tiny-soccersim-rust/docs/tsrc-language/README.md

# `.tsrc` Language Reference

`.tsrc` (Tiny Soccer Sim Rust C) is a minimal C-like DSL for scripting soccer matches in tssr. It lets you define teams, assign players, script goals, and control output format — all from a plain text file.

## Invocation

### Via `--script` flag

```bash
tssr --script match.tsrc              # table output
tssr --script match.tsrc --json       # JSON output
```

### Via shebang

Add this as the first line of your `.tsrc` file:

```tsrc
#!/usr/bin/env tssr
```

Then make it executable and run directly:

```bash
chmod +x match.tsrc
./match.tsrc
```

## Language Syntax

### Team Declaration

```tsrc
string var_name = "Team Name";
```

Declares a variable that holds a team name. Variables can be referenced later in `players[]`, `goal()`, and `match()`.

**Rules:**
- Variable names must be alphanumeric + underscores
- Duplicate variable names are an error
- The string value is the team's display name

### Player Assignment

```tsrc
players["Player Name"] = var_name;
players["Player Name"] = "Team Name";
```

Assigns a player to a team. The right side can be either a previously declared variable or a string literal.

**Rules:**
- The team (right side) must resolve to a team that appears in `match()`
- The same player cannot be added to the same team twice
- Variables must be declared before use (forward references are an error)

### Scripted Goals

```tsrc
goal(minute, team, player);
```

Scripts a specific goal event. When any `goal()` appears, the match score becomes deterministic.

| Argument | Type | Description |
|----------|------|-------------|
| `minute` | integer (1-90) | Minute the goal was scored |
| `team` | variable or string | The team that scored |
| `player` | string literal | The player who scored |

**Rules:**
- Minute must be between 1 and 90
- Team must be one of the two match teams
- Player must be on that team's roster
- The same player cannot score at the same minute twice
- Variables must be declared before use

### Match Selection

```tsrc
match(var_home, var_away);
```

Selects which two teams play. **Required** — every `.tsrc` script must contain exactly one `match()`.

**Rules:**
- Both variables must be previously declared
- Home and away must be different teams
- Both teams must have at least one player assigned

### Output Mode Directive

```tsrc
#define JSON
#define ASCII_TABLE
#define UNICODE_TABLE
```

Sets the output format for the match. Optional — defaults to `UNICODE_TABLE`.

**Rules:**
- Only one `#define` per script
- Must be one of the three known modes
- Unknown names produce an error

The `--json` CLI flag always overrides the script's `#define`.

## Complete Grammar

```
script          = statement*
statement       = define | string_decl | player_insert | goal_stmt | match_stmt
define          = "#define" identifier
string_decl     = "string" identifier "=" string_literal ";"
player_insert   = "players" "[" string_literal "]" "=" (identifier | string_literal) ";"
goal_stmt       = "goal" "(" number "," (identifier | string_literal) "," string_literal ")" ";"
match_stmt      = "match" "(" identifier "," identifier ")" ";"
comment         = "//" .* "\n"
shebang         = "#!" .* "\n"
```

## Output Modes

| Mode | `#define` | CLI flag | Description |
|------|-----------|----------|-------------|
| Unicode table | `UNICODE_TABLE` (default) | — | Box-drawing characters (`╔`, `═`, `║`) |
| ASCII table | `ASCII_TABLE` | — | ASCII-only (`+`, `-`, `|`) |
| JSON | `JSON` | `--json` | Machine-readable JSON |

## Scripted Goals Behavior

When `goal()` is used, the match becomes deterministic:

| Field | Behavior with `goal()` | Behavior without |
|-------|------------------------|-------------------|
| Score | Count of goals per team | Random 0-5 |
| Scorers | Exact `(player, minute)` from script | Random names + minutes |
| Shots | `max(score, random(4..=18))` — floor = goals | Random 4-18 |
| Shots on target | `max(score, random(1..shots))` | Random |
| Possession | Still random | Random |

## Variable Resolution

Variables are resolved at parse time by looking up their declared value:

```tsrc
string home = "GNU United";
string away = "BSD Athletic";

players["Richard Stallman"] = home;        // resolves to "GNU United"
players["Theo de Raadt"] = away;           // resolves to "BSD Athletic"

goal(12, home, "Richard Stallman");        // goal for "GNU United"
goal(34, "BSD Athletic", "Theo de Raadt"); // literal also works

match(home, away);                          // GNU United vs BSD Athletic
```

You can mix variables and literals freely. Forward references (using a variable before its `string` declaration) are an error.

## Validation

The parser is strict. Any inconsistency produces an error and exits immediately.

### Error Conditions

| Error | Cause |
|-------|-------|
| `undefined variable 'x'` | Variable used before `string x = ...` declaration |
| `variable 'x' redefined` | Two `string x = ...` declarations |
| `players[...] = "X" which is not a match team` | Roster team isn't in `match()` |
| `duplicate player "X" on team "Y"` | Same player added to same team twice |
| `"X" has no players assigned` | A match team has zero players |
| `match() has the same team for both home and away` | Both `match()` args resolve to same team |
| `no match() directive found` | Missing `match()` |
| `goal() minute must be between 1 and 90` | Invalid minute |
| `player "X" is not on team "Y"` | Goal references unregistered player |
| `duplicate goal` | Same player scores same minute twice |
| `undefined variable 'x' in goal()` | Goal uses undeclared team variable |
| `duplicate #define` | More than one `#define` in script |
| `unknown #define 'FOO'` | Unrecognized output mode |

## Full Example

```tsrc
#!/usr/bin/env tssr

// GNU United vs BSD Athletic
#define ASCII_TABLE

string home = "GNU United";
string away = "BSD Athletic";

players["Richard Stallman"] = home;
players["Brian Fox"] = home;
players["Linus Torvalds"] = home;
players["Theo de Raadt"] = away;
players["Jordan Hubbard"] = away;
players["Ken Thompson"] = away;

goal(12, home, "Richard Stallman");
goal(34, away, "Theo de Raadt");
goal(56, home, "Brian Fox");
goal(78, "BSD Athletic", "Ken Thompson");
goal(89, home, "Linus Torvalds");

match(home, away);
```

**Output:**
```
+------------------------------------+
+         TSSR MATCH RESULT          +
+------------------------------------+
+   GNU United  3-2  BSD Athletic    +
+------------------------------------+
+                                    +
+Shots          4     5              +
+On Target      3     2              +
+Possession   48%   52%              +
+                                    +
+Goals:                              +
+GNU United: Richard Stallman (12')  +
+GNU United: Brian Fox (56')         +
+GNU United: Linus Torvalds (89')    +
+BSD Athletic: Theo de Raadt (34')   +
+BSD Athletic: Ken Thompson (78')    +
+------------------------------------+
```