proper argument parsing

Makefile

@@ -14,7 +14,7 @@ LINKasd  += $$(pkgconf --libs ncurses readline sqlite3)
 
 OBJECT.d:=object/
 SOURCE.d:=source/
-SOURCE:=bash_history.yy.cpp main.cpp cli.cpp tui.cpp storage.cpp damerau_levenshtein.cpp
+SOURCE:=argument_yy.tab.cpp bash_history.yy.cpp main.cpp cli.cpp tui.cpp storage.cpp damerau_levenshtein.cpp
 OBJECT:=$(addprefix ${OBJECT.d},$(addsuffix .o,$(basename ${SOURCE})))
 SOURCE:=$(addprefix ${SOURCE.d},${SOURCE})
 
@@ -24,7 +24,10 @@ ${OUTPUT}: ${OBJECT}
 	${LINK.cpp} ${OBJECT} ${LINKasd} -o ${OUTPUT}
 
 object/%.yy.cpp: source/%.l
-	${LEX} --prefix=$*_ --header-file=$(basename $@).hpp -o $@ $<
+	flex --prefix=$*_ --header-file=$(basename $@).hpp -o $@ $<
+
+object/%.tab.cpp: source/%.y
+	bison --name-prefix=$*_ --header=$(basename $@).hpp -o $@ $<
 
 object/%.o: object/%.l.cpp
 	${COMPILE.cpp} $< -o $@

documentation/TODO.md

@@ -1,3 +1,4 @@
 + make case insensitive search optional
 + make fuzzy searching optional
 + make (potentially slow) queries cancel using multi threading
++ the same suggestion should only show up once

source/argument_yy.y

@@ -0,0 +1,29 @@
+%token HELP VERSION
+%token TUI ENABLE
+%token LEVENSTEIN
+%{
+    #include "stdio.h"
+    extern void usage(void);
+    extern void version(void);
+    extern void enable(void);
+    extern void argument_yy_error(const char * const s);
+    extern int argument_yy_lex(void);
+%}
+%%
+histui_args: global_args verb_and_args
+    ;
+
+global_args: %empty
+    | HELP              { usage();   exit(0); }
+    | VERSION           { version(); exit(0); }
+    ;
+
+verb_and_args: ENABLE   { enable(); exit(0); }
+    | TUI tui_args      { ; }
+    ;
+
+tui_args: %empty
+    | LEVENSTEIN        { ; }
+    ;
+
+%%

source/cli.cpp

@@ -4,19 +4,17 @@
 #include <stdlib.h>
 #include <string.h>
 
-using namespace std;
+#include "argument_yy.tab.hpp"
+
+int * arg_tokens;
 
-[[ noreturn ]]
 void version() {
     puts(
     # include "version.inc"
     );
-
-    exit(0);
 }
 
-[[ noreturn ]]
-void usage(int exit_value) {
+void usage(void) {
     // TODO
     puts(
         "histui [options] <verb>\n"
@@ -27,37 +25,56 @@ void usage(int exit_value) {
         "\t\tenable : print a bash script to enable histui in the current shell\n"
         "\t\ttui    : run histui normally\n"
     );
-    exit(exit_value);
 }
 
-void parse_global_options(const int argc, const char * const * const argv) {
-    for(int i = 1; i < argc; i++) {
-        if (argv[i][0] != '-') {
-            return;
-        }
-        if (not strcmp(argv[i], "-v")
-        ||  not strcmp(argv[i], "--version")) {
-            version();
-        }
-        if (not strcmp(argv[i], "-h")
-        ||  not strcmp(argv[i], "--help")) {
-            usage();
-        }
-    }
+int argument_yy_lex(void) {
+    static int i = 0;
+    return arg_tokens[i++];
 }
 
-verb_t get_verb(const int argc, const char * const * const argv) {
-    for(int i = 1; i < argc; i++) {
-        if (argv[i][0] == '-') {
-            continue;
-        }
-        if (not strcmp(argv[i], "tui")) {
-            return TUI;
-        }
-        if (not strcmp(argv[i], "enable")) {
-            return ENABLE;
-        }
-        return ERROR;
-    }
-    return ERROR;
+void argument_yy_error([[ maybe_unused ]] const char * const s) {
+    puts("Argument parsing failed.");
+    usage();
+    exit(2);
+}
+
+void parse_arguments(const int argc, const char * const * const argv) {
+    if (argc < 2) {
+        usage();
+        exit(1);
+    }
+
+    /* Lexical analysis of a poor man.
+     * Using Flex would be problematic because our input
+     *  is not stored in an actual buffer (not in a defined
+     *  behaviour way anyways).
+     */
+    int tokens[argc];
+    int token_empty_head = 0;
+    for (int i = 1; i < argc; i++) {
+        if (!strcmp(argv[i], "--help")
+        ||  !strcmp(argv[i], "-h")) {
+            tokens[token_empty_head++] = HELP;
+        } else
+        if (!strcmp(argv[i], "--version")
+        ||  !strcmp(argv[i], "-v")) {
+            tokens[token_empty_head++] = VERSION;
+        } else
+        if (!strcmp(argv[i], "tui")) {
+            tokens[token_empty_head++] = TUI;
+        } else
+        if (!strcmp(argv[i], "enable")) {
+            tokens[token_empty_head++] = ENABLE;
+        } else
+        if (!strcmp(argv[i], "--levenstein")) {
+            tokens[token_empty_head++] = LEVENSTEIN;
+        } else {
+            tokens[token_empty_head++] = YYUNDEF;
+        }
+    }
+    tokens[token_empty_head++] = YYEOF;
+
+    arg_tokens = tokens;
+
+    argument_yy_parse();
 }

source/cli.hpp

@@ -1,11 +1,3 @@
 #pragma once
 
-typedef enum {
-    TUI,
-    ENABLE,
-    ERROR,
-} verb_t;
-
-extern void parse_global_options(const int argc, const char * const * const argv);
-extern verb_t get_verb(const int argc, const char * const * const argv);
-[[ noreturn ]] void usage(int exit_value = 0);
+void parse_arguments(const int argc, const char * const * const argv);

source/main.cpp

@@ -40,17 +40,19 @@ bind -x '"\e[A": _histui_run'
 bind -x '"\C-r": _histui_run'
         )delim"
     );
-    exit(0);
+}
+
+void export_result(const char * const result) {
+    int fd[2];
+    pipe(fd);
+    dprintf(3, result);
+    close(fd[0]);
+    close(fd[1]);
 }
 
 signed main(int argc, char * argv[]) {
-    parse_global_options(argc, argv);
-    verb_t verb = get_verb(argc, argv);
-    switch (verb) {
-        case ENABLE: enable();
-        case ERROR:  usage(1);
-        case TUI:    break;
-    }
+    // NOTE: never returns on error
+    parse_arguments(argc, argv);
 
     init();
 
@@ -72,11 +74,7 @@ signed main(int argc, char * argv[]) {
     }
 
     query(rl_line_buffer, 1, selection_offset + selection_relative);
-    int fd[2];
-    pipe(fd);
-    dprintf(3, get_entry().command);
-    close(fd[0]);
-    close(fd[1]);
+    export_result(get_entry().command);
 
     deinit();
 

source/storage.cpp

@@ -4,6 +4,8 @@
 #include <sqlite3.h>
 #include "damerau_levenshtein.hpp"
 
+//const char * * const query_method;
+
 static sqlite3 * db;
 static sqlite3_stmt * stmt = NULL;