否则如果

Adds an else-if branch after a previous 如果 branch.

Aliases: else if

Syntax: 否则如果 <condition> <block>

Category#

control-flow

Related#

• 如果
• 否则

Examples#

radix/corpus/si/sin.fab (canonical · keyword)#

Adds an else-if branch after a previous 如果 branch.

# =============================================================================
# 否则如果 — Adds an else-if branch after a previous 如果 branch.
# =============================================================================
#
# What this teaches:
#   • Else-if chains — `否则如果 <condition> { body }` adds intermediate conditional
#     branches between `如果` and `否则`
#   • First match wins: evaluation stops at the first `如果` or `否则如果` whose
#     condition is `真`
#
# Common mistakes:
#   • TODO: forgetting that `否则如果` blocks are skipped once a preceding branch
#     matches
#
# See also: 如果, 否则
# =============================================================================

# si-sin-secus (poetic if-else-if chain)
#
# 如果 <cond> { }
# 否则如果 <cond> { }
# 否则 { }
#
# GRAMMAR:
#   ifStmt :← '如果' expr block ('否则如果' expr block)* ('否则' block)?
#
# EXPECTED OUTPUT:
#   Afternoon (hour=14 matches first 否则如果 branch).

main {
    const int hour ← 14
    if hour ≺ 6 {
        print "Late night"
    }
    elif hour ≺ 12 {
        print "Morning"
    }
    elif hour ≺ 18 {
        # 14 ≥ 12 and 14 < 18
        print "Afternoon"
    }
    elif hour ≺ 22 {
        print "Evening"
    }
    else {
        print "Night"
    }
}

Expected output:

Afternoon

radix/corpus/sin/sin.fab (canonical · keyword)#

Adds an else-if branch after a previous 如果 branch.

# =============================================================================
# 否则如果 — Adds an else-if branch after a previous 如果 branch.
# =============================================================================
#
# What this teaches:
#   • Standalone else-if — `否则如果` provides an intermediate conditional branch
#     evaluated only when the preceding `如果` condition was `假`
#   • Chains: `如果 { } 否则如果 { } 否则 { }` for multi-way branching
#
# Common mistakes:
#   • Writing `否则 如果` instead of the canonical `否则如果` for else-if branches.
#
# See also: 如果, 否则
# =============================================================================

# 否则如果 — else-if branch
#
# GRAMMAR:
#   elseIfClause :← '否则如果' expr block
#
# EXPECTED OUTPUT:
#   Scalar stdout smoke (see body).
#
# BACKEND:
#   Cross-ref: 如果/sin.fab.
#

main {
    const int score ← 85
    if score ≥ 90 {
        print "excellent"
    }
    elif score ≥ 80 {
        print "good"
    }
    else {
        print "needs work"
    }
}

Expected output:

good