (ell, (*result = ell_string (buf.s, buf.len))); diff --git a/repl.c b/repl.c index 03d832a..e84af3a 100644 --- a/repl.c +++ b/repl.c @@ -36,7 +36,7 @@ run (struct ell *ell, struct ell_v *program) { ell->error = NULL; ell->memory_failure = false; } else { - ell_print_seq (result); + ell_print_seq (&ell_stdout_printer, result); putchar ('\n'); ell_free_seq (result); }